JPH11341541A - Packet transfer method for mobile communication system, terminal base station used for mobile communication system, and mobile communication system - Google Patents

Abstract

(57) [Summary] [Problem] To enable highly reliable packet communication by receiving transmission packets from terminals at a plurality of base stations. A terminal for transmitting an uplink control packet requesting packet transmission to a base station of a communication partner, and a response packet defining transmission timing of a packet from the terminal in response to the uplink control packet. A base station of a communication partner to be transmitted, a second base station that secures a channel for a predetermined time to receive a transmission packet corresponding to the uplink control packet when receiving an uplink control packet addressed to the other station; A transmission packet transmitted from the terminal is received via the second base station at a timing corresponding to the response packet, and the transmission packets received from the first and second base stations have less transmission errors. And choose
A mobile communication system having a base station control station for transferring to a network.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet transfer method for a mobile communication system including a base station and a base control station, and more particularly, to a code division multiple access (CDMA).
The present invention relates to a packet transfer method of a mobile communication system of a reservation system to which an ion multiple access (ion multiple access) system is applied, a terminal base station used in the mobile communication system, and a mobile communication system.

[0002]

2. Description of the Related Art (1) As a reservation type packet system, a portable mobile communication terminal (hereinafter, terminal) transmits a reservation packet to a base station and receives a response packet from the base station, so that the terminal transmits to the base station. Japanese Patent Application Laid-Open No. 9-55693 discloses a technique for determining the timing and frequency of a transmission packet (hereinafter, time scheduling).

(2) As a high-speed handover method, in a region where a terminal can receive radio waves from a plurality of base stations, the terminal frequently measures the electric field strength received from the base station. The one that selects a strong base station and switches the partner base station at high speed is the '97 IEICE.
Communication Society Conference, Handover control procedure in DS-CDMA packet mobile communication, application of handover in DS-CDMA packet mobile communication ".

[0004]

In the above reservation type packet system, studies based on communication procedures and components at the time of handover are not sufficiently performed.

In the high-speed handover method, since communication is always performed with a single base station, a packet is received by a plurality of base stations, an error is detected, and a packet having no or few errors is transmitted. Impossible.

In a region where a terminal can receive radio waves from a plurality of base stations, when performing a packet mode communication method, the transmission probability of a transmission packet is improved by performing a soft handover between base stations. There is a need to.

An object of the present invention is to solve the above problems in the reservation type packet system and the high-speed handover system and to improve the establishment of transmitting a transmission packet, a packet transfer method of a mobile communication system, and a terminal base station used in the mobile communication system. And a mobile communication system.

[0008]

In order to achieve the above object, a transfer method according to the present invention comprises a plurality of base stations, a terminal capable of wirelessly communicating with any of the plurality of base stations, and A base station control station accommodating a plurality of base stations;
In a packet transfer method of a mobile communication system having a network connected to the base station control station, the terminal transmits an uplink control packet requesting that a base station of a communication partner perform packet transmission, The base station transmits a response packet in response to the uplink control packet, and the base station that is not the communication partner and receives the uplink control packet receives a transmission packet corresponding to the uplink control packet. In order to secure a channel for a certain period of time, the terminal transmits a transmission packet according to the contents of the response packet, and each of the plurality of base stations that have received the transmission packet transmits the received transmission to the base station control station. The base station control station, which has transferred the packet and received the transmission packet, determines whether the transmission packets from the plurality of base stations have transmission errors. Configured to forward to the network by selecting a less transmission packet.

Further, according to the transfer method of the present invention, a plurality of base stations, a terminal capable of communicating with any one of the plurality of base stations by radio, and a base accommodating the plurality of base stations are provided. In a packet transfer method of a mobile communication system having a station control station and a network connected to the base station control station, the terminal transmits an uplink control packet requesting to perform packet transmission to a communication partner base station. Each of the base stations receiving the uplink control packet transmits a response packet defining a timing at which the terminal should transmit a transmission packet in response to the uplink control packet, and responds to the response packet from the plurality of base stations. The terminal that has received the transmission packet according to the response packet received last, each of the plurality of base stations that have received the transmission packet, The received transmission packet is transferred to the base station control station, and the base station control station that has received the transmission packet selects a transmission packet with a small transmission error among the transmission packets from the plurality of base stations, and selects the transmission packet from the network. Was configured to be forwarded to

[0010] Further, the terminal of the present invention comprises a plurality of base stations,
A terminal capable of wirelessly communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a network connected to the base station control station In the terminal used in the mobile communication system, a means for creating an uplink control packet for a communication partner base station of the plurality of base stations,
Means for transmitting an uplink control packet, timing means for measuring time together with transmission of the uplink control packet, and receiving a response packet from the base station even if the time counted by the timing means is equal to or greater than a certain value. Control means for retransmitting the uplink control packet if not present, means for receiving a response packet transmitted from the base station in response to the uplink control packet and defining a timing at which a transmission packet should be transmitted, And control means for controlling transmission of a transmission packet in accordance with the response packet.

[0011] The base station of the present invention further comprises a plurality of base stations,
Mobile communication including a terminal capable of communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a network connected to the base station control station A control unit for allocating a channel for receiving a transmission packet transmitted from the terminal according to a response packet of another base station when the base station used in the system receives an uplink control packet not addressed to the terminal from the terminal; It was comprised so that it might have.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where a terminal has one receiver will be described below.

FIG. 1 shows a conceptual diagram of a communication network at the time of handover. FIG. 2 shows a communication procedure when the terminal has one receiver.

The terminal 101 always measures the control signal electric field strength from a nearby base station (step 250).

A terminal 101 is a base station 104 having a cell range 102
Base station 10 from the area where radio waves can be received only from
4 and when entering the area where radio waves can be received from the base station 105 having the cell range 103 (state 201), the terminal 101
Transmits an uplink control packet including a list of base stations as communication candidates to the base station 104 that is performing communication using the radio link 107 that has already been set, and reports the packet to the base station control station 106 (step 251).

FIG. 9 shows a configuration of an uplink control packet including a list of base stations that are communication candidates.

A preamble 901 for synchronous capture / following of a packet, a packet type 902 for discriminating a packet type, a terminal ID 903 for discriminating a terminal, and an electric field intensity measured at the terminal are not less than a certain value. Therefore, it is composed of a base station list 904 as a communication candidate and an error detection code CRC code 905.

The base station performs error detection using a CRC code.

The base station control station 106 communicates with the listed base station 1
04 and 105 are notified that terminal 101 will start handover processing (step 252). The terminal 101 also steps the electric field strength from the listed base stations 104 and 105.
Measurement is performed at a speed higher than 250 (step 253). This is because the field strengths from different listed base stations change frequently within the handover area. Thereby, the terminal is located in an area where the cell range 102 and the cell range 103 overlap, or the terminal is located in the cell range 102 or the cell range 103.
Can be detected with high accuracy, and it can be accurately determined whether the present invention is applied or normal communication is applied. In other words, it is possible to accurately determine whether or not a plurality of base stations should receive a transmission packet from a terminal.

The received electric field strength from the base station 104
(State 202), the terminal 101 transmits an uplink control packet including the ID of the base station 104 to the base station 104 using the wireless link 107 (step 254). At this time, the base station 105 also monitors the uplink control packet for the base station 104 to which the terminal is connected (step 254 '). Here, monitoring refers to an operation in which the base station 105 receives an uplink control packet transmitted from the terminal 101 by a vacant receiver. Therefore, if a receiver for receiving the uplink control packet cannot be secured when receiving the uplink control packet for communication with another terminal, the monitoring operation is not performed.

FIG. 10 shows the structure of an uplink control packet including the ID of the connection destination base station 104.

This uplink control packet is used to reserve a receiver for a base station, which is a communication partner, for transmitting a packet, and to control the terminal to notify the transmission timing at which the terminal transmits the packet from the base station. Packet. The uplink control packet includes a preamble 1001 for capturing and following the synchronization between the terminal and the base station, and a packet type 100
2. It is composed of a terminal ID 1003, which is information for specifying a terminal, a base station ID 1004 indicating a base station of a connection destination, and a CRC code 1005 for correcting a transmission error of a transmission packet.

Next, terminal 101 transmits an uplink control packet to base station 104 (step 255).

FIG. 11 shows the structure of this uplink control packet.

This uplink control packet also reserves a receiver for a base station which is a communication partner in order to transmit a packet, and is used for controlling the base station to notify a transmission timing at which a terminal transmits a packet. Packet. This uplink control packet is obtained by adding the number of transmission packets (number of time slots) 1104 to be reserved to the one shown in FIG.

The base station 104 that has received the uplink control packet shown in FIG. 11 performs channel assignment and transmits a response packet to the terminal 101 (step 256). Terminal 101 receives this response packet and transmits a transmission packet according to the scheduling of base station 104 (step 257). Base station 1
04 transfers the received transmission packet to the base station control station 106 (step 258).

[0027] Also, the base station 10
Base station 105 having a lower control signal electric field strength as compared to 4 monitors the uplink control packet from terminal 101 shown in FIG. 11 (step 259). Here, monitoring refers to an operation in which the base station 105 receives an uplink control packet transmitted from the terminal 101 by a vacant receiver. Therefore, if a receiver for receiving the uplink control packet cannot be secured when receiving the uplink control packet for communication with another terminal, the monitoring operation is not performed.

When terminal 101 transmits an uplink control packet and base station 105 receives it (when the receiver is vacant), base station 105 uses a channel to receive a transmission packet from terminal 101. The mobile station makes an assignment, receives a transmission packet transmitted from the terminal 101 in accordance with the scheduling of the base station 104 (step 260), and transfers the received transmission packet to the base station control station 106 (step 26).
1).

The base station control station 106 selects one of the transmission packets transferred in step 258 or step 261 and transmits it to the network side (step 262). C at base station
Error detection is performed by the RC code, and the base station control station 106
Then, transmission packets from the base station 104 and the base station 105 are received, and a packet having few errors is selected and error correction is performed. The error-corrected transmission packet is transferred to the public network 107.

By using this method, only when the receiver of the base station monitoring the uplink control packet is idle, transmission errors can be reduced as compared with the case where a transmission packet is transferred from one base station 104. Can be reduced.

FIG. 15 shows a time schedule of a terminal and a base station from transmission of an uplink control packet to transmission of a transmission packet in this communication procedure.

The terminal 101 transmits the uplink control packet shown in FIG.
01 is set in the timer, and if the response packet from the base station 104 is not received by the
01 is to transmit the uplink control packet shown in FIG. 11 to the base station 104 again. Also, base stations 104 and 105
Is the timeout period 15 after receiving the uplink control packet shown in FIG. 11 in steps 255 and 259.
02 and 1503 are set in the respective timers. If a transmission packet is not received by each base station even after the time has elapsed, channel assignment is released and no transmission packet is received.

In the case of FIG. 2, there may be a means for omitting the process of transmitting the uplink control packet including the ID of the base station 104 to which the terminal 101 is connected to the base station 104 (step 254). As shown in FIG. 12 and FIG.
It is necessary to include the connection destination base station IDs 1201 and 1301 in the uplink control packet transmitted in 1451 and step 1455. In this way, the uplink control packets shown in FIGS. 12 and 13 play roles corresponding to FIGS. 9 and 11, respectively.

FIG. 5 shows a schematic configuration of the terminal 101. The terminal includes an antenna 500, a CDMA transceiver 510 connected to the antenna 500, and a packet controller 5 connected to the CDMA transceiver.
30 and the data processing device 5 connected to the packet control unit 530
05 and.

The data processing device 505 includes a microprocessor (MPU) 501, a memory 502 for storing data and programs, and a plurality of input / output devices connected to an internal bus via an I / O interface 503. . As the input / output device, there is usually an operation panel for designating the telephone number of the other party.
b, a display 504c, a keyboard 504d, and the like can be added.

FIG. 6 shows a detailed configuration of CDMA transmitting / receiving section 510 of the terminal.

Reference numerals 612 and 613 denote wireless modules for performing modulation / demodulation of a baseband signal and reception / transmission processing at a high / intermediate frequency. In the transmission circuit, in each of the uplink control channel and the transmission channel, the encoding circuits 620a and 620b perform error correction encoding of the transmission packet, and then perform the PN generator 62
The transmission packets are spread by multipliers 614a and 614b using the PN sequence unique to each channel generated by 1a and 621b, and sent to the wireless module for transmission 613. At this time, spreading processing in the transmission channel is performed in synchronization with the reference timing 605c generated from the PN generator 619.

On the other hand, in the receiving circuit, the received signal output from the receiving wireless module 612 is input to the multiplier 614c,
The spectrum is despread using the PN code unique to the base station generated by N generator 619. The output of the multiplier 614c is input to multipliers 614d, 614e, and 614f provided corresponding to the response channel, the transmission channel, and the pilot channel.
Each channel generated in 7 is despread by a unique orthogonal code.

In the response channel, the signal despread with the orthogonal code is input to the decoding circuit 616d via the accumulator 615d.
FIG. 5 shows the decoded signal of the error correction via a signal line 605d.
To the packet control unit 530.

In the pilot channel, the signal despread by the orthogonal code is subjected to a DLL (Delayed Locked) through an accumulator 615f.
(Loop) input to the circuit 618 for simultaneous tracking. The PN generator 619 generates a PN sequence in synchronization with the output of the DLL circuit 618. Further, the decoding circuits 616d and 616e are provided with an accumulator 615f.
To operate in synchronization with the pilot signal output from

The received signal output from the receiving radio module 612 is input to a multiplier 614c ', and the spectrum is despread using a PN code unique to the base station generated by a PN generator 622. The output of the multiplier 614c 'is a multiplier 614 provided for the response channel, the transmission channel, and the pilot channel.
The signals are input to d ', 614e', and 614f 'and despread by an orthogonal code unique to each channel generated by an orthogonal code generator 617'.

In the response channel, the signal despread by the orthogonal code is input to the decoding circuit 616d 'via the accumulator 615d', and the error-corrected decoded signal is input via the signal line 605d '. The packet is transferred to the packet control unit 530 of FIG.

In the pilot channel, the signal despread by the orthogonal code is transferred to a DLL (Delayed Locked) via an accumulator 615f '.
d Loop) input to the circuit 618 for simultaneous tracking. The PN generator 622 generates a PN sequence in synchronization with the output of the DLL circuit 618. Further, the decoding circuits 616d 'and 616e'
Operate in synchronization with the pilot signal output from 5f.

In the transmission channel, the signal despread by the orthogonal code is input to a decoding circuit 616e via an accumulator 615e, and is decoded for error correction, and is decoded via an accumulator 615e '. The signal is combined with the signal input to the circuit 616e ', and the decoded signal of the error correction is transferred to the packet control unit 530 in FIG. 5 via the signal line 605e.

Further, the received signal output from receiving radio module 612 is input to multiplier 624, and spectrum despreading is performed using a PN code unique to the base station generated by PN generator 629. This PN generator is controlled by a code switching signal 627. The output of the multiplier 624 measures the electric field intensity of the control signal in the electric field intensity measuring device 626 of the control signal via the accumulator 625, and outputs the control signal 623 to the packet control unit 530 in FIG.
Transfer to

FIG. 16 shows an example of the configuration of the packet control unit 530 of the mobile terminal.

The decoded data of the response channel is decoded by the monitoring routine 1602 of the digital signal processing device DSP1601, and the contents of the response packet are divided into an uplink schedule control routine 1604 and a downlink schedule control routine 16.
The busy tone signal provided at 05 and received on the response channel is provided to a busy tone calculation routine 1603.

The packet reception processing circuit 1606 in the downlink transmission channel performs the downlink schedule control routine 16
05 and the reference timing signal 605c. The transmission data is temporarily stored in the transmission buffer 1608, is input to the transmission packet structure creation circuit 1609 according to the control signal from the uplink schedule control routine 1604, and the data packet is transmitted to the transmission channel. The uplink schedule control routine 1604 generates a transmission channel designation signal 606b for transmitting a transmission packet according to the content of the response packet, and activates the transmission packet structure creation circuit 1609 at the timing of the time slot designated by the base station. . The PN generator 621b generates a PN code of the channel specified by the transmission channel specifying signal 606b.

A busy tone value calculation routine 1603
Calculates the busy tone value from the busy tone signal received on the response channel, and notifies the uplink schedule control routine 1604 of the traffic status report. The uplink schedule control routine 1604 controls the generation of uplink control packets according to the traffic situation, and when there is transmission data in the transmission buffer and there is no instruction to suppress the uplink control packets from the base station, the uplink schedule control routine 1604 It activates the control packet 1607 and instructs transmission of an uplink control packet. The transmission processing of the transmission packet is also performed at the reference timing 16
This is performed in a time slot synchronized with 05c.

Based on a control signal from the base station search control device 1610, the handover start determination device 1611 makes a handover start determination, and the connection destination base station determination device 1612 determines a connection destination base station. Further, based on this information, a transmission packet is created in the uplink control packet structure creation device 1609, and the same packet is transmitted through the transmission channel 1606b. At this time, the measurement of the electric field strength of the control signal in the handover start determination and the determination of the connection base station is performed in a time-division manner using the same receiver.

FIG. 7 shows a schematic configuration of base stations 104 and 105. The base station includes an antenna 701, a CDMA transmitting / receiving unit 702, a packet control unit 703, and a base station control station interface 704 connected to the base station control device 106 interposed between the base station and the mobile communication network.

FIG. 8 shows a detailed configuration of CDMA transmitting / receiving section 702 of the base station. Reference numerals 802 and 803 denote wireless modules for reception and transmission, respectively, which perform modulation / demodulation of a baseband signal and transmission / reception processing at a high / intermediate frequency. The response control packet transmitted by the base station is input to the encoding circuit 805a via the response channel signal line 804a. For example, after performing encoding for error correction using a convolutional code or the like, the spectrum is spread by the orthogonal code for the response channel output from the orthogonal code generator 807 in the multiplier 806a.
Is input to Similarly, the transmission data output to the plurality of signal lines 804b corresponding to the transmission channel is encoded by the encoding circuit 80.
After being coded by 5b, the spectrum is spread by an orthogonal code corresponding to each transmission channel in a multiplier 806b, and then supplied to an adder 808. The pilot signal '1' is also coded by the coding circuit 805c, and is spectrally spread by the multiplier 806c with the orthogonal code unique to the pilot channel.
808. The reference timing signal output on signal line 804c is supplied to orthogonal encoder 807 and PN generator 809a. The output of the adder 808 is output to the
The spectrum is spread by a PN (long code) unique to each base station output from the generator 809a, and then supplied to the transmission radio module 803.

On the other hand, the signal received and processed by the wireless module 802 for reception includes a matched filter 810a for the uplink control channel and a plurality of matched filters for the transmission channel.
810b to 810b '. The received packet of the uplink control channel is subjected to despreading processing of the received signal by the matched filter 810a using the PN unique to the uplink control channel, and the packet separation circuit 811 separates packets having a temporal overlap from each other, thereby performing reception processing. Is done.

In this case, if the period of the PN sequence applied to the despreading is set equal to the number of taps of the matched filter, the output of the matched filter becomes the result of the despreading process, so that high-speed synchronization is possible. The uplink control packets separated from each other are supplied to the packet control unit 703 shown in FIG. 7 after the decoding circuit 812a performs decoding processing with error correction such as Viterbi decoding.

The received signal of the transmission channel is subjected to the first synchronous acquisition in the matched filters 810b to 810b ', and thereafter, the PN generator 80 starts from the acquired timing.
9b to 809b ', a PN sequence corresponding to each channel is generated.
Despreading is performed by multiplying by the PN sequence corresponding to each channel generated from b to 809b ′, and accumulators 814 to 8
At 14 ′, the result of despreading for one symbol is accumulated, and the accumulated result is transmitted to the packet control unit shown in FIG. 7 via decoding circuits 812b to 812b ′.
Supply 703.

FIG. 18 shows the packet control units of the base stations 104 and 105.
703 shows a detailed configuration. The packet control unit 703 has a digital signal processing device DSP1801, and the reception data of the uplink control channel (contents of the uplink control packet) is decrypted by the decryption routine 1802 of the DSP 1801, and then by the uplink schedule control routine 1803, Assignment processing (scheduling) of a transmission channel and a time slot is performed. By transmitting the transmission channel and the time slot determined by the uplink schedule control routine 1803 to the response packet generation circuit 1807, and generating the response packet generation circuit 1807 and transmitting the response packet addressed to each terminal through the response channel, each mobile terminal It is possible to make the uplink transmission packet from the base station to the base station according to the scheduling of the base station. Also, the uplink schedule control device 18
03 to PN generator 8
09b to 809b 'and matched filters 810b to 810b'.

Data received from each transmission channel is input to reception processing circuits 1806b to 1806b 'provided for each transmission channel via signal lines 815b to 815b', and is transmitted as a data packet to the base station controller shown in FIG. Transferred to the station interface 704. On the other hand, the downstream data packets are temporarily stored in the transmission buffers 1809a and 1809b, and then subjected to transmission control according to the schedule performed by the downstream schedule control routine 1805 of the DSP. That is, according to the downlink schedule, the response packet created by the response packet structure creation circuit 1807 is first transmitted from the response channel, and then
In a predetermined time slot of the transmission channel determined by the downlink schedule, the transmission packet structure creation circuit 1808a
The data packet generated in ~ 1808a 'is transmitted. In addition,
In the present embodiment, in order to suppress the issue of uplink control packets from the mobile terminal when the transmission channel is busy, the number of uplink control packets received on the uplink control channel and the uplink schedule control routine 1803 Depending on the transmission channel usage state information that is
A busy tone value routine 1804 generates busy tone information, and notifies this to each mobile terminal on the response channel 804a.

The terminal 101 measures the electric field strength of the control signal from the neighboring base station using the electric field strength measuring device 616d ', and when it enters the area where the radio waves of the base stations 104 and 105 can be received, A control signal is transmitted from the station search control device 1610 to the handover start determination device 1611. In addition, in order to determine a connection destination base station in this area, a field strength measurement device is used.
Using 616d ', the electric field strength of the control signals from base stations 104 and 105 is measured at high speed, and the control signal is transmitted from base station search control device 1610 to connected base station device 1612.

The above-mentioned electric field intensity measurement is performed in a time-division manner using the same receiver. The signals from the handover determination start device 1611 and the connection destination base station 1612 are transmitted to the uplink control packet structure creation device 1607, and transmit the uplink control packet using the uplink control channel 606a. Also,
The terminal 101 receives a response packet using the response channel monitoring standby / connection device 1602 using the response channel 605d, calculates a busy tone value from the busy tone signal received on the response channel using the busy tone value calculation device 1603, and calculates traffic information. Notify the uplink schedule control routine 1604.

Upstream schedule control routine 1604
Controls the generation of uplink control packets according to the traffic situation, and when there is transmission data in the transmission buffer 1608,
If there is no instruction to suppress the uplink control packet from the base station, the uplink control packet structure creation circuit 1607 is activated at an arbitrary timing to instruct the transmission of the uplink control packet. The transmission processing of the transmission packet is also performed in a time slot synchronized with the reference timing 605c.

The base station receives a list of base stations as communication candidates using the uplink control channel and transmits the list to the base station control station via the handover control device 1810. In addition, a signal notifying the start of the handover process received from the base station control station is transmitted to the uplink schedule control device via the handover control device 1810.

According to the uplink control signal from the uplink control channel, in the base station, the uplink control packet device 1802 decodes the uplink packet, and the uplink schedule control device 1803
Are assigned to control signals 818b to 818b ′.
And matched filters 810b to 810b ′ and PN generator 809
Channel assignment control signals 818b to 818b 'are transmitted to b to 809b'. Also, the busy tone value calculation device 1804 calculates the busy tone of the uplink control channel, the response packet structure creation device 1807 creates a response packet, and transmits the response packet using the response channel 804a. Next, the transmission packets received by the transmission channel receivers 1806b to 1806b 'are transmitted to the base station control station 106 using the transmission channels 815b to 815b'.

In the base station control station 106, the handover control unit 1901 receives the list of base stations that are communication candidates and transmits the start of the handover process to the base stations in the handover area. Further, the transmission packet received from the base station is transmitted to the selection / combination device 1903 via the switch 1902, and further the error correction is performed in the codec device 1904, and the transmission packet is transmitted to the fixed network.

When the Terminal Owns Two Receivers FIG. 3 shows a communication procedure when the terminal owns two receivers. Using the conceptual diagram of FIG. 1 and the communication procedure of FIG. 3, a description will be given of an implementation means when the terminal has two receivers. Terminal 1
The configuration of 01 can be realized by a configuration in which a receiver for receiving a response channel is further added to the configuration shown in FIGS. 6 and 7, and the configurations of the base stations 104 and 105 are the same as the configurations shown in FIGS. It can be realized with the same configuration.

The terminal 101 always measures the electric field strength of a control signal from a neighboring base station (step 350).

Terminal 101 is a base station 104 having a cell range 102
Base station 10 from the area where radio waves can be received only from
4 and when entering an area where radio waves can be received from the base station 105 having the cell range 103 (state 301), the terminal 101
Transmits an uplink control packet shown in FIG. 9 including a list of base stations that are communication candidates to the base station 104 that is currently communicating using the radio link 107, and reports it to the base station control station 106 (step 351). ).

The base station control station 106 controls the listed base station 1
04 and 105 are notified that terminal 101 starts the handover process (step 352). Further, terminal 101 measures the electric field strength of the control signals from the listed base stations 104 and 105 faster than in step 350 (step 353).
The uplink control packets shown in FIG. 10 are individually transmitted to the two base stations 104 and 105 having a strong electric field strength (step 35).
4), receive response packets from each base station (step 355).

The terminal 101 transmits the transmission packet to the base stations 104 and 105 in accordance with the individual scheduling, and each base station transmits the received transmission packet to the base station control station 10.
Transfer to 6 (step 356).

At this time, as shown in FIG. 17, after the terminal 101 transmits the uplink control packet shown in FIG. 11 in step 354, a time-out time 1701 is provided, and the response packet is not received by the terminal 101 even if the time exceeds this time. If
Terminal 101 transmits again the uplink control packet shown in FIG. 11 to base station 104, and if at least one response packet is received by terminal 101, terminal 101 transmits the transmission packet to the base station that is the source of the response packet. Shall be transmitted. Base station
104 and 105, after receiving the uplink control packet shown in FIG. 11 in step 354, provide timeout periods 1702 and 1703, and if the transmission packet is not received at the base station beyond this time, release the channel assignment It is assumed that no transmission packet is received.

The base station control station 106 selects one of the transmission packets transferred in step 356 and transmits it to the network side (step 357). The base station performs error detection using a CRC code, and the base station control station 106 receives transmission packets from the base station 104 and the base station 105, selects a packet with a small number of errors, and performs error correction. The error-corrected transmission packet is transferred to the public network 107.

By using this method, the base station can
By receiving transmission packets with different time scheduling by one receiver, it becomes possible for the base station control station to transmit the transmission packets received by any of the base stations.

In the communication system shown in FIGS.
An example is considered in which the uplink control packet shown in FIG. 11 is transmitted to one or more base stations that are communication candidates.

Referring to FIG. 4, another example of a communication procedure using a terminal having two receivers will be described.

This is a method in which the terminal 101 receives a response packet first and transmits the scheduled transmission packet in accordance with the response packet finally received and the transmission packet scheduled. At this time, as shown in FIG. 16, after the terminal 101 transmits the uplink control packet shown in FIG. 11 in step 354, a time-out time 1601 is provided. 101 again shows the base station 104
If the terminal 101 transmits the uplink control packet shown in FIG. 11 and at least one response packet is received by the terminal 101, the terminal 101 transmits a transmission packet to the base station that has transmitted the response packet. In addition, the base stations 104 and 105 provide timeout periods 1602 and 1603 after receiving the uplink control packet shown in FIG. 11 in step 354, and if a transmission packet is not received by the base station even after the timeout period, channel allocation is performed. To cancel the transmission packet.

The base station control station 106 selects one of the transmission packets transferred in step 451 and transmits it to the network side (step 452). The base station performs error detection using a CRC code, and the base station control station 106 receives transmission packets from the base station 104 and the base station 105, selects a packet with a small number of errors, and performs error correction. The error-corrected transmission packet is transferred to the public network 107. By using this method, the transmission packets are received by the receivers of the two base stations, so that the base station control station 106 can transmit the transmission packets with no or little error rate.

[0076]

According to one embodiment of the present invention, when performing packet mode communication by CDMA, a terminal transmits a transmission packet to a plurality of base stations using a reservation type packet mode communication at the time of handover. This makes it possible to transmit information to be transmitted more reliably and at higher speed.

According to an embodiment of the present invention, when a terminal is located in an area where communication with a plurality of base stations is possible, the transfer method of the present invention, that is, a plurality of base stations receive transmission packets from the terminal. Or whether one base station receives a transmission packet from a terminal can be switched with high accuracy.

Further, according to one embodiment of the present invention, transmission packets are transmitted in accordance with response packets from a plurality of base stations, so that it is possible to transmit information to be transmitted more reliably and at higher speed.

Further, according to the embodiment of the present invention, even when a response packet cannot be received, it is possible to prevent the terminal from operating for a long time.

Further, according to the embodiment of the present invention, when a transmission packet cannot be received, the channel is not wastefully occupied for a long time.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a communication network at the time of handover.

FIG. 2 is a diagram showing a communication procedure when a terminal owns one receiver.

FIG. 3 is a diagram showing a communication procedure when the terminal has two receivers.

FIG. 4 is a diagram showing another communication procedure when the terminal has two receivers.

FIG. 5 is a configuration diagram of a terminal 101.

FIG. 6 is a diagram showing a detailed configuration of a CDMA transmitting / receiving section 510 of the terminal 101.

FIG. 7 is a configuration diagram of base stations 104 and 105.

FIG. 8 is a detailed configuration diagram of a CDMA transmitting / receiving section 702 of the base station.

FIG. 9 is a configuration diagram of an uplink control packet including a list of base stations serving as communication candidates.

FIG. 10 is a configuration diagram of an uplink control packet including an ID of a connection destination base station.

FIG. 11 is a configuration diagram of an uplink control packet.

FIG. 12 is a diagram showing a control packet including a base station list and a base station ID of a communication partner.

FIG. 13 is a diagram showing a control packet including a connection destination base station ID.

FIG. 14 is a diagram showing a communication procedure when the terminal owns one receiver.

FIG. 15 is a diagram showing a time schedule of a terminal and a base station in the communication procedure of FIG. 2;

FIG. 16 is a diagram illustrating an example of a configuration of a packet control unit 703 of a mobile terminal.

FIG. 17 is a diagram showing a time schedule of a terminal and a base station in the communication procedure of FIGS.

FIG. 18 shows a packet control unit 70 of the base stations 104 and 105.
3 is a detailed configuration diagram of FIG.

FIG. 19 is a configuration diagram of a base station control station.

[Explanation of symbols]

 101 terminal 104 base station 105 base station 106 base station control station 107 public network 500 antenna 510 CDMA transmitting / receiving section 530 packet control section 505 data processing device 701 antenna 702 CDMA transmitting / receiving section 703 packet control section 704 base station control station interface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Yano 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kazutoshi Higuchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Hitachi Multimedia System Development Division

Claims (19)

[Claims] 1. A plurality of base stations, a terminal capable of wirelessly communicating with any of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station control station. In the packet transfer method for a mobile communication system having a connected network, the terminal transmits an uplink control packet requesting a base station of a communication partner to perform packet transmission, and the base station of the communication partner includes the uplink. In response to the control packet, a response packet is transmitted, and the base station which is not the communication partner and has received the uplink control packet sets a channel to receive a transmission packet corresponding to the uplink control packet. Securing time, the terminal transmits a transmission packet according to the content of the response packet, and each of the plurality of base stations receiving the transmission packet, Transferring the received transmission packet to the base station control station, and receiving the transmission packet, the base station control station selects a transmission packet with a small transmission error among the transmission packets from the plurality of base stations, and selects the transmission packet. A packet transfer method for a mobile communication system, comprising: 2. The packet transfer method for a mobile communication system according to claim 1, wherein the uplink control packet is a preamble for acquiring or following a synchronization with a base station as a communication partner, and information for specifying a terminal. A packet transfer method for a mobile communication system, comprising: a transmission packet number indicating a packet number to be transmitted; and information for error correction of the transmission packet. 3. The packet transfer method for a mobile communication system according to claim 1, wherein the response packet defines a timing at which the terminal should transmit the packet. A packet transfer method for a mobile communication system. 4. The control method according to claim 1, wherein when the terminal receives a control signal having a field strength of a predetermined value or more from a plurality of base stations, the control signal has a field strength of a certain value or more. Characterized in that the measurement of the electric field strength is performed at a higher speed than in the case of receiving from a single base station. 5. A plurality of base stations, a terminal capable of wirelessly communicating with any one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station. In a packet transfer method for a mobile communication system having a network connected to a station control station, the terminal includes:
An uplink control packet requesting that a packet be transmitted to a communication partner base station is transmitted, and each of the base stations receiving the uplink control packet transmits a response packet defining a timing at which the terminal should transmit a transmission packet. And
The terminal that has received the response packets from the plurality of base stations transmits a transmission packet according to the respective response packets, and each of the plurality of base stations that has received the transmission packet receives the response packet from the base station control station. A packet transfer method for a mobile communication system, comprising: transmitting a transmission packet; and receiving the transmission packet, a base station control station selects the transmission packet with a small transmission error and transfers the transmission packet to the network. 6. A plurality of base stations, a terminal capable of communicating with any one of the plurality of base stations by radio, a base station control station accommodating the plurality of base stations, and a base station. In a packet transfer method for a mobile communication system having a network connected to a station control station, the terminal includes:
A base station of the communication partner transmits an uplink control packet requesting transmission of a packet, and the base station receiving the uplink control packet transmits a transmission packet in response to the uplink control packet. The terminal that has transmitted the response packet defining the timing to be transmitted, and has received the response packets from the plurality of base stations, transmits a transmission packet in accordance with the last received response packet, and transmits the transmission packet according to the plurality of base stations that have received the transmission packet. Each transfers the received transmission packet to the base station control station, and the base station control station that has received the transmission packet selects a transmission packet with a small transmission error among the transmission packets from the plurality of base stations. A packet transfer method for a mobile communication system. 7. The packet transfer method for a mobile communication system according to claim 1, wherein said terminal comprises:
A packet transfer method for a mobile communication system, comprising: transmitting the uplink control packet, starting time measurement, and retransmitting the uplink control packet when no response packet is received from any of the base stations within a predetermined time. . 8. The packet transfer method for a mobile communication system according to claim 7, wherein the base station receiving the uplink control packet receives the uplink control packet, starts time measurement, and starts the time measurement within a predetermined time. A packet transfer method for a mobile communication system, characterized in that when a transmission packet is not received from a terminal, a channel for receiving the transmission packet is released. 9. A terminal for transmitting an uplink control packet requesting to perform packet transmission, and a first packet for transmitting a response packet defining transmission timing of a packet from the terminal in response to the uplink control packet. A base station and a second base station that does not transmit the response packet and that secures a channel for a certain period of time to receive a transmission packet corresponding to the uplink control packet upon receiving the uplink control packet; Via the first and second base stations, a transmission packet transmitted from the terminal is received at a timing corresponding to the response packet, and among the transmission packets received from the first and second base stations, A mobile communication system, comprising: a base station control station that selects one with a smaller transmission error and transfers it to a network. 10. A plurality of base stations, a terminal capable of wirelessly communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station. In the terminal used in the mobile communication system having a network connected to the station control station,
For the base station of the communication partner among the plurality of base stations, a means for creating an uplink control packet and a timing for transmitting a transmission packet transmitted from the base station in response to the uplink control packet are specified. A terminal for receiving a response packet; and a control unit for controlling transmission of a transmission packet in accordance with the response packet. 11. The terminal according to claim 10, wherein a timer means for measuring time together with the transmission of the uplink control packet, and the terminal receives the response packet even if the time counted by the timer means becomes a predetermined value or more. If not, the terminal retransmits the uplink control packet. 12. The terminal according to claim 10, wherein said terminal has a plurality of receivers, and when said response packet is received from a plurality of base stations, each of said plurality of response packets is specified. A terminal for transmitting a transmission packet in accordance with a timing to be transmitted. 13. The terminal according to claim 10, wherein the terminal has a plurality of receivers, and when the response packet is received from a plurality of base stations, the terminal includes a last one of the plurality of received response packets. A terminal that transmits a transmission packet in accordance with timing specified in a response packet received by the terminal. 14. A terminal according to claim 13, wherein said terminal has means for transmitting an uplink control packet and timing time, and said response packet received within a predetermined time by said time measuring means. A terminal that sets a response packet received last at the last as the last response packet. 15. A plurality of base stations, a terminal capable of wirelessly communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station. In the terminal used in the mobile communication system having a network connected to the station control station,
The terminal measures an electric field strength of a control signal from a plurality of base stations at a first speed during communication with a specific base station that is one of the plurality of base stations, and the first speed Means for measuring the control signals from the plurality of base stations at a second speed faster than the first speed when it is determined that the electric field strengths of the control signals from the plurality of base stations are greater than or equal to a certain value during the measurement. Means for transmitting a list of a plurality of base stations whose electric field strength of the control signal is equal to or greater than a certain value to the base station control station via the specific base station; and Means for determining a station, means for creating an uplink control packet for transmitting a transmission packet to the base station determined by the means for determining the connection destination base station, and means for creating the uplink control packet Send generated uplink control packet Means for transmitting, in response to the uplink control packet from the determined base station, a timing for transmitting a transmission packet, receiving a response packet, and transmitting the transmission packet according to the response packet. A terminal used in a mobile communication system, comprising: 16. A plurality of base stations, a terminal capable of communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station control station. In the base station used in the mobile communication system having a network connected to the station, when receiving an uplink control packet not addressed to the own station from the terminal,
A base station comprising control means for allocating a channel for receiving a transmission packet transmitted from the terminal according to a response packet of another base station. 17. The base station according to claim 16, further comprising means for transferring a transmission packet received from the terminal through the allocated channel to a base station control station. 18. The base station according to claim 16, wherein, after receiving said uplink control packet, said assigned channel is released when no transmission packet is received for a predetermined time. 19. A plurality of base stations, a terminal capable of communicating with at least one of the plurality of base stations, a base station control station accommodating the plurality of base stations, and a base station control station. In the base station used in the mobile communication system having a network connected to a station, when receiving an uplink control packet not addressed to the own station from the terminal, means for creating a response packet of the own station, Transmitting means for transmitting a response packet to the terminal, receiving means for receiving a transmission packet transmitted from the terminal according to the response packet of the own station, and transmitting the transmission packet received by the receiving means to the base station control station A base station characterized in that: