JP2005287074A - Data link transmission control method, mobile communication system, base station, mobile station, mobile station control program, and computer-readable recording medium - Google Patents

Data link transmission control method, mobile communication system, base station, mobile station, mobile station control program, and computer-readable recording medium Download PDF

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JP2005287074A
JP2005287074A JP2005134527A JP2005134527A JP2005287074A JP 2005287074 A JP2005287074 A JP 2005287074A JP 2005134527 A JP2005134527 A JP 2005134527A JP 2005134527 A JP2005134527 A JP 2005134527A JP 2005287074 A JP2005287074 A JP 2005287074A
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packet
base station
mobile station
station
data link
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JP2005134527A
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JP4276207B2 (en
Inventor
Shinzo Okubo
Toru Otsu
Yasushi Yamao
Hitoshi Yoshino
仁 吉野
信三 大久保
徹 大津
泰 山尾
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Ntt Docomo Inc
株式会社エヌ・ティ・ティ・ドコモ
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Priority to JP2005134527A priority patent/JP4276207B2/en
Publication of JP2005287074A publication Critical patent/JP2005287074A/en
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Abstract

<P>PROBLEM TO BE SOLVED: To increase throughput and to improve the performance of an entire system by shortening the transmission latency of a packet while coping with the movement of a mobile station. <P>SOLUTION: A base station 202 includes: a transceiver 207 for receiving data from a wireless network and transmitting data to the wireless network; a data link transmission control section 203 which performs data link transmission control and controls constitutive sections in the base station 202 while including automatic resending request control for giving a unique number or the like as identification information to each packet in order to execute automatic resending control; a packet copy section 206 for copying a packet; a delivery section 205 for delivering the copied packet to the other base station; and a storage section 204 which functions as a temporary storage region for packet data by the data link transmission control section 203 through a base station 208 . <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data link transmission control method, a mobile communication system, a base station, a mobile station, a mobile station control program, and a computer-readable recording medium, and more particularly, a packet between a mobile station and a plurality of base stations. A data link transmission control method for performing data link transmission control including automatic retransmission request control for performing transmission / reception of data, a mobile communication system configured by a mobile station and a plurality of base stations and transmitting / receiving information by packets, and a mobile communication system The present invention relates to a base station, a mobile station, a mobile station control program to be executed by a computer mounted on the mobile station, and a computer-readable recording medium.

  FIGS. 5 and 6 are configuration diagrams and flowcharts for explaining a data link transmission control method including automatic retransmission request control in a conventional mobile communication system.

  In the base station 2, a packet input from the network 1 at the arrow T1 in FIG. 6 is first input to the data link transmission control unit 3, and data link transmission control is executed while performing automatic retransmission request control. The data link transmission control unit 3 assigns a packet number to enable identification of the inputted packet, and a CRC (cyclic redundancy check) so that an error occurring during transmission can be detected for the packet. ) Etc. are added, and then the packet is stored and output to the transceiver 5 via the switch 4. The transceiver 5 then modulates the transmission signal and transmits it to the mobile station 31 via the base station antenna 6 (arrow T2 in FIG. 6).

  On the other hand, in the mobile station 31, after the signal from the mobile station antenna 32 is received by the transceiver 33, the received packet is output to the data link transmission control unit 34, and data link transmission control including automatic retransmission request control is performed. Execute. The data link transmission control unit 34 performs error detection using the parity added to the input packet. If there is an error in the packet as a result of the detection, the data link transmission control unit 34 transmits a NACK (Negative Acknowledgment) signal to the base station 2, thereby transmitting a retransmission request for the packet to the data link transmission of the base station 2. The control unit 3 is notified (arrow T3 in FIG. 6). The data link transmission control unit 3 retransmits the packet requested for retransmission (arrow T4 in FIG. 6).

  When there is no error in the packet, the data link transmission control unit 34 outputs the packet from the data input / output terminal 35 and transmits an ACK (Acknowledgment) signal to the base station 2 to reach the packet. The confirmation is notified to the data link transmission control unit 3 of the base station 2 (arrow T5 in FIG. 6). Then, the data link transmission control unit 3 deletes the packet having the packet number stored for retransmission.

  By the way, when the mobile station 31 moves and the communication quality between the mobile station 31 and the base station 2 that has been communicating so far deteriorates and the communication quality with other base stations 12 becomes good, The mobile station 31 requests the base station 2 to communicate with the base station 2 via the base station 12 (arrows T6 and T7 in FIG. 6). In response to the request, the data link transmission control unit 3 of the base station 2 transfers the packet subjected to the automatic retransmission request control to the changed base station 12 by changing the connection destination of the switch 4 from the transceiver 5 to the network 1. This is made possible (arrows T8 and T9 in FIG. 6). Then, control is performed so that the data link transmission control unit 13 of the base station 12 outputs the data to the transceiver 15 via the switch 14 as it is without executing automatic retransmission request control (arrow T10 in FIG. 6).

  With this method, the automatic retransmission request control is performed as it is by one data link transmission control unit 3 (arrows T8 to T16 in FIG. 6) regardless of the change of the communication partner base station. Packet transmission is possible without resetting the packet number.

  Even when the base station 22 is further away from the base station 2, packet transmission can be performed while performing automatic retransmission request control using the above method.

As for handover of a conventional mobile communication system, as described in Patent Document 1 below, the base station switching performed at the time of handover is performed by the virtual zone control device, so that The amount of handover control was reduced, and the instantaneous interruption time of the communication line was shortened.
Japanese Patent Laid-Open No. 10-136426

  However, in the data link transmission control method in the conventional mobile communication system as described above, the data link of the base station 2 in which a series of packet transmissions is started for data link transmission including automatic retransmission request control regardless of movement of the mobile station. Since the transmission control unit 3 performs the batch processing, the packet transmission delay time increases because the transfer between the base stations after the data link transmission control increases as the mobile station moves. Further, there is a problem that the throughput is lowered due to the increase in the transmission delay time.

  As described above, in the data link transmission control method in the conventional mobile communication system, one base station performs data link transmission control including automatic retransmission request control even when the mobile station moves into a cell of another base station. Thus, the mobility of the mobile station can be accommodated, but there is a problem that the throughput is lowered due to an increase in the transmission delay time.

  In addition, a technique is also known in which a line control station for performing retransmission control is provided separately from a base station in a mobile communication system in order to reduce the load on an exchange in the network (for example, also described in Patent Document 1 above). Yes.

  However, in this technique, a packet that arrives from the network first arrives at the line control station, is duplicated by the line control station, and is distributed to the distribution destination base station. The distribution-destination base station receives a signal designating the base station to which the packet is to be transmitted from the mobile station. The distribution-destination base station determines whether or not the local station should transmit based on the signal, and when determining that the local station should transmit, transmits the packet to the mobile station. At this time, if an error occurs in the packet received by the mobile station, the mobile station requests the line control station to retransmit the packet via the base station. As described above, since the line control station, not the base station, retransmits the packet, there is a problem in that the delay time until the retransmission increases, and the amount of traffic between the line control station and the base station increases.

  On the other hand, in the system described in Patent Document 1, although the amount of handover control is reduced, the time required for one handover and retransmission is still the same as before or requires extra time, and communication is interrupted. There was a problem.

  The present invention has been made in order to solve the above-described problems, and can improve throughput and overall system performance by reducing packet transmission delay time while accommodating movement of a mobile station. An object of the present invention is to provide a data link transmission control method, a mobile communication system, a base station, a mobile station, a mobile station control program, and a computer-readable recording medium.

  In order to achieve the above object, a data link transmission control method according to the present invention performs data link transmission control including automatic retransmission request control for transmitting and receiving packets between a mobile station and a plurality of base stations. A link transmission control method, wherein one base station stores and duplicates a packet to which identification information for identifying the packet is added to a packet addressed to the mobile station, and the one base station The duplicated packet is distributed to other base stations, the other base station accumulates the distributed packets, and one or more base stations including the one base station are added with the identification information. The transmitted packet or the distributed packet is transmitted to the mobile station.

  That is, in this method, one base station out of a plurality of base stations has identification information (for example, a unique number, a character, a symbol, or a combination thereof) for identifying the packet addressed to the mobile station. Is added to the base station, and the duplicated packet is distributed to other base stations. As for the packet with the identification information added, one base station may add the identification information to the packet at its own station, or it may receive a packet with the identification information added in advance from another base station. Also good.

  Then, another base station accumulates the distributed packet. Thereafter, one or a plurality of base stations including one base station transmits the packet to which the identification information is added or the distributed packet to the mobile station. In this way, since a line control station for distributing packets is not provided separately from the base station, packets are accumulated in each base station, and one or a plurality of base stations transmit packets to the mobile station. Traffic can be reduced, and by reducing the packet transmission delay time, the throughput can be increased and the performance of the entire system can be improved.

  In the data link transmission control method according to the present invention, a base station (including one base station and another base station) deletes the packet due to a timer timeout for the packet, or the same packet as the packet. It is desirable to delete the packet by notifying that the mobile station has reached the mobile station, or to delete the packet corresponding to the identification information based on the notification of the identification information for specifying the packet to be deleted . As a result, it is possible to facilitate the process of deleting packets being accumulated in the base station.

  At this time, when one base station notifies the other base station of the identification information for specifying the packet to be deleted, the identification information is stored each time the one base station deletes the packet. The first method for notifying, the second method for notifying the identification information of the packet last deleted within a predetermined time, or the identification information of the packet when a specific packet determined based on a predetermined rule is deleted It is desirable to use one method or a combination of a plurality of methods among the third methods of notifying the user.

  In the data link transmission control method according to the present invention, when one base station receives a request from the mobile station to designate a new base station as a packet distribution destination base station, the one base station It is desirable to duplicate the packet with the identification information added at the station and distribute the duplicated packet to the new base station. As a result, the new base station can obtain a packet to which the identification information stored in one base station is added, and can operate as a packet distribution destination base station in accordance with a request from the mobile station. It becomes possible.

  In the data link transmission control method according to the present invention, when another base station receives a request from the mobile station to exclude the other base station from the base station to which the packet is distributed, It is desirable to delete the packet addressed to the mobile station stored in the base station. Thereby, in the base station excluded from the base station to which the packet is distributed, the packet addressed to the mobile station being stored is deleted, and the unnecessary packets can be quickly arranged. The other base station may receive a request from the mobile station to be excluded directly from the mobile station, or may receive it via one base station.

  In the data link transmission control method according to the present invention, when one base station, another base station, or both receive and accumulate packets addressed to a mobile station, the packets are accumulated. To the mobile station, and after receiving the notification, the mobile station selects one base station from the notified base stations, requests the base station to transmit a packet, It is desirable for the station to transmit the packet. That is, not only one base station but also other base stations store packets addressed to the mobile station, so that the mobile station selects the packet by notifying the mobile station that the packet is stored. Transmission of the packet from one base station that requested transmission to the mobile station is realized.

  At this time, if one base station, another base station, or both receive a transmission request from the mobile station while accumulating a plurality of packets addressed to the mobile station, the packet is sent to the mobile station. It is desirable to notify the mobile station that a plurality of packets addressed to the mobile station are accumulated. As a result, it is possible to collectively notify the mobile station that packets are being accumulated, and the load of the notification process can be reduced. For example, a mode in which a packet transmitted from the base station is notified by piggybacking that there is a subsequent packet is conceivable.

  Further, in the data link transmission control method according to the present invention, when a mobile station changes a base station that transmits a packet addressed to the mobile station, the mobile station notifies the change source base station to stop transmission thereafter, and changes It is desirable to notify the destination base station that it requests transmission of a packet addressed to itself and the identification information of the first packet to be transmitted. As a result, communication with the base station of the change source is stopped, and packet transmission from the base station of the change destination to the mobile station resumes from the packet corresponding to the identification information of the first packet to be transmitted according to the request of the mobile station. Thus, it is possible to smoothly change the base station that transmits the packet addressed to the mobile station.

  In the data link transmission control method according to the present invention, the mobile station measures the reception quality of signals transmitted from a plurality of base stations, and the mobile station determines its own station based on the reception quality for each base station. It is preferable that one base station that transmits a packet addressed to the mobile station is selected, and the mobile station requests the selected one base station to transmit a packet addressed to itself. Thereby, for example, a base station having the highest reception quality can be selected as one base station, and packet transmission from the selected base station to the mobile station can be realized in a good state.

  In the data link transmission control method according to the present invention, the mobile station measures the reception quality of signals transmitted from a plurality of base stations, and the mobile station determines its own station based on the reception quality for each base station. The mobile station selects one base station that transmits the addressed packet, the mobile station notifies the selected one base station of the reception quality for each base station, and the one base station receives the reception quality for each base station. Based on the base station, each of the other base stations determines whether or not to transmit the packet to be distributed from the one base station to the mobile station, and the one base station performs a transmission operation based on the determination result. It is desirable to instruct other base stations. Thereby, according to the operation instruction to each of the other base stations according to the above determination result based on the reception quality for each base station, it is possible for other base stations to appropriately perform the transmission operation or the transmission avoidance operation. Become.

  Also, in the data link transmission control method according to the present invention, when the mobile station receives the same packet from each of the plurality of base stations, it is desirable to perform diversity reception on the packet, thereby improving reception quality. it can.

  In the data link transmission control method according to the present invention, the mobile station measures the reception quality of signals transmitted from a plurality of base stations, and the mobile station or each base station determines the reception quality for each base station. Based on this, it is desirable to request the base station to change the communication state to change the communication state. As a result, an appropriate communication state transition request corresponding to the time-average reception quality is issued from the mobile station, and the base station can transition to an appropriate communication state.

  The communication state includes a first state in which no packet is transmitted to and received from the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station, and the added packet is transmitted to the mobile station. To the second state that can be transmitted to the mobile station, identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, and the duplicated packet is distributed, A third state in which the packet after the addition can be transmitted, and a fourth state in which the duplicate packet is received from the base station in the third state and the duplicate packet can be transmitted to the mobile station It is desirable to have a configuration including

  Also, in the data link transmission control method according to the present invention, one base station encapsulates the identification information and the packet to be distributed, and represents the length of the identification information representing the length of the encapsulated packet obtained by the encapsulation. And the total length of the packet to be distributed is recorded in the header of the encapsulated packet to distribute the encapsulated packet, and the length of the encapsulated packet recorded in the header of the encapsulated packet that has been distributed If the length obtained by subtracting the length of the header of the encapsulated packet from the length of the packet to be distributed recorded in the header of the packet to be distributed is not equal, the encapsulated packet is configured to include identification information. It is desirable to judge that In this case, the base station can reliably determine whether or not the distributed encapsulated packet includes identification information, and can smoothly execute control based on the identification information.

  By the way, the invention relating to the data link transmission control can also be understood as the invention of the following mobile communication system. Since these inventions are the same in terms of technical idea, they exhibit the same actions and effects.

  That is, the mobile communication system according to the present invention is a mobile communication system that includes a mobile station and a plurality of base stations, and performs data link transmission control including automatic retransmission request control while performing transmission / reception of information by packets. A base station that replicates a packet in which identification information for identifying the packet is added to the packet addressed to the mobile station; a distribution unit that distributes the copied packet to other base stations; Storing means for storing the packet to which the identification information is added or a packet distributed from another base station, and transmission means for transmitting the packet to which the identification information is added or the distributed packet to the mobile station; , Provided.

  At this time, in the mobile communication system according to the present invention, it is desirable that the base station further includes a deletion unit that deletes the packet stored by the storage unit.

  Here, the first method of notifying the identification information of the deleted packet every time the base station deletes the packet, the first notification of the identification information of the packet deleted last within a predetermined time. The method should be deleted by one method or a combination of a plurality of methods in the second method, or when a specific packet defined based on a predetermined rule is deleted and the identification information of the packet is notified. It is desirable to further include a deletion packet notification means for notifying other base stations of packet identification information.

  In addition, the mobile communication system according to the present invention is configured to further include packet retransmission means for retransmitting a packet in response to the retransmission request when the base station receives the packet retransmission request from the mobile station. Is desirable.

  Further, in the mobile communication system according to the present invention, when the base station receives and stores packets addressed to the mobile station, the mobile communication system further includes an accumulation notification means for notifying the mobile station that the packets are being accumulated. And the transmission means transmits a packet to the mobile station in response to a request from the mobile station, and when the mobile station receives the notification, 1 It is desirable to further include a selection unit that selects one base station, and a transmission request unit that requests the selected base station to transmit a packet.

  Here, when the base station receives a transmission request from the mobile station while accumulating a plurality of packets addressed to the mobile station, the base station transmits the packet to the mobile station by the transmission means, and It is desirable to further comprise notification control means for controlling the mobile station to notify the mobile station that a plurality of packets are being stored.

  Further, in the mobile communication system according to the present invention, when a mobile station changes a base station that transmits a packet addressed to the mobile station, the mobile station notifies the change source base station to stop transmission thereafter, and It is desirable that the base station further includes a change notification means for requesting transmission of a packet addressed to the base station and identification information of the first packet to be transmitted.

  In the mobile communication system according to the present invention, the mobile station measures the reception quality of signals transmitted from a plurality of base stations, and the packet addressed to the mobile station based on the reception quality of each base station. It is desirable to further include a selection unit that selects one base station that transmits the packet, and a transmission request unit that requests the selected one base station to transmit a packet addressed to itself.

  In the mobile communication system according to the present invention, the mobile station measures the reception quality of signals transmitted from a plurality of base stations, and the packet addressed to the mobile station based on the reception quality of each base station. Selecting means for selecting one base station that transmits the received signal, and reception quality notifying means for notifying the selected one base station of the reception quality for each base station, wherein the base station serves as one base station. Judgment means for judging whether to transmit a packet to be distributed from the own station to the mobile station based on the reception quality for each base station when the own station is selected. And an instruction means for instructing another base station to perform a transmission operation based on the determination result.

  In the mobile communication system according to the present invention, it is preferable that the mobile station further includes diversity receiving means for performing diversity reception on the packet when receiving the same packet from a plurality of base stations. .

  Further, in the mobile communication system according to the present invention, the mobile station is configured to measure each reception quality of signals transmitted from a plurality of base stations and each base station based on the reception quality for each base station. Determining means for determining which communication state among the plurality of communication states, and a state transition requesting means for requesting the base station to change the communication state based on the determination result, It is desirable to have a configuration further comprising

  Here, a plurality of predetermined communication states are added to the first state in which packets are not transmitted / received to / from the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station. A second state in which a later packet can be transmitted to the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, A third state in which the packet is distributed and the packet after the addition can be transmitted, and the duplicate packet is received from the base station in the third state, and the duplicate packet is transmitted to the mobile station. It is desirable to have a configuration including a fourth state that can be used.

  Further, in the mobile communication system according to the present invention, the distribution unit includes an encapsulation unit that encapsulates the identification information and the packet to be distributed, and a length of the identification information that represents a length of the encapsulated packet obtained by the encapsulation. And the total length of the packet to be distributed is recorded in the header of the encapsulated packet and the encapsulated packet distributing means for distributing the encapsulated packet, and the recorded in the header of the encapsulated packet distributed When the length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet is not equal to the length of the packet to be distributed recorded in the header of the packet to be distributed, the encapsulated packet is identified by the identification information. It is desirable that the configuration includes a configuration determination unit that determines that the configuration is included.

  By the way, the main part of the invention related to the data link transmission control and the invention related to the mobile communication system can be understood as the invention of the base station and the invention of the mobile station described below. Since these inventions are the same in terms of technical idea, they exhibit the same actions and effects.

  That is, the base station according to the present invention is a base station that, together with a mobile station, constitutes a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information using packets, A plurality of units, a duplicating unit for duplicating a packet to which identification information for identifying the packet is added to a packet addressed to the mobile station, and a distributing unit for distributing the duplicated packet to other base stations; A storage means for storing the packet to which the identification information is added and a packet distributed from another base station, and a transmission means for transmitting the stored packet to the mobile station. Features.

  Here, one base station that transmits a packet addressed to the mobile station is selected based on the reception quality of signals transmitted from a plurality of base stations, and the reception quality of each base station is notified to the one base station Whether or not to transmit a packet to be distributed from the mobile station to the mobile station based on the reception quality of each base station when the mobile station selects the base station as the one base station. It is desirable to further comprise a determination means for determining each of the other base stations, and an instruction means for instructing the other base station to perform a transmission operation based on the determination result.

  In the base station according to the present invention, the distribution means includes an encapsulation means for encapsulating the identification information and the packet to be distributed, and the length of the identification information indicating the length of the encapsulated packet obtained by the encapsulation. An encapsulated packet distribution means for distributing the encapsulated packet by recording the total value of the length of the packet to be distributed in the header of the encapsulated packet, and the capsule recorded in the header of the encapsulated packet that has been distributed If the length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet is not equal to the length of the packet to be distributed recorded in the header of the packet to be distributed, the encapsulated packet receives identification information. It is desirable to include a configuration determination unit that determines that the configuration is included.

  A mobile station according to the present invention is a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, Measuring means for measuring the reception quality of the signal transmitted from the base station, selection means for selecting one base station for transmitting a packet addressed to the own station based on the reception quality for each base station, and the selected One base station comprises transmission request means for requesting transmission of a packet addressed to the own station.

  The mobile station according to the present invention is a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information using packets, Based on the reception quality of the station, it is determined for each of the other base stations whether or not to transmit the packet scheduled to be distributed from the own station to each of the other base stations, and the transmission operation based on the determination result is determined for the other base station. Selects a measurement unit that measures the reception quality of signals transmitted from multiple base stations that have the function of instructing and one base station that transmits packets addressed to itself based on the reception quality of each base station And a reception quality notifying unit for notifying the selected one base station of the reception quality of each base station.

  A mobile station according to the present invention is a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, Based on the measurement means for measuring the reception quality of the signal transmitted from the base station and the reception quality for each base station, it is determined which of the predetermined communication states each base station is in. And a state transition requesting unit for requesting the base station to change the communication state based on the determination result.

  Here, a plurality of predetermined communication states are added to the first state in which packets are not transmitted / received to / from the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station. A second state in which a later packet can be transmitted to the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, A third state in which the packet is distributed and the packet after the addition can be transmitted, and the duplicate packet is received from the base station in the third state, and the duplicate packet is transmitted to the mobile station. It is desirable to comprise including the 4th state which can be performed.

  In addition, it is desirable to further include diversity receiving means for performing diversity reception for the same packet when receiving the same packet from a plurality of base stations.

  By the way, the invention according to the above mobile station can be described as follows as a mobile station control program to be executed by a computer mounted on the mobile station.

  That is, the mobile station control program according to the present invention is mounted on a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by packets. 24. A mobile station control program to be executed by a computer, as shown in FIG. 24, based on measurement step S441 for measuring reception quality of signals transmitted from a plurality of base stations, and reception quality for each base station The computer includes a selection step S442 for selecting one base station for transmitting a packet addressed to the own station, and a transmission request step S443 for requesting the selected one base station to transmit a packet addressed to the own station. It is made to perform.

  The mobile station control program according to the present invention is installed in a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information using packets. A mobile station control program to be executed by a computer, as shown in FIG. 25, based on the reception quality of each base station, whether or not to send a packet to be distributed from the own station to the mobile station. Measuring each of the other base stations and measuring reception quality of signals transmitted from a plurality of base stations having a function of instructing another base station to perform a transmission operation based on the determination result, Based on the reception quality of the base station, a selection step S452 for selecting one base station for transmitting a packet addressed to the own station, and one selected base And a reception quality notification step S453 to notify the reception quality for each base station to the station, and characterized by causing the computer to perform.

  The mobile station control program according to the present invention is installed in a mobile station that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information using packets. 26. A mobile station control program to be executed by a computer, as shown in FIG. 26, based on measurement step S461 for measuring reception quality of signals transmitted from a plurality of base stations, and reception quality for each base station Then, a determination step S462 for determining which of the predetermined communication states each base station is in, and a transition of the communication state to the base station to which the communication state should be changed based on the determination result The computer is caused to execute a transition request step S463 for requesting the above.

  A computer-readable recording medium according to the present invention stores any one of the above-described mobile station control programs. As shown in FIG. 27, the mobile station control program recorded on the recording medium 62 can be read by the reading unit 61 </ b> A of the computer 61 mounted on the mobile station 60.

  By the way, the present invention can also adopt the following aspects.

  A data link transmission control method according to the present invention is a data link transmission control method for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets between a mobile station and a plurality of base stations, When the mobile station requests connection to another base station while connecting to the one base station, the one base station transfers the data link transmission control information to the other base station. It is also possible to adopt an embodiment that does this.

  A mobile communication system according to the present invention is a mobile communication system that includes a mobile station and a plurality of base stations, and transmits and receives information using packets. The mobile station transmits and receives packets to and from the base station. Mobile station transmission control means for performing data link transmission control including automatic retransmission request control for performing, and connection request means for requesting connection with a base station serving as a communication partner, wherein the base station includes the mobile station Base station transmission control means for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets to and from the base station, and transfer means for transferring data link transmission control information to other base stations. When the base station transmission control means has a connection request with another base station from the mobile station, the transfer means transfers the data link transmission control information to the other base station. It may be employed.

  A data link transmission control apparatus according to the present invention is a data link transmission control apparatus mounted on a base station that transmits and receives information to and from a mobile station by using a packet, and performs automatic retransmission for transmitting and receiving packets. When there is a connection request between the mobile station and the transfer means for transferring the data link transmission control information related to the data link transmission control including the request control to the other base station, the other base station A mode having base station transmission control means for causing the base station to transfer the data link transmission control information by the transfer means may also be adopted.

  Since the invention related to the data link transmission control method, the invention related to the mobile communication system, and the invention related to the data link transmission control device are the same in terms of technical idea, the following will be described by the invention related to the data link transmission control method.・ Explain the effect.

  The data link transmission control method is a method for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets between a mobile station and a plurality of base stations. When a connection with another base station is requested during connection with the other base station, one base station transmits data link transmission control information related to data link transmission control including automatic retransmission request control for transmitting and receiving packets to other base stations. Transfer to station. As a result, a series of data link transmission control information is transferred between the base stations executing the data link transmission control according to the movement of the mobile station, and the new base station takes over the data link transmission control and the unreachable confirmation is performed. Resend only packets.

  Therefore, compared to the case where one base station continuously performs data link transmission control as in the prior art, an increase in packet transmission delay time due to an increase in packet transfer between base stations can be avoided. By reducing the packet transmission delay time, the throughput can be increased and the performance of the entire system can be improved.

  In such a data link transmission control method, one base station may transfer data link transmission control information to another base station simultaneously with the transfer timing of the packet addressed to the mobile station to the other base station. Alternatively, the packet may be transferred to another base station at a timing different from the transfer timing of the packet addressed to the mobile station.

  That is, in the mobile communication system, the transfer means provided in the base station also transfers the packet addressed to the mobile station to another base station, and the base station transmission control means transmits the data link transmission control information, It can be configured such that the transfer unit transfers the packet addressed to the mobile station to the other base station simultaneously with the transfer timing or at a different timing. In the data link transmission control device, the transfer means also transfers a packet addressed to the mobile station to another base station, and the base station transmission control means sends the data link transmission control information to the other base station. It can be configured such that the transfer means transfers the packet to the other base station at the same time as or at a different timing from the transfer timing of the packet addressed to the mobile station to the base station.

  Further, in the data link transmission control method, one base station serving as a transfer source, based on a connection request from a mobile station to another base station, transmits data link transmission control information related to the mobile station or the mobile station. When the packet addressed to the mobile station is received after the packet and the data link transmission control information are transferred to another base station, it is desirable to transfer the received packet to the other base station. Further, in the mobile communication system, the base station transmission control means provided in the base station is configured to send data link transmission control information related to the mobile station or address to the mobile station based on a connection request from the mobile station to another base station. When the packet addressed to the mobile station is received after the packet and the data link transmission control information are transferred to another base station, the received packet is transferred to the other base station by the transfer means. Is desirable. Further, in the data link transmission control device, the base station transmission control means, based on a connection request from the mobile station to another base station, data link transmission control information related to the mobile station, or a packet addressed to the mobile station When the packet addressed to the mobile station is received after the data link transmission control information is transferred to the other base station, the received packet is preferably transferred to the other base station by the transfer means. .

  In this case, since the packet addressed to the mobile station received by one base station (transfer base station) after being transferred to another base station is transferred to the other base station without exception, The data link transmission control can be taken over more reliably, and the reliability of the data link transmission control can be improved.

  Further, in the data link transmission control method, another base station that is a transfer destination receives data related to the mobile station from one base station immediately after a connection request from the mobile station to the other base station is received. When the link transmission control information or the packet addressed to the mobile station and the data link transmission control information are received before receiving the packet addressed to the mobile station, it is desirable to store the received packet in the memory. Further, in the mobile communication system, the base station transmission control means provided in the base station receives the mobile station from the previously connected base station immediately after the connection request from the mobile station to the base station. Data link transmission control information, or a packet addressed to the mobile station and a packet addressed to the mobile station before receiving the data link transmission control information, the received packet is stored in a memory It is desirable. Further, in the data link transmission control device, the base station transmission control means was connected before immediately after the connection request with the base station on which the data link transmission control device is mounted is from the mobile station. If the packet addressed to the mobile station is received from the base station before receiving the data link transmission control information related to the mobile station, or the packet addressed to the mobile station and the data link transmission control information, the received packet It is desirable to configure to store in memory.

  In this case, in the other base station that is the transfer destination, immediately after the connection request from the mobile station to the other base station, the data link transmission control information related to the mobile station from the one base station, or Since the received packet addressed to the mobile station is stored in the memory without being discarded until the packet addressed to the mobile station and the data link transmission control information are received, the data link transmission between the base stations is performed. Control takeover can be executed more reliably and the reliability of data link transmission control can be improved.

  Further, in the data link transmission control method, when another base station that is a transfer destination receives a packet retransmission request from a mobile station and does not receive a packet addressed to the mobile station from one base station, It is desirable to transmit a packet transfer request addressed to the mobile station to the one base station. In the above mobile communication system, the base station transmission control means provided in the base station receives a packet retransmission request from the mobile station and receives a packet addressed to the mobile station from the previously connected base station. If not, it is desirable that a transfer request for a packet addressed to the mobile station is transmitted to the previously connected base station. In the data link transmission control device, the base station transmission control means receives a packet retransmission request from the mobile station and does not receive a packet addressed to the mobile station from a previously connected base station. In this case, it is desirable that a transfer request for a packet addressed to the mobile station is transmitted to the previously connected base station.

  In this case, if another base station as a transfer destination receives a packet retransmission request from the mobile station, but does not receive a packet addressed to the mobile station from one base station of the transfer source, Since the transfer request for the packet addressed to the mobile station is transmitted to the base station, the packet addressed to the mobile station can be transferred earlier, and the throughput can be increased by speeding up the processing relating to the takeover.

  By the way, the takeover of data link transmission control from one base station to another base station is not limited to a mode in which a packet addressed to a mobile station and data link transmission control information are simultaneously transferred. May be transferred automatically. That is, in the data link transmission control method, when there is a connection request from a mobile station to another base station, one base station transfers only the data link transmission control information for the mobile station, and the other base station When the packet transfer request for the mobile station is received from the mobile station, the packet addressed to the mobile station may be transferred to the other base station. Also, in the mobile communication system, when the base station transmission control means provided in the base station has a connection request with another base station from the mobile station, only the data link transmission control information for the mobile station is transferred, When a transfer request for the packet addressed to the mobile station is received from another base station, the packet addressed to the mobile station may be transferred to the other base station. Further, in the data link transmission control device, when there is a connection request from the mobile station to another base station, the base station transmission control means transfers only the data link transmission control information for the mobile station, When a transfer request for the packet addressed to the mobile station is received from the base station, the packet addressed to the mobile station may be transferred to the other base station.

  In this way, when one base station communicates with another base station and receives a transfer request for the packet addressed to the mobile station from the other base station to which the transfer is made, By transferring the packet addressed to the mobile station to the station, the data link transmission control can be taken over more reliably.

  Note that it is desirable to transfer packets not only in units of packets but also in units of blocks obtained by dividing one packet. By enabling transfer in units of blocks, it is possible to retransmit only unreachable blocks between base stations, and there is an advantage that the amount of packet transfer can be reduced.

  By the way, in the data link transmission control method, one base station encapsulates the data link transmission control information and the packet to be transferred, and represents the length of the encapsulated packet obtained by the encapsulation. The total value of the length of the packet to be transferred and the length of the packet to be transferred are recorded in the header of the encapsulated packet, the encapsulated packet is transferred, and the encapsulated packet recorded in the header of the transferred encapsulated packet is recorded. When the length obtained by subtracting the length of the header of the encapsulated packet from the length is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred, the encapsulated packet transmits the data link transmission control information. It is desirable to judge that it is configured.

  Further, in the mobile communication system, the transfer means encapsulates the data link transmission control information and the packet to be transferred, and the data link transmission represents the length of the encapsulated packet obtained by the encapsulation. The total value of the length of the control information and the length of the packet to be transferred is recorded in the header of the encapsulated packet, and the encapsulated packet transfer means for transferring the encapsulated packet and the header of the encapsulated packet transferred If the length obtained by subtracting the header length of the encapsulated packet from the recorded length of the encapsulated packet is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred, the encapsulation Configuration determining means for determining that the packet is configured to include data link transmission control information; Rukoto is desirable.

  In the data link transmission control device, the transfer means includes the encapsulation means for encapsulating the data link transmission control information and the packet to be transferred, and the data representing the length of the encapsulated packet obtained by the encapsulation. The total value of the length of the link transmission control information and the length of the packet to be transferred is recorded in the header of the encapsulated packet, the encapsulated packet transfer means for transferring the encapsulated packet, and the encapsulated packet transferred When the length of the encapsulated packet recorded in the header minus the length of the encapsulated packet header is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred, Configuration determining means for determining that the encapsulated packet includes data link transmission control information. Configuration and it is desirable to.

  In these inventions, it is possible to reliably determine whether or not the encapsulated packet transferred includes data link transmission control information in one base station, and smoothly execute control based on the data link transmission control information. It becomes possible to do.

  By the way, a mode different from the above, that is, a base station that performs data link transmission control, instead of data link transmission control information, control base station identification information for identifying a base station that performs data link transmission control, A mode of transmitting to the mobile station can also be adopted.

  That is, the data link transmission control method according to the present invention is a data link transmission control method for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets between a mobile station and a plurality of base stations. The base station that performs data link transmission control transmits control base station identification information for identifying the base station that performs data link transmission control to the mobile station, instead of the data link transmission control information. May adopt a mode of recognizing a base station that performs the data link transmission control based on the control base station identification information.

  A mobile communication system according to the present invention is a mobile communication system that includes a mobile station and a plurality of base stations, and transmits and receives information using packets. The base station transmits and receives packets to and from the mobile station. Base station transmission control means for performing data link transmission control including automatic retransmission request control for performing transmission and reception, and control base station identification information for identifying a base station performing data link transmission control instead of data link transmission control information Transmitting means to the mobile station, the mobile station recognizes a base station that performs the data link transmission control based on the control base station identification information, and communicates with the base station. Mobile station transmission control means for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets, and connection request means for requesting connection with a base station as a communication partner. A manner that can be adopted.

  The data link transmission control device according to the present invention is a data link transmission control device mounted on a base station that transmits and receives information to and from a mobile station by using a packet, and transmits a packet to and from the mobile station. Base station transmission control means for performing data link transmission control including automatic retransmission request control for performing transmission and reception, and control base station identification information for identifying a base station performing data link transmission control instead of data link transmission control information It is also possible to adopt a mode having transmitting means for transmitting to the mobile station.

  In this case, the base station that performs data link transmission control transmits, to the mobile station, control base station identification information for identifying the base station that performs data link transmission control instead of the data link transmission control information. The station can recognize the base station that performs the data link transmission control based on the control base station identification information. As a result, the mobile station performs data link transmission control including automatic retransmission request control for transmitting and receiving packets to and from the base station that performs the data link transmission control (for example, a connection request with a new base station). It can be performed. In this way, the mobile station and the base station can reduce the amount of control information transmitted and received by performing data link transmission control using the control base station identification information instead of the data link transmission control information. The amount of network traffic can be reduced.

  By the way, in the data link transmission control method, the base station encapsulates the control base station identification information and the packet to be transferred, and represents the length of the control base station identification information indicating the length of the encapsulated packet obtained by the encapsulation. And the total length of the packet to be transferred is recorded in the header of the encapsulated packet to transfer the encapsulated packet, and the length of the encapsulated packet recorded in the header of the encapsulated packet that has been transferred If the length obtained by subtracting the length of the header of the encapsulated packet from the length of the packet to be transferred recorded in the header of the packet to be transferred is not equal, the encapsulated packet includes control base station identification information. It is desirable to judge that it is configured.

  In the mobile communication system, the transmission means includes control means for encapsulating control base station identification information and a packet to be transferred, and control base station identification representing the length of the encapsulated packet obtained by the encapsulation. A total value of the length of the information and the length of the packet to be transferred is recorded in the header of the encapsulated packet, and the encapsulated packet transfer means for transferring the encapsulated packet, and recorded in the header of the transferred encapsulated packet When the length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred, It is preferable to include a configuration determination unit that determines that the configuration includes control base station identification information.

  In the data link transmission control device, the transmission means includes a control base that encapsulates the control base station identification information and the packet to be transferred, and a control base that represents the length of the encapsulated packet obtained by the encapsulation. An encapsulated packet transfer means for transferring the encapsulated packet by recording the total value of the length of the station identification information and the length of the packet to be transferred in the header of the encapsulated packet, and the header of the encapsulated packet that has been transferred If the length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet recorded in the packet is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred And a configuration determining means for determining that the packet is configured to include control base station identification information. There.

  In these inventions, the base station can reliably determine whether or not the transferred encapsulated packet includes control base station identification information, and smoothly executes control based on the control base station identification information. Is possible.

  According to the present invention, it is possible to increase the throughput and improve the performance of the entire system by shortening the packet transmission delay time while accommodating the movement of the mobile station.

  Various embodiments of a data link transmission control method and a mobile communication system according to the present invention will be described.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG. First, the configuration of the mobile communication system in the first embodiment will be described with reference to FIG. The mobile communication system according to the first embodiment includes a mobile station 131 and a plurality of base stations 102, 112, and 122. The base stations can communicate with each other via the network 1. Yes.

  The mobile station 131 receives data from the wireless network via the mobile station antenna 32 and transmits / receives data to / from the wireless network, and data for performing data link transmission control including automatic retransmission request control described later. The link transmission control unit 34 includes a data input / output terminal 35 as an input / output terminal for packet data. Among these, the data link transmission control unit 34 includes a mobile station transmission control unit 34A that performs data link transmission control including automatic retransmission request control for transmitting and receiving packets to and from the base station, and a base station that is a communication partner. And a connection request unit 34B for requesting connection.

  The base station 102 performs transmission and reception of data from the wireless network and transmission of data to the wireless network via the base station antenna 6 and data link transmission control including automatic retransmission request control described later. A data link transmission control unit 103 that controls each component in the base station 102, a transfer unit 105 that transmits data link transmission control information to the base station to be changed when receiving a request to change the base station, and data The storage unit 104 functions as a temporary storage area for packet data and the like by the link transmission control unit 103. The other base stations 112 and 122 are configured similarly to the base station 102.

  Next, the operation in the first embodiment will be described. Here, when the mobile station monitors the communication quality with the nearest one or more base stations and determines that another base station can perform communication with better communication quality than the currently communicating base station, The mobile station shall request a base station change. Initially, it is assumed that the mobile station 131 has good communication quality with the base station 102 and can communicate only with the base station 102.

  In the base station 102, a packet input from the network 1 by the arrow S1 in FIG. 2 is input to the data link transmission control unit 103, and data link transmission control including automatic retransmission request control is performed. The data link transmission control unit 103 first assigns a packet number to enable packet identification, and then stores the packet and outputs it to the transceiver 5.

  If the packet number described in the header of the packet input to the data link transmission control unit 103 can be identified, the packet is stored as it is without adding a new packet number as described above. Output to the transceiver 5. The transceiver 5 modulates the input packet into a transmission signal and then transmits the packet to the mobile station 131 via the base station antenna 6 (arrow S2 in FIG. 2).

  On the other hand, in the mobile station 131, after the signal from the mobile station antenna 32 is received by the transceiver 33, the received packet is input to the data link transmission control unit 34, and data link transmission control including automatic retransmission request control is performed. . The data link transmission control unit 34 performs error detection using the parity added to the input packet. If there is an error in the packet as a result of detection, the data link transmission control unit 34 transmits a NACK (Negative Acknowledgment) signal to the base station 102, thereby requesting the retransmission of the packet to the data link transmission control unit 103. (Arrow S3 in FIG. 2). Then, the data link transmission control unit 103 retransmits the packet with the stored packet number (arrow S4 in FIG. 2).

  If there is no error in the packet, the data link transmission control unit 34 outputs the packet from the data input / output terminal 35 and transmits an ACK (Acknowledgment) signal to the base station 102 to reach the packet. The confirmation is notified to the data link transmission control unit 103 of the base station 102 (arrow S5 in FIG. 2). Then, the data link transmission control unit 103 deletes the packet with the packet number stored for retransmission.

  Next, when the mobile station 131 moves, the communication quality between the mobile station 131 and the base station 102 that has been communicating so far deteriorates and the communication with the adjacent base station 112 becomes good. 131 first transmits a base station change request to the data link transmission control unit 103 of the base station 102 via the base station 112 (arrows S6 and S7 in FIG. 2). In the present embodiment, a method of notifying a change destination base station number together with a request for changing a base station is adopted.

The data link transmission control unit 103 of the base station 102 that has received the request to change the base station transmits data link transmission control information to the base station 112 that is the change destination via the transfer unit 105 (arrow in FIG. 2). S8). This embodiment will be described as a method using a packet number that has not been confirmed as data link transmission control information and the latest packet number. Then, the data link transmission control unit 103 deletes all the stored packets for the mobile station 131 and stops packet transmission. Further, the packet addressed to the mobile station 131 arriving at the data link transmission control unit 103 as indicated by arrow S9 in FIG. 2 is set to be transferred to the base station 112 as it is by the transfer unit 105 as indicated by arrow S10. .
In the data link transmission control unit 113 of the base station 112 that is the change destination, if the packet addressed to the mobile station 131 is input before the data link transmission control information from the base station 102 is input, the data link transmission control information is The packet is temporarily stored in the storage unit 114 until it is input. Then, after inputting the data link transmission control information, the packet stored in the storage unit 114 is given the number next to the latest packet number, which is the data link transmission control information, and so on. The process (arrows S11, S12, S13, S14) is performed and transmitted.

  Further, even if the mobile station moves into a cell of another base station, the above-described operation enables the data link transmission control method of the present invention.

  In this way, it is not necessary to execute the procedure for resetting the packet number, and the data link transmission control unit of the base station directly communicating with the mobile station can be used. Data link transfer control along the route can be performed, and the packet transfer delay time can be shortened compared to the conventional case.

  Next, the above operation will be described more specifically with reference to FIG.

  First, the mobile station 131 is in a state where the communication quality with the base station 102 of the change source is good. When the change-destination base station 112 is a base station adjacent to the base station 102 that is performing data link transmission control, there is not much influence of an increase in traffic due to retransmission and an increase in delay time. When the station 102 performs data link transmission control including automatic retransmission request control and the change-destination base station becomes a base station 122 remote from the base station 102 performing the data link transmission control, the mobile station An embodiment will be described in which a packet and data link transmission control information are transferred to the change destination base station 122, and data link transmission control including automatic retransmission request control is performed in the change destination base station 122.

  At the point (1) in FIG. 3, a packet addressed to the mobile station is input from the network to the base station 102. The base station 102 assigns packet number 1 to the input packet, adds a CRC, stores the packet, and transmits the packet to the mobile station 131. The mobile station 131 transmits an arrival confirmation to the base station 102 because no error is detected in the received packet. Then, the base station 102 deletes the stored packet of the packet number 1 by confirming the arrival of the packet number 1.

  Next, at the point (2) in FIG. 3, a packet addressed to the mobile station is input to the base station 102. The base station 102 assigns a packet number 2 and adds a CRC, stores the packet, and transmits the packet to the mobile station 131. Since an error is detected in the packet received by the mobile station 131 this time, a NACK (Negative Acknowledgment) signal is transmitted to the base station 102 to request the base station 102 to retransmit the packet with the packet number 2. The base station 102 retransmits the packet with the packet number 2 in response to the retransmission request. However, since an error is detected in the packet received again, the mobile station 131 requests the base station 102 to retransmit the packet number 2 again. At this time, since the communication quality with the base station 112 is better than that with the base station 102, the base station 102 is requested to change the base station via the base station 112. Since the base station 112 is an adjacent base station of the base station 102, the base station 102 performs data link transmission control including automatic retransmission request control as it is, and therefore controls the base station 112 to transmit as it is. Then, the packet with the packet number 2 as the retransmission packet is transmitted to the mobile station 131 via the base station 112. Since the mobile station 131 has not detected an error in the received packet, the mobile station 131 transmits an ACK (Acknowledgment) signal to the base station 102 via the base station 112, thereby transmitting an arrival confirmation to the base station 102. Since the base station 102 confirms the arrival of the packet with the packet number 2, the stored packet with the packet number 2 is deleted.

  The next packet is input to the base station 102 at the point (3) in FIG. The base station 102 assigns the packet number 3 and adds the CRC, stores the packet, and transmits the packet to the mobile station 131 via the base station 112. Since the mobile station 131 has not detected an error in the received packet, the mobile station 131 transmits an arrival confirmation to the base station 102 via the base station 112. The base station 102 deletes the stored packet of the packet number 3 by confirming the arrival of the packet number 3.

  The next packet is input to the base station 102 at time (4) in FIG. In the same manner as described above, packet number 4 is added and CRC is added and the packet is stored, and then transmitted to mobile station 131 via base station 112. Here, since an error is detected in the packet received by the mobile station 131, the base station 102 is requested to retransmit the packet number 4 through the base station 112. At this time, since the communication quality with the base station 122 is better than that with the base station 112, the mobile station 131 requests the base station 102 to change the base station via the base station 122. Since the base station 102 is not the adjacent base station, the base station 102 notifies the base station 122 of a change in data link transmission control including automatic retransmission request control.

  Here, by notifying the mobile station 131 of the base station number that is currently performing data link transmission control, the base station 122 can recognize that it is necessary to perform data link transmission control for the mobile station 131 thereafter. Therefore, in this case, the base station 102 does not need to make the notification. Then, it requests a device that changes the packet transmission destination in the network to input the subsequent packet addressed to the mobile station to the base station 122. This apparatus has a function capable of changing a packet transmission destination using location registration information of the mobile station 131 or the like. In addition, since the base station 102 receives the base station change request immediately after transmitting the retransmission packet with the packet number 4, the mobile station 131 has not notified the arrival confirmation or the retransmission request for the packet. Therefore, the base station 102 does not output the data link transmission control information to the base station 122 until the arrival confirmation of the retransmission packet or a retransmission request is notified. Therefore, the base station 122 at this time is in a state that only keeps accumulating the packets addressed to the mobile station inputted at the time (5) in FIG.

  Then, it is assumed that the mobile station 131 has not detected an error in the retransmission packet. Therefore, the mobile station 131 transmits an arrival confirmation of the packet number 4 to the base station 102 via the base station 122. Since the arrival of the retransmission packet number 4 has been confirmed in the base station 102, only the fact that the latest packet number is 4 is notified as the data link transmission control information to the base station 122 which is the change destination base station. If there is a packet whose arrival has not been confirmed, the packet number whose arrival has not been confirmed and the latest packet number are notified. Further, since there is no packet addressed to the mobile station that is transmitted and received using the base station 112, the base station 102 notifies the base station 112 of this fact. Thereby, the base station 112 can release the resources of the base station 112 allocated to the mobile station 131.

  In addition, the base station 122 determines that the packet input from the time point (5) in FIG. 3 and accumulated is the packet number 4 because the latest packet number as the data link transmission control information from the base station 102 is 4. The number 5 is assigned to the packet, and after the CRC is added, the packet is stored and transmitted to the mobile station 131. The mobile station 131 transmits an arrival confirmation to the base station 122 because no error is detected in the received packet. The base station 122 deletes the stored packet of the packet number 5 by confirming the arrival of the packet number 5.

  As described above, the data link transmission control method of the present invention can be performed regardless of the movement of the mobile station 131 by repeating the above operation.

  According to the first embodiment, it is not necessary to execute a procedure for resetting the packet number, and the data link transmission control unit of the base station that is directly communicating with the mobile station 131 can be used. Regardless of the movement of the station 131, the data link transfer control can always be performed on the shortest path, the packet transfer delay time can be shortened compared to the conventional case, and the system throughput can be increased.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. First, it is assumed that the communication quality between the mobile station 131 and the base station 102 is good. That is, the mobile station 131 can communicate only with the base station 102.

  The base station 102 inputs a packet input from the network 1 to the data link transmission control unit 103 and performs data link transmission control including automatic retransmission request control. In the present embodiment, a case will be described in which one packet is divided into a plurality of blocks so as to be adapted to a radio frame. As specified in FIG. 4B, the data link transmission control unit 103 divides the input packet into a plurality of blocks, and in order to maintain the order of the divided blocks, After assigning a packet number so that the packet before division can be identified, an error detectable parity such as CRC is added and output to the transceiver 5 so that an error occurring during transmission can be detected. The transceiver 5 modulates the input block into a transmission signal, and then transmits the block to the mobile station 131 via the base station antenna 6. FIG. 4A shows a packet configuration in the data link transmission control unit of the first embodiment.

  On the other hand, in the mobile station 131, after the signal from the mobile station antenna 32 is received by the transceiver 33, the received block is output to the data link transmission control unit 34. The data link transmission control unit 34 performs error detection using the parity added to the input block. If there is no error in the block as a result of detection, the data link transmission control unit 34 notifies the data link transmission control unit 103 of the base station 102 of the arrival confirmation of the block. If there is an error in the block, the data link transmission control unit 34 notifies the data link transmission control unit 103 of the base station 102 of a retransmission request for the block. Then, the data link transmission control unit 103 retransmits the stored block. In this way, when all blocks for one packet are received without error, the data link transmission control unit 34 synthesizes the blocks by performing the reverse operation of dividing the data link transmission control unit 103 into the respective blocks. After forming one packet, the data input terminal 35 outputs the packet.

  Next, a case where the base station is changed due to movement of the mobile station 131 will be described. In this embodiment, the mobile station can receive packets from a plurality of base stations at the same time without limiting the number of base stations that communicate simultaneously with the mobile station. Further, as described in the first embodiment, it is naturally possible even when the number of simultaneously communicating partner base stations with the mobile station is one.

  Communication quality between the mobile station 131 and the base station 102 that has been communicating until now is slightly deteriorated, and the communication with the adjacent base station 112 is improved, and communication with the two base stations of the base station 102 and the base station 112 is possible. Suppose that In this case, the mobile station 131 requests the data link transmission control unit 103 of the base station 102 to connect to the base station. Since the communication quality is only slightly deteriorated, the mobile station 131 is in communication with the two stations of the base station 102 and the base station 112, unlike the first embodiment. The data link transmission control unit 103 of the base station 102 that has received the connection request notifies the base station 112 that the mobile station 131 is requesting connection. Then, the data link transmission control unit 103 associates a part of the packets addressed to the mobile station 131 input thereafter with the packet number, and transmits the packet to the base station 112 via the transfer unit 105. The data link transmission control unit 113 performs automatic retransmission request control for each block, but the data link transmission control unit in either base station associates packet numbers to maintain the order of packets received by the mobile station. Done in In the present embodiment, the data link transmission control unit 103 of the base station 102 associates the packet numbers. The data link transmission control unit 113 of the base station 112 divides the packet input from the base station 102 into blocks, and then determines the block number and the packet number before division associated with the data link transmission control unit 103. Then, after further adding parity, the data is transmitted to the mobile station 131.

  Next, it is assumed that the communication quality between the mobile station 131 and the base station 102 is further deteriorated and only communication with the base station 112 is possible. In this case, the mobile station 131 requests the data link transmission control unit 103 of the base station 102 to stop packet transmission from the base station 102 via the base station 112 with good communication quality. Upon receiving the request, the data link transmission control unit 103 of the base station 102 transfers the packet including the block whose arrival has not been confirmed, the packet number of the packet, the block number whose arrival has not been confirmed, and the latest packet number. The data link transmission control information is transmitted to the data link transmission control unit 113 of the base station 112 via the unit 105. The block or packet addressed to the mobile station 131 is stored as it is until a transfer request for the block or packet addressed to the mobile station 131 is received from the base station 112. Further, the packet addressed to the mobile station input from the network 1 is stored as it is until the transfer request is made.

  At a certain timing, the base station 112 requests the base station 102 that transmitted the data link transmission control information to transfer the packet or block addressed to the mobile station. This certain timing may be a point in time when a signal for promoting data transmission transmitted from the mobile station is received. Upon receiving the transfer request, the data link transmission control unit 103 of the base station 102 deletes all the stored blocks or packets addressed to the mobile station 131 after transferring them to the base station 112, and thereafter the base station 102 The packet addressed to the mobile station 131 arriving at is set to be transferred to the base station 112 as it is. The data link transmission control unit 113 of the base station 112 divides the packet including the block whose arrival has not been confirmed transferred from the base station 102 into each block, and then sends only the block for which retransmission is requested to the mobile station 131. resend. Since the block has a fixed length, only the necessary block can be retransmitted if the input packet and its packet number and block number are known. Further, a new packet addressed to the mobile station 131 input to the base station 112 is given a packet number based on the latest notified packet number. Note that the data link transmission control unit 103 can also transfer only necessary blocks.

  With the above operation, the data link transmission control method of the present invention can be realized.

  As described above, since the data link transmission control unit of the base station communicating with the mobile station can be used without resetting the packet number, the data link transfer control is always performed on the shortest path regardless of the movement of the mobile station. Thus, the packet transfer delay time can be shortened compared to the conventional case, and the system throughput can be increased.

  The data link transmission control information includes the following items, and any of them can be adopted. (1) packet number for which arrival confirmation has not been performed, (2) packet number for which arrival confirmation has been performed, (3) packet number for which retransmission has been requested, (4) latest packet number, (5) Block number for which arrival confirmation has not been performed, (6) Block number for which arrival confirmation has been performed, (7) Block number for which retransmission has been requested, (8) Latest block number, (9) Above (1) to Items such as the combination of (8) can be adopted.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. Initially, the structure of the mobile communication system in 3rd Embodiment is demonstrated based on FIG.7, FIG.22, FIG.23. As shown in FIG. 7, the mobile communication system according to the third embodiment includes a mobile station 231 and a plurality of base stations 202, 212, and 222, and each base station is connected via the network 1. It is possible to communicate with each other.

  The mobile station 231 includes a transceiver 233 that receives data from the wireless network and transmits data to the wireless network via the mobile station antenna 232, and a data link that performs data link transmission control including automatic retransmission request control described later. The transmission control unit 234 includes a data input / output terminal 235 as an input / output terminal for packet data.

  Among these, the data link transmission control unit 234 is functionally composed of functional blocks shown in FIG. That is, the data link transmission control unit 234 selects one base station from the base stations upon reception of the packet accumulation notification from the base station, and sends a packet addressed to itself based on the reception quality of each base station. When changing the selection unit 234A that selects one base station to transmit, the transmission request unit 234B that requests the selected base station to transmit a packet, and the base station that transmits a packet addressed to itself, In addition to notifying the base station of the transmission suspension, the change time notification unit 234C for notifying the base station of the change destination of the transmission request and the target first packet number, and measuring the reception quality of signals transmitted from the plurality of base stations Measurement unit 234D, reception quality notification unit 234E for notifying the base station at the position selected based on the reception quality of the reception quality for each base station, and the reception quality for each base station Based on the determination unit 234F that determines which communication state each of the base stations is in a predetermined plurality of communication states, and based on the determination result, the communication state transitions to the base station that should change the communication state And a state transition request unit 234G for requesting. The transceiver 233 includes a diversity receiving unit 233A that performs diversity reception on the packets when receiving the same packets from a plurality of base stations.

  On the other hand, as shown in FIG. 7, the base station 202 receives a data from a wireless network via a base station antenna 208 and transmits / receives data to / from the wireless network, and an automatic retransmission control described later. A data link transmission control unit 203 that performs data link transmission control including automatic retransmission request control such as assigning a unique number as identification information to each packet for execution, and controls each component in the base station 202; A packet duplication unit 206 that duplicates the packet, a distribution unit 205 that distributes the duplicated packet to other base stations, and a storage unit 204 that functions as a temporary storage area for packet data and the like by the data link transmission control unit 203. It consists of

  Among these, the data link transmission control unit 203 is functionally composed of functional blocks shown in FIG. That is, the data link transmission control unit 203 includes a packet addressed to the mobile station based on an identification information adding unit 203A for adding identification information for identifying the packet, a timer timeout, or a packet arrival notification from the mobile station. A first deletion unit 203B that deletes the packet, a second deletion unit 203C that deletes the packet based on a timer timeout or notification of the number of the deleted packet from another base station, and the base station as a packet distribution destination base 3rd deletion part 203D which deletes the packet addressed to the mobile station stored in its own station based on a request from the mobile station to be excluded from the station, and notifies the other base station of the number of the packet to be deleted A deletion packet notification unit 203E to be transmitted, a distribution control unit 203F that distributes a packet to a base station that is a new packet distribution destination, and a retransmission request from the mobile station A packet retransmission unit 203G that retransmits the packet in response to the packet, a storage notification unit 203H that notifies the mobile station that the packet is stored when a packet addressed to the mobile station is received and stored, A notification for controlling to transmit a packet to the mobile station and to notify the mobile station that a plurality of packets are accumulated when a transmission request is received from the mobile station while a plurality of packets are accumulated. Control unit 203I, determination unit 203J for determining whether to transmit a packet to be distributed from the own station to the mobile station based on reception quality for each base station, and the determination result And an instruction unit 203K for instructing another base station to perform the transmission operation based on the above. The other base stations 212 and 222 are configured in the same manner as the base station 202.

  By the way, each of the base stations enters one of the four states shown in FIG. 8A with respect to the mobile station 231 and transitions to each state in response to a request from the mobile station 231. Here, these four states will be described.

  The first is an idle state. This state is a state in which the base station is not transmitting or receiving packets to the mobile station 231.

  The second is a packet transmittable state. In this state, when the base station receives a packet from the network 1, it can transmit the packet to the mobile station after adding a unique number to the packet. In addition, this state is a state in which only one base station can be present at a point in time (a plurality of base stations cannot be in the same state at the same time), and the other base stations are in an idle state.

  The third is a packet duplication and transmission enabled state. This state is a state in which the base station performs the following series of operations. That is, when the base station receives a packet from the network 1, it assigns a unique number to the packet, and then duplicates the packet including the number, and copies the packet (hereinafter referred to as “replicated packet”). Is distributed to other base stations requested by the mobile station 231. When the base station receives a packet transmission request from the mobile station 231, the base station transmits the packet to the mobile station 231. This is a state in which such an operation is performed. In addition, this state is also a state in which only one base station can be present at a point in time (a plurality of base stations cannot be in the state at the same time), and the other base stations are in a duplicate packet transmission state described later, Or it is idle.

  The fourth is a state where a duplicate packet can be transmitted. In this state, when the base station receives a duplicate packet from a base station in a state where packet duplication and transmission is possible, and the base station receives a request for packet transmission from the mobile station 231, the duplicate packet can be transmitted to the mobile station. State. This state is a state that occurs in another base station when a certain base station transitions to a packet duplication and transmittable state.

  Next, the operation of the third embodiment will be described. First, operations of the base station and the mobile station 231 in each of the above states will be described.

(1) Operations of Base Station and Mobile Station in Packet Transmission-Enabled State When the following equation (1) holds, the i-th base station with Ψ i = 1 transmits a packet to mobile station 231 The other base stations (i ≠ j) in which ψ j = 0 is in an enabled state are in an idle state.

Here, Pmed (i) is a time-average received power value (for example, a median short-term received power) related to a broadcast signal or a common pilot signal transmitted by the i-th base station, or the time-average The ratio between the received power and the interference power (hereinafter referred to as “time-average received power to interference power ratio”). Pmed_max represents the maximum value of the time-average received power value or the maximum value of the time-average received power to interference power ratio for the first to Nth base stations. Ψ i represents a binary value (1 or 0) as a result of comparing and determining the difference between Pmed_max and Pmed (i) with respect to a predetermined threshold Th. Further, in the present embodiment, a case where N = 3 will be described, and the base station 202, the base station 212, and the base station 222 in FIG. 7 are respectively referred to as the first base station, the second base station, and the third base station. As a base station.

The case where the above formula (1) is established means that a plurality of base stations (in this embodiment, base stations are measured) at the mobile station 231 as in the case where the mobile station 231 is located at the point A in FIG. 202 to base station 222) is a case where a time-average received power value such as a broadcast signal or a common pilot signal or a received power-to-interference power ratio is increased by one. This is the case where, for example, Ψ 1 = 1, Ψ 2 = 0, and Ψ 3 = 0, and the base station 202 is ready to transmit packets to the mobile station 231, and the base station 212 and the base station 222 is in an idle state.

  Processing when a packet arrives at the base station in the packet transmission enabled state will be described with reference to FIG. The base station 202 assigns a unique number to the packet arriving from the network 1 by the data link transmission control unit 203, and stores it after adding CRC or the like for error detection of the received packet at the mobile station. (S301 and S302 in FIG. 10). Then, the data link transmission control unit 203 transmits the packet to the mobile station 231 by controlling the packet duplication unit 206 to output the packet duplication unit 206 as it is to the transceiver 207 (S303). The mobile station 231 performs error detection processing (S304) for the received packet, and if no error is detected, notifies the base station 202 of packet arrival confirmation (S305 and S306). If an error is detected, the mobile station 231 notifies the base station 202 of a packet retransmission request (S305 and S307). When the notification from the mobile station 231 is the arrival confirmation, the base station 202 deletes the accumulated packet corresponding to the unique number (S308 and S310). When the notification from the mobile station 231 is a retransmission request, the base station 202 retransmits the packet corresponding to the unique number (S308 and S309).

(2) Operations of Base Station and Mobile Station in Idle State As described above, the j-th base station with Ψ j = 0 is in an idle state with respect to the mobile station.

  Processing when a packet arrives at the idle base station will be described with reference to FIG. Here, base station 212 and base station 222 are in an idle state. In the base station 212 in the idle state, the data link transmission control unit 213 controls the distribution unit 215 so that the packet addressed to the mobile station 231 is directly transferred to another base station or the base station 202 in a packet transmission enabled state. . For this reason, when the packet arrives at the base station 212, the base station 212 transfers the packet to another base station that is the transfer destination or the base station 202 (S311 and S312 in FIG. 11).

  Since the base stations 212 and 222 have the same configuration, even when a packet arrives at the base station 222, the same operation as described above is performed.

(3) Operation of base station and mobile station in packet duplication and transmission enabled state, and duplicate packet transmission enabled state If any of the plurality of base stations satisfying Ψ i = 1, when the following equation (2) holds: One base station is in a packet duplication and transmission enabled state for the mobile station 231, and a base station in which ψ i = 1 and is not in the packet replication and transmission enabled state is in a duplicate packet transmission enabled state.

  The symbols used are the same as in equation (1).

When Expression (2) holds, the time average received power value or the time average received power measured at the mobile station 231 as in the case where the mobile station 231 is located at the point B in FIG. When a plurality of interference power ratios are large, for example, when Ψ 1 = 1, Ψ 2 = 1, and Ψ 3 = 0 as in the present embodiment, either one of the base station 202 or the base station 212 is used. One base station is ready for packet duplication and transmission. Any one of these base stations may be a base station that is in a packet transmittable state before the transition, or a base station having a large time average received power value or a time average received power to interference power ratio. Is possible. In the present embodiment, the description will be continued assuming that the base station 202 is in a packet duplication and transmission enabled state and the base station 212 is in a replicated packet transmission enabled state.

  Processing when a packet arrives at the base station 202 in a packet duplication and transmission enabled state will be described with reference to FIG. The base station 202 adds a unique number to the packet arriving from the network 1, adds a CRC or the like for error detection of the received packet at the mobile station, stores the packet, and The packet is duplicated including S (S321 and S322 in FIG. 12). Then, the base station 202 distributes the duplicate packet to the base station 212 that is ready to transmit the duplicate packet (S323), and the base station 212 accumulates the distributed packet (S324). Further, the base station 202 notifies the mobile station 231 that the packets addressed to the mobile station 231 are accumulated (S325b).

  Further, as described above, the mobile station 231 is in a state in which the base station having the maximum time-average received power value or the time-average received power-to-interference power ratio is in a packet duplication and transmission enabled state. Request a transition. Thereby, the base station which notifies the mobile station 231 of a new packet can be made into one. This can be realized because the base station with the highest time-average reception quality is notified. In this case, extra power for the notification can be reduced and interference can be suppressed.

  However, if the influence of the interference does not matter so much, as shown in S325b and S325a of FIG. 12, the base station that received the packet (the base station in the packet duplication and transmission enabled state or the base station in the duplicate packet transmission ready state). It is also possible to notify the mobile station 231 each of the stations).

  The mobile station 231 that has received the notification instantaneously transmits signals such as broadcast signals and common pilot signals transmitted from a plurality of base stations (two stations of the base station 202 and the base station 212 in this embodiment) at that time. A base station having the maximum received power or instantaneous received power to interference power ratio is selected (S326), and the selected base station is requested to transmit a packet to the mobile station 231 (S327). A specific method for this request is made possible by requesting the base station for the number of the base station that can identify the base station and the number of the notified packet.

  In addition, the request method is a method of directly requesting a selected base station via an uplink, or a request received by an unselected base station is notified to the selected base station via the inter-base station network. Can be adopted. This is because the instantaneous reception quality between the mobile station and each base station differs between the uplink and the downlink, and even if the downlink reception quality is the highest between the selected base station and the mobile station, the reception of the uplink This is because the quality can be the highest between other base stations and mobile stations.

  Then, the base station (base station 202 in this embodiment) that has received the request transmits the packet to the mobile station 231 (S328). At this time, the base station 202 may notify the mobile station 231 that a plurality of packets addressed to the mobile station 231 are accumulated. This is because the base station does not need to notify again about the subsequent packets accumulated by this.

  The mobile station 231 performs error detection processing (S329) on the received packet, and when no error is detected, notifies the base station 202 of packet duplication and transmission possible state when the error is not detected (S330 and S331). This notification may be made directly to the base station 202 or via the base station 212. If an error is detected, the mobile station 231 selects a base station that has the highest instantaneous or time-average reception quality at that time (S332), and requests the base station to retransmit the packet. Notification is made (S333).

  Receiving the arrival confirmation, the base station 202 deletes the accumulated packet corresponding to the unique number (S334 and S337). In addition, the base station 202 notifies the base station 212 of the packet transmission enabled state (S336). Receiving the notification, the base station 212 deletes the duplicate packet accumulated by the notification (S338).

  On the other hand, when receiving the retransmission request, the base station 202 retransmits the packet corresponding to the unique number (S333, S334, S335).

  As described above, without providing a line control station for distributing packets separately from the base station, packets are accumulated in each base station, and one or a plurality of base stations transmit packets to the mobile station. The traffic in the network can be reduced, and the throughput of the system can be improved by increasing the throughput by shortening the packet transmission delay time.

  In FIG. 12, the three methods shown in FIG. 14 can be adopted for the copy packet deletion notification in S336 from the base station 202 to the base station 212.

  That is, in the first method, as shown in FIG. 14A, the base station 202 notifies the base station 212 of the unique packet number of the packet to be deleted every time the arrival confirmation from the mobile station in S331 is received. (A1). At this time, the corresponding packet stored in the base station 202 may be deleted simultaneously with the notification.

  In the second method, the base station 202 notifies the latest packet number within a predetermined time. That is, the base station 202 starts the process of FIG. 14B upon receiving the arrival confirmation from the mobile station in S331, starts a deletion timer in which a predetermined deletion interval time is set (B1), and The packet number corresponding to the arrival confirmation is stored (B2). At this time, the corresponding packet stored in the base station 202 may be deleted at the same time. Thereafter, when a new arrival confirmation is received (positive determination at B3), the packet number corresponding to the arrival confirmation is stored (B2). When the deletion timer times out (positive determination at B4), the latest packet number among the packet numbers stored at that time, that is, the arrival confirmation received within the predetermined time counted by the timer is used. The number of the latest packet among the corresponding packets is notified (B5).

  Further, in the third method, the base station 202 performs notification by deleting a specific packet (for example, every 10 deleted packets). That is, the base station 202 starts the processing of FIG. 14C by receiving the arrival confirmation from the mobile station in S331, resets the counter n = 1 (C1), and then receives a packet corresponding to the above arrival confirmation. The number is stored (C2). At the same time as this storage, the corresponding packet stored in the base station 202 may be deleted (the same applies to C5). Thereafter, when a new arrival confirmation is received (positive determination at C3), the counter n is incremented by one (C4), and the packet number corresponding to the arrival confirmation is stored (C5). When the counter n reaches 10, that is, when arrival confirmation is received for 10 packets, an affirmative determination is made in C6, and the latest packet number among the packet numbers stored at that time is notified (C7). ).

  Among the above methods, the first method has an advantage in that buffer management becomes easy although the frequency of notification is high and the amount of traffic due to notification is large. In general, the second method has an advantage that the amount of traffic due to notification is reduced although the frequency of notification is low and buffer management becomes complicated. The third method is generally in an intermediate position between the first and second methods in terms of both traffic and buffer management.

  In the present embodiment, by appropriately adopting the above three methods, it is possible to control both the traffic amount and the buffer management with a good balance.

  By the way, a timer may be employed as a trigger for deleting packets accumulated in the base stations 202 and 212 in FIG. This example will be described with reference to FIG.

  That is, as shown in FIG. 13, the base station 202 assigns a unique number to the packet arriving from the network 1 and adds a CRC or the like for error detection of the received packet at the mobile station. The packet is accumulated and the packet is duplicated including the number (S321 and S322X in FIG. 13). At this time, the base station 202 starts a deletion timer for timing the deletion timing regarding the accumulated packets, triggered by the input of the packet to the base station 202 at this time. Note that the base station 202 may start a deletion timer when the target packet is transmitted for the first time.

  Then, the base station 202 distributes the duplicate packet to the base station 212 that is in a state where the duplicate packet can be transmitted (S323). The base station 212 accumulates the distributed packets, and starts a deletion timer that measures the deletion timing for the accumulated packets, triggered by the input of the packets to the base station 212 (S324X). Further, the base station 202 notifies the mobile station 231 that the packets addressed to the mobile station 231 are accumulated (S325b).

  Further, as described above, the mobile station 231 performs state transition so that the base station having the maximum time-average received power value or the time-average received power to interference power ratio is in a packet duplication and transmission enabled state. , It is possible to make one base station that notifies a mobile station of a new packet. This can be realized because the base station with the highest time average reception quality is notified. In this case, extra power for the notification can be reduced and interference can be suppressed.

  However, if the influence of the interference does not matter so much, as shown in S325b and S325a of FIG. 12, the base station that received the packet (the base station in the packet duplication and transmission enabled state or the base station in the duplicate packet transmission ready state). It is also possible to notify the mobile station 231 each of the stations).

  The mobile station 231 that has received the notification receives instantaneous reception power of signals such as broadcast signals and common pilot signals transmitted from a plurality of base stations (two stations of the base station 202 and the base station 212 in this case) at that time, or A base station that maximizes the instantaneous received power to interference power ratio is selected (S326), and the base station is requested to transmit the packet (S327). A specific method for this request is made possible by requesting the base station for the number of the base station that can identify the base station and the number of the notified packet.

  The requesting method is a method of directly requesting the selected base station via an uplink, or notifying the selected base station of the request received by the unselected base station via the inter-base station network. The method can be adopted. This is because the instantaneous reception quality between the mobile station and each base station differs between the uplink and the downlink, and even if the downlink reception quality is the highest between the selected base station and the mobile station, the reception of the uplink This is because the quality can be the highest between other base stations and mobile stations.

  The base station (in this case, the base station 202) that has received the request transmits the packet to the mobile station 231 (S328). At this time, the base station 202 may notify the mobile station 231 that a plurality of packets addressed to the mobile station 231 are accumulated.

  The mobile station 231 performs error detection processing (S329) on the received packet, and when no error is detected, notifies the base station 202 of packet duplication and transmission possible state when the error is not detected (S330 and S331). This notification may be made directly to the base station 202 or via the base station 212. If an error is detected, the mobile station 231 selects a base station that has the highest instantaneous or time-average reception quality at that time (S332), and requests the base station to retransmit the packet. Notification is made (S333).

  Thereafter, when receiving a retransmission request from the mobile station 231, the base station 202 retransmits a packet corresponding to the unique number (S333, S334, S335).

  In the example of FIG. 13, in the base station 202, when the deletion timer started in S322X times out, the stored packet corresponding to the timer is deleted (S336X and S337). The base station 212 also deletes the stored packet corresponding to the timer when the deletion timer started in S324X times out (S336Y and S338).

  According to such processing in FIG. 13, it is not necessary to perform deletion notification (S336 in FIG. 12), so that an increase in traffic between base station networks due to these control packets can be suppressed. Further, since arrival confirmation of packets from the mobile station (S331 in FIG. 13) is not necessarily required, further traffic reduction can be achieved. Note that the timeout value of the deletion timer in FIG. 13 is set to a time when a retransmission request for the packet is considered not to arrive.

  By the way, although this embodiment demonstrated the case where there was one base station (FIG. 12, FIG. 13) which transmits a packet, when interference etc. do not become a problem so much, or the same packet transmitted from several base stations is moved. When the reception quality can be improved by diversity reception in the station, the base station 202 and the base station 212 can also transmit the same packet. Next, this example will be specifically described with reference to FIG.

  The base station 202 adds a unique number to the packet arriving from the network 1, adds a CRC or the like for error detection of the received packet at the mobile station, stores the packet, and The packet is duplicated including S (S341 and S342 in FIG. 15). Then, the base station 202 distributes the duplicate packet to the base station 212 that is ready to transmit the duplicate packet (S343), and the base station 212 accumulates the distributed packet (S344).

  Next, each of the base station 202 and the base station 212 notifies the mobile station that there is a stored packet (S345). When the mobile station is in a state where it can receive a packet, the notification in S345 can be omitted. Then, each of the base station 202 and the base station 212 transmits the accumulated packet to the mobile station (S346).

  The mobile station 231 performs error detection processing (S347) for the received packet. At this time, it is also possible to perform diversity on the same packet transmitted from a plurality of base stations. As the diversity method, the first method of combining the same bits of the same received packet for each bit as it is, or the first method of combining for each bit after weighting with the received power or the received power to interference power ratio. The second method, the third method for selecting a packet in which no error is detected from the packets after error detection, and the like can be employed. If no error is detected, the mobile station 231 notifies the packet arrival confirmation to the base station 202 in a packet duplicatable and transmittable state (S348 and S349).

  Receiving the arrival confirmation, the base station 202 deletes the accumulated packet corresponding to the unique number (S351 and S355). In addition, the base station 202 notifies the base station 212 that is in a state where the duplicate packet can be transmitted (S354). Receiving the notification, the base station 212 deletes the accumulated duplicate packet based on the notification (S356). The notification in S354 can be omitted by the method using the timer as shown in FIG.

  On the other hand, when an error is detected in S348, the mobile station notifies the base station 202 or the base station 212 of a packet retransmission request (S350). When the base station 202 receives the retransmission request, the base station 202 redistributes the retransmission packet to the base station 212 or notifies the retransmission packet number (S352). Then, each of the base station 202 and the base station 212 retransmits the requested packet (S353).

Further, in FIG. 9, when the mobile station 231 moves and arrives near the point C, a large time-average received power value or a time-average received power to interference power ratio is further obtained. For example, when Ψ 1 = 1, Ψ 2 = 1, and Ψ 3 = 1, similarly, the base station 202 distributes a copy of the packet arriving at the base station 202 to the base station 212 and the base station 222.

  Next, operations of the base station and the mobile station in various events transitioning from one state to another state shown in FIG. 8B will be described.

(4) Description of Event A In the mobile station, the mobile station 231 changes from the state in which the above equation (1) is established to the state in which the equation (2) is established, whereby the mobile station 231 is in a packet transmission enabled state. Requests ( i -th base station where Ψ i = 1) to transition to a packet duplication and transmission enabled state, and allows duplicate packet transmission to an idle state base station that newly becomes Ψ i = 1 Requesting to change to a state is event A (see FIGS. 8A and 8B).

  A base station that makes a transition from the packet transmittable state to the packet copy and transmittable state will be described as a base station 202, and a base station that makes a transition from the idle state to the replicated packet transmit state will be specifically described with reference to FIG.

When the equation (1) is changed to the equation (2), the mobile station 231 shifts to the packet duplication and transmission enabled state with respect to the base station 202, and the base station that newly becomes Ψ i = 1. The base station number that identifies the station 212 is notified to the base station 202 (S361 and S362 in FIG. 16).

  Receiving the notification, the base station 202 requests the base station 212 to make a transition to a copy packet transmittable state (S363) and copies the packet addressed to the mobile station 231 stored at that time. (S364) and distribute the duplicate packet to the base station 212 (S366). Then, the base station 202 transitions to a packet duplication and transmission enabled state (S367).

  In response to the transition request from the base station 202, the base station 212 transitions to a copy packet transmittable state (S365). Further, the base station 212 accumulates the distributed copy packet (S368). As a result, even if retransmission is requested to the base station 212, it is possible to perform retransmission immediately.

  Packets that arrive at the base station 202 thereafter are duplicated by the base station 202 and distributed to the base station 212 as described above.

(5) Explanation of Event B In the mobile station, the base station in a state where the duplicate packet can be transmitted is set to Ψ i = 0 by changing from the state where Equation (2) is satisfied to the state where Equation (1) is satisfied. When only the base station in the packet duplication and transmission enabled state becomes Ψ i = 1 (for other base stations, Ψ i = 0), the mobile station 231 receives the packet duplication and transmission ready base station. Requesting the base station in the packet transmittable state and requesting the base station in the replica packet transmittable state to transition to the idle state is event B (see FIGS. 8A and 8B). .

  A base station that transitions from a packet duplication / transmission enabled state to a packet transmittable state is referred to as base station 202, and a base station that transitions from a duplicate packet transmittable state to an idle state is referred to as base station 212, which will be described in detail with reference to FIG. .

The mobile station 231 transitions to the packet transmittable state with respect to the base station 202 when the formula (2) to the formula (1) is satisfied, and Ψ i = 0, that is, the base station 212 in the idle state. Is notified to the base station 202 (S371 and S372 in FIG. 17). Since the two base stations handle packets addressed to the mobile station, a method of requesting to the base station 212 is also possible. In this case, it is possible to request the base station 212 to transition to the idle state and to notify the base station number (base station 202) to transition to the packet transmittable state. In the present embodiment, the description will be continued as the former method.

  Receiving the notification, the base station 202 requests the base station 212 to transition to an idle state (S373), and transitions to a packet transmittable state (S374).

  The base station 212 shifts to the idle state and deletes the accumulated packet (S375). The base station 202 does not copy any packet that arrives thereafter, and does not distribute it to other base stations.

(6) Explanation of Event C In the mobile station, the base station in the packet duplicatable and transmittable state becomes Ψ i = 0 by transitioning from the state in which Equation (2) is established to the state in which Equation (1) is established. When the base station in a state where the replica packet can be transmitted becomes Ψ i = 1, the mobile station 231 requests the base station in the packet replica and transmittable state to transition to the idle state, and transmits the replica packet. An event C is a request for a base station in a possible state to transition to a packet transmittable state.

  A base station that transitions from a packet duplication / transmission enabled state to an idle state is referred to as a base station 202, and a base station that transitions from a duplicate packet transmittable state to a packet transmittable state is referred to as a base station 212, which will be specifically described with reference to FIG. .

  When the mobile station 231 enters a state in which the formula (1) is established from the formula (2), the mobile station 231 shifts to the idle state with respect to the base station 202 and specifies the base station 212 that transitions to the packet transmittable state. The base station 202 is notified of the station number (S381 and S382 in FIG. 18).

  Receiving the notification, the base station 202 requests the base station 212 to shift to a packet transmittable state. Since the base station to which the unique number is assigned is changed, the base station 202 further stores the packet currently accumulated (packet for which arrival confirmation has not been obtained) as specified in the first embodiment. And the latest value of the unique number assigned to the packet are notified (S383a). When this event occurs, the base station 212 also accumulates packets, so it is possible to send only different packets accumulated at both base stations by making an inquiry to the base station 212 (S383b). . Therefore, either method of S383a or S383b is performed.

  Then, the base station 202 transitions to the idle state and deletes the accumulated packets (S384). In addition, when the base station 202 receives a packet addressed to the mobile station 231 in the idle state, the base station 202 sends the packet to the base station 212 as described in “(2) Operation of the base station and mobile station in the idle state”. Control to transfer as it is.

  On the other hand, the base station 212 transitions to a packet transmittable state in response to a transition request from the base station 202 (S385).

(7) Explanation of Event D In the mobile station, the time average from the base station where Ψ i = 1 is newly established while transitioning from the state in which Equation (1) is established to the state in which Equation (2) is established When the mobile station 231 becomes a base station in a packet transmittable state (i.sup.th base station where Ψ i = 1, for example, the maximum received power value or the time average received power to interference power ratio becomes maximum) ) To request a transition to a replica packet transmittable state, and request an idle state base station that newly becomes Ψ i = 1 to transition to a packet replicable and transmittable state. It is.

  A base station that transitions from a packet transmittable state to a replicated packet transmittable state is referred to as base station 202, and a base station that transitions from an idle state to a packet replicated and transmittable state is referred to as base station 212, which will be described in detail with reference to FIG. .

  When the formula (1) is changed to the formula (2), the mobile station 231 shifts to a copy packet transmittable state with respect to the base station 202 and newly shifts to a packet copy and transmittable state. The base station 202 is notified of the base station number that identifies the base station (S391 and S392 in FIG. 19).

  Receiving the notification, the base station 202 requests the base station 212 to transition to a packet duplication and transmission enabled state. Then, since the base station to which the unique number is assigned is changed, the base station 202 further transmits the packet (arrival confirmation can be obtained) currently stored in the base station 202, as specified in the first embodiment. The packet number) and the latest value of the unique number assigned to the packet (S393). This is because the base station 212 makes a transition from an idle state in which packets addressed to the mobile station are not accumulated. Then, the base station 202 transitions to a copy packet transmittable state (S394).

  Based on these notifications, the base station 212 transitions to a packet duplication and transmittable state and accumulates the packets sent from the base station 202 (S395). Then, the base station 212 controls to duplicate a packet that newly arrives at the base station 212 and distribute the duplicate packet to the base station 202.

(8) Explanation of Event E In the mobile station, equation (2) is satisfied, and the base station where the time-average received power value or the time-average received power to interference power ratio is maximized has changed. For this reason, the mobile station 231 requests the base station in the packet replication and transmission enabled state to transition to the replication packet transmission enabled state, and sends the packet replication and transmission enabled state to the base station in the replication packet transmission enabled state. Requesting to make a transition to is event E.

  The base station that transitions from the packet duplication and transmission enable state to the duplicate packet transmission ready state is the base station 202, and the base station that transits from the duplicate packet transmission possible state to the packet duplication and transmission possible state is the base station 212 with reference to FIG. This will be specifically described.

  When the base station that maximizes the time-average received power value or the time-average received power to interference power ratio changes from the base station 202 to the base station 212, the mobile station 231 transmits a duplicate packet to the base station 202. A request is made to make a transition to a possible state and a request is made to the base station 212 to make a transition to a packet duplication and transmission possible state (S401 and S402 in FIG. 20).

  Receiving the notification, the base station 202 shifts to a copy packet transmittable state (S404). Then, since the base station to which the unique number is assigned is changed, the base station 202 specifies the number of the packet (packet for which arrival confirmation has not been obtained) currently stored, as specified in the first embodiment. And the latest value of the unique number assigned to the packet. In addition, since the base station 212 also stores the packets, the base station 202 can transmit only different packets stored in both base stations by making an inquiry to the base station 212 (S403). ). The packets stored in the base station 202 are stored as they are. However, in the case of a method of deleting due to timeout, a deletion timer is started at this point for all the stored packets.

  Based on these notifications, the base station 212 transitions to a packet duplication and transmittable state (S405). Then, the base station 212 controls to duplicate a packet that newly arrives at the base station 212 and distribute the duplicate packet to the base station 202.

  According to the third embodiment described above, without providing a line control station for distributing packets separately from the base station, packets are accumulated in each base station, and one or a plurality of base stations transmit the packets to the mobile station. Therefore, the traffic in the network can be reduced, and the throughput of the system can be improved by increasing the throughput by reducing the packet transmission delay time.

[Fourth Embodiment]
Next, operations related to handover transmission control will be described with reference to FIG. The configuration of the mobile communication system is the same as that of the third embodiment shown in FIG.

  The mobile station obtains time-average reception quality (eg, propagation loss here) between the mobile station and the plurality of base stations by receiving broadcast signals, common pilot signals, and the like transmitted from the plurality of base stations. Then, the mobile station notifies the obtained time-average reception quality to the base station in a packet duplicating and transmitting enabled state to which a unique number is added. The base station in the packet duplicatable and transmittable state instructs each base station in the replica packet transmittable state to transmit in units of packets based on the notified plurality of time average reception qualities. Each base station transmits a new packet according to the instruction. Also, at the time of retransmission, only the base station that has requested retransmission by the mobile station retransmits the packet.

The transmission instruction in units of packets by the base station to which the unique number is added is specifically executed as follows. The base station to which the unique number is added obtains S i (j) based on the following equation (3) using a plurality of time-average propagation losses, and this S for the packet input to the own station. “Identifiers that instruct transmission” are added in the order of base stations having smaller i (j). In addition, when the S i (j) is the same, the base station to which the unique number is added adds “an identifier for instructing transmission” to the base station having a smaller time-average propagation loss. For the propagation loss of the following equation (3), the desired signal / interference power ratio (CIR), the received signal / interference power ratio (SIR), and the desired signal / noise power, which are indicators of reception quality, are further shown. Any of the ratio (CNR) and the received signal-to-noise power ratio (SNR) may be used.

Incidentally, i number of base stations, j represents the number of packets input after updating L i.

  As an example, an operation after the time average propagation loss is updated in a state where there are three base stations (i = 1 to 3) capable of transmitting packets to the mobile station will be described. Further, i = 1 is a base station in a packet duplication and transmission enabled state, i = 2 and 3 are base stations in a replicated packet transmission enabled state, and the respective time average propagation losses are as follows.

Propagation loss between the first base station (i = 1) and the mobile station: L 1 = 1

Propagation loss between the second base station (i = 2) and the mobile station: L 2 = 2

Propagation loss between the third base station (i = 3) and the mobile station: L 3 = 3

The first packet after the update of the time average propagation loss is defined as the Kth packet. Since each S i (j) is all zero at this time, the base station to which the unique number is added adds an identifier so as to transmit from the first base station having the smallest propagation loss.

This identifier can be 1 bit long. That is, a packet with an identifier of “1” is operated to transmit, and a packet with an identifier of “0” is operated to accumulate without being transmitted, so that an instruction with a 1-bit identifier can be made. . Each S i (j) value after addition of the identifier is as follows.

Next, the (K + 1) th packet is input. Since S 2 (0) and S 3 (0) are zero at this point, the base station to which the unique number is added adds an identifier to transmit from the second base station, which has a smaller propagation loss. . And each S i (j) value at this time is as follows.

At the time when the (K + 2) th packet is input, since only S 3 (0) is zero and the minimum value, the base station to which the unique number is added transmits an identifier to transmit from the third base station. Is added. And each S i (j) value at this time is as follows.

  In this way, the base station to which the unique number is added copies the input packet and, when distributing the duplicate packet, allows transmission of the packet to a certain base station based on the above equation (3). Enable the identifier for. FIG. 21 shows the calculation result of equation (3) and the state of the identifier for the subsequent (K + 3) to (K + 10) th packets.

As shown in FIG. 21, when the (K + 3) -th packet is input thereafter, S 1 (1) is the minimum value as described above, so that the base station to which the unique number is added is the first An identifier is added to transmit from the th base station.

When the (K + 4) th packet is input, since S 1 (2) and S 2 (1) are equal to “2/6”, the base station to which the unique number is added has a smaller propagation loss. An identifier is added to transmit from a certain first base station.

Since S 2 (1) is the minimum value when the (K + 5) th packet is input, the base station to which the unique number is added adds an identifier so as to be transmitted from the second base station. .

When the (K + 6) th packet is input, since S 1 (3) and S 3 (1) are equal to “3/6”, the base station to which the unique number is added has a smaller propagation loss. An identifier is added to transmit from a certain first base station.

Since S 3 (1) is the minimum value when the (K + 7) th packet is input, the base station to which the unique number is added adds an identifier so as to be transmitted from the third base station. .

When the (K + 8) th packet is input, since S 1 (4) and S 2 (2) are equal to “4/6”, the base station that adds the unique number has a smaller propagation loss. An identifier is added to transmit from a certain first base station.

Since S 2 (2) is the minimum value when the (K + 9) th packet is input, the base station to which the unique number is added adds an identifier so as to be transmitted from the second base station. .

Since S 1 (5) is the minimum value when the (K + 10) th packet is input, the base station to which the unique number is added adds an identifier so as to be transmitted from the first base station. .

  Each base station transmits only a packet having an identifier of 1 to the mobile station.

When the time-average propagation loss is updated, the base station to which the unique number is added clears S i (j) by resetting j = 0, and then continues the above processing.

  When the mobile station requests retransmission, the mobile station selects a base station that has the smallest propagation loss at that time, and requests the selected base station to retransmit the packet. The reason why packets can be retransmitted from an arbitrary base station selected by the mobile station in this way is that each base station accumulates distributed duplicate packets.

  With the configuration and operation described above, each base station can perform appropriate packet transmission based on a time-average propagation loss without performing a procedure for informing packet arrival from a mobile station, Since the retransmission packet can be immediately transmitted from the base station having the minimum propagation loss at that time, it is possible to perform a quick retransmission while reducing interference with other cells or other mobile stations.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 28, the mobile communication system in the fifth embodiment includes a mobile station 1131 and a plurality of base stations 1102 and 1112 as in the mobile communication system (FIG. 1) of the first embodiment described above. Thus, the base stations can communicate with each other via the network 1.

  Among these, the configuration of the mobile station 1131 is the same as that of the mobile station 131 of the first embodiment. Regarding the configuration of the base station 1102, a packet duplicating unit 1107 for duplicating a packet is added to the base station 102 of the first embodiment, and the duplicating packet is distributed to other base stations instead of the transfer unit 105 in FIG. In addition, a transfer / distribution unit 1105 is provided that transfers packets to a base station that performs other data link transmission control. The data link transmission control unit 1103 performs data link transmission control including automatic retransmission request control for transmitting and receiving packets to and from the mobile station, and performs data link transmission control instead of data link transmission control information. This is different from the first embodiment in that control base station identification information for identifying a base station to be transmitted is transmitted to the mobile station. Further, the base station 1112 has the same configuration as the base station 1102.

  Next, the operation in the fifth embodiment will be described. Here, initially, the wireless communication quality between the mobile station 1131 and the base station 1102 is good, but the wireless communication quality between the mobile station 1131 and the base station 1112 is not good. It is assumed that the initial state is that only communication is possible. The operation in this initial state will be described with reference to FIG.

  In the base station 1102, the packet input from the network 1 in S41 of FIG. 29 is input to the data link transmission control unit 1103, and the data link transmission control unit 1103 performs data link transmission control including automatic retransmission request control. Here, the data link transmission control unit 1103 gives identification information to each packet (S42). The identification information used in this embodiment includes packet identification information for enabling identification of a packet input to the data link transmission control unit 1103, and a control base station that performs the data link transmission control (that is, identification information). And control base station identification information for enabling identification of the base station to which the information is assigned. Further, the data link transmission control unit 1103 adds a CRC or the like to the packet for error detection of the received packet, and stores the added packet (that is, a packet with identification information) in the storage unit 104. It outputs to the transmitter / receiver 5 with (S42). The transceiver 5 modulates the packet into a transmission signal, and then transmits the transmission signal to the mobile station 1131 via the base station antenna 6 (S43).

  On the other hand, the mobile station 1131 receives and demodulates the signal from the mobile station antenna 32 by the transceiver 33, and then inputs the packet obtained by the demodulation to the data link transmission control unit 1034. The data link transmission control unit 1034 performs data link transmission control including automatic retransmission request control, and performs error detection on the input packet using the added CRC (S44). If there is an error in the packet as a result of the detection, the data link transmission control unit 1034 recognizes the number of the packet requesting retransmission and the base station 1102, which is the control base station, based on the assigned identification information. Then, a NACK signal is transmitted to the base station 1102 based on the recognition result (S45). As a result, a retransmission request for the packet is notified to the data link transmission control unit 1103. As this notification method, a method of directly reporting to the base station 1102, a method of notifying through another base station, or the like can be employed. Then, the data link transmission control unit 1103 determines that the ACK signal has not been input (S47), and retransmits the stored packet (S43).

  On the other hand, if there is no error in the packet in error detection, the data link transmission control unit 1034 recognizes the base station 1102 that is the control base station based on the assigned identification information, and based on the recognition result. An ACK signal is transmitted to the base station 1102 (S46). As a result, the arrival confirmation of the packet is notified to the data link transmission control unit 1103. The data link transmission control unit 1103 determines that the ACK signal has been input (S47), and deletes the packet stored for retransmission (S48).

  Next, due to the movement of the mobile station 1131, the communication quality between the mobile station 1131 and the base station 1102 that has been communicating with the mobile station 1131 has deteriorated, and has become comparable to the communication quality with the adjacent base station 1102. In this case, as described in the above-described embodiment, the mobile station 1131 requests the base station 1102 to transmit the same packet from the base station 1102 and the base station 1112 (S49). In response to the request, when a packet is input to the base station 1102 after that time (S50), the data link transmission control unit 1103 of the base station 1102 performs the same processing as S42 on the packet (S51) Is transmitted to the mobile station 1131 by the machine 5 (S52), and the packet is duplicated by the packet duplicating unit 1107 (S53), and the duplicated packet is distributed to the data link transmission control unit 1113 of the base station 1112 by the transfer / distribution unit 1105. (S54).

  Since the data link transmission control unit 1113 is controlled by the data link transmission control unit 1103 to output the distribution packet to the transceiver 15 as it is, the same packet is transmitted from the base station 1102 and the base station 1112 (S52). .

  Here, whether the data link transmission control unit 1113 outputs the arrived packet as it is or performs data link transmission control including the automatic retransmission request control as described above is that identification information is given to the arrived packet. It becomes possible by detecting whether or not it is. That is, when the data link transmission control unit 1113 detects that identification information is added to the input packet, the data link transmission control unit 1113 outputs the arrived packet to the transceiver 15 as it is. On the other hand, when the data link transmission control unit 1113 detects that the identification information is not given to the input packet, the data link transmission control unit 1113 performs data link transmission control including automatic retransmission request control.

  The mobile station 1131 performs error detection on the received packet as described above (S55), and outputs NACK or ACK to the base station 1102 (S56 and S57). In the same way as described above, the base station 1102 determines whether or not ACK has been input (S58). If it is NACK, the packet is retransmitted (S52). If it is ACK, the stored packet is deleted. (S59).

  Next, it is assumed that the communication quality between the mobile station 1131 and the base station 1102 has deteriorated and the communication quality with the base station 1112 has improved. The operation when a packet is transmitted from a plurality of base stations to a mobile station in this transition state will be described with reference to FIG.

  The mobile station 1131 notifies the data link transmission control unit 1103 of the base station 1102 of a request for changing the base station that executes data link transmission control (S61 in FIG. 30). As for the notification, a method of notifying directly to the base station 1102, a method of notifying through another base station, and the like can be adopted as described above.

  Upon receiving the base station change request, the data link transmission control unit 1103 requests the base station 1112 that is the change destination to start data link transmission control for the mobile station 1131 via the transfer / distribution unit 1105 (S62). Further, after this time, the packet input to the data link transmission control unit 1103 is set to be transferred to the base station 1112 by the transfer / distribution unit 1105 as it is. Therefore, when a packet is input to the data link transmission control 1103 (S63), the packet is transferred as it is to the base station 1112 by the transfer / distribution unit 1105 (S64).

  The change source data link transmission control unit 1103 continues the data link transmission control only for the packets stored for retransmission, as is the case with the operations from S52 to S59 in FIG. That is, for these packets, the data link transmission control unit 1103 of the change source performs retransmission control as it is until the arrival confirmation is completed. Also at this time, the same packet is transmitted from the base station 1102 and the base station 1112 to the mobile station 1131 as described above.

  On the other hand, the data link transmission control unit 1113 of the base station 1112 that is the change destination performs data link transmission including automatic retransmission request control for packets that have arrived without identification information added (packets that have arrived in S64 or S65). Take control. Here, the data link transmission control unit 1113 gives identification information to each packet, adds CRC or the like to the packet for error detection of the received packet, and adds the packet (that is, the identification information is added). (Added packet) is stored in the storage unit 114 (S66) and output to the transceiver 15. The transceiver 15 modulates the packet into a transmission signal, and then transmits the transmission signal to the mobile station 1131 via the base station antenna 16 (S67).

  The packet provided with the identification information is duplicated by the duplicating unit 1117 (S68), and the duplicated packet is distributed to the data link transmission control unit 1103 of the base station 1102 via the transfer / distribution unit 1115 (S69). In the data link transmission control unit 1103, since identification information is added to the packet, the packet is controlled to be output to the transceiver 5 as it is, so that the same packet is transmitted from the base station 1102 and the base station 1112. (S67).

  The mobile station 1131 performs error detection on the received packet as described above (S70), recognizes the base station 1112, and outputs NACK or ACK to the base station 1112 (S71 and S72). The base station 1112 determines whether or not an ACK has been input (S73). If it is NACK, the packet is retransmitted (S67). If it is ACK, the stored packet is deleted (S74).

  Next, in the same manner as described above, packets are transmitted from a single base station to the mobile station in a transition state in which the communication quality between the mobile station 1131 and the base station 1102 deteriorates and the communication quality with the base station 1112 becomes better. The operation in this case will be described with reference to FIG.

  As described in the above-described embodiment, the data link transmission control unit 1113 of the base station 1112 receives a request for receiving packet transmission from only the base station 1112 from the mobile station 1131 (S81 in FIG. 31). Control not to duplicate the packet. Therefore, when a packet is input to the base station 1102 after that time (S82), the packet is transferred to the base station 1112 (S83), and the above-described processing is executed only by the base station 1112 (S84 to S90). .

  That is, the data link transmission control unit 1113 of the base station 1112 gives identification information to each packet, adds CRC or the like to the packet for error detection of the received packet, and adds the packet (that is, , The packet to which the identification information is attached) is stored in the storage unit 114 (S84) and output to the transceiver 15. The transceiver 15 modulates the packet into a transmission signal, and then transmits the transmission signal to the mobile station 1131 via the base station antenna 16 (S85).

  The mobile station 1131 performs error detection on the received packet as described above (S86), recognizes the base station 1112 and outputs NACK or ACK to the base station 1112 (S87 and S88). The base station 1112 determines whether or not an ACK has been input (S89). If it is NACK, the packet is retransmitted (S85). If it is ACK, the stored packet is deleted (S90).

  As described above, the control base station that performs data link transmission control transmits control base station identification information for identifying the control base station to the mobile station instead of the data link transmission control information. Can recognize the control base station based on the control base station identification information, and the mobile station can perform data link transmission control including automatic retransmission request control (for example, a new base station and Connection request, etc.). In this way, the mobile station and the base station can reduce the amount of control information transmitted and received by performing data link transmission control using the control base station identification information instead of the data link transmission control information. The amount of network traffic can be reduced.

  Further, in the present embodiment, the identification information has always been described as including information for identifying a base station and information for identifying a packet. However, only the data link transmission control unit of one base station performs automatic retransmission. In a state where data link transmission control including request control is being executed, the data link transmission control unit of two or more base stations includes identification information only with information for identifying a packet, and data link transmission control includes automatic retransmission request control. In a state in which transmission control is being executed, the present invention is possible without increasing the number of bits of identification information by configuring identification information with information identifying a packet and information identifying a base station.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described. In the sixth embodiment, the first method for transferring only the data link transmission control information from one base station to another base station, the data link transmission control information and the packet are simultaneously transferred, or identification information is added. A second method for transferring the received packets will be described in order. In this embodiment, a case where an IP (Internet Protocol) packet is used will be described. However, the present embodiment is applicable to any packet having a packet configuration similar to that of the IP packet.

  First, the first method will be described. FIG. 32 shows an example of a device configuration for executing the first method. In the mobile communication system shown in FIG. 32, a plurality of base stations 2102 and 2112 can communicate with each other via the network 1.

  The base station 2102 includes a transceiver 5 that receives data from the wireless network and transmits data to the wireless network via the base station antenna 6, and a data link that includes the automatic retransmission request control described in the first embodiment. A data link transmission control unit 2103 that performs transmission control and controls each component in the base station 2102, and transmits data link transmission control information to the base station to be changed when receiving a request to change the base station An encapsulation and transfer unit 2105 that performs encapsulation described later, a storage unit 2104 that functions as a temporary storage area for packet data and the like by the data link transmission control unit 2103, and decapsulates the received encapsulated packet (capsule And a decapsulation unit 2106.

  Of these, the encapsulation and transfer unit 2105 is functionally composed of functional blocks shown in FIG. That is, the encapsulation and transfer unit 2105 includes the encapsulation unit 2105A that encapsulates the data link transmission control information and the packet to be transferred, and the data link transmission control information that represents the length of the encapsulated packet obtained by the encapsulation. The total value of the length of the packet and the length of the packet to be transferred is recorded in the header of the encapsulated packet, and the encapsulated packet transfer unit 2105B that transfers the encapsulated packet is recorded in the header of the encapsulated packet that has been transferred When the length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet is not equal to the length of the packet to be transferred recorded in the header of the packet to be transferred, Is configured to include data link transmission control information, It is constituted comprise.

  The other base station 2112 is configured in the same manner as the base station 2102 as described above.

  Next, the operation according to the first method will be described. The data link transmission control unit 2103 of the base station 2102 outputs the data link transmission control information to the encapsulation and transfer unit 2105. As shown in FIG. 34, the encapsulation and transfer unit 2105 sets the IP address of the base station 2102 as the source IP address of the IP header and the IP address of the base station 2112 as the destination IP address. . Further, in order to transfer the data link transmission control information to the base station as UDP or TCP data, a number representing UDP or TCP is set in the protocol number, and an IP header part and an IP data part (UDP or TCP) are set in the packet length. A total value of the lengths of the TCP header part and the UDP or TCP data part) is set. Then, data link transmission control information to be transferred is input to the UDP or TCP data part, and an IP packet to be transferred to the base station is configured. The configured IP packet is sent to the network 1. The sent IP packet reaches the base station 2112 by the set destination IP address.

  In the base station 2112, the arrived IP packet is input to the decapsulation unit 2116. The decapsulation unit 2116 performs processing according to the flowchart shown in FIG. FIG. 35 also describes a processing procedure according to a second method described later.

  First, the protocol number of the outermost IP header part of the input packet is identified (S501 in FIG. 35). In this example, since the identified protocol number does not represent IP encapsulation (determination is negative in S502), the UDP or TCP data portion in the IP data portion is extracted to obtain data link transmission control information. (S507). The extracted data link transmission control information is input to the data link transmission control unit 2113. The data link transmission control unit 2113 executes the data link transmission control described in the above-described embodiment based on the input data link transmission control information.

  For example, when the data link transmission control information includes information for identifying a mobile station such as the IP address or machine number of the mobile station and a number that uniquely identifies the packet of the latest packet, The number next to the number is used for automatic packet retransmission control. Further, when the data link transmission control information includes information for identifying the mobile station and ACK information from the mobile station or deletion information of the stored packet, the mobile station stored in the storage unit 2114 The packet corresponding to the ACK addressed or the packet corresponding to the deletion information is deleted.

  Next, a second method (a method of transferring data link transmission control information and a packet at the same time or transferring a packet with identification information added) will be described. In the second method, when a packet accumulated as ACK waiting and information uniquely identifying the packet are transferred to the handover destination base station due to handover or site diversity during packet transmission, etc., it is held as waiting for transmission. A packet, information for uniquely identifying the packet, and control base station identification information for transmission from the handover destination base station when transferring the packet and information for uniquely identifying the packet to the handover destination base station When transferring both or one of the above, information for uniquely identifying the packet, control base station identification information, information indicating whether or not to transmit the packet, or a combination of these and a duplicate packet can be transmitted. This is used when distributing to other base stations.

  FIG. 36 shows an apparatus configuration example for executing the second method. The base station 2202 shown in FIG. 36 further includes a packet duplicating unit 2206 for duplicating the packet in addition to the configuration of the base station 2102 of FIG. 32, and the duplicated packet is transferred to another base station instead of the encapsulation and transfer unit 2105. An encapsulation and distribution unit 2205 that distributes to a station and performs encapsulation described later is provided.

  Of these, the encapsulation and distribution unit 2205 is functionally composed of functional blocks shown in FIG. That is, the encapsulation and distribution unit 2205 includes the encapsulation unit 2205A that encapsulates the data link transmission control information and the packet to be distributed, and the data link transmission control information that represents the length of the encapsulated packet obtained by the encapsulation. The total value of the length of the packet and the packet to be distributed is recorded in the header of the encapsulated packet, and the encapsulated packet distributing unit 2205B for distributing the encapsulated packet is recorded in the header of the encapsulated packet that has been distributed If the length obtained by subtracting the header length of the encapsulated packet from the length of the encapsulated packet and the length of the packet to be distributed recorded in the header of the packet to be distributed are not equal, Is configured to include data link transmission control information, It is constituted comprise.

  The other base station 2212 is configured in the same manner as the base station 2202 as described above.

  Next, the operation according to the second method will be described. Here, a case will be described in which a packet with duplicate identification information added is distributed from the base station 2202 to the base station 2212.

  The data link transmission control unit 2103 of the base station 2202 inputs the packet with the identification information added to the packet duplication unit 2206. The packet duplicating unit 2206 outputs the input packet to which the identification information is added to the transmission / reception transmitter / receiver 5, and after duplicating the packet, outputs the packet to the encapsulation and distribution unit 2205. As shown in FIG. 37, the encapsulation and distribution unit 2205 includes the IP address of the base station 2202 as the source IP address of the IP header (a) and the IP address of the base station 2212 as the destination IP address. Set. Further, in order to transfer an IP packet to be transferred to the target mobile station to another base station, a number indicating IP encapsulation is set in the protocol number, and the IP header (a) and the target number are set in the packet length. A total value of the lengths of the IP packet and identification information transferred to the base station is set.

  In the IP data part of the IP header part (a), an IP packet to be transferred to the target mobile station and identification information are input to constitute an IP packet to be transferred to the base station. The configured IP packet is sent to the network 1. The sent IP packet reaches the base station 2212 by the set destination IP address.

  In the base station 2112, the arrived IP packet is input to the decapsulation unit 2116. The decapsulation unit 2116 performs processing according to the flowchart shown in FIG. 35, as described above. First, the protocol number of the outermost IP header part of the input packet is identified (S501 in FIG. 35). In the case of this example, the identified protocol number represents IP encapsulation (Yes is determined in S502), so the packet length of the outermost IP header portion (IP header portion (a) in FIG. 37) is analyzed. Thus, the packet length X1 of the packet transferred to the base station is acquired (S503). Next, the packet length X2 of the packet transferred to the target mobile station is acquired by analyzing the packet length of the second IP header part (IP header part (b) in FIG. 37) from the outside (S504). When the following expression (4) using the obtained packet lengths X1 and X2 and the length of the outermost IP header portion is satisfied (when affirmative determination is made in S505), there is no identification information, that is, It is determined that there is only an IP packet to be transferred to the target base station in the IP data part of the IP header part (a).

  (X1)-(length of the outermost IP header) = (X2) (4)

  In this case, the following processing is performed as an IP packet extracted from the IP data portion of the IP header portion (a) and transferred to the target mobile station (S508). In other words, the extracted IP packet to be transferred to the target mobile station is input to the data link transmission control unit 2113, and the data link transmission control unit 2113 performs the same processing on the input IP packet in the above-described embodiment. The data link transmission control described above is executed.

  On the other hand, when Formula (4) is not materialized (when negative determination is made in S505), it is determined that there is identification information, and the following processing is performed (S506). In this case, information of length X2 from the beginning of the IP data part of the IP header part (a) is extracted as an IP packet to be transferred to the target mobile station, and the IP data of the IP header part (a) is extracted. The rest of the part is extracted separately as identification information. The extracted IP packet and identification information transferred to the target mobile station are input to the data link transmission control unit 2113. The data link transmission control unit 2113 uses the input IP packet and the identification information. The data link transmission control described in the above embodiment is executed.

  Here, the cases of the IP packets having two different configurations shown in FIGS. 34 and 37 have been described as the packets to be transferred or distributed to the base station. However, by using the method described above, it is possible to change from one base station to another. If the packet to be transferred or distributed to the base station includes only the data link transmission control information, includes the data link transmission control information and the IP packet to be transferred to the target mobile station, or is an IP packet to which identification information is added. In some cases, it is possible to identify cases where only IP packets to be transferred to a target mobile station are included, and it is possible to smoothly execute control based on data link transmission control information and identification information.

  According to each embodiment described above, an increase in transmission delay time is suppressed by changing a base station that performs data link transmission control including automatic retransmission request control according to movement of a mobile station, compared with the prior art. It is also possible to increase the throughput. In addition, even if the base station that performs data link transmission control including automatic retransmission request control changes, a new base station takes over by transferring a series of data link transmission control information, so that only unreachable packets or blocks are retransmitted. Therefore, a decrease in throughput can be avoided.

  Further, each base station accumulates packets, thereby reducing a retransmission delay time and an increase in traffic in the network between base stations. Also, smooth packet transmission is possible even during handover.

  In addition, when a mobile station exists in a range of a predetermined reception level to be handed over, by transmitting the same packet from a plurality of base stations, by switching the base station when the mobile station moves out of the range, More efficient data link transmission can be realized by eliminating the time required for handover control and reducing the delay until retransmission while realizing handover control at the base station closest to the mobile station.

1 is a system configuration diagram of a mobile communication system according to first and second embodiments. FIG. It is a time chart for demonstrating operation | movement of 1st Embodiment. It is an operation | movement correlation diagram for demonstrating the operation | movement in 1st Embodiment concretely. (A) is a figure which shows the packet structure in the data link transmission control part of 1st Embodiment, (b) is a figure which shows the packet and block structure in the data link transmission control part of 2nd Embodiment. It is a system configuration | structure figure of the conventional mobile communication system. It is a time chart for demonstrating operation | movement of the data link transmission control method in the conventional mobile communication system. It is a system block diagram of the mobile communication system which concerns on 3rd Embodiment. (A) is a state transition diagram for demonstrating the transmission control method which concerns on 3rd Embodiment, (b) is a table | surface which shows the state transition for every event. It is a figure for demonstrating the position of the mobile station in 3rd Embodiment. It is a figure for demonstrating the process when a packet arrives at the base station of a packet transmission possible state. It is a figure for demonstrating the process when a packet arrives at the base station of an idle state. It is a figure for demonstrating the process when a packet arrives at the base station of a packet duplication and transmission possible state. It is a figure for demonstrating the example which employ | adopted the timer as a trigger which deletes the packet accumulate | stored in each base station by the process of FIG. FIG. 13 is a diagram for explaining various methods related to packet deletion notification from the base station 202 to the base station 212 in FIG. 12. The first method, (b) is a second method for notifying the number of the last deleted packet within a predetermined time, and (c) is the number of the last deleted packet every time 10 packets are deleted. A third method of notifying each of the above is shown. FIG. 13 is a diagram for explaining an example in which base stations 202 and 212 in FIG. 12 transmit the same packet to a mobile station, respectively. 6 is a diagram for explaining operations of a target base station and a mobile station in event A. FIG. FIG. 6 is a diagram for explaining operations of a target base station and a mobile station in event B. 6 is a diagram for explaining operations of a target base station and a mobile station in an event C. FIG. 7 is a diagram for explaining operations of a target base station and a mobile station in event D. FIG. 7 is a diagram for explaining operations of a target base station and a mobile station in an event E. FIG. It is a table | surface for demonstrating the operation | movement of the packet transmission handover transmission control in 4th Embodiment. It is a figure which shows the functional block which comprises the data link transmission control part in the base station of 3rd Embodiment. It is a figure which shows the functional block which comprises the data link transmission control part in the mobile station of 3rd Embodiment. It is a flowchart which shows the 1st aspect of the mobile station control program which concerns on this invention. It is a flowchart which shows the 2nd aspect of the mobile station control program which concerns on this invention. It is a flowchart which shows the 3rd aspect of the mobile station control program which concerns on this invention. It is a block diagram of the recording medium with which the mobile station control program was recorded, and its peripheral device. It is a system configuration | structure figure of the mobile communication system which concerns on 5th Embodiment. It is a figure for demonstrating the operation | movement in the initial state in 5th Embodiment. It is a figure for demonstrating operation | movement in the case of transmitting a packet from a some base station to a mobile station in the transition state of 5th Embodiment. It is a figure for demonstrating operation | movement in the case of transmitting a packet from a single base station to a mobile station in the transition state of 5th Embodiment. It is a system configuration | structure figure of the mobile communication system which performs the 1st method which concerns on 6th Embodiment. (A) is a functional block diagram of the encapsulation and transfer unit, and (b) is a functional block diagram of the encapsulation and distribution unit. It is a figure which shows the structure of the IP packet which concerns on the 1st method of 6th Embodiment. It is a flowchart which shows the process sequence which concerns on the 1st, 2nd method of 6th Embodiment. It is a system configuration | structure figure of the mobile communication system which performs the 2nd method which concerns on 6th Embodiment. It is a figure which shows the structure of the IP packet which concerns on the 2nd method of 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Network 2, 12, 22, 102, 112, 122, 1102, 1112 ... Base station 3, 13, 23, 34, 103, 113, 123, 1034, 1103, 1113 ... Data link transmission control part, 1105 DESCRIPTION OF SYMBOLS 1115 ... Transfer / distribution part 1107, 1117 ... Packet duplication part 4, 14, 24 ... Switch, 104, 114, 124 ... Accumulation part, 105, 115, 125 ... Transfer part 5, 15, 25, 33 ... Transceiver, 6, 16, 26 ... Base station antenna, 31, 131, 1131 ... Mobile station, 32 ... Mobile station antenna, 34A, 1034A ... Mobile station transmission control unit, 34B, 1034B ... Connection request unit, 35 ... Data Input / output ends, 202, 212, 222 ... base station, 203 ... data link transmission control unit, 203A ... identification information addition unit, 203B ... deletion unit, 20 C ... Deletion unit, 203D ... Deletion unit, 203E ... Deletion packet notification unit, 203F ... Distribution control unit, 203G ... Packet retransmission unit, 203H ... Accumulation notification unit, 203I ... Notification control unit, 203J ... Judgment unit, 203K ... Instruction unit 204 ... Accumulation unit, 205 ... Distribution unit, 206 ... Packet replication unit, 207 ... Transceiver, 208 ... Base station antenna, 231 ... Mobile station, 232 ... Mobile station antenna, 233 ... Transceiver, 233A ... Diversity reception unit, 234 ... Data link transmission control unit, 234A ... Selection unit, 234B ... Transmission request unit, 234C ... Change time notification unit, 234D ... Measurement unit, 234E ... Reception quality notification unit, 234F ... Determination unit, 234G ... State transition request unit, 235 ... Data input / output terminal, 2102, 2112, 2202, 2212 ... Base station, 2103, 2113 ... Data link transmission Control unit, 2104, 2114 ... accumulation unit, 2105, 2115 ... encapsulation and transfer unit, 2105A ... encapsulation unit, 2105B ... encapsulated packet transfer unit, 2105C ... configuration determination unit, 2106, 2116 ... decapsulation unit, 2205, 2215 ... encapsulation and distribution unit, 2205A ... encapsulation unit, 2205B ... encapsulated packet distribution unit, 2205C ... configuration determination unit, 2206, 2216 ... packet duplication unit.

Claims (39)

  1. A data link transmission control method for performing data link transmission control including automatic retransmission request control for transmitting and receiving packets between a mobile station and a plurality of base stations,
    One base station accumulates and duplicates a packet to which identification information for identifying the packet is added to a packet addressed to the mobile station,
    The one base station distributes the duplicated packet to another base station;
    The other base station accumulates the distributed packet,
    One or a plurality of base stations including the one base station transmit the packet with the identification information added or the distributed packet to the mobile station.
    A data link transmission control method.
  2. The base station is
    Delete the packet due to a timeout of the timer for the packet, or
    Deleting the packet by notification that the same packet as the packet has reached the mobile station, or
    Or, based on the notification of the identification information for specifying the packet to be deleted, the packet corresponding to the identification information is deleted.
    The data link transmission control method according to claim 1.
  3. When the one base station notifies the other base station of identification information for specifying the packet to be deleted,
    Based on a first method for notifying the identification information every time the one base station deletes a packet, a second method for notifying the identification information of the packet last deleted within a predetermined time, or a predetermined rule Of the third method of notifying the packet identification information when a specific packet to be defined is deleted, one method or a combination of a plurality of methods is used.
    The data link transmission control method according to claim 2, wherein:
  4. The one base station is
    When receiving a request from the mobile station to designate a new base station as a base station to which a packet is distributed, copy the packet with the identification information added and stored in the one base station,
    Distributing the duplicated packet to the new base station;
    2. The data link transmission control method according to claim 1, wherein:
  5. The other base station is
    When receiving a request from the mobile station to exclude the other base station from the base station to which the packet is distributed, the packet addressed to the mobile station stored in the other base station is deleted.
    2. The data link transmission control method according to claim 1, wherein:
  6. When the one base station, the other base station, or both receive and accumulate packets addressed to the mobile station, notify the mobile station that the packets are being accumulated,
    After the mobile station receives the notification, the mobile station selects one base station from the notified base stations, requests the base station to transmit a packet,
    The requested base station transmits the packet;
    2. The data link transmission control method according to claim 1, wherein:
  7. The one base station, the other base station, or both,
    When a transmission request is received from the mobile station while a plurality of packets addressed to the mobile station are stored, the packet is transmitted to the mobile station and a plurality of packets addressed to the mobile station are stored. Notify the mobile station,
    7. The data link transmission control method according to claim 6, wherein:
  8. When the mobile station changes a base station that transmits a packet addressed to the mobile station,
    Notifying the change source base station to stop transmission thereafter, and notifying the change destination base station of requesting transmission of a packet addressed to the own station and identification information of the first packet to be transmitted,
    2. The data link transmission control method according to claim 1, wherein:
  9. The mobile station measures reception quality of signals transmitted from a plurality of base stations,
    The mobile station selects one base station that transmits a packet addressed to itself based on reception quality for each base station,
    The mobile station requests the selected one base station to transmit a packet addressed to the mobile station.
    2. The data link transmission control method according to claim 1, wherein:
  10. The mobile station measures reception quality of signals transmitted from a plurality of base stations,
    The mobile station selects one base station that transmits a packet addressed to itself based on reception quality for each base station,
    The mobile station notifies the selected one base station of the reception quality for each base station,
    Based on the reception quality for each base station, the one base station determines for each of the other base stations whether or not to transmit the packet scheduled to be distributed from the one base station to the mobile station. ,
    The one base station instructs another base station to perform a transmission operation based on the determination result;
    2. The data link transmission control method according to claim 1, wherein:
  11. When the mobile station receives the same packet from each of a plurality of base stations, the mobile station performs diversity reception on the packet.
    2. The data link transmission control method according to claim 1, wherein:
  12. The mobile station measures reception quality of signals transmitted from a plurality of base stations,
    The mobile station or each base station requests the base station to change the communication state based on the reception quality for each base station, to request the communication state transition.
    2. The data link transmission control method according to claim 1, wherein:
  13. The communication state is
    A first state in which no packet is transmitted to or received from the mobile station;
    A second state in which identification information for specifying the packet is added to the packet addressed to the mobile station, and the packet after the addition can be transmitted to the mobile station;
    Identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, the packet after the duplication is distributed, and the packet after the addition can be transmitted 3 state,
    A fourth state capable of receiving a duplicated packet from the base station in the third state and transmitting the duplicated packet to the mobile station;
    The data link transmission control method according to claim 12, comprising:
  14. The one base station is
    Encapsulating the identification information and the packet to be distributed;
    Representing the length of the encapsulated packet obtained by the encapsulation, the total value of the length of the identification information and the length of the packet to be distributed is recorded in the header of the encapsulated packet, and the encapsulated packet is distributed.
    The length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet recorded in the header of the encapsulated packet that has been distributed, and the length of the packet to be distributed recorded in the header of the packet to be distributed If the lengths are not equal, it is determined that the encapsulated packet is configured to include identification information.
    2. The data link transmission control method according to claim 1, wherein:
  15. A mobile communication system composed of a mobile station and a plurality of base stations, which transmits and receives information by packets and performs data link transmission control including automatic retransmission request control,
    The base station is
    Duplicating means for duplicating a packet to which identification information for identifying the packet is added to the packet addressed to the mobile station;
    A distribution means for distributing the duplicated packet to other base stations;
    Storage means for storing a packet to which the identification information is added at the own station or a packet distributed from another base station;
    Transmitting means for transmitting the packet to which the identification information is added or the distributed packet to the mobile station;
    A mobile communication system comprising:
  16. The base station is
    The mobile communication system according to claim 15, further comprising a deletion unit that deletes the packet stored by the storage unit.
  17. The base station is
    A first method of notifying the identification information of the deleted packet every time the base station deletes the packet, a second method of notifying the identification information of the last deleted packet within a predetermined time, or a predetermined Of the third method of notifying the identification information of a packet when a specific packet determined based on the rule is deleted, the identification information of the packet to be deleted is changed by one method or a combination of a plurality of methods. The mobile communication system according to claim 16, further comprising deletion packet notification means for notifying the base station of the received packet.
  18. The base station is
    16. The mobile communication system according to claim 15, further comprising packet retransmission means for retransmitting a packet in response to the retransmission request when a packet retransmission request is received from the mobile station.
  19. The base station is
    Storage notification means for notifying the mobile station that the packet is stored when receiving and storing the packet addressed to the mobile station,
    The transmission means transmits a packet to the mobile station in response to a request from the mobile station,
    The mobile station
    A selection means for selecting one base station from the notified base stations when the notification is received;
    Transmission request means for requesting the selected base station to transmit a packet;
    The mobile communication system according to claim 15.
  20. The base station is
    If a transmission request is received from the mobile station while a plurality of packets addressed to the mobile station are stored, the transmission means transmits the packet to the mobile station and stores a plurality of packets addressed to the mobile station. 20. The mobile communication system according to claim 19, further comprising notification control means for controlling the accumulation notification means to notify the mobile station of the fact.
  21. The mobile station is
    When changing the base station that transmits packets addressed to itself, notify the source base station to stop transmission and request the destination base station to transmit packets addressed to itself. 16. The mobile communication system according to claim 15, further comprising a change notification means that notifies the identification information of the first packet to be transmitted.
  22. The mobile station is
    Measuring means for measuring reception quality of signals transmitted from a plurality of base stations;
    Based on the reception quality for each base station, selection means for selecting one base station that transmits a packet addressed to the own station;
    Transmission request means for requesting the selected one base station to transmit a packet addressed to the own station;
    The mobile communication system according to claim 15, further comprising:
  23. The mobile station is
    Measuring means for measuring reception quality of signals transmitted from a plurality of base stations;
    Based on the reception quality for each base station, selection means for selecting one base station that transmits a packet addressed to the own station;
    Reception quality notification means for notifying the selected one base station of the reception quality for each base station;
    Further comprising
    The base station is
    When the own station is selected as the one base station, whether or not to transmit a packet to be distributed from the own station to the mobile station based on the reception quality of each base station is determined by the other base station. A judging means for judging each;
    Instruction means for instructing another base station to perform a transmission operation based on the determination result;
    The mobile communication system according to claim 15, further comprising:
  24. The mobile station is
    16. The mobile communication system according to claim 15, further comprising diversity receiving means for performing diversity reception for each packet when receiving the same packet from a plurality of base stations.
  25. The mobile station is
    Measuring means for measuring reception quality of signals transmitted from a plurality of base stations;
    Determining means for determining which communication state each of the base stations is in a predetermined plurality of communication states based on the reception quality for each base station;
    Based on the determination result, a state transition requesting means for requesting a transition of the communication state to the base station that should transition the communication state;
    The mobile communication system according to claim 15, further comprising:
  26. The predetermined plurality of communication states are:
    A first state in which no packet is transmitted to or received from the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station, and the added packet is transmitted to the mobile station. A second state that is possible, and identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, the packet after the duplication is distributed, and the packet after the addition And a fourth state in which a duplicate packet can be received from the base station in the third state and a duplicate packet can be transmitted to the mobile station. It is configured,
    26. The mobile communication system according to claim 25.
  27. The distribution means is:
    Encapsulation means for encapsulating the identification information and the packet to be distributed;
    A capsule that distributes the encapsulated packet by recording the total value of the length of the identification information and the length of the packet to be distributed, which represents the length of the encapsulated packet obtained by encapsulation, in the header of the encapsulated packet Packet distribution means,
    The length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet recorded in the header of the encapsulated packet that has been distributed, and the length of the packet to be distributed recorded in the header of the packet to be distributed Configuration determining means for determining that the encapsulated packet includes identification information if the lengths are not equal; and
    The mobile communication system according to claim 15, comprising:
  28. A mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, is a base station configured with a mobile station,
    A plurality of mobile communication systems are included;
    Duplicating means for duplicating a packet to which identification information for identifying the packet is added to the packet addressed to the mobile station;
    A distribution means for distributing the duplicated packet to other base stations;
    Storage means for storing the packet to which the identification information is added and the packet distributed from another base station in the own station;
    Transmitting means for transmitting the accumulated packets to the mobile station;
    Base station equipped with.
  29. A mobile station that selects one base station that transmits packets addressed to the mobile station based on reception quality of signals transmitted from a plurality of base stations, and notifies the reception quality of each base station to the one base station , When the local station is selected as the one base station, whether to transmit a packet to be distributed from the local station to the mobile station based on the reception quality for each base station. Determining means for determining each of the base stations;
    Instruction means for instructing another base station to perform a transmission operation based on the determination result;
    The base station according to claim 28, further comprising:
  30. The distribution means is:
    Encapsulation means for encapsulating the identification information and the packet to be distributed;
    A capsule that distributes the encapsulated packet by recording the total value of the length of the identification information and the length of the packet to be distributed, which represents the length of the encapsulated packet obtained by encapsulation, in the header of the encapsulated packet Packet distribution means,
    The length obtained by subtracting the length of the header of the encapsulated packet from the length of the encapsulated packet recorded in the header of the encapsulated packet that has been distributed, and the length of the packet to be distributed recorded in the header of the packet to be distributed Configuration determining means for determining that the encapsulated packet includes identification information if the lengths are not equal; and
    The base station according to claim 28, comprising:
  31. A mobile communication system that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, and a plurality of base stations,
    Measuring means for measuring reception quality of signals transmitted from a plurality of base stations;
    Based on the reception quality for each base station, selection means for selecting one base station that transmits a packet addressed to the own station;
    Transmission request means for requesting the selected one base station to transmit a packet addressed to the own station;
    Mobile station equipped with.
  32. A mobile communication system that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, and a plurality of base stations,
    Based on the reception quality for each base station, it is determined for each of the other base stations whether or not the mobile station is to transmit a packet to be distributed from its own station, and the transmission operation based on the determination result is changed to Measuring means for measuring reception quality of signals transmitted from a plurality of base stations having a function of instructing the base station;
    Based on the reception quality for each base station, selection means for selecting one base station that transmits a packet addressed to the own station;
    Reception quality notification means for notifying the selected one base station of the reception quality for each base station;
    Mobile station equipped with.
  33. A mobile communication system that configures a mobile communication system that performs data link transmission control including automatic retransmission request control while performing transmission and reception of information by a packet, and a plurality of base stations,
    Measuring means for measuring reception quality of signals transmitted from a plurality of base stations;
    A determination means for determining which communication state each of the base stations is in a predetermined plurality of communication states based on the reception quality for each base station;
    Based on the determination result, a state transition requesting means for requesting a transition of the communication state to the base station that should transition the communication state;
    Mobile station equipped with.
  34. The predetermined plurality of communication states are:
    A first state in which no packet is transmitted to or received from the mobile station, and identification information for identifying the packet is added to the packet addressed to the mobile station, and the added packet is transmitted to the mobile station. A second state that is possible, and identification information for identifying the packet is added to the packet addressed to the mobile station, the packet after the addition is duplicated, the packet after the duplication is distributed, and the packet after the addition And a fourth state in which a duplicate packet can be received from the base station in the third state and a duplicate packet can be transmitted to the mobile station. It is configured,
    34. The mobile station according to claim 33.
  35. The mobile station according to any one of claims 31 to 34, further comprising diversity receiving means for performing diversity reception on the packet when receiving the same packet from a plurality of base stations.
  36. A mobile station control program for causing a computer mounted on a mobile station configured with a plurality of base stations to execute a mobile communication system that performs transmission and reception of information by packets and performs data link transmission control including automatic retransmission request control. And
    A measurement step for measuring reception quality of signals transmitted from a plurality of base stations;
    A selection step of selecting one base station that transmits a packet addressed to the base station based on reception quality for each base station;
    A transmission request step for requesting the selected one base station to transmit a packet addressed to itself;
    Is executed by the computer.
  37. A mobile station control program for causing a computer mounted on a mobile station configured with a plurality of base stations to execute a mobile communication system that performs transmission and reception of information by packets and performs data link transmission control including automatic retransmission request control. And
    Based on the reception quality for each base station, it is determined for each of the other base stations whether or not the mobile station is to transmit a packet to be distributed from its own station, and the transmission operation based on the determination result is changed to A measurement step of measuring reception quality of signals transmitted from a plurality of base stations having a function of instructing the base station;
    A selection step of selecting one base station that transmits a packet addressed to the base station based on reception quality for each base station;
    A reception quality notification step of notifying the selected one base station of the reception quality for each base station;
    Is executed by the computer.
  38. A mobile station control program for causing a computer mounted on a mobile station configured with a plurality of base stations to execute a mobile communication system that performs transmission and reception of information by packets and performs data link transmission control including automatic retransmission request control. And
    A measurement step for measuring reception quality of signals transmitted from a plurality of base stations;
    A determination step for determining which communication state each of the base stations is in a predetermined plurality of communication states based on the reception quality for each base station;
    Based on the determination result, a transition request step for requesting a transition of the communication state to the base station that should transition the communication state;
    Is executed by the computer.
  39. A computer-readable recording medium on which the mobile station control program according to any one of claims 36 to 38 is recorded.

JP2005134527A 2001-04-26 2005-05-02 Data link transmission control method, mobile communication system, and base station Expired - Fee Related JP4276207B2 (en)

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