JP2990106B2 - Mobile communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a mobile communication system.

[0002]

2. Description of the Related Art A conventional mobile communication system is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-66776. This includes one-to-one communication and one-to-one communication with a specific mobile station via the base station while controlling the broadcast state by the mobile station that has requested the paging.
A technology for performing communication with N is disclosed.

[0003]

The conventional mobile communication system is a one-way communication from a fixed station requesting a simultaneous incoming call, and the mobile station receiving the incoming call transmits the signal to the fixed station. Even if there is data to be provided, it is necessary to perform new communication after the current communication is completed, and the service is not sufficient. Further, there is also a problem that efficient data communication cannot be performed because wireless channels used for communication are substantially one-way communication despite being allocated to uplink and downlink, respectively. There is a teleterminal system that enables data transmission / reception by polling control. However, despite providing bidirectional data communication, the mobile station transmits data at the time of data arrival from the base station. Cannot be performed, so it is a one-way communication when viewed instantaneously, which is not a reasonable data communication.

Accordingly, an object of the present invention is to provide a mobile communication system capable of performing two-way communication between a fixed station and a mobile station.

[0005]

In order to achieve this object, a mobile communication system according to the present invention is provided in a mobile communication system for transmitting and receiving data to and from a plurality of mobile stations by polling control of a base station. The base station comprises:
While receiving data transmitted from one specific mobile station using a confirmed data transfer procedure, transmitting data to at least one mobile station using an unconfirmed data transfer procedure. The mobile station receives data from the base station by a non-confirmation type data transfer procedure which is simultaneously transmitted while receiving the polling control, while confirming the data transmission procedure from the base station by the polling control. Is used to transmit data.

According to this configuration, since the uplink data transfer procedure and the downlink data transfer procedure are performed simultaneously and individually, data can be transferred simultaneously in the uplink / downlink, and efficient data communication is possible. Also, by using the continuous transmission method as the downlink data transfer procedure, data can be transferred to a plurality of mobile stations at the same time.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a mobile communication system according to the present invention. A. Configuration of Mobile Communication System The mobile communication system according to the present embodiment includes a control station 1, a plurality of base stations 21, 22,..., 2n, and fixed stations 31, 32.
And mobile stations 41, 42, 43, 51, 44, 52, 5
3 and 61 are provided. The control station 1 includes fixed stations 31 and 3
2 and the base stations 21, 22,..., 2n and the mobile stations 41, 42, 43, 51, 44, 52, 53, 61. The fixed station 31 is connected to the control station 1 via the public network 50, and the fixed station 32 and the base station 21,
, 2n are connected to the control station 1 by dedicated lines. , 2n and the mobile station 4
1, 42, 43, 51, 44, 52, 53, and 61 are connected via a wireless line.

Mobile stations 41, 42, 43, 51, 44, 5
The tens place of the codes of 2, 53 and 61 is assigned by a group. For example, the mobile stations 41, 42, 43 and 44 are group numbers "4", and the mobile stations 51, 52 and 53 are group numbers "5". , The mobile station 61 has the group number “6”. Also, in this figure, base stations 21, 22,.
The dotted ellipses drawn in a shape surrounding each of the base stations 2
, 2n, and the mobile stations existing in each ellipse are connected to the base station via a wireless line. For example, mobile stations 41, 42, 43, and 51 existing in the uppermost ellipse are connected to the base station 21 via a wireless line.

B. FIG. 2 is a diagram showing the structure of a downlink radio channel transmitted from the base station to the mobile station in a time division manner, and FIG. 3 is transmitted in a time division manner from the mobile station to the base station. FIG. 3 is a diagram illustrating a structure of an uplink wireless burst. (A) Structure of Downlink Radio Channel In FIG. 2, (A) shows that radio carriers transmitted from the base station are time-division multiplexed into four channels, and channels 1 to 4 are repeatedly allocated in a period called a frame. Is represented. Here, four multiplexes are tentatively used, but the number of multiplexes is not related to the present invention. (B) is the reception timing of the mobile station. (C) is a downlink radio signal (a signal from a base station to a mobile station in a communication channel),
One channel is composed of a header part and a data part.

(D) is the detailed information of the header part,
It is composed of a "transmission instructor number", a "control field", a "destination number", and a "disassembly bit". The “transmission instructor number” designates a mobile station to which a transmission instruction is given, and the “control field” is used to retransmit data transmitted from the mobile station when an error occurs on a wireless line. Things. The “destination number” designates a mobile station at which data transmitted from the base station arrives. The "disassembly bit" is information such as a data number necessary for assembling data transmitted from the base station. The "transmission instructor number" and "control field" are used for retransmission of uplink data for polling control, and the "destination number" and "disassembly bit" are used for transmission of downlink data.

(B) Structure of Uplink Radio Burst In FIG. 3, (a) shows the transmission / reception timing of the mobile station, and (b) shows the uplink radio burst transmitted from the mobile station (from the mobile station to the base station in the communication channel). ), Which comprises a header section and a data section. (C) is detailed information of the header part of (b), and is composed of a "sender number" and a "control field". The “transmitter number” designates the number of the mobile station, and the “control field” is used for retransmitting data transmitted from the mobile station when an error occurs on a wireless line. FIG. 4 is a diagram showing a disassembly method for passing a wireless line in a time-division manner, and FIG. 5 shows a sequence of polling control by a base station.

C. Operation of Mobile Communication System In the mobile communication system according to the present embodiment, data communication is performed by fixed stations 31 and 32 and mobile stations 41 and 42 via a communication network including control station 1 and base stations 21, 22,. ,
43, 51, 44, 52, 53, 61.

(A) Securing a communication channel and shifting to a communication channel of a mobile station Data communication is started by a "data communication request" signal from one fixed station (originating terminal). The “data communication request” signal includes the number information of its own station (fixed station) registered in the control station 1 and the number information of one or more mobile stations (called terminals) to which data communication is to be performed (called terminal number). Information). When the control station 1 receives the "data communication request" signal transmitted from the fixed station requesting the data communication, the target mobile station transmits to any base station based on the called terminal number information included in the signal. Search for the registered location from the location registration information. When finding the base station in which the target mobile station is located, the base station secures a communication channel and controls transition of the mobile station to the communication channel.

For example, if the fixed station 31 has the group number "4"
When performing communication with the mobile stations 41, 42, 43, and 44, the base stations including the mobile stations 41, 42, 43, and 44 with the group number “4” are the base stations 21 and 22. After selecting a base station, a communication channel is secured. The mobile stations 41, 42, 43, and 51 exist in the wireless zone of the base station 21, but the control station 1 performs control to shift the mobile stations 41, 42, and 43 to the secured communication channel. Similarly, the base station 22 performs control to shift to a communication channel in which only the mobile station 44 is secured.

(B) Procedure between a fixed station, a base station, and a mobile station Data transmission from a mobile station to a fixed station via a base station is performed using a retransmission procedure by polling control from the base station. For example, in the data communication started from the fixed station 31 to the mobile stations 41, 42, 43, and 44 having the group number “4”, three communication channels, ie, mobile stations, are used in the base station 21 for the group communication. Stations 41, 4
2, 43 exist. The base station 21 sets the “transmission instructor number” 41, 42, 43 shown in (d) of FIG. 2 to move the three mobile stations 41, 42, 43 in order to perform polling. I do.

When each of the mobile stations 41, 42, and 43 determines that its own number is set to "transmission instructor's letter", it transmits data at the transmission timing shown in FIG. At this time, information to be set in the control field is different depending on whether data that fits in one burst is transmitted or not. Therefore, when data that fits in one burst is transmitted, a bit having the meaning of one burst signal is included in the “control field”. When transmitting information that does not fit into one burst, a bit having a meaning of transmission start (corresponding to SABM in HDLC, which is general) is set in the "control field" and transmitted. "Control field"
The transmission start to be set to has the meaning of the retransmission procedure setting.

Each of the mobile stations 41, 42, and 43 continues to transmit data while being subjected to polling control from the base station 21, but a "control field" includes a modulo 2 sequence number and a bit having a meaning during data transmission. Set and send. At the end of data transmission, a sequence number of modulo 2 and a bit meaning the end of data transmission are set in the "control field" and transmitted.

In the base station 21, each mobile station 41, 42, 43
If the "control field" which is the information of the header part of the rising radio burst sent from
The retransmission procedure is set for the mobile station and polling is continuously performed. For example, referring to the sequence of FIG. 5, the mobile stations 41, 4 having the group number "4"
The polling of the base station 21 for the mobile stations 4
1 → 42 → 43 → 41 → 42... When the transmission start is received from the mobile station 42, “42” is set again in the “transmission instructor” of the downlink signal at the next timing, and the transmission is started. The polling is continuously performed to the mobile station 42 that has transmitted the. In the "control field" at that time, a transmission start response and a sequence number of a burst to be transmitted next are designated. The sequence number is a repetition number of modulo 2 such as 0 → 1 → 0 → 1 → 0.

Further, the base station 21 transmits a burst response to the signal from the mobile station 42 every time in order to protect the signal from being lost. If the signal from the mobile station 42 cannot be received, the base station 21 immediately transmits the burst response. The transmitted sequence number is set in the header portion, and the mobile station 42 is urged to retransmit.
If the response signal from the base station 21 has a sequence number different from the sequence number to be transmitted next, the mobile station 42 determines that the response signal has not been reached and retransmits the previously transmitted signal (burst).

Further, the base station 21 repeats the above-mentioned retransmission procedure until receiving the data transmission end from the mobile station 42, and performs control to prevent data loss. Thereafter, upon receiving the data transmission end from the mobile station 42, the mobile station 42 sends an end response at the next downstream timing, and
, And polls the mobile station 43 next from the next downstream timing. The base station 21 receives and assembles data from the mobile station 43 by polling control, adds the sender number to the data, and transmits the data to the fixed station as needed.

(C) Data transmission from the fixed station to the mobile station via the base station The fixed station specifies a destination and transmits data to the control station 1.
When receiving data from the fixed station, the control station 1 determines whether the signal is a data communication request or transmission data to the mobile station, and if it determines that the signal is transmission data, selects a base station to be transmitted according to a destination. I do. The destination is specified by group,
It can be set either individually. After selecting a base station to be transmitted, data is transmitted to the base station. At this time, when there are a plurality of the base stations, the control station 1 sends the same data to each of the plurality of base stations.

When the base station receives the data from the control station 1, the destination is set to the "destination number" shown in FIG. 2 (d), and the data is decomposed as shown in FIG. 4 (b). It is transmitted to the mobile station. The transmission procedure from the base station to the mobile station uses a continuous transmission method to reduce the frequency of data loss. Since some transmission data can be transmitted in one burst and some data can be transmitted over a plurality of bursts, the information on the point is referred to as a “disassembly / reassembly bit” (ARIB-S, which is a standard for automobile telephones).
(Corresponding to the one defined in TD-27), the data can be restored on the mobile station side. The "disassembly bit" is composed of information on the first, middle, and end of transmission data, a sequence number in a modulo format, and information on the current number of transmissions in the number of consecutive transmissions. When the mobile station determines that its own number is set in the “destination number” of the header part of the data received from the base station, the mobile station restores the data using the “disassembly bit” of the header part.

As described above, in this embodiment, the base station-initiated polling control method is used on the communication channel for the procedure of transferring uplink data from the mobile station to the base station, and the base station communicates with the mobile station. At the time of a call connection on the control channel, a transmission instruction is sequentially given to one or a plurality of mobile stations existing in the assigned channel. The mobile station specified by the “transmission commander number” in the header part of the downlink radio signal, if there is data to be transmitted, sets up a data link with the base station using the “control field”. After the setting, the data is transferred using the retransmission procedure. Then, the link is released when the data transmission is completed. When the base station finishes receiving data from a mobile station that has requested transmission, it gives a transmission instruction to the next mobile station.

The procedure for transferring downlink data from the base station to the mobile station is a continuous transmission method without depending on the retransmission procedure. The mobile station to be received is designated by the "destination number" so that the transmitted data can be assembled by the mobile station. The transmission is performed in such a manner that a "disassembly bit" in which the order of transmission and the like are described is attached. "Destination number"
The mobile station designated by (1) performs reception of the data portion and assembly after the reception. As the “destination number”, an individual mobile station number or a group number can be set, an individual mobile station number is set in data addressed to an individual mobile station, and a group number is set in data addressed to a group. When a group number is set in the “destination number”, the data communication is broadcast to the group.

As described above, the header portion is defined for each of the downlink radio signal and the uplink radio burst, and the uplink data transfer procedure and the downlink data transfer procedure are performed simultaneously and individually. And efficient data communication can be performed. Further, by using a continuous transmission method for downlink radio signals, data can be simultaneously transmitted to a plurality of receiving terminals.

[0026]

According to the present invention, a header section is provided at the head of an information section of a downlink radio signal transmitted from a base station to a mobile station in a time division manner, and an uplink transmitted from the mobile station to the base station in a time division manner. A header section is provided at the head of the information section of the wireless burst so that the base station can perform polling control on the mobile station while transmitting data, so that data is received from the mobile station requested to transmit. And efficient data communication can be realized. Further, by using the continuous transmission method as the downlink data transfer procedure, data can be simultaneously transmitted to a plurality of receiving terminals.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a structure of a wireless channel of the mobile communication system according to the embodiment.

FIG. 3 is a diagram showing a structure of a wireless channel of the mobile communication system according to the embodiment.

FIG. 4 is a diagram showing disassembly / assembly of data in a wireless section of the mobile communication system according to the embodiment.

FIG. 5 is a diagram showing a polling control sequence of the mobile communication system according to the embodiment.

[Explanation of symbols]

1 control station 21, 22, ..., 2n base station 31, 32 fixed station 41, 42, 43, 44, 51, 52, 53, 61 mobile station 50 public network

Claims (4)

(57) [Claims] 1. A mobile communication system for transmitting and receiving data to and from a plurality of mobile stations in a time-division manner by polling control of a base station, wherein the base station uses a confirmation-type data transfer procedure to specify a specific one of the mobile stations. While receiving data transmitted from the mobile station, the mobile station transmits data to at least one mobile station using an unconfirmed data transfer procedure, and the mobile station performs polling control from the base station. A mobile communication system for receiving data according to a non-confirmation type data transfer procedure transmitted simultaneously while receiving the data, and transmitting data according to a confirmation type data transfer procedure for polling control from the base station. . 2. A transmission instruction number indicating a mobile station that gives a transmission instruction to a downlink radio signal transmitted from the base station to the mobile station, and an error occurs in data transmitted from the mobile station on a radio line. Information, such as a control field for retransmitting the data, a destination number indicating a mobile station to receive data transmitted from the base station, and a data number necessary for assembling data transmitted from the base station. And a sender number indicating a mobile station number of the mobile station in an uplink radio burst signal transmitted from the mobile station to the base station, and a header transmitted from the mobile station. And a control field for retransmitting the data when an error occurs on the wireless line, and adding a header portion composed of a control field for transferring the uplink data from the mobile station to the base station. A transmission instruction is sequentially given to one or a plurality of mobile stations, and when data is transmitted from the mobile station specified by the transmission instructor number, after receiving the data, the next mobile station is transmitted to the next mobile station. In the transfer of downlink data from the base station to the mobile station, the base station specifies the mobile station to be received with the destination number, and the mobile station together with the specified destination number and the disassembly / reassembly bit. The mobile communication system according to claim 1, wherein 3. The mobile station specified by the transmission instructor number,
If there is data to be transmitted, after setting up a data link to the base station using the control field, perform data transfer using a retransmission procedure, and release the data link after data transfer is completed. The mobile communication system according to claim 1, wherein 4. The mobile communication system according to claim 1, wherein the base station uses a continuous transmission method as a downlink data transfer procedure to the mobile station.