JP3499670B2 - Wireless communication method, wireless base station device, and wireless terminal device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a wireless terminal connected to an ATM network via a wireless channel provided by a wireless base station connected to the ATM network.
There wireless communication method for communicating with terminals connected to the ATM network, Ru <br/> relates to a radio base station apparatus and radio terminal apparatus.

[0002]

2. Description of the Related Art In recent years, mobile phones and PHSs (Personal Handyphones) have been used as personal communication flows.
Wireless and mobile terminals such as e System) have become popular.

Currently, these mobile terminals mainly support only voice, but it is expected that the number of terminals handling multimedia such as moving images and data will gradually increase.

On the other hand, ATM (Asynchronous)
Transfer Mode technology is wideband ISDN
And is used for communication using fixed-length packets called ATM cells. ATM
The technology enables flexible support for various media with different speeds and quality of service on the same communication platform. Therefore, it holds great promise as an infrastructure for future multimedia communication.

From such a background, an idea of a system called an ATM wireless network, in which an ATM network is used as a backbone network and accommodates wireless terminals and mobile terminals which handle various media, is considered.

For example, Kaiyama and Adachi: "Mobile Multimedia Network" (1994 Autumn Meeting of the Institute of Electronics, Information and Communication Engineers) is to be accommodated in an ATM network.
The case of a conventional wireless terminal and the case of a broadband ISDN terminal are listed. In the former, an ATM cell is terminated in a wireless base station in an ATM network, and information is transmitted / received by another wireless protocol. On the other hand, in the latter, the ATM cells flow on the wireless line as they are and are transmitted through the terminal and the ATM network.

In an ATM wireless network, normally, there is not much error in the wired part, but in the wireless part, data loss due to noise is considered. When data is missing, (1) nothing is done,
Possible methods are (2) error correction, data prediction on the receiving side to make some complement, and (3) retransmission.

The method (1) of performing nothing as it is, although it may detect an error, does not correct the error of the bit by using it, but receives the data as it is. This is generally applied to applications that are less susceptible to errors such as voice.

(2) is real-time communication,
Moreover, this is a solution when there is a strict demand for delay such that retransmission cannot be performed. Therefore, it is necessary to add a code that can correct an error even if the band is wasted a little. Alternatively, a method of estimating and complementing the data on the receiving side may be considered. This method is often used when there is a high correlation between before and after data such as in a moving image.

On the other hand, (3) is usually used for data communication which does not require real time. For example, the TCP protocol is designed to detect that an ACK signal indicating that it has been correctly received is not returned to the transmission source and retransmit the packet. When performing retransmission control at the transmitting end and the receiving end in this way, the longer the distance between the two terminals, the longer the retransmission takes. Therefore, it is generally difficult to guarantee real-time property in high-speed communication.

In the ATM radio network, however, it is common sense that the distance is about 100 m when the radio part with a high frequency of error is a standard such as PHS or wireless LAN. Therefore, if the retransmission is not performed end-to-end via the ATM network but only the wireless part, the retransmission time can be significantly shortened, and the severe delay requirement in the case of (2) Even if things are impossible, it becomes possible to communicate in a relatively real time.

The seemingly contradictory retransmission control of the wireless part and the real-time communication may have excellent effects depending on the application. Especially in the ATM wireless network, the quality of the ATM network is good, and the wireless part has a certain quality of service (QoS of Quality of Ser).
Vice) will be required. Therefore, in order to realize personal multimedia communication in the future, it is important to make the technology compatible with both.

First, what can be simply considered is a retransmission method according to the degree of real time. For example, if it takes 100 milliseconds for one retransmission, and if there is no problem if received within 1 second as a real-time value, it can be retransmitted up to 10 times.

The above case is applicable when it is possible to allocate a band more than the current band for retransmission, in addition to the band used for current communication. However, in general, the wireless band is rarely used with such a margin.

However, if the PHS is used to its full bandwidth like a PHS that does not consider retransmission,
Bandwidth for re-sending cannot be secured. Therefore, in the case of considering retransmission, it will be necessary to secure a communication band in which a minimum necessary extra band is added to the normal communication band in advance for communication.

Next, there is a problem of a buffer capacity that can be mounted on the wireless terminal. In the case of wired terminals that do not need to consider portability, or wireless base stations that accommodate wireless terminals in the network, it is not so difficult to secure a buffer suitable for the system. Be done. However, in the case of, for example, a portable wireless terminal, the buffer amount is limited due to the restriction on the size of carrying.

For example, if it is possible to retransmit 10 times on the communication line, it is necessary for the wireless terminal to secure at least 10 times the buffer capacity of the retransmission unit for rearranging the received data. If that is not possible, the number of retransmissions will be severely limited.

From the above, in order to make both real-time communication and wireless retransmission compatible, an appropriate transmission method considering the allowable range of delay as a real-time application, the transmission band, and the buffer amount of the wireless terminal is taken into consideration. I need to think.

However, conventionally, no technique has been studied in consideration of these matters. In particular, no study has been made to perform communication in consideration of the service quality of the ATM wireless network under such conditions.

[0020]

As described above, no study has been made so far in which relatively real-time communication is performed by retransmitting only the wireless part. In particular, considering the real-time property that allows a certain amount of resending, a transmission band with some margin for resending, and a buffer prepared for controlling the order of the resent data, the quality is reasonably good. There was no way to think of a good way to communicate.

[0021] Therefore, the present invention is non-line terminal, the radio base station,
A wireless communication method that enables real-time communication with quality guaranteed as much as possible while retransmitting data between end-to-end according to the capability of the wireless transmission path.
An object is to provide a line base station device and a wireless terminal device .

[0022]

According to a first aspect of the present invention, a wireless communication method in which a wireless base station connected to a network and a wireless terminal communicate via a wireless channel provided by the wireless base station. In the radio base station, the radio base station receives a plurality of types of information with different priorities regarding discard from the network, and includes a first type of information including the received plurality of types of information.
Wireless packet is transmitted to a wireless terminal via a wireless channel, a reception response from the wireless terminal corresponding to the transmitted first wireless packet is received, and when the received reception response indicates abnormal reception, A second wireless packet including only information having a higher priority regarding discarding among a plurality of types of information included in the wireless packet is retransmitted to the wireless terminal. That is, the wireless base station device receives from the network a plurality of types of information having different priorities regarding discarding, and a means for transmitting a first wireless packet including the received plurality of types of information to a wireless terminal via a wireless channel. A means for receiving a reception response from the wireless terminal in response to the transmitted first wireless packet, and a plurality of types of information included in the first wireless packet when the received reception response indicates abnormal reception. And a means for retransmitting a second wireless packet containing only higher priority information regarding discarding to the wireless terminal.

According to a second aspect of the present invention, there is provided a radio base station device connected to a network, the radio base station device communicating with a radio terminal via a radio channel provided by the radio base station device. , Means for receiving a plurality of types of information having different priorities regarding discard from the network, means for transmitting a first wireless packet containing the received plurality of types of information to a wireless terminal via a wireless channel, and a means for transmitting the first Means for receiving a reception response from the wireless terminal in response to the wireless packet and, when the received reception response indicates abnormal reception, retransmits the first wireless packet up to a predetermined number of times so that the reception response indicates normal reception. A first retransmission unit and a plurality of packets included in the first wireless packet when the number of retransmissions of the first wireless packet by the first retransmission unit exceeds a predetermined number. Comprising a second retransmission means for retransmitting the second wireless packet containing only higher information priority regarding disposal of information of the kind to the wireless terminal.

[0024]

According to a third aspect of the present invention, in a wireless communication method in which a wireless base station connected to a network and a wireless terminal communicate with each other via a wireless channel provided by the wireless base station, the wireless terminal is discarded. Transmitting a first wireless packet including a plurality of types of information with different priorities regarding the wireless base station via a wireless channel, receiving a reception response from the wireless base station in response to the transmitted first wireless packet, and receiving When the received reception response indicates abnormal reception, the first
Of the plurality of types of information included in the wireless packet, the second wireless packet including only information having a higher priority regarding discarding is retransmitted to the wireless base station. That is, the wireless terminal device transmits a first wireless packet including a plurality of types of information with different priorities regarding discarding to a wireless base station via a wireless channel, and a wireless base station that responds to the transmitted first wireless packet. A unit for receiving a reception response from the station, and a second reception unit including only information having a higher priority regarding discard among a plurality of types of information included in the first wireless packet when the received reception response indicates abnormal reception. Means for retransmitting the wireless packet to the wireless base station.

In the fourth aspect of the present invention, in a wireless terminal device that communicates with a wireless base station via a wireless channel provided by a wireless base station connected to a network, a plurality of types of information with different priorities regarding discarding Means for transmitting a first wireless packet including a packet to a wireless base station via a wireless channel, a means for receiving a reception response from the wireless base station in response to the transmitted first wireless packet, and a received reception response When abnormal reception is indicated, first retransmission means for retransmitting the first wireless packet to the wireless base station up to a predetermined number of times so that the reception response indicates normal reception, and the first wireless packet by the first retransmission means. Of the plurality of types of information included in the first wireless packet when the number of times of retransmission of the ; And a second retransmission means for retransmitting a line packet to the radio base station.

Thus, according to the present invention, it relates to disposal.
Retransmits wireless packets containing only high priority information
Information to be sent with high priority for disposal.
Compared to the case of retransmitting a wireless packet containing both low information
In comparison, the congestion of the wireless transmission line due to retransmission is reduced.
And there is no need to re-transmit between the wireless base station and wireless terminal.
, Real-time communication with the quality guaranteed as much as possible
It can be performed. That is, according to the present invention, when performing retransmission for errors in data generated in the radio link between the radio base station and a wireless terminal, it determines the threshold of such times retransmission in accordance with the priority of the data, as By controlling the retransmission, it is possible to effectively use the given range of wireless link capacity and to transmit more important data more reliably, enabling real-time communication with quality guaranteed as much as possible. Becomes

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the overall configuration of the communication system according to this embodiment. As a backbone network, for example, at least one wireless base station 102 is connected to an ATM network 101. Information and control signals by ATM cells flow in the interface 103 between the wireless base station 102 and the ATM network 101.

The ATM network 101 may accommodate a plurality of terminals 105 and may be connected to another network 109 via an interworking unit (IWU) 108.

The radio base station 102 accommodates at least one radio terminal 104, and the downlink radio communication link 106 from the radio base station 102 to the radio terminal 104 and the uplink from the radio terminal 104 to the radio base station 102. The wireless terminal 14 is connected to the ATM network 1 via the wireless communication link 107.
01 is connected.

The radio communication links 106 and 107 are not limited to a single link for upstream and downstream links, and may have separate links for control or multiple links for communication. There may be cases. Further, it is not necessarily symmetrical, and there is a possibility that the speed and the band are different, or they may change. In each case, it depends on the communication capability of the wireless terminal 104, the communication protocol between the wireless terminal 104 and the wireless base station 102, and the like.

Between the wireless base station 102 and the wireless terminal 104, via wireless communication links 106 and 107, for example,
A wireless packet 201 as shown in FIG. 2 is transmitted and received,
I think that the actual communication will take place. However, as an actual transmission form, it is conceivable that these are time-divided or divided into a plurality of links for transmission. The uplink wireless link and the downlink wireless link may have different wireless packet lengths and formats.

As shown in FIG. 2, the wireless packet 201
Is roughly divided into a header section 204, a data section 203, and a trailer section 202.

The header section 204 is composed of, for example, a synchronization pattern 205 for synchronizing packets, a packet identifier 206 for distinguishing a packet from other packets, control information such as information 207 regarding the contents of the data section 203, and the like. It The information 207 regarding the data part is, for example,
It includes a connection identifier of information carried by the wireless packet, information about service quality if necessary, and error protection information for the header portion 204. The error protection may be separately added to only the synchronization pattern.

The trailer unit 202 is, for example, the data unit 2
03 length information 208 indicating the length and error control information 209 for the wireless packet. However, in consideration of high speed, it is desirable that the wireless packet length is constant, and in that case, the length of the data section 203 is obvious and the length information 208 may be omitted.

Regarding the data section 203, various modes can be considered depending on the protocol of the wireless link, but basically it seems to depend on which layer information the wireless packet handles.

FIG. 3 shows a specific example of the structure of the data section 203.

FIG. 3A shows a case in which a plurality of ATM cells, that is, a cell header information section 302 and a cell payload 303 are formed. Cell header information section 30
2 is not limited to the ATM cell header itself, but HEC
The header may be a 4-octet excluding (Header Error Control), the header information may be compressed in some form, or may be replaced so that it can be uniquely identified. The cell payload section 303 is considered to be 48 octets, but a part thereof may be mixed in the cell header section 302. For example, AAL (ATM Ada
patation layer) Type 1 SAR (Se)
It is also possible to mix the information of the gmt And Reassembly) header into the cell header part 302 and put only 47 octets into the cell payload part 303. Further, in FIG. 3A, a plurality of ATM cells are configured, but one ATM cell, or less than one ATM cell may be a unit of the wireless packet data section.

FIG. 3B shows a cell header section 305 in which only the cell header information sections of a plurality of ATM cells are collected at one location.
And a configuration example in the case where other components are accommodated in the cell payload unit 306. The cell header information of each ATM cell accommodated in the cell header section 305 and the cell payload section 306 have the same characteristics as in FIG. 3A.

In FIG. 3C, the information related to the header portion of the ATM cell is stored in the wireless packet header portion 204 of FIG. 2, and the payload portion of the ATM cell is stored in the data portion 203 of the wireless packet. The case where only the unit 308 is included is shown.

In FIG. 3D, one unit is AAL data. For example, PDU (Proto) of the SAR layer
col Data Unit) payload, CPCS
(Common Part Convergence
Subscriber) PDU, SSCS (Service)
e Specific Convergence Su
PDU, AAL IDU (Info)
mation Data Unit), AAL SDU
(Service Data Unit) and the like. Also for these, one or less AAL data may be included in the wireless packet.

FIG. 3E shows a packet of Layer 2 or higher,
For example, a case is shown in which an IP packet or the like enters the data unit 203 as it is.

With respect to the data portion 203 of these wireless packets, when the information portion that is significant than the size of the data portion, that is, the information portion to be inserted therein is small, the remaining portion is padded. Good. Such a form may occur, for example, when the wireless packet has a fixed length.

Next, regarding the wireless communication method in the communication system having such a configuration, a case where data (wireless packet) is transmitted from the wireless base station 102 to the wireless terminal 104 via the downlink wireless communication link 106, and a case where the wireless terminal is used 10
4 from the wireless base station 102 to the uplink wireless communication link 10
The case where data (wireless packet) is transmitted via 7 will be described separately.

First, the former case will be described. That is, a case will be described where the wireless base station 102 transmits a wireless packet to the wireless terminal 104, the wireless terminal 104 returns a reception response of the wireless packet, and the wireless base station 102 performs retransmission control based on the response.

An example of the configuration of the radio base station 102 for realizing such downlink communication is shown in FIGS. 4 and 5, and an example of the configuration of the radio terminal 104 is shown in FIG.

In FIG. 4, the wireless base station 102 is
Reception circuit 102a as an interface for connection to the ATM network 101, the wireless antenna 10 2 b for performing wireless communication with the wireless terminal 104, and a wireless transceiver circuit 102c as a wireless interface connected to it, the buffer The memory 102d, a retransmission counter 102e that counts the number of times of cell retransmission, a transmission / reception circuit 102a, a wireless transmission / reception circuit 102c, a buffer memory 102d, and a retransmission control unit 102f connected to the retransmission counter 102e.

The radio transceiver circuit 102c is the transceiver circuit 1
At least the significant information portion of the ATM cell from the ATM network 101 received via 02a is converted into a wireless packet and transmitted to the wireless terminal 104 via the wireless channel 106, while the response from the wireless terminal 104 is wirelessly transmitted. It is adapted to be received via the channel 107.

When the reception response from the wireless terminal 104 indicates an abnormal reception, the retransmission control unit 102f excludes the ATM cells forming the packet to be transmitted, which have a lower priority regarding discarding. Is retransmitted. That is, based on the information on the number of cell retransmissions obtained from the retransmission counter 102e, the retransmission control of the cells temporarily stored in the buffer memory 102d is performed on the transmission / reception circuit 102a and the wireless transmission / reception circuit 102c. On the contrary, the transmission / reception circuit 102a or 10
Control for accumulating the cells received at 2c in the buffer memory 102d is performed.

FIG. 5 shows another example of the configuration of the radio base station 102. The part different from FIG. 4 is the retransmission control section 102.
AT, which is transmitted / received by the transmission / reception circuit 102a.
This is provided with a format conversion unit 102g for converting the format between the M cell and the wireless packet transmitted / received by the wireless transmission / reception circuit 102c.

The radio base station 10 as shown in FIG. 4 and FIG.
2 performs wireless communication with the wireless terminal 104 configured as shown in FIG.

FIG. 6 shows the result of monitoring the quality of a wireless packet received as a reception response by the wireless base station 10.
3 shows an example of the configuration of the wireless terminal 104 having the function of returning to 2.

In FIG. 6, the radio terminal 104 includes a transmission / reception antenna 104a for performing radio communication with the radio base station 102, and the radio transmission / reception circuit 1 connected thereto.
04b, a service function unit 104c, a data quality management unit 104d that checks the quality of data received as a wireless packet such as an error and a delay, a buffer memory 104e, a wireless transmission / reception circuit 104b, and a service function unit 104.
c, data quality management unit 104d, buffer memory 104
The control unit 104f has a function of transmitting the data quality information of the wireless packet received by connecting to the e or the retransmission request through the wireless transmission / reception circuit 104b.

When the data quality management unit 104d detects that the data quality of the received wireless packet does not meet a certain standard, the control unit 104f indicates to that effect.
To notify.

The control unit 104f has the data quality management unit 10
Based on the notification from 4d, a signal indicating deterioration of quality or a retransmission request signal is transmitted via the wireless transmission / reception circuit 104b and the transmission / reception antenna 104a.

Next, a more specific structure of the radio base station 102 will be described with reference to FIG.

In FIG. 7, the radio base station 102 mainly comprises an ATM cell transmitting / receiving section 200 and a receiving ATM cell storage FIFO (First In First Out).
First-in first-out) buffer 201, transmission ATM cell accumulation FIFO buffer 202, retransmission ATM cell accumulation F
It is composed of an IFO buffer 203, a wireless / ATM cell format conversion unit 204, a narrow band wireless transmission / reception unit 205, a wide band wireless transmission / reception unit 206, and a control unit 207.

The ATM cell transmission / reception unit 200 is an interface unit with the ATM network 101, and the control unit 2
It operates based on the timing signal given from 07, A
The ATM cell included in the received signal input from the TM network 101 is extracted, and the receiving ATM cell storage FI is extracted.
Function to output to FO buffer 201 and ATM read from transmission ATM cell storage FIFO buffer 202
It has at least a function of converting a cell into a signal to be transmitted to the ATM network 101 and outputting the signal.

ATM cell storage FIFO buffer 2 for reception
Reference numeral 01 stores an ATM cell input from the ATM cell transmission / reception unit 200 based on a write address signal and a write timing signal given from the control unit 207, and a read address based on a read timing signal given from the control unit 207. It has at least a function of reading an ATM cell from the area (head address) designated by the signal and outputting the ATM cell to the wireless / ATM format conversion unit 204.

ATM cell storage FIFO buffer 2 for transmission
02 is a wireless / ATM based on a write address signal and a write timing signal given from the control unit 207.
The ATM cell input / output unit 200 stores the ATM cells input from the format conversion unit 204, and reads the ATM cells from the area (start address) designated by the read address signal based on the read timing signal supplied from the control unit 207. It has at least the function of outputting to.

ATM cell storage FIFO buffer 2 for retransmission
03 is a receiving ATM based on a write address signal and a write timing signal given from the control unit 207.
Of the data portion of the ATM cells accumulated in the cell accumulation FIFO buffer 201, the ATM cells (hereinafter referred to as the retransmitted ATM cells) excluding those having a low priority for discarding are accumulated, and the read timing given from the control unit 207. It has at least a function of reading an ATM cell from an area (head address) designated by the read address signal based on the signal and outputting the ATM cell to the wireless / ATM format conversion unit 204.

The connection management table 208 manages the channels and wireless channels on the ATM network 101 allocated to the wireless base station 102 and their use status, and also manages the ATM network 10
An ATM having which ATM cell header is associated with which wireless channel
Priority of each connection, congestion status, retransmission count threshold, ATM cell header conversion, additional information, wireless packet header conversion and additional information, wireless channel information (time slot) , Frequency, code) etc., and control section 207, wireless / ATM cell format conversion section 20.
The connection control information can be read and written based on the timing signal given from the No. 4.

Radio / ATM cell format converter 20
4 operates based on a timing signal given from the control unit 207, and receives ATM cell storage FIFO buffer 2
01 and the retransmission ATM cell storage buffer 203 respectively create a wireless packet from the ATM cell and the retransmitted ATM cell, and based on the control signal from the control unit 207, the wideband wireless transmission / reception unit 206 or the narrowband wireless transmission / reception. The function of outputting to the unit 205 and the retransmission A from the ATM cells input from the receiving ATM cell storage FIFO buffer 201 except those with low priority regarding discarding
ATM cell storage buffer 20 for converting to TM cells and retransmitting
3, the control information, the ATM cell, and the retransmitted ATM cell are extracted from the wireless packet input from the narrowband wireless transmission / reception unit 205 or the wideband wireless transmission / reception unit 206, and the control information is transmitted to the control unit 207. Cell, retransmission AT
ATM cell storage FIFO buffer 202 for transmitting M cells
And the function of outputting to.

The narrow band wireless transmission / reception unit 205 is a wireless / ATM
A function of converting a wireless packet as shown in FIG. 8 input from the format conversion unit 204 into a narrow band wireless transmission signal and outputting the narrow band wireless transmission signal to the wireless terminal 104, and receiving a narrow band wireless transmission signal from the wireless terminal 104, It has at least a function of extracting a wireless packet included in the received signal as shown in FIG. 8 and outputting it to the wireless / ATM format conversion unit 104.

The wideband wireless transmission / reception unit 206 is a wireless / ATM
A function of converting a wireless packet input from the format conversion unit 204 as shown in FIG. 8 into a wideband wireless transmission signal and outputting the wideband wireless transmission signal to the wireless terminal 104, and receiving a wideband wireless transmission signal from the wireless terminal 104 and receiving the received signal. It has at least a function of extracting a wireless packet included in the signal as shown in FIG. 8 and outputting it to the wireless / ATM format conversion unit 204.

The control section 207 comprises a clock source, a timing signal generating section, an abnormal reception detecting section and the like.

The timing signal generator of the controller 207 is
The counter values of the retransmission counter 208 and the retransmission counter 209, the clock signal of the clock source of the control unit 207, the connection control information of the connection management table 208, the control signal given from the wireless / ATM format conversion unit 204, the ATM cell header, the wireless Based on the control information in the header section 204 of the packet, the ATM cell transmitting / receiving section 200 and the receiving ATM cell storage FIFO buffer 20
1, transmission ATM cell storage FIFO buffer 202, retransmission ATM cell storage FIFO buffer 203, wireless / A
A control signal given to the TM cell format conversion unit 204, the narrow band wireless transmission / reception unit 205, the wide band wireless transmission / reception unit 206, etc. is created.

The abnormal reception detector of the controller 207 is
If the response signal from the wireless terminal 104 included in the control signal input from the ATM format conversion unit 204 is abnormal reception or normal reception, and if abnormal reception is detected, control is performed. The timing signal generation unit of the unit 207 is notified.

At this time, in the timing creation unit of the control unit 207, the retransmission counter 208 and the retransmission counter 209 are incremented, and the counter value C of the retransmission counter 208 is increased.
When NT1 is larger than the retransmission count threshold TH1, the counter value CNT2 of the retransmission counter 209 is the retransmission count threshold TH2.
Retransmission counter 20 corresponding to the case of larger value
It has a function of creating a control signal for clearing the counter value of 8 or 209.

The retransmission counter 208 controls the control unit 20 when abnormal reception is detected by the abnormal reception detection unit of the control unit 207.
The counter value CNT1 based on the control signal given from 7
Is incremented and the counter value CNT1 is cleared based on the control signal given from the control unit 207 when the counter value CNT1 is larger than the retransmission count threshold TH1.

The retransmission counter 209 controls the control unit 20 when abnormal reception is detected by the abnormal reception detecting unit of the control unit 207.
The counter value CNT2 based on the control signal given from 7
Is incremented and the counter value CNT2 is cleared based on a control signal given from the control unit 207 when the counter value CNT2 is larger than the retransmission count threshold TH2.

Next, in the communication system configured as shown in FIG. 1, the wireless terminal 104 is connected to the wireless base station 102 and the AT.
ATM network 1 via M network 101
The operation in the case of communicating with the terminal 105 connected to 01 will be described with reference to the flowcharts shown in FIGS.

At this time, the wireless terminal 104 sets the wireless base station 10
A case of receiving data (radio packet) from No. 2 will be described. Here, mainly when the response when the wireless terminal 104 receives a wireless packet from the wireless base station 102 indicates abnormal reception, the ATM cell data included in the abnormal wireless packet Of the wireless base station 10 in the case of retransmitting the data excluding a portion having a low priority regarding discarding as a wireless packet.
2 (control unit 207) will be described.

Further, "low priority regarding discarding" means data whose importance is low and which is unavoidable even if it is discarded as compared with data having higher priority.

Each step of FIGS. 9 to 11 will be described below.

(Steps S1 and S2) First, the terminal 10
From 5 to the wireless terminal 104, transmission / reception control is performed in the same manner as in a conventional wireless communication system such as an ATM network or PHS, a wired channel and a wireless channel are allocated, and a connection is set. After that, the terminal 105
Communication is started using the connection set between the wireless terminal 104 and the wireless terminal 104. At this time, the wireless base station 102
Is an ATM from the terminal 105 via the network 101.
When the cell is received, it is stored in the receiving ATM cell storage FIFO buffer 201.

(Steps S5 to S7) Control Unit 207
Is the start address (A1) of the receiving ATM cell storage FIFO buffer 201 and the retransmission ATM cell storage FIFO.
The empty state (empty state) is checked based on the start address (A2) of the O buffer 203. Then, based on the result, the receiving ATM cell storage FIFO buffer 20
ATM cell from the first address of 1 and ATM for retransmission
The retransmitted ATM cell is read from the head address of the cell accumulation FIFO buffer 203, a wireless packet of the format shown in FIG. 8 is created, and the wireless packet is transmitted to the wireless terminal 104.

ATM cell storage FIFO buffer 2 for reception
01 and retransmission ATM cell storage FIFO buffer 20
3 is in the Empty state, the data portion 2 of the wireless packet is the same as the wireless packet k104 shown in FIG.
The empty cell is inserted into the ATM cell inserting unit 220 and the retransmission ATM cell inserting unit 221 of No. 03.

ATM cell storage FIFO buffer 2 for retransmission
When only 03 is in the empty state, as in the wireless packet k103 shown in FIG. 8C, the ATM cell insertion unit 220 of the data unit 203 of the wireless packet reads from the start address of the receiving ATM cell storage FIFO buffer 201. ATM cell insertion unit 22 for inserting and retransmitting an ATM cell
Insert an empty cell in 1.

Reception ATM cell storage FIFO buffer 2
When only 01 is in the empty state, a retransmission AT is sent to the retransmission ATM cell insertion unit 221 of the data unit 203 of the wireless packet as in the wireless packet k102 shown in FIG. 8B.
A retransmitted ATM cell read from the head address of the M cell accumulation FIFO buffer 203 is inserted, and an empty cell is inserted in the ATM cell insertion unit 220.

ATM cell storage FIFO buffer 2 for reception
01 and retransmission ATM cell storage FIFO buffer 20
When both 3 are not in the Empty state, FIG.
Like the wireless packet k101 shown in FIG.
Insert the ATM cell read from the first address of 1,
The retransmission ATM cell insertion unit 221 has a retransmission ATM cell insertion unit 221 which has a retransmission ATM cell storage FIFO buffer 203.
The retransmitted ATM cell read from the first address of the is inserted.

Upon receiving one of the wireless packets as shown in FIG. 8 transmitted from the wireless base station 102, the wireless terminal 104 wirelessly sends a response signal indicating whether the wireless packet is normally received or abnormally received. It transmits to the base station 104.

(Steps S8 to S10, S19) The radio base station 102 which has received the response signal from the radio terminal 104.
Clears the counter values of the retransmission counters 208 and 209 when the response signal is normally received. And
The pointers WP1 and WP2 at the end addresses (write address: cells are not stored in the area designated by this address) of the ATM cell storage FIFO buffer 201 for reception and the ATM cell storage FIFO buffer 203 for retransmission are written. After shifting to the head address direction, the process returns to step S3.

(Steps S9, S11 to S12) In the case of abnormal reception, the counter value CNT1 of the retransmission counter 208 and the counter value CN of the retransmission counter 209.
After incrementing T2, it is compared with retransmission count thresholds TH1 and TH2, respectively.

Here, the respective counter values of the retransmission counters 208 and 209 will be represented as (CNT1, CNT2). The process after the comparison result returns to step S3 in the case of (threshold value TH1 or less, threshold value TH2 or less), and
If greater than H1 and less than or equal to threshold TH2), then step S20.
If the threshold value is equal to or smaller than the threshold value TH1 and larger than the threshold value TH2, the process proceeds to step S30.
If larger than H2), the process proceeds to step S40.

(Steps S20 to S24) The counter value CNT1 of the retransmission counter 208 is cleared and the reception ATM
A from the top address of the cell accumulation FIFO buffer 201
The ATM cell is read out, a retransmitted ATM cell excluding the one having a low priority regarding discarding is created, and the retransmitted ATM cell is created.
The cell accumulation FIFO buffer 203 is accumulated at the address indicated by the last address (write address) pointer WP2, the last address pointer WP2 is incremented, and the process returns to step S3.

(Steps S30 to S31) The counter value CNT2 of the retransmission counter 209 is cleared, and the AT for retransmission is sent.
The last address pointer W of the M cell accumulation buffer 203
The value of P2 is updated (shifted to the head address direction), and the process returns to step S3.

(Steps S40 to S45) Counter values CNT1 and C of the retransmission counters 208 and 209, respectively.
ATM cell storage buffer 20 for clearing NT2 and retransmitting
After shifting the last address pointer WP2 of No. 3 toward the first address, the receiving ATM cell accumulation buffer 201
Of the receiving ATM cell storage buffer 201, while reading out the ATM cell from the beginning address of the same, creating a retransmitted ATM cell excluding the one having a lower priority for discarding, and accumulating it at the address indicated by the end address pointer WP2. The address pointer WP1 is shifted in the head direction, and the process returns to step S3.

Here, when the cell buffers of the receiving ATM cell storage buffer 201 and the retransmission ATM cell storage buffer 203 are in the full state (FULL), a certain address which is not the address area of both buffers is set. Be sure to give instructions.

Also, the receiving ATM cell accumulation buffer 20
1. When the cell buffer of the retransmission ATM cell storage buffer 203 is in the Empty state, the end addresses of the two buffers (write address pointers) WP1 and WP2 are instructed. That is, the Empty state means step S
19, step S24, step S31, step S4
5, the WP1 and WP2 are in a state of indicating the head address.

The ATM cell received by the radio base station 102 via the ATM network 101 is the last address WP1 of the receiving ATM cell accumulation buffer 201.
After being written in the address area designated by, the value of the last address WP1 is incremented. ATM for receiving
When the cell accumulation buffer 201 is in the FULL state, even if the received ATM cell is discarded, the value is stored in the beginning in the same way as when the value of the ATM cell accumulation buffer K102 is read. It is also possible to discard the existing ATM cells and store the received ATM cells at the last address.

Also, the receiving ATM cell accumulation buffer 20
1 and the retransmission ATM cell accumulation buffer 203, when conflicts occur in updating the last address pointers WP1 and WP2 and writing data to the respective cell accumulation buffers so that reading / writing can be simultaneously executed asynchronously. May be configured to write the data after detecting the state and updating the last address pointers WP1 and WP2, or asynchronous reading / writing is possible.
A configuration in which a logical FIFO is built in the port RAM may be used.

In addition, each ATM connection unit (VPI
A logical FIFO may be constructed for each unit or for each VCI unit.

Here, each time a reception response is received from the wireless terminal 104, the corresponding ATM cell is retransmitted, and if the transmission / reception of the ATM cell is successful, the operation algorithm of the Stop & Wait format for transmitting the next ATM cell is used. Although an example is shown, it is also possible to apply to a Select Repeat (SR) format operation algorithm that continuously transmits a plurality of ATM cells and returns a reception response when abnormal reception occurs to request retransmission. .

Further, the threshold values (TH) of the respective counter values (CNT1, CNT2) of the retransmission counters 208, 209 are set.
1, TH2) is not specified, but TH1 = 0,
That is, if (0, TH2) and, when a response returns a reception error from the wireless terminal 104, among the ATM cells contained in the wireless packet for which the the received abnormality, having low prioritization Li Ti on Waste The excluded data is TH
This is the case of retransmitting twice (this case is referred to as the first embodiment).

Further, TH1 ≠ 0, that is, (TH1,
In the case of TH2), when a response to the reception abnormality is returned from the wireless terminal 104, the wireless packet having the reception abnormality is retransmitted TH times once, and when the reception abnormality is still returned, it is included in the wireless packet. of ATM cell, the information except those with low prioritization Li Ti on waste T
This is a case of retransmitting H2 times (this case is referred to as the second embodiment).

Note that (N1, 0) means that the ATM cell is retransmitted up to N1 times and the retransmitted ATM cell is not retransmitted. In the case of (0, N2), the ATM cell is retransmitted. This means converting to ATM cells and retransmitting up to N2 times. In the case of (N1, N2), ATM cells are retransmitted up to N1 times, and then ATM cells are retransmitted.
This means that the data is converted into M cells and retransmitted up to N2 times.

In the above description, the bandwidth of the channel on the ATM network 101 set between the terminal 105 and the radio base station 102, the radio base station 102 and the radio terminal 1
04, the bandwidth of the wireless channel set between the wireless base station 102 and the wireless terminal 1 is not described.
In consideration of the fact that re-transmission with 04, the bandwidth for the re-transmission is compared with the bandwidth of the channel on the ATM set work 101, and the extra bandwidth of the radio channel is allocated for communication. It may be configured to perform.

Further, when a retransmission occurs, a request may be made to increase the transfer rate on demand.

Also, in the above description, the radio base station 102
Determines whether or not to retransmit the retransmission counter 208, 2
The determination was made based on the counter values CN1 and CN2 of 09, but instead of using the retransmission counters 208 and 209,
Timer management may be performed by using the time of the first transmission from the wireless base station 102, the time of the output from the wireless terminal 104 of the response transmission source, and the like as parameters. In this case, if a timer is replaced in place of the retransmission counters 208 and 209, a timeout threshold is replaced in place of the retransmission count thresholds TH1 and TH2, and a timer is cleared (reset) instead of being cleared in the retransmission counters 208 and 209, the same as above. The re-transmission operation can be realized by the algorithm.

Also, the CLP determines whether or not to retransmit.
(Cell Loss Priority) may be used. In other words, CLP = 1 is not retransmitted to cells (cells that perform low priority processing with respect to the cell loss rate), and CLP = 0.
The cell may be controlled to be retransmitted (a cell that performs high priority processing with respect to the cell discard rate). Also, the retransmission control may be performed by changing the retransmission count threshold value, the timeout threshold value, and the like depending on the CLP value. Also,
Retransmission control may be performed by using both the retransmission counter and timer management.

By the way, in the retransmission control algorithm shown in FIGS. 9 to 11, the information part (payload) of the ATM cell to be transferred has a high priority information part and a low priority information part as shown in FIG. 12 (a). Since the configuration is composed of two parts, the thresholds (TH1, TH
2) was used two times. However, FIG.
As shown in (b), the information part of the ATM cell may be composed of N parts according to the priority, and a control may be performed by setting a threshold value of the number of retransmissions for each part.

The retransmission count thresholds (TH1, TH2) and the timeout value are set at the time of the first wireless packet transfer of the wireless base station 102, and thereafter they are not changed until the transfer of the wireless packet is completed or the packet is discarded. However, the number of retransmissions may be determined and changed by an instruction from the receiving side depending on the buffer amount in the wireless terminal 104 on the receiving side.

Next, a retransmission control method in radio base station 102 having the configuration shown in FIGS. 4 and 5 will be described.

When the radio base station 102 receives ATM cells from the ATM network 101, they receive the ATM cells shown in FIG.
The format conversion unit 102g converts the format into a format suitable for the wireless transmission protocol.
Generally, one or a plurality of ATM cells are accommodated in one wireless packet and wirelessly transmitted. A retransmission control method in such a case will be described next.

First, when the wireless terminal 104 returns a reception abnormality response to the first transmission of the radio packet, the AT included in the radio packet having the reception abnormality.
Of M cells, for the case of a predetermined number of times retransmission except those with low prioritization Li tee on Waste, 13 to 1
This will be described with reference to FIG.

As shown in FIG. 13A, the ATM cell A
~ C, ATM cells A and C have high priority and
Cell B has a lower priority than that. In the first transmission, the ATM cells A, B, and C are all accommodated in the wireless packet, but in the retransmission, the ATM cell B having a low priority is excluded, and only the ATM cells A and C having a high priority are wireless packets. Housed in. This makes it possible to reduce the traffic at the time of retransmission and reduce the congestion in wireless transmission.

When the retransmission is repeated, the packet length may be further changed during the retransmission. For example, in FIG.
As shown in (b), the ATM cell D that was not included in the wireless packet in the first transmission at the time of retransmission
The same effect can be obtained by incorporating and transmitting the information of. When the retransmission is repeated, another ATM cell may be incorporated or removed from the contents of the wireless packet during the retransmission.

In FIG. 14, of the ATM cells A to F, A, C and D have a high priority, and the ATM cells B, E and F have a high priority.
Shall be lower than that. ATM for the first transmission
Cells A to F are sequentially packetized and transmitted, but in retransmission, ATM cells with high priority are transmitted with short packets, and ATM cells B, E, and F with low priority are accommodated together in one packet. Sent.

As a result, an ATM cell having a high priority is transmitted with a small delay time, and an ATM cell having a low priority is
Since the header overhead is reduced by being put together, it becomes possible to perform wireless transmission according to the service quality request while suppressing a decrease in data throughput.

When a response to the abnormal reception is returned from the wireless terminal 104 in response to the first transmission of the wireless packet, the wireless packet having the abnormal reception is retransmitted a predetermined number of times, and the abnormal reception is still returned. further, among the ATM cells contained in the wireless packet, the case where the information other than having a low plug <br/> ion Li tee on waste retransmits a predetermined number of times, will be described with reference to FIGS. 15 16 .

An ATM cell received by the transmission / reception circuit 102a of the radio base station 102 as shown in FIG. 4 or 5 via the ATM network 101 is converted into a predetermined radio packet format by the format conversion unit 102g. After being transmitted, or as it is, it is transmitted to the wireless terminal 104 via the wireless transmission / reception circuit 102c. The retransmission control unit 102f controls the retransmission of the ATM cell when a response indicating the abnormal reception of the wireless packet is returned from the wireless terminal 104. At this time, the retransmission counter 10 determines the number of retransmissions.
Count with 2e.

FIG. 15 is a diagram for explaining the retransmission control method when the radio base station 102 has the configuration shown in FIG. 4, and FIG. 16 shows the case where the radio base station 102 has the configuration shown in FIG. It is a figure for demonstrating the method of retransmission control.

In FIG. 15, the ATM cells A to C are used until the number of retransmissions counted by the retransmission counter 102e is m.
Are sequentially accommodated in a wireless packet and transmitted to the wireless terminal 104, and the AT having a high priority after the number of retransmissions (m + 1)
Only the M cells A and C are accommodated in a wireless packet and transmitted, and the ATM cell B having a lower priority is discarded and the wireless terminal 1
Do not send to 04.

The structure of the wireless packet at the m-th retransmission and the structure of the wireless packet at the (m + 1) -th retransmission may be different. That is, in FIG.
As shown in, every ATM cell is retransmitted until the number of retransmissions counted by the retransmission counter 102e is m.
In the (m + 1) th and subsequent retransmissions, priority cells A and C
Only the non-priority cell B is retransmitted, and the non-priority cell B is not retransmitted.

As a result, it becomes possible to reduce the congestion of the wireless transmission line due to the retransmission.

As is apparent from the above description, in the second embodiment, when the abnormal reception is returned from the wireless terminal 104, the information part of the ATM cell having the high priority regarding discard is regarded as the information. After retransmitting both low information for a certain number of times, it is retransmitted with information excluding the low priority part regarding discard.
In the first embodiment, when an abnormal reception is returned from the wireless terminal 104, it is immediately retransmitted with information excluding a portion having a low priority for discarding the ATM cell.

Next, a third embodiment will be described.

According to the first and second embodiments, the wireless terminal 1 guarantees the order of the ATM cells arriving at the wireless base station 102 at least for each connection and packetizes them.
04 can be sent.

On the other hand, the third embodiment guarantees the order of the ATM cells that have arrived for each priority.

FIG. 17 is for explaining the outline of the retransmission control method according to the third embodiment.

In FIG. 17, a wireless packet (priority packet A) composed of an ATM cell having a high priority from the wireless base station 102 to the wireless terminal 104 and an AT having a low priority are provided.
A wireless packet (non-priority packet B) composed of M cells is transmitted, and the wireless terminal 104 cannot correctly receive them, or an ACK signal indicating that they have been correctly received reaches the wireless base station 104 correctly. For some reason, the wireless base station 102 needs to retransmit.

At this time, the radio base station 102 retransmits the priority packet A and does not retransmit the non-priority packet B, thereby reducing the packet congestion of the downlink radio channel due to the retransmitted radio packet. This is generally
It also applies when you have more priorities.

The radio base station 10 having the configuration shown in FIG.
Regarding 2, the reproduction control method according to the third embodiment will be described more specifically.

In the radio base station 102 shown in FIG.
When an ATM cell is received from the M network 101 via the transmission / reception circuit 102a, the format conversion unit 102g
Is converted into a wireless packet in the wireless transmission / reception circuit 10
2c to the wireless terminal 104. In the radio base station 102, in order to reduce the influence of the throughput decrease due to the increase in the overhead of the radio packet header of the radio transmission / reception circuit 102c, the ATM cells received from the ATM network 101 via the transmission / reception circuit 102a are temporarily stored in the buffer memory 102d. However, cells having the same discard priority are collected and transmitted as wireless packets.

For example, as shown in FIG. 18, of the received ATM cells A to F, the ATM cell A with the highest priority,
C and D are transmitted to the wireless terminal 104 as one priority packet, and the low priority ATM cells B, E, and F are each transmitted as one non-priority packet.

A radio packet in the radio section between the radio base station 102 and the radio terminal 104 has, for example, as shown in FIG. 19, a header section having at least a 1-bit field indicating the priority of discard.

The radio base station 102 receives a signal indicating abnormal reception of a radio packet from the radio terminal 104, or when a signal indicating normal reception cannot be received within a preset time, the radio packet Is retransmitted, the priority packet is retransmitted and the non-priority packet is discarded without being retransmitted.

By performing such priority control, it is possible to reduce the discard rate of high-priority packets while reducing the increase in overhead as compared with the case where priority control is not performed.

The third embodiment is the same as the first embodiment described above.
And it is easily realized by only changing the packet generation policy of the wireless base station 102 in the second embodiment.

In the description of the third embodiment, the ATM set between the terminal 105 and the radio base station 102 is used.
Although the bandwidth of the channel on the network 101 and the bandwidth of the wireless channel set between the wireless base station 102 and the wireless terminal 104 are not described, the bandwidth between the wireless base station 102 and the wireless terminal 104 is not described. In consideration of the fact that retransmission is performed, as shown in FIG. 20, the bandwidth (1302) of the wireless channel is compared with the bandwidth (1301) of the channel on the ATM network 101, and However, the communication may be performed by allocating only the extra number.

Also, when retransmission occurs, a request may be made to increase the transfer rate on demand, and the band 1304 may be added in response to the request.

When the bandwidth of the wireless channel is not excessively allocated to the bandwidth of the channel on the ATM network 101, the traffic increases by the amount of retransmission on the wireless channel, and the cell discard and the like are extra by that amount. As a result, the required quality may not be met for the allocated bandwidth. On the other hand, in this case, even if the band of the wireless channel is widened and rescued, the ATM network 10
If the bandwidth of the channel above 1 is also increased proportionally, the number of cells arriving at the radio base station 102 will increase, and conversely A
There arises a problem that the resource utilization efficiency is deteriorated by securing the extra band of the TM network 101.

As described above, according to the first embodiment, when the response from the wireless terminal 104 indicates abnormal reception, the wireless base station 102 includes the abnormal wireless packet. By retransmitting the information of the ATM cell information excluding the one with the low priority regarding discarding in a wireless packet, the wireless by retransmission is compared with the case of retransmitting both the one with the high priority regarding discarding and the one with the low priority regarding discarding. It is possible to reduce congestion on the transmission path.

Further, according to the second embodiment, when the response from the wireless terminal 104 indicates abnormal reception, the wireless base station 102 retransmits the abnormal wireless packet a certain number of times. Thus, when the number of discards is as low as possible and the number of discards is suppressed as much as possible, when the number of times is exceeded, the information excluding the one having lower priority regarding discard from the information of the ATM cells included in the wireless packet is removed. By retransmitting in a wireless packet, it is possible to reduce the congestion of the wireless transmission line due to the retransmission as in the case of the first embodiment.

Further, according to the first and second embodiments, the order of ATM cells arriving at the radio base station 102 can be guaranteed at least for each connection and packetized and transmitted to the radio terminal 104. .

Further, according to the third embodiment, the radio base station 102 collects only ATM cells having the same priority with respect to discard into a radio packet, and transmits the packet to the radio terminal 104. It is possible to reduce the overhead of the header, and if the response indicates abnormal reception, retransmit the abnormal wireless packet if the discard priority does not satisfy the specified threshold. Instead, by retransmitting only the wireless packets having a priority higher than the threshold, it is possible to reduce the discard rate of the wireless packets having a high priority. That is, according to the third embodiment, it is possible to reduce the overhead of the header of the wireless packet and reduce the discard rate of the high priority packet. That is, the order of the ATM cells arriving at the wireless base station 102 can be guaranteed for each priority and transmitted to the wireless terminal 104.

Further, according to the above-mentioned first to third embodiments, the connection management table 20 of the radio base station 104.
8 (see FIG. 7), the retransmission count threshold value and the timeout threshold value for each connection are stored, and based on this, the threshold value can be set in accordance with the QOS guaranteed value for each connection.

Further, this connection management table 20
8 is rewritten by the control unit 207 (see FIG. 7), the connection congestion state, the wireless terminal 104
It is possible to dynamically switch the retransmission control method according to the state such as the remaining buffer amount, and it is possible to more flexibly and finely deal with the QOS guarantee.

Further, by performing the retransmission control using the timer value instead of the number of times of retransmission, the wireless terminal 104 receives information that is meaningless even if it is transmitted after the guaranteed value of the delay time has passed.
Can be reduced to sending to.

If the bandwidth of the channel set on the ATM network 101 and the bandwidth of the radio channel are equally allocated, if the retransmission is frequently performed and the execution throughput of the radio channel is reduced, the cell is discarded. Although it has a drawback that it is likely to occur, an extra radio channel bandwidth is allocated by the amount of the bandwidth required for retransmission compared to the channel bandwidth on the ATM network 101 (in the case of downlink, on the radio channel. So that the execution throughput on the wireless network is less than or equal to the execution throughput on the channel set on the ATM network 101. Assignment) to solve the above drawbacks. It can be, it is possible to reduce the congestion of the radio transmission path due to retransmission.

Next, regarding the wireless communication method in the communication system configured as shown in FIG. 1, when transmitting data (wireless packet) from the wireless terminal 104 to the wireless base station 102 via the upstream wireless communication link 107. Will be described. That is, the wireless terminal 104 to the wireless base station 10
2 transmits a wireless packet to the wireless base station 102, and the wireless base station 102 returns a wireless packet reception response.
A case will be described in which the retransmission control is performed by the user.

First, the fourth embodiment will be described.

In the communication from the wireless terminal 104 to the wireless base station 102, when an error is detected in the wireless packet transmitted from the wireless terminal 104, the wireless base station 102 notifies the wireless terminal 104 of the wireless packet number and resends it. Let me do it. At this time, the wireless packet to be retransmitted is given a priority regarding discarding, and only the packet with high priority is retransmitted, or it is retransmitted regardless of the priority up to a certain number of times, and the higher priority is given for further retransmission. Retransmit only packets.

FIG. 21 shows the configuration of the radio base station 102 to which such a retransmission control method is applied. That is, the wireless base station 102 shown in FIG.
04 has a function of receiving a wireless packet from 04 and monitoring the quality of the wireless packet, and returning the result as a reception response to the wireless base station 102. Therefore, at least a transmission / reception circuit 102h as an interface for connecting to the ATM network 101 is provided. , A wireless antenna 102i for performing wireless communication with the wireless terminal 104, a wireless transmission / reception circuit 102j as a wireless interface connected to the wireless antenna 102i, a buffer memory 102k, an antenna 102i, and a wireless terminal received via the wireless transmission / reception circuit 102j. error detecting unit performs error detection of the data contained in the wireless packet from 104 102 l, format conversion unit for converting a format of the ATM cell and radio packets transmitted and received by radio transceiver circuit 102 j which is transmitted and received by the transmission and reception circuit 102 h 102 n and Transceiver circuit 102h, a radio transceiver circuit 102j, a buffer memory 102k, the error detection unit 102
1. The control unit 102m is connected to the format conversion unit 102m and controls the overall operation.

The control unit 102m controls the transmission of a reception response to the radio base station 102 based on the error detection result of the radio packet transmitted from the radio terminal 104 side of the error detection unit 102l, and the transmission / reception circuit. Control for accumulating the ATM cells received at 102h in the buffer memory 102k is performed.

FIG. 22 shows an example of the structure of the wireless terminal 104.

In FIG. 22, the wireless terminal 104 mainly has a transmitting / receiving antenna 104h for performing wireless communication with the wireless base station 102, a wireless transmitting / receiving circuit 104i connected thereto, and a user inputs data. An input / output unit 104j having a function as a user interface for outputting information to the user, a packet configuration unit 104k that decomposes transmission data input from the input / output unit 104j into packets, and assembles received data from received wireless packets. , A buffer memory 104l including a buffer memory for transmission to the wireless base station 102 and a buffer memory for retransmission to the wireless base station 102, and a wireless transceiver circuit 104i, an input / output unit 104j, a packet configuration unit 104k, and a buffer. It is connected to the memory 104l and controls all of these. Both a control unit 104m responsible for retransmission control of the wireless packet between the radio base station 102.

When the control unit 104m performs retransmission control, the retransmission counter 104n counts the number of retransmissions.

Between the radio base station 102 and the radio terminal 104, for example, TDMA-TDD (Time Division Multip
le Access-Time Division Duplex) to communicate. In this case, the slot configuration is shown in FIG. That is, in the case of 4-multiplex TDMA-TDD, of the 8 slots, 1 slot each for uplink and downlink is used as a retransmission slot, and another pair of slots for uplink and downlink is used for communication. ing. Therefore, the retransmission slot can be shared by the wireless terminals communicating with the other three sets of slots for retransmission. Since the retransmission slot is shared, it may collide with retransmissions of other wireless terminals. This means that the retransmission slot should be used in the NAK transmitted by the wireless base station 104 to the wireless terminal at any timing. It will be solved by showing the key.

[0152] to the wireless terminal 104, uplink, downlink, each one slot is allocated for communication, it can communicate with the radio base station 10 2.

Also, the wireless terminal 104 and the wireless base station 1
In 02, transmission and reception can be performed simultaneously for two slots.

The wireless packet transmitted from the wireless terminal 104 to the wireless base station 102 is given priority. The priority here indicates whether or not to discard the wireless packet, as in the CLP described above.

There are two possible configurations of the wireless packet transmitted from the wireless terminal 104 to the base station 102, as shown in FIGS.

FIG. 24 shows an example of the structure of wireless packets to which a priority is assigned for each wireless packet.

In the configuration example of the wireless packet shown in FIG. 25,
One wireless packet is composed of a plurality of subpackets, and each subpacket is given a priority.

In the following description, FIGS.
The wireless packet and sub-packet having the configuration shown in 5 may be collectively referred to as a packet.

When the wireless terminal 104 and the wireless base station 102 communicate with each other, first, the wireless terminal 104 transmits a call request (setup message) to the wireless base station 102. The call request indicates whether or not this communication is tolerant of delay. Upon receipt of the call request, the wireless base station 102 checks a free line and allocates a physical slot as shown in FIG. 24 when a line satisfying the request exists, and a call loss occurs when no line exists. .

When the line is established, the wireless terminal 104
The transmission data is packetized and the transmission is started as a wireless packet. At this time, each wireless packet or each sub-packet is given a priority.

When the wireless terminal 104 transmits a wireless packet to the wireless base station 102 and the base station 102 receives the wireless packet normally (when there is no error), the base station 1
02 transmits an ACK message to the wireless terminal 104, and when an error (abnormality) is detected in the wireless packet received by the wireless base station 102, the wireless base station 102 transmits a NAK message to the wireless terminal 104. This AC
The packet number of the corresponding wireless packet or subpacket is attached to the K and NAK messages.

Next, the wireless terminal 104 sends an ACK, NAK
The processing operation when the is received will be described.

The retransmission method here is Select
This is an ive Repeat (SR) method, and basically, the wireless terminal 104 continuously transmits packets, and when a NAK is returned from the wireless base station 102, only the corresponding wireless packet or subpacket is transmitted. This is a method of resending. At this time, the maximum number of retransmissions of one packet is MX. In other words, if the packet cannot be correctly received even if it is retransmitted MX times, the retransmission of this packet is given up.

The buffer memory 104l provided in the wireless terminal 104 has a buffer memory for transmission and a buffer memory for retransmission, and the packets accumulated in the buffer memory for transmission are sequentially transmitted as wireless packets. When the transmission of the wireless packet is completed, the packet is copied to the retransmission buffer memory and erased from the transmission buffer memory.

When the ACK message is received from the radio base station 102, the packet of the corresponding number is erased from the retransmission buffer memory, and the packet transmission in the transmission buffer memory is continued as it is.

On the other hand, when the NAK message is received from the radio base station 102, the corresponding packet in the retransmission buffer memory is retransmitted (at this time, the retransmission counter 104
The counter value of n is incremented by 1). When an ACK message is returned from the wireless base station 102 in response to this retransmission packet, or when the number of retransmissions reaches MX, it is erased from the retransmission buffer memory.

Next, the wireless terminal 104 sets the wireless base station 102
The processing operation when the NAK message is received from will be described in more detail.

This processing operation differs depending on whether or not to retransmit the packet having received the NAK message. That is, whether or not to retransmit the packet is determined by whether or not the communication currently being performed, which is indicated in the call request (setup message), allows the delay.

First, the case where the wireless packet has the structure shown in FIG. 24 will be described with reference to FIG. Here, a case is shown in which, when the wireless terminal 104 retransmits, a communication slot previously assigned to the wireless terminal 104 is used.

When the response message transmitted from the wireless base station 102 corresponding to the wireless packet transmitted from the wireless terminal 104 is NAK and the communication allows delay, the packet in which an error is detected is sent. Retransmit buff
A general SR method of reading out from the memory and resending is performed (steps S100 to S103).

On the other hand, when the delay is not allowed, if the packet that has received the NAK is a packet with a high priority, the process proceeds to step S103, and the packet is retransmitted, and if it is a packet with a low priority, it is not retransmitted. That is, the low priority packet corresponding to NAK is deleted from the retransmission buffer memory (steps S102 and S104).

Resending is performed up to MX times. When the packet is correctly received or retransmitted up to MX times, the packet is erased from the retransmission buffer memory (steps S105 to S106).

Next, as shown in FIG. 23, in the slot in which communication is currently being performed, packet transmission is continued as it is, and the packet for which NAK has been received is transmitted in the retransmission slot according to the delay allowance. Such as resending
A case where a method of simultaneously performing communication using two slots is adopted will be described with reference to the flowchart shown in FIG. The same steps as those in FIG. 26 are designated by the same reference numerals, and the description thereof will be omitted.

In step S102 of FIG. 27, if the delay tolerance is severely limited, retransmission can be performed using the retransmission slot. In this case, the packets to be retransmitted in the retransmission slot are all the packets that have received the NAK, or only the packets with high priority among the packets that have received the NAK (steps S110 to S112).

When wireless terminal 104 receives NAK and retransmits a packet, wireless terminal 104 transmits the corresponding packet in the retransmission slot designated by wireless base station 102, and the communication up to that point is also transmitted in the transmission slot. continue. The radio base station 104 receives packets from both the retransmission slot and the transmission slot, performs error detection, and performs a reception response for each packet in two slots. Then, when there is no packet to be retransmitted from the wireless terminal 104, the transmission is continued again with only one slot.

In the description of FIGS. 26 and 27, the maximum number of retransmissions MX may be different for packets with high priority and packets with low priority. For example, the maximum number of retransmissions of a high priority packet is MXH, and the maximum number of retransmissions of a low priority packet is MXL ((MXH)).
> (MXL)).

Next, a case where the wireless packet has the structure shown in FIG. 25 will be described with reference to FIG. The same steps as those in FIG. 26 are designated by the same reference numerals, and the description thereof will be omitted. Further, here, a case is shown in which, when the wireless terminal 104 performs retransmission, a communication slot previously assigned to the wireless terminal 104 is used.

When the delay between the wireless terminal 104 and the wireless base station 102 is not allowed, if the NAK-received wireless packets have subpackets with high priority, they are retransmitted, If it is composed only of subpackets with a low priority, it will not be retransmitted (step S10).
2, step S120).

At this time, when the wireless terminal 104 receives the NAK, it checks the priority of each subpacket in the corresponding wireless packet. When the presence of a sub-packet having a high priority is detected, the packet is read from the retransmission buffer memory and retransmitted. On the other hand, when it is detected that the priority of all the subpackets forming the wireless packet corresponding to NAK is low, the packet is erased from the retransmission buffer memory and is not retransmitted.

Even when the radio packet is composed of a plurality of subpackets, the same processing operation as in FIG. 27 can be performed by using the retransmission slot at the time of retransmission.
In this case, what is retransmitted using the retransmission slot is
Depending on the delay tolerance, it may be all the subpackets in the NAKed wireless packet, or N
Only the high priority subpacket in the wireless packet that has received the AK may be used.

Further, if NAK is still returned after all subpackets in the NAK-received wireless packet are retransmitted a predetermined number of times, the NAK-received wireless packet has a high priority. It is also possible to take out only the subpacket, recreate a new wireless packet, and retransmit the packet a predetermined number of times.

That is, as shown in FIG. 29, the wireless terminal 104 takes out only the subpacket having a high priority among the NAK-received wireless packets, recreates a new wireless packet, and retransmits it. At that time, a new wireless packet is formed only by subpackets having a high priority in one wireless packet, or a subpacket having a high priority is extracted from a plurality of wireless packets and a new wireless packet is newly created. A method of configuring can be considered.

In the above description of FIGS. 26 to 28, the maximum number of times of retransmission of a packet in which an error is detected is determined by the retransmission counter 104n, but not by the counter but by a timer after transmitting the packet. The maximum number of retransmissions may be determined. That is, the packet can be retransmitted any number of times within a certain time after being transmitted.

The radio base station 102 and the radio terminal 104 are also provided.
The maximum number of retransmissions may be determined according to the buffer capacity at that time.

Furthermore, it is possible to gradually reduce the amount of information according to the number of retransmissions. That is, the first retransmission is performed regardless of the priority, and when the number of retransmissions exceeds a certain threshold, only the packet with high priority is retransmitted.

As described above, according to the fourth embodiment, when the response from the wireless base station 102 indicates abnormal reception, the wireless terminal 104 includes the abnormal wireless packet. Of the packets or subpackets that are dropped, the ones that have a lower priority for discarding are retransmitted as wireless packets. Congestion can be reduced. If the response from the wireless base station 102 indicates abnormal reception, the wireless terminal 10
In No. 4, the abnormal wireless packet is retransmitted a certain number of times, and the number of packets or sub-packets included in the wireless packet is exceeded when the number of times is exceeded while the priority of discarding is as low as possible, but the discarding is also suppressed. Of the packets, except those with low priority regarding discarding, retransmit by wireless packet,
It is possible to reduce congestion on the wireless transmission path due to retransmission.

Also, when an error is detected in a packet and the packet is retransmitted, by using a slot dedicated to retransmission, it becomes possible to perform retransmission control according to the service quality of communication, particularly, the delay tolerance. Further, it is possible to deal with the case where the bandwidth available for communication is not always constant and increases more than the bandwidth available at the start of communication.

Next, a fifth embodiment will be described.

Here, a retransmission control method for a wireless terminal that satisfies the requirement for real-timeness while keeping the bandwidth of the wireless link from the wireless terminal 104 to the wireless base station 102 having the configuration shown in FIG. 22 constant. A description will be given with reference to the flowchart shown in FIG.

When transmission is started, the wireless terminal 104 transmits wireless packets until the end of transmission is instructed by the user (step S200).

First, the operation while the wireless packet transmitted from the wireless terminal 104 is normally received by the wireless base station 104 will be described.

The data input by the user is coded in the packet construction unit 104k, and the buffer memory 1
The data is stored in the transmission buffer memory 04l and held at least until the data is completely transmitted or discarded.

The processing of the packet configuration unit 104k is determined by the type of the wireless terminal 104 and the user's request, and for example, the processing of ATM cell conversion may be performed.

Here, it is assumed that the data input to the input / output unit 104j is divided into high-priority data that cannot be discarded and low-priority data that can be discarded, and is output. The priority data and the low priority data are separately stored.

The packet construction unit 104k creates, for example, a wireless packet containing high priority data and low priority data, and the wireless transmission / reception circuit 104i transmits the wireless packet to the wireless base station 102 via the wireless link 107. Yes (step S201).

When the wireless base station 102 normally receives the wireless packet, the wireless base station 102 transmits a normal reception notification indicating normal reception to the wireless terminal 104. When the wireless transmission / reception circuit 104i of the wireless terminal 104 receives the normal reception notification (step S
202), the same processing as above is performed on the next input data. That is, while the normal reception notification is being received from the wireless base station 102, the above-described operation (steps S200 to S) is performed unless the user gives an instruction to end the transmission.
202) is repeated.

Next, the operation when the wireless packet transmitted from the wireless terminal 104 is not normally received by the wireless base station 102 will be described.

When the wireless base station 102 cannot normally receive the wireless packet transmitted by the wireless terminal 104, for example, the wireless terminal 1 sends a normal reception notification indicating normal reception.
Do not send to 04. If the wireless transmission / reception circuit unit 104i of the wireless terminal 104 does not receive the normal reception notification within the predetermined time, the wireless terminal 104 determines that the wireless base station 102 has not successfully received the wireless packet (step S202). .

When the wireless base station 102 cannot normally receive a wireless packet and transmits an abnormal reception notification to the wireless terminal 104, the wireless transmission / reception circuit 104i of the wireless terminal 104 receives the abnormal reception notification. As a result, the wireless terminal 104 determines that the wireless base station 102 has not successfully received the wireless packet (step S20).
2).

As described above, when the wireless terminal 104 detects the abnormal reception of the wireless base station 102, the wireless terminal 104 discards the low priority data out of the data which is not normally received by the wireless base station 102, and the packet configuration. The unit 104k packetizes only the high-priority data into a wireless packet in order from the oldest in time, and the wireless base station 102 transmits the wireless packet via the wireless transmission / reception circuit 104i.
(Step S203).

When the radio base station 102 cannot normally receive the radio packet transmitted in this way, the radio packet is retransmitted if it is within a predetermined allowable delay time. If it is within the allowable delay time, the retransmission is repeated, and when the allowable delay time is exceeded, the retransmission is stopped and the high priority information included in the wireless packet exceeding the allowable delay time is discarded. Then, in the packet configuration unit 104k, the high-priority data is wirelessly packetized in the order of oldness, and the wireless packet is transmitted to the wireless base station 102 via the wireless transmission / reception circuit 104i (steps S204-).
Step S206).

On the other hand, when the wireless base station 102 normally receives the retransmitted wireless packet as described above, the wireless terminal 104 determines whether or not there is a delay in the transmission of the input data and the wireless packet, and In the case where the above occurs, the delay is reduced by packetizing only the high-priority data and transmitting the packet. If no delay has occurred, the high-priority data and the low-priority data of the input data are packetized and transmitted (step S204, steps S207 to S208).

By performing the processing operation as shown in FIG. 30, the wireless terminal 104 does not increase the bandwidth of the wireless link, and does not cause a delay time longer than a predetermined value, thus reducing the error. It becomes possible to send data.

Next, detailed processing operations at the time of transmitting a wireless packet in the wireless terminal 104 having the configuration shown in FIG. 22 will be described with reference to the flowchart shown in FIG.

When the transmission is started, the transmission input information counter i for counting the input data to be transmitted to the radio base station 102 and the transmission packet counter j for counting the number of radio packets transmitted by the radio terminal 104 are set to "1". (Step S300).

The packet construction unit 104k includes a radio packet Si including high priority data Cih and low priority data Cil.
(Step S301), and the wireless transmission / reception circuit 104
The wireless packet Si is transmitted via i (step S3
02).

If there is a transmission end instruction, the transmission is terminated (step S303), but if there is no transmission termination instruction, the counter j is incremented by "1" (step S304).

The radio base station 102 normally receives the radio packet Si and transmits a normal reception notice Ai to the radio terminal 104. When the wireless terminal 104 receives the normal reception notification Ai within a predetermined time (step S305),
The transmitted input data is discarded (step S306), and the counter i is incremented by "1" (step S306).
307).

When the values of the counters i and j are equal (step S308), it means that there is no delay due to the retransmission between the data input by the user and the transmission of the wireless packet. Packetize the input data of.

If the values of the counters i and j are not equal in step S308, the counter i is incremented by "1" (step S309). Furthermore, i is (j-
1) If not less (step S310), it indicates that there is no delay due to retransmission between the data input by the user and the transmission of the wireless packet, and therefore the process returns to step S301, and the next input data is packetized.

On the other hand, in step S305, the wireless terminal 10
4 does not receive the normal reception notification Ai from the radio base station 102, the process proceeds to step S320, and it is determined whether the difference (j-i) between the values of the counters j and i is less than or equal to a predetermined allowable delay D. To do. At this time, if the judgment is “true”,
In order to show that the delay due to the retransmission between the data input by the user and the transmission of the wireless packet is less than the allowable delay,
In step S321, the packet configuration unit 104k
The oldest high-priority data Cih that has not been discarded and the next oldest high-priority data C (i + 1) h are included in the wireless packet Si, the process returns to step S302, and the wireless transmission / reception circuit 10
4i to the radio base station 102.

When the determination in step S320 is "false", it means that the delay due to the retransmission between the user's data input and the transmission of the wireless packet is equal to or more than the allowable delay. Therefore, the oldest high priority not discarded is set. The data Cih is discarded (step S322), the counter i is incremented by "1" (step S323), and then step S32.
Go to 1 and packetize.

At step S310, the counter i is set to (j-
1) In the following cases, in order to indicate that a delay due to retransmission occurs between the user's data input and the transmission of the wireless packet, the process proceeds to step S321, only the high-priority data is packetized, and it is created in step S302. The transmitted packet Si is transmitted to the wireless base station 102.

By performing the processing operation as shown in FIG. 31, the wireless terminal 104 does not increase the bandwidth of the wireless link, and does not cause a delay time longer than a predetermined value, and the number of errors is smaller. It becomes possible to send data.

As described above, according to the above fourth and fifth embodiments, the wireless terminal 104 to the wireless base station 10 are connected.
When data is transmitted in the up direction to 2, the radio packet whose reception at the radio base station 102 is abnormal is controlled by controlling the transmission of the radio packet according to the priority regarding the discard of the data included in the radio packet. It is possible to suppress the delay time that may occur due to the retransmission of the packet within a predetermined time, and to suppress the significant loss of information to the user.

[0216]

As described above, according to the present invention,
Effective use of the range of radio link capacity provided
More important data can be transmitted more reliably,
Real-time communication is performed with the quality guaranteed as much as possible.
You can

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a wireless packet.

FIG. 3 is a diagram showing a configuration example of a data part of the wireless packet of FIG.

FIG. 4 is a diagram showing a configuration example of a wireless base station.

FIG. 5 is a diagram showing another configuration example of a wireless base station,
The figure which showed the case of the wireless base station which has the conversion function of a cell and a wireless packet.

FIG. 6 is a diagram showing a configuration example of a wireless communication terminal.

FIG. 7 is a block diagram showing a detailed configuration of a wireless base station.

FIG. 8 is a diagram showing a configuration example of a wireless packet.

FIG. 9 is a flowchart for explaining a retransmission control processing operation in the radio base station.

FIG. 10 is a flowchart for explaining the processing operation of retransmission control in the wireless base station.

FIG. 11 is a flowchart for explaining the processing operation of retransmission control in the wireless base station.

FIG. 12 is a diagram for explaining the structure of an ATM cell having a plurality of priorities.

FIG. 13 is a diagram for explaining the outline of the processing operation of retransmission control of the radio base station according to the first embodiment.

FIG. 14 is a diagram for explaining an outline of another retransmission control processing operation of the radio base station according to the first embodiment.

FIG. 15 is a diagram for explaining the outline of the processing operation of retransmission control of the radio base station according to the second embodiment.

FIG. 16 is a diagram for explaining an outline of another retransmission control processing operation of the radio base station according to the second embodiment.

FIG. 17 is a diagram for explaining an outline of the processing operation of retransmission control of the wireless base station according to the third invention.

FIG. 18 is a diagram for explaining a configuration example of a wireless packet according to the third embodiment.

FIG. 19 is a diagram for explaining another configuration example of the wireless packet according to the third embodiment.

FIG. 20 is a diagram schematically showing a case where retransmission control is performed by increasing the band when performing retransmission.

FIG. 21 is a diagram showing a configuration example of a radio base station according to the fourth and fifth embodiments.

FIG. 22 is a diagram showing a configuration example of a wireless communication terminal according to fourth and fifth embodiments.

FIG. 23 is a view showing communication between a wireless base station and a wireless communication terminal.
The figure for demonstrating the slot structure in case of multiple TDMA-TDD.

FIG. 24 is a diagram showing a configuration example of a wireless packet on an uplink wireless link from a wireless communication terminal to a wireless base station.

FIG. 25 is a diagram showing another configuration example of a radio packet on an uplink radio link from a radio communication terminal to a radio base station.

FIG. 26 is a flowchart for explaining a retransmission control processing operation in the wireless communication terminal.

FIG. 27 is a flowchart for explaining another processing operation of retransmission control in the wireless communication terminal, showing a case where a communication slot and a retransmission slot are used.

FIG. 28 is a flowchart for explaining still another processing operation of retransmission control in the wireless communication terminal.

FIG. 29 is a diagram for explaining a method of reconfiguring a wireless packet when the wireless packet is retransmitted.

FIG. 30 is a flowchart for explaining a processing operation when performing retransmission control while keeping the bandwidth of a wireless link constant.

FIG. 31 is a flowchart for explaining in more detail the processing operation when performing retransmission control while keeping the bandwidth of the wireless link constant.

[Explanation of symbols]

101 ... ATM network, 102 ... Wireless base station, 1
04 ... Wireless communication terminal, 105 ... Terminal, 106 ... Wireless downlink (channel), 107 ... Wireless uplink (channel), 108 ... IWU, 109 ... Other networks.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Mitsugi 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center Co., Ltd. (72) Takefumi Sakamoto Komukai-shiba, Kawasaki-shi, Kanagawa No. 1 in Research & Development Center, Toshiba Corp. (56) Reference JP-A-8-107417 (JP, A) JP-A-9-191314 (JP, A) JP-A-7-221789 (JP, A) JP-A-7-221789 (JP, A) 7-288531 (JP, A) Patent 3039257 (JP, B2) Patent 3450771 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/56 H04L 1/16 H04L 12/28 300 H04Q 7/38

Claims (6)

(57) [Claims] 1. A wireless communication method in which a wireless base station connected to a network and a wireless terminal communicate with each other via a wireless channel provided by the wireless base station, wherein the wireless base station relates to discarding from the network. Receiving a plurality of types of information having different priorities, transmitting a first wireless packet including the received plurality of types of information to the wireless terminal via the wireless channel, and responding to the transmitted first wireless packet. When a reception response from the wireless terminal is received and the received reception response indicates abnormal reception, only information having a higher priority regarding the discard is included among the plurality of types of information included in the first wireless packet. A wireless communication method for retransmitting a second wireless packet to the wireless terminal. 2. A wireless base station device connected to a network, wherein the wireless base station device communicates with a wireless terminal via a wireless channel provided by the wireless base station device, the priority relating to discarding from the network. Means for receiving a plurality of different types of information, a means for transmitting the received first wireless packet including the plurality of types of information to the wireless terminal via the wireless channel, and the transmitted first wireless packet Means for receiving a reception response from the wireless terminal in response to the request, and when the received reception response indicates abnormal reception, the priority of the discard is selected from a plurality of types of information included in the first wireless packet. And a means for retransmitting a second wireless packet containing only high information to the wireless terminal. 3. A radio base station device connected to a network
And a wireless channel provided by the wireless base station device.
In the wireless base station device that communicates with the wireless terminal via
hand, Priority of discarding from the network
Means for receiving different types of information, A first wireless packet including the received plurality of types of information
To the wireless terminal via the wireless channel
Means and The wireless terminal in response to the transmitted first wireless packet
A means for receiving a reception response from the end, When the received reception response indicates abnormal reception, the reception
As the response indicates normal reception, the first message
A line packet to the wireless terminalFirst resending means
When, Retransmission times of the first wireless packet by the first retransmitting means
When the number exceeds the predetermined number, the first wireless packet
Of the multiple types of information included in the
A second wireless package containing only higher priority information
Second retransmitting means for retransmitting the packet to the wireless terminal.
Wireless base station device. 4. A wireless communication method in which a wireless base station connected to a network and a wireless terminal communicate with each other via a wireless channel provided by the wireless base station, wherein the wireless terminal has a plurality of types with different priorities regarding discarding. Is transmitted to the radio base station via the radio channel, a reception response from the radio base station in response to the transmitted first radio packet is received, and the received A radio that retransmits to the radio base station a second radio packet containing only information having a higher priority regarding the discard among a plurality of types of information included in the first radio packet when the reception response indicates abnormal reception. Communication method. 5. In a wireless terminal device that communicates with a wireless base station via a wireless channel provided by a wireless base station connected to a network, a first wireless packet including a plurality of types of information with different discard priorities. To the radio base station via the radio channel, means for receiving a reception response from the radio base station in response to the transmitted first radio packet, and the reception response received is abnormally received. , A means for retransmitting to the radio base station a second radio packet containing only information of a higher priority regarding the discarding out of a plurality of types of information included in the first radio packet. Terminal device. 6. A wireless terminal device communicating with a wireless base station via a wireless channel provided by a wireless base station connected to a network, wherein a first wireless packet containing a plurality of types of information with different priorities regarding discarding. To the radio base station via the radio channel, means for receiving a reception response from the radio base station in response to the transmitted first radio packet, and the reception response received is abnormally received. Indicates, the first response means retransmits the first wireless packet to the wireless base station up to a predetermined number of times so that the reception response indicates normal reception, and the first wireless processing by the first retransmission means. When the number of times the packet is retransmitted exceeds the predetermined number, the priority of the discard is selected from among a plurality of types of information included in the first wireless packet. Wireless terminal device a second wireless packet containing only have information and a second retransmission means for retransmitting to the radio base station.