JPH0847045A - Digital radio communication system - Google Patents

Abstract

PURPOSE:To avoid a data error in the transmission reception of packet data via a relay station. CONSTITUTION:A mobile terminal equipment sets a frequency channel to 1 to enter a reception standby state in the step S101 and then checks whether or not a data transmission request to the mobile terminal equipment is in existence (step S102). When the absence of the data transmission request is discriminated, the processing by the step S102 continues till the data transmission request comes. When the data transmission request comes, the processing enters the subroutine and a relay station makes discrimination as to whether or not packet data from a sender terminal equipment have an error. When any error is detected, the relay station makes re-transmission request to the sender side mobile terminal equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital wireless communication system composed of mobile terminals that transmit and receive data in packet units.

[0002]

2. Description of the Related Art Conventionally, in an evenly distributed wireless digital communication system using a low-speed frequency hopping method in which data is transmitted and received in packet units and a frequency channel used is changed from a plurality of frequency channels, one mobile terminal is different from another. When performing packet data transmission to the mobile terminal, the transmission mobile terminal transmits transmission request data to the destination mobile terminal on the control frequency channel. The destination terminal receiving this transmission request data transmits the reception permission data to the transmitting mobile terminal in the same control frequency channel. Then, when the transmission mobile terminal receives the reception permission data, it sends the packet data to the destination mobile terminal.

If the transmitting mobile terminal cannot receive the reception permission data due to some trouble, the transmitting mobile terminal transmits the packet data via the relay station. Also in the transmission of the packet data via the relay station, the transmitting mobile terminal transmits the transmission request data to the relay station on the frequency channel for controlling the relay station. The relay station receiving this transmission request data transmits the transmission request data to the destination mobile terminal on the frequency channel for controlling the mobile terminal.

When the destination mobile terminal receives the transmission request data, it transmits the reception permission data to the relay station through the control channel of the relay station, and the relay station receiving the data transmits the reception permission data to the control frequency channel of the mobile terminal. The reception permission data is sent to the transmitting mobile terminal by. The transmitting mobile terminal receiving the reception permission data transmits packet data to the relay station on the designated frequency channel, and the relay station receiving this data sends the packet data to the destination mobile terminal on the designated frequency channel. I am trying.

[0005]

However, even in the evenly distributed wireless digital communication system using the low-speed frequency hopping method, when transmitting packet data from one mobile terminal to another mobile terminal, the transmitting mobile terminal is
I could not receive the reception permission data directly from the destination mobile terminal,
When transmitting packet data via the relay station, the destination mobile terminal, as a relay station, temporarily stores the received packet data and then transmits the packet data via the station having the function of transmitting the accumulated packet data. Therefore, there is a problem in that more data errors occur than when data is sent directly from the mobile terminal on the sending side.

When the transmitting mobile terminal cannot directly receive the reception permission data from the destination mobile terminal and transmits the packet data through the relay station, the relay station receives the radio wave when receiving the transmission data. Since the received data is transmitted at the level, if the received radio wave level at the relay station is low, the transmission level will also be low, and the destination mobile terminal will not experience data error as compared to the case of receiving the data directly from the sending mobile terminal. There is a problem of frequent occurrence.

The present invention has been made in view of the above problems, and an object thereof is digital radio communication capable of avoiding a data error when transmitting / receiving packet data between mobile terminals via a relay station. It is to provide a system.

[0008]

[Means for Solving the Problems] and

In order to achieve the above object, the invention according to claim 1 is composed of a plurality of wireless terminals for transmitting and receiving data on a plurality of frequency channels, and relays communication between the plurality of wireless terminals. In a digital wireless communication system including a relay unit, a first determination unit that determines whether or not there is an error in data sent from the first wireless terminal to the relay unit among the plurality of wireless terminals, When the first determination means determines that the data has an error, it is determined that the relay means issues a retransmission request for the data to the first wireless terminal, and the data has no error. In the case of, the means for accumulating the data in the relay means, the means for transmitting the accumulated data to a second wireless terminal among the plurality of wireless terminals, and the means for transmitting the data to the second wireless terminal. Data is incorrect Second judging means for judging whether or not there is, and when the second judging means judges that the data has an error, the second wireless terminal retransmits the data to the relay means. And means for issuing a request.

The invention according to claim 3 is a digital radio comprising a plurality of radio terminals for transmitting and receiving data on a plurality of frequency channels, and comprising a relay means for relaying communication between the plurality of radio terminals. In the communication system, among the plurality of wireless terminals, a means for accumulating data sent from the first wireless terminal to the relay means, a means for determining a data transmission level by the relay means, and the relay Means for transmitting the stored data at the transmission level to a second wireless terminal of the plurality of wireless terminals, the transmission level being determined by the relay means by the first means.
Is determined regardless of the reception level at the time of receiving the data sent from the wireless terminal.

In the above configuration, it functions so as to avoid a data error when transmitting / receiving the packet data via the relay station.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. [First Embodiment] FIG. 1 is a diagram conceptually showing the system configuration of a digital radio communication system according to the first embodiment of the present invention. In the figure, the circle 100 indicated by the solid line,
Reference numeral 101 is a range within which the radio waves of the mobile terminals 1 and 2 reach, respectively, and a large filled circle 102 is a range within which the radio waves of the relay station 3 reach. It is assumed that the relay station 3 is installed in a range where the radio wave from the mobile terminal can reach, and the radio wave from the relay station 3 is also installed in a range where the radio wave from the mobile station can reach each mobile terminal.

FIG. 2 is a block diagram showing the internal structure of the mobile terminal which constitutes the digital radio communication system according to this embodiment. In the figure, reference numeral 1 is a mobile terminal main body, 2
Is a wireless LAN adapter unit, and 3 is a LAN controller. A CPU (central control unit) 4 controls the entire wireless adapter unit 2. The data required for the control by the CPU 4 is stored in the RAM 5.

Reference numeral 6 is a communication controller for assembling / disassembling packets, 7 is a bit synchronization circuit (DPLL),
8 is a radio unit including a modulation / demodulation unit (not shown), and
9 is an antenna. In addition, 10 is a data bus for exchanging data by mutually connecting the LAN controller 3, the CPU 4 and the like, and 11 is from the wireless unit 8 to C.
A carrier detection signal sent to PU4, and 12 is C
It is a channel selection signal from the PU 4 to the wireless unit 8.

FIG. 3 is a block diagram showing the internal structure of a relay station which constitutes the digital radio system according to this embodiment. The relay station main body 21 shown in the figure includes a CPU 22 for controlling the entire station and a RAM 2 for storing control information and the like.
3, a communication controller 24 that is connected to the CPU 22 and the RAM 23 via a data bus 28, and assembles and disassembles packets, a bit synchronization circuit (DPLL) 25, a wireless unit 26 including a modulation / demodulation unit (not shown), and the like. It is composed of an antenna 27 for transmitting and receiving data by radio waves.

A carrier detection signal 29 and a channel selection signal 30 are exchanged between the CPU 22 and the radio section 26. Hereinafter, the transmitting operation and the receiving operation in the digital wireless communication system according to the present embodiment will be described in detail. FIG. 4 is a flowchart showing the operation of the mobile terminal 1 (transmission terminal) according to this embodiment. As shown in the figure, the mobile terminal 1 sets the frequency channel to 1 in step S101 to enter the reception standby state, and then the mobile terminal 1
Check whether there is a data transmission request (step S)
102). Here, if it is determined that there is no data transmission request, the processing in step S102 is continued until it is determined. If there is a data transmission request, the process of subroutine 1 described below is started (step S
103).

FIG. 5 is a flow chart showing the detailed processing procedure of the subroutine 1 of FIG. When the subroutine 1 shown in the figure is entered, the frequency channel is first switched to X1 (step S201), and then the use status of the frequency channel X1 is monitored (step S202). If it is determined that the channel is not free, the process of step S202 is continued until it is free. However, if the channel is vacant, the control packet (XX packet) shown in FIG. 12 is transmitted to the receiving terminal 2 on the frequency channel X1 (step S20).
3).

Next, the frequency channel is switched to X2,
A reception permission packet (XXX) reception standby state is entered (step S204), and it is checked whether or not that XXX has been received (step S205). Here, if it is determined that XXX has not been received, it is checked whether or not there is a timeout by a predetermined timer (step S206). If no time-out is detected in step S206, the process returns to step S205. If there is a time-out, the value of the counter M (not shown) is incremented by 1 (step S207). Then, it is checked whether the value of the counter M is larger than N (step S208).

If the value of the counter M is N or less,
The process returns to step S201, but the value of the counter M is N.
If it is larger than the value, the value of the counter M is reset (step S209). Then, LEDY display is performed (step S210), and the process proceeds to Z, that is, because the parameter in step S103 shown in FIG. 4 is Z = B, the process indicated by the connector B described later is performed.

If it is determined in step S205 that the packet XXX is received, then the XX
X is stored in the designated place (step S211), and the value of the counter M is reset (step S212). And
Exit from the processing of this subroutine 1. However, the variables in this subroutine 1 are X1 = 1, XX = transmission request, X
2 = 2, XXX = reception permission packet, M = 1, Y = 1,
Let Z = B.

Next, the processing of the subroutine 2 (step S104) shown in FIG. 4 will be described with reference to the flowchart shown in FIG. First, step S301 in FIG.
Then, the frequency channel is switched to the designated channel, and the packet data transmission standby state is entered. Next, the usage status of the designated frequency channel is monitored (step S302), and if the channel is not available,
The process of step S302 is continued until it becomes free. However, if it is determined that the channel is free, the packet data shown in FIG. 13 is transmitted to the destination terminal (XXXX) on the designated frequency channel (step S303).

Next, it is checked whether or not the reception confirmation is returned (step S304), and if it is not returned, it is checked whether or not a predetermined timer has timed out (step S305). If it is determined that the time-out has not occurred, the process returns to step S304 again.
However, if the timeout is determined in step S305, the value of the counter M is incremented by 1 (step S3
06).

On the other hand, if it is determined in step S304 that the reception confirmation is returned, the reception confirmation data is stored in the designated place (step S307), and then it is checked whether or not the reception data has an error (step S307). S308). If it is determined that there is an error, the process proceeds to step S306 described above. Then, following the process of step 306, it is checked in step S309 whether the value of the counter M is larger than N (step S309). If the value of the counter M is less than or equal to N, the process returns to step S302, but if the value of the counter M is greater than N, the value of the counter M is reset (step S310), LE.
DY is displayed (step S311).

After that, the process shifts to Z. Since the parameter Z = B in step S104 of FIG. 4,
Here, the processing for the connector B described later will be performed. If it is determined in step S308 that the received data has no error, the value of the counter M is reset (step S31
2) Exit from the processing of this subroutine 2.

FIG. 7 shows the subroutine 1 of step S103 and step S103 according to the parameter Z = B shown in FIG.
14 is an operation flowchart in the case where the processing is moved to the connector B from the subroutine 2 of 104. Here, first, it is checked whether or not there is a relay station capable of transmitting and receiving (step S40
1) If the relay station does not exist, the LEDY of the mobile terminal 1 is displayed (step S402). However, if it is determined that there is a relay station, the relay operation described later is started (step S403). When the processing in these steps S402 and S403 is completed, the processing indicated by A, that is, the transmission operation in the mobile terminal 1 (transmission terminal) is completed.

Next, the operation of the mobile terminal 2 (reception terminal) will be described. FIG. 8 is a flowchart showing the reception operation of the mobile terminal 2 (reception terminal). As shown in the figure,
First, the mobile terminal 2 switches the frequency channel to 1 (step S501) and checks whether or not a transmission request packet has been received from the mobile terminal 1 (step S502).
Here, if it is determined that the transmission request packet has not been received, the above step S502 is performed until it is received.
Continue processing in.

However, when the transmission request packet is received, the process of the subroutine 1 is started (step S50).
3). However, the variables of the subroutine 1 in step S503 are X1 = 2, XX = reception permission, X2 = designated channel, XXX = packet data, M = 3, Y = 4, Z = C.
And After returning from the processing in the subroutine 1, next, the usage status of the designated frequency channel is monitored (step S504). If the channel is not free, the monitoring processing in step S504 is performed until it is free. to continue. If it is determined that the channel is idle, the reception confirmation packet is transmitted to the mobile terminal 1 on the designated channel (step S505).

After that, the operation processing in the mobile terminal 2 is ended. Even when the process moves from the step S503 to the connector C according to the parameter Z = C, the operation in the mobile terminal 2 is similarly ended. Next, step S403 (FIG. 7) described above.
The relay operation in 1 will be described for each of the mobile terminal 1, the relay station 3, and the mobile terminal 2.

FIG. 9 is a flowchart showing the relay operation of the mobile terminal 1 (transmitting terminal). As shown in the figure, first, the processing of subroutine 1 is started (step S60).
1). However, the subroutine 1 of this step S601
, The variables are X = 24, XX = request to send, X2 = 2, X
XX = reception permission packet, M = 4, Y = 5, and Z = D.

When the process returns from the subroutine 1, the subroutine 2 (step S602) is entered next. However,
The variable in the subroutine 2 of this step S602 is X
Let XXX = relay station, M = 5, Y = 6, Z = D. Then, after that, the transmission operation in the mobile terminal 1 ends. Even when the process is started from step S601 and step S602 according to the parameter Z = D there, the transmission operation in the mobile terminal 1 is similarly ended.

FIG. 10 is a flowchart showing the relay operation in the relay station 3. As shown in FIG.
Switch the frequency channel to 24 (step S70
1) Next, it is checked whether or not a transmission request packet has been received from the mobile terminal 1 (step S702). If it is determined that the transmission request packet has not been received,
The processing in step S702 is continued until it is received.

Next, the processing of subroutine 1 (step S
703). However, the variables in the subroutine 1 of this step S703 are X1 = 1, XX = transmission request, X
2 = 24, XXX = reception permission packet, M = 5, Y =
6. Let Z = E. Next, the process of subroutine 1 is started again (step S704). However, this step S
The variables in subroutine 1 of 704 are X1 = 2 and XX =
Receive permission, X2 = 2, XXX = packet data, M =
6, Y = 7 and Z = E.

Subsequently, the usage status of the designated frequency channel is monitored (step S705). If the channel is not free, step S705 is performed until it is free.
The monitoring process in 705 is continued. However, if it is determined that the channel is free,
A reception confirmation packet is transmitted (step S706). After that, the processing moves to the subroutine 2 (step S70).
7). However, the subroutine 2 of this step S707
, The variables are: XXX = mobile terminal 2, M = 7, Y = 8,
Let Z = E. Then, although the operation in the relay station 3 is finished, the operation in the relay station 3 is similarly performed even when the operation moves to the connector E according to the parameter Z = E in step S703, step S704, and step S707. finish.

Finally, with reference to the flow chart shown in FIG. 11, the receiving operation at the mobile terminal 2 (reception terminal) will be described. First, the frequency channel of the mobile terminal 2 is switched to 1 (step S801 in FIG. 11), and then the relay station 3
It is checked whether or not a transmission request packet has been received from (step S802). If it is determined that the transmission request packet has not been received, the process in step S802 is continued until it is received.

However, if it is determined in step S802 that the transmission request packet has been received, the process proceeds to the subroutine 1 (step S803). However, the variable in the subroutine 1 of this step S803 is X1 = 24,
XX = reception permission, X2 = designated channel, XXX = packet data, M = 7, Y = 8, Z = F. After returning from the processing in the above-described subroutine 1, next, the usage status of the designated frequency channel is monitored (step S80).
4) If it is determined that the channel is not free, the process of step S804 is continued until it is free. If it is determined that the channel is free, a reception confirmation packet is transmitted to the relay station (step S805).

After that, the relay operation in the mobile terminal 2 is ended, but the reception operation in the mobile terminal 2 is also ended when the process moves from the step S803 to the connector F according to the parameter Z = F there. As described above, according to the present embodiment, the relay station determines whether or not there is an error in the packet data from the transmitting side terminal, and if an error is detected, the relay station sends the error to the transmitting side. By making a retransmission request to the mobile terminal, it is possible to avoid a data error when transmitting / receiving packet data between mobile terminals via a relay station. [Second Embodiment] A second embodiment according to the present invention will be described below. Since the system concept of the digital wireless communication system according to the present embodiment and the internal configuration of the mobile terminal are the same as the system concept and the mobile terminal according to the first embodiment, their illustration and description will be given here. Omit it.

FIG. 14 is a block diagram showing the internal structure of a relay station that constitutes the digital radio system according to this embodiment. The relay station main body 41 shown in the figure includes a CPU 42 for controlling the entire station, a RAM 43 for storing control information and the like,
It is connected to the CPU 42 and the RAM 43 via a data bus 49, and has a communication controller 44 for assembling / disassembling packets, a bit synchronization circuit (DPLL) 45, and a radio unit 46 including a modulation / demodulation unit (not shown).

The relay station 41 further includes a CPU 4
2 is configured by a transmission level setting unit 47 for setting the transmission level of the radio wave from the radio unit 46 and an antenna 48 for transmitting and receiving data by the radio wave, and C
Between the PU 42 and the wireless unit 46, the carrier detection signal 5
0, the channel selection signal 51 is exchanged. Less than,
The transmitting operation and the receiving operation in the digital wireless communication system according to the present embodiment will be described in detail.

FIG. 15 is a flowchart showing the operation of the mobile terminal 1 (transmission terminal) according to this embodiment. As shown in the figure, the mobile terminal 1 sets the frequency channel to 1 in step S101a to enter the reception standby state, and then checks whether or not there is a data transmission request from the mobile terminal 1 (step S102a). Here, if it is determined that there is no data transmission request, this step S102 is performed until it is determined.
Continue processing in a. If there is a data transmission request, the process of subroutine 1 described below is started (step S103a).

FIG. 16 is a flow chart showing the detailed processing procedure of the subroutine 1 of FIG. When the subroutine 1 shown in the figure is entered, the frequency channel is first switched to X1 (step S201a), and then the usage status of the frequency channel X1 is monitored (step S202).
a). If it is determined that the channel is not free, the process of step S202a is continued until it is free. But if the channel is free,
Similar to the first embodiment, the control packet (XX packet) shown in FIG. 12 is transmitted to the receiving terminal 2 on the frequency channel X1 (step S203a).

Next, the frequency channel is switched to X2,
A reception permitting packet (XXX) reception standby state is entered (step S204a), and it is checked whether or not that XXX has been received (step S205a). Here, if it is determined that XXX has not been received, it is checked whether or not there is a timeout by a predetermined timer (step S206a).

If a time-out cannot be detected in step S206a, the process returns to step S205a, but if it is determined that there is a time-out, LEDY is displayed (step S207a) and the process is executed in Z, that is, in FIG.
The parameter in step S103a shown in 5 is Z = B '
Therefore, the process moves to the process indicated by the connector B ′ described later.

If it is determined in step S205a that the packet XXX has been received, the process of this subroutine 1 is exited. However, the variables in this subroutine 1 are X1 = 1, XX = transmission request, X2 = 2, XX.
X = reception permission packet, Y = 1, Z = B ′. Next, the processing of the subroutine 2 (step S104a) shown in FIG. 15 will be described with reference to the flowchart shown in FIG.

First, in step S301a of FIG.
The frequency channel is switched to the designated channel, and the packet data transmission standby state is entered. Next, the usage status of the designated frequency channel is monitored (step S3).
02a), if the channel is not free, the process of step S302a is continued until it is free. However, if it is determined that the channel is free, the packet data shown in FIG. 13 is transmitted to the destination terminal (XXXX) on the designated frequency channel, as in the first embodiment (step S303a). ).

Next, it is checked whether or not the reception confirmation is returned (step S304a), and if it is not returned, it is checked whether or not a predetermined timer has timed out (step S305a). If it is determined that the timer has not timed out, step S3 is executed again.
Returning to the processing of 04a, if the timeout is determined in step S305a, LEDY is displayed (step S307a).

After that, the process shifts to Z, as shown in FIG.
Since the parameter is Z = B 'in step S104a, the process proceeds to the connector B'which will be described later.
On the other hand, if it is determined in step S304a that the reception confirmation is returned, it is checked whether or not the received data has an error (step S306a). If it is determined that there is an error, the above step S307a is performed. Move on to the display processing of. However, if it is determined in step S306a that there is no error in the received data, the processing of this subroutine 2 is exited.

Note that FIG. 18 is an operation flowchart in the case where the processing is moved from the subroutine 1 of step S103a and the subroutine 2 of step S104a to the connector B'according to the parameter Z = B 'shown in FIG.
The processing relating to the connector B'here is the first processing shown in FIG.
Since it is the same as the processing according to the embodiment, the same processing step is denoted by the same reference numeral and the description thereof is omitted.

Next, the operation of the mobile terminal 2 (reception terminal) according to the second embodiment will be described. FIG. 19 is a flowchart showing the reception operation of the mobile terminal 2 (reception terminal) according to this embodiment. As shown in the figure, first, the mobile terminal 2
Switches the frequency channel to 1 (step S501
a) It is checked whether or not a transmission request packet has been received from the mobile terminal 1 (step S502a). If it is determined that the transmission request packet has not been received, the process in step S502a is continued until the packet is received.

However, if it is determined that the transmission request packet has been received, the process moves to the subroutine 1 (step S503a). However, the variables of subroutine 1 in step S503a are X1 = 2, XX = reception permission,
X2 = designated channel, XXX = packet data, Y =
4, and Z = C '. After returning from the processing in the above-mentioned subroutine 1, next, the usage status of the designated frequency channel is monitored (step S504a), and if the channel is not available, the step S5 is performed until it becomes available.
The monitoring process at 04a is continued. If it is determined that the channel is vacant, the mobile terminal 1
A reception confirmation packet is transmitted on the designated channel (step S505a).

After that, the operation processing in the mobile terminal 2 is terminated, but from the step S503a, the parameter Z = C
Also when moving to the connector C'according to ', the operation in the mobile terminal 2 is similarly ended. Next, in step S403a described above.
The relay operation in (FIG. 18) will be described for each of the mobile terminal 1, the relay station 3, and the mobile terminal 2.

FIG. 20 is a flow chart showing the relay operation of the mobile terminal 1 (transmission terminal). As shown in the figure,
First, the process of subroutine 1 is started (step S601).
a). However, the variables in the subroutine 1 of this step S601a are X = 24, XX = transmission request, X2 = 2,
It is assumed that XXX = reception permission packet, Y = 5, and Z = D ′.

Returning from the processing in this subroutine 1,
Next, the subroutine 2 (step S602a) is entered. However, it is assumed that the variables in the subroutine 2 of step S602a are XXX = relay station, Y = 6, Z = D '. Then, after that, the transmission operation in the mobile terminal 1 ends. Even when the process is started from step S601a and step S602a according to the parameter Z = D ', the transmission operation in the mobile terminal 1 is similarly ended.

FIG. 21 is a flow chart showing the relay operation in the relay station 3 according to this embodiment. As shown in the figure, the relay station 3 first switches the frequency channel to 24 (step S701a), and then checks whether or not a transmission request packet is received from the mobile terminal 1 (step S701a).
702a). If it is determined that the transmission request packet has not been received, the processing in step S702a is continued until it is received.

Next, the processing of subroutine 1 (step S
703a). However, the variables in the subroutine 1 of this step S703a are X1 = 1, XX = transmission request, X2 = 24, XXX = reception permission packet, Y = 6,
Let Z = E '. Next, the process of subroutine 1 is performed again (step S704a). However, this step S
The variables in subroutine 1 of 704a are X1 = 2, XX
= Reception permission, X2 = 2, XXX = Packet data, Y =
7, and Z = E '.

Subsequently, the usage status of the designated frequency channel is monitored (step S705a). If the channel is not available, the monitoring process in step S705a is continued until it becomes available. However, if it is determined that the channel is free, a reception confirmation packet is transmitted to the mobile terminal 1 (step S706).
a).

After that, the processing moves to the subroutine 2 (step S707a). However, this step S707a
Variables in Subroutine 2 are XXXX = destination terminal (mobile terminal 2), Y = 8, and Z = E ′. Then, after that, the operation in the relay station 3 ends, but the above step S7 is performed.
Even when the process moves from 03a, step S704a, and step S707a to the connector E ′ according to the parameter Z = E ′ in each, the operation in the relay station 3 is similarly ended.

Referring to the flow chart shown in FIG. 22,
A reception operation at the mobile terminal 2 (reception terminal) will be described. First, the frequency channel of the mobile terminal 2 is switched to 1 (step S801a in FIG. 22), and then it is checked whether a transmission request packet has been received from the relay station 3 (step S802a). Here, if it is determined that the transmission request packet has not been received, the process in step S802a is continued until it is received.

However, if it is determined in step S802a that the transmission request packet has been received, subroutine 1
The process shifts to step S803a. However, the variable in the subroutine 1 of this step S803a is X1 =
24, XX = reception permission, X2 = designated channel, XXX =
Packet data, Y = 8 and Z = F '. After returning from the processing in the above-described subroutine 1, next, the usage status of the designated frequency channel is monitored (step S80).
4a), if it is determined that the channel is not free, the process of step S804a is continued until it is free. If it is determined that the channel is free, the reception confirmation packet is transmitted to the relay station through the designated channel (step S805a).

After that, the relay operation in the mobile terminal 2 is ended, but the reception operation in the mobile terminal 2 is also ended when the process moves from the step S803a to the connector F'according to the parameter Z = F 'there. As described above, in the present embodiment, the relay station performs the relay processing regardless of the reception level of the packet data from the transmission side terminal, and the reception data is transmitted from the relay station to the transmission side at a constant transmission level. By transmitting, it is possible to avoid a data error when transmitting / receiving packet data between mobile terminals via a relay station.

The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0060]

As described above, according to the present invention,
It is possible to avoid a data error when transmitting / receiving the packet data via the relay means.

[Brief description of drawings]

FIG. 1 is a diagram showing a system concept of a digital wireless communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a mobile terminal according to the first embodiment.

FIG. 3 is a block diagram showing an internal configuration of a relay station according to the first embodiment.

FIG. 4 is a flowchart showing an operation of the transmitting terminal according to the first embodiment.

FIG. 5 is a flowchart showing an operation procedure of subroutine 1 of the transmission terminal.

FIG. 6 is a flowchart showing an operation procedure of a subroutine 2 of the transmitting terminal.

FIG. 7 is an operation flowchart when processing is transferred from a subroutine 1 and a subroutine 2 to a connector B.

FIG. 8 is a flowchart showing an operation of the receiving terminal according to the first embodiment.

FIG. 9 is a flowchart showing a relay operation of the transmitting terminal according to the first embodiment.

FIG. 10 is a flowchart showing a relay operation procedure in the relay station according to the first embodiment.

FIG. 11 is a flowchart showing a relay operation of the receiving terminal according to the first embodiment.

FIG. 12 is a diagram showing a packet format according to the first embodiment.

FIG. 13 is a diagram showing a packet format according to the first embodiment.

FIG. 14 is a block diagram showing an internal configuration of a relay station according to a second embodiment of the present invention.

FIG. 15 is a flowchart showing an operation of the transmitting terminal according to the second embodiment.

16 is a flowchart showing a processing procedure of a subroutine 1 of step S103a shown in FIG.

17 is a flowchart showing a processing procedure of a subroutine 2 of step S104a in FIG.

FIG. 18 is a flowchart showing a processing procedure when processing in subroutine 1 and subroutine 2 moves to a connector B ′.

FIG. 19 is a flowchart showing a receiving process in the mobile terminal 2 according to the second embodiment.

FIG. 20 is a flowchart showing a relay operation of the mobile terminal 1 (transmission terminal) according to the second example.

FIG. 21 is a flowchart showing a relay operation in the relay station 3.

FIG. 22 is a flowchart showing a relay operation of the mobile terminal 2 (reception terminal) according to the second example.

[Explanation of symbols]

 1 mobile terminal main body 2 wireless adapter 3 LAN controller 4, 22, 42 CPU 5, 23, 43 RAM 6, 24, 44 communication controller 7, 25, 45 bit synchronous circuit 8, 26, 46 wireless unit 47 transmission level setting Department

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Claims (5)

[Claims] 1. A digital wireless communication system comprising a plurality of wireless terminals for transmitting and receiving data on a plurality of frequency channels, and comprising relay means for relaying communication between the plurality of wireless terminals, wherein the plurality of wireless terminals are provided. A first judgment means for judging whether or not there is an error in the data sent from the first wireless terminal to the relay means; and a case in which the first judgment means has an error in the data. If determined, means for issuing a resend request for the data from the relay means to the first wireless terminal; and means for storing the data in the relay means if it is determined that the data has no error. , The stored data is stored in the second of the plurality of wireless terminals.
Means for transmitting to the wireless terminal, the second determining means for determining whether or not there is an error in the data transmitted to the second wireless terminal, and an error in the data by the second determining means. And a means for issuing a request to retransmit the data from the second wireless terminal to the relay means when it is determined that there is a digital wireless communication system. 2. The digital wireless communication system according to claim 1, wherein the digital wireless communication system has an evenly distributed system configuration for transmitting the data in packet units. 3. A digital wireless communication system comprising a plurality of wireless terminals for transmitting and receiving data on a plurality of frequency channels, the relaying means for relaying communication between the plurality of wireless terminals, wherein the plurality of wireless terminals are provided. Of the plurality of wireless terminals, the means for accumulating data sent from the first wireless terminal to the relay means, the means for determining the data transmission level by the relay means, and the plurality of wireless terminals from the relay means. , A means for transmitting the accumulated data to the second wireless terminal at the transmission level, wherein the transmission level is set when the relay means receives the data transmitted from the first wireless terminal. A digital wireless communication system characterized by being determined irrespective of the reception level of. 4. The digital wireless communication system according to claim 3, wherein the transmission level is constantly maintained at a constant level. 5. The digital wireless communication system according to claim 3, wherein the digital wireless communication system has an evenly distributed system configuration for transmitting the data in packet units.