JP3534597B2 - Mobile wireless data transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile wireless data transmission system in consideration of data transmission outside a radio wave communication area.

[0002]

2. Description of the Related Art In conventional mobile wireless data transmission, when data is transmitted to a terminal outside the radio wave coverage area, when data is relayed through a base station or a relay station, or when data is transmitted outside the radio wave coverage area in advance. The main method has been to transmit and receive control signals for selecting a route to a terminal and set a route to perform data transmission. Naturally, the base station and the relay station had to be installed in advance, and when the mobile unit came off the station, communication became impossible. Also, relay route selection is possible by sequentially transmitting route selection information, but when terminals in the system move at high speed and the network form changes significantly, there is a delay in route selection and traffic of route selection There was a big problem.

FIG. 23 shows the concept of a conventional mobile radio data transmission system. In FIG. 23, the radio wave notification areas Am, An, Ap, and Aq centering on the base stations M, N, P, and Q are continuously formed in a movable range, and the radio wave notification areas Am to Aq are included. Terminals M1, M2, N1, N2, N
3, P1 and Q1 are connected to the terminal M1 via the base stations M to Q.
Data is transmitted and received between Q1 and Q1. Terminals in the same radio wave notification area, for example, terminals M1 and M2 transmit / receive data via the base station M in the radio wave notification area Am, and terminals existing in different radio wave notification areas, for example, the terminal M1 and the terminal The base station M and the base station N can communicate with N1 by exchanging data. Data communication using a mobile phone corresponds to this method. In this case, the terminal needs to send and receive control information related to movement between cells to the base station, and send and receive control information and data related to movement of the terminal between base stations. Also, it is not possible to communicate with terminals outside the cell,
In order to make a wide range of moving area a communicable area, it is necessary to install a large number of base stations and consider communication between the base stations, which requires a large capital investment.

As a measure for solving this problem,
JP-A-9-83528 and JP-A-8-274777.
There is a system disclosed in the publication.

FIG. 24 is a diagram of the system disclosed in Japanese Patent Laid-Open No. 9-83528. In FIG. 24, the base station R
From the base station R to the route generation packet (first packet) from all terminals R1, R2, R
Send to 3. The terminal R3 that has received the packet returns the information (second packet) to the base station R, and also transmits the route generation packet (first packet) to another terminal. If the terminal R4 outside the radio wave notification area Ar can receive this packet, it similarly returns the second packet. In this way, the communication path including the terminals outside the radio wave notification area Ar is detected. In this case, the route generation packet (first packet) transmitted from the base station R is transmitted at regular intervals, but the position of the terminal changes greatly depending on the transmission timing and the interval, and the position of the terminal changes greatly. It is conceivable that communication will not be possible on existing communication paths. Also, in this system, the base station R is indispensable,
Route search and route selection control are essential at ~ R5 and base station R.

FIG. 25 shows a system disclosed in Japanese Patent Laid-Open No. 8-274777, and FIG. 26 shows a communication correlation table Y when the system is realized. In this system, each terminal S,
Each of T, U, V, W, and X has a data transmission / reception function and a relay function, collects whether or not it can directly communicate with its own terminal, and creates a communication correlation table Y that summarizes the communication availability information of all terminals. Thus, a system is realized by selecting a terminal that serves as a relay station, adding information addressed to the terminal that serves as the relay station to a transmission packet, and transmitting the packet. In this case, all terminals S to X
It is necessary for each terminal to share the communication availability information collected in step 1, which requires information exchange and control functions. Therefore, in a system having a large amount of movement, it is necessary to frequently exchange the communication permission / prohibition information, the traffic becomes large, and a delay occurs during the information exchange, resulting in a time in which communication becomes impossible.

[0007]

As described above, in the conventional mobile radio communication system, cells are mainly composed of base stations and relay stations, and data transmission is carried out through the base stations and relay stations. , The communicable area was largely dependent on the location of those stations. Also, in order to realize communication with terminals outside the cell, each terminal adds a relay function to the data transmission / reception function, and in parallel with data transmission / reception, each terminal collects positional relationship information with adjacent terminals, and It was intended to realize data communication while sequentially searching for routes based on information.

In this case, control for route selection is required at each terminal and information on adjacent terminals, which is a condition for route selection, needs to be exchanged between the terminals. In a large wireless communication system, a time delay may occur until information is collected and a route is selected, and there is a problem that data transmission / reception becomes impossible during this time. In addition, since the quality of the wireless line is not constant unlike the wired line, it is possible that the information may be erroneous or may disappear when exchanging information on adjacent terminals. There is a time delay. Therefore, there is a problem that the packet to be transmitted does not arrive because the positional relationship of the terminals has already changed since the packet was transmitted in the past route selection.

In order to solve the above problems, the present invention enables data transmission even in a situation where the line quality is not constant such as a wireless line, and is required for route selection even when the amount of movement of a terminal is large. It is an object of the present invention to provide a mobile wireless data transmission system that can continue communication without time.

[0010]

According to a first aspect of the present invention, there is provided a mobile radio data transmission system, wherein a data transfer method between a plurality of mobile terminals is provided.
Data transmission to a terminal outside the radio wave coverage area.
In the mobile radio data transmission method for transmission, each terminal has a receiving unit for receiving a packet, an error detecting unit for detecting whether the received packet is normal, and an error detecting unit for detecting whether the received packet is an erroneous packet. A means for discarding the packet and a judging means for determining whether or not the packet meets a copy transfer condition preset in each terminal by identifying the header portion of the packet when the received packet is normal And a transfer unit that copies and transfers the packet when the header unit of the normally received packet satisfies the copy transfer condition, and the determination unit is provided in the header unit of the normally received packet. The transfer means normally comprises a means for judging whether or not the source terminal number indicating the source of the packet concerned matches the own terminal number. Wherein the packet transmission source terminal number is provided with a means for discarding packets the received If a match with the own terminal number.

In the mobile wireless data transmission system according to the invention of claim 2, the judging means according to claim 1 is a transmission destination which is provided in a header portion of a packet which is normally received and which indicates a transmission destination of the packet. The transfer means is provided with means for judging whether the terminal number matches the own terminal number, and the transfer means is provided in the header section of the packet if the destination terminal number of the packet normally received does not match the own terminal number. It is less than or equal to the maximum transfer count preset for each terminal by referring to the packet transfer count that stores the number of times that the relevant packet has been transferred and the terminal transfer flag that indicates which terminal has already been transferred. And a means for copying and transferring a normally received packet when the packet is not transferred to the own terminal, and the receiving means is provided when the destination terminal number matches the own terminal number. Wherein the packet is always received is provided with means for receiving when a packet received newly by the history.

In the mobile radio data transmission system according to the invention of claim 3, the transfer means according to claim 1 or 2 transmits the packet with the source terminal number provided in the header part of the packet normally received. It is characterized by comprising means for copying and transferring the packet only within the closed area of the address information of the hierarchical structure based on the address information consisting of the destination terminal number and the hierarchical information indicating the classification of each terminal into the hierarchical structure. .

In the mobile radio data transmission system according to the invention of claim 4, the judgment means according to claim 1 or 2 is characterized in that the packet priority and the packet priority provided in the header part of the packet which is normally received. A means for identifying the header portion of the received packet based on the copy transfer availability and the maximum number of transfers for the packet priority is provided, and the transfer means is provided with means for copying and transferring the packet based on the packet priority. Is characterized by.

According to the mobile radio data transmission system of the invention of claim 5, each terminal according to claim 1 or 2,
If the destination number of the received packet is its own terminal, a means to detect an error in the received packet and request retransmission of the packet, a means to retransmit the corresponding packet when a retransmission request is received, and A means for adding a retransmission request flag that expects a retransmission request of the corresponding data to the header portion of the transmitted / received packet, and a retransmission request flag preset by the source terminal by analyzing the header portion of the received packet. Check and resend control means, based on the information in the header part of the received packet, if it recognizes that the packet could not be received normally, a means for returning a resend request packet and urging a resend request, and a resend request packet When it is received, a means to retransmit the corresponding packet, and when the packet is received normally, a normal reception packet indicating that the packet was received normally is returned to the source terminal. Means for, characterized by comprising a.

In the mobile radio data transmission system according to the invention of claim 6, each terminal according to claim 1 or claim 2 or claim 5 transmits the data corresponding to the header part of the normally received packet. A means for setting a retransmission request flag that expects a retransmission request and transmitting the packet, and a means for automatically changing the number of packet transfers unless a retransmission request packet or a normally received packet is received again within a fixed time. It is characterized by having and.

A mobile radio data transmission system according to the invention of claim 7 is characterized in that each terminal according to claim 1 or 2 is:
A link state recognition means for recognizing and determining a terminal within the radio communication area of the own terminal, a means for broadcasting the above link information to another terminal at a constant cycle, and a link status table for receiving link information other than the own terminal from another terminal Means for creating a packet, a means for adding a relay flag indicating that the copy transfer of the packet is executed to the header portion of the packet transmitted and received in the system, and a terminal outside the radio wave communication area based on the link state table. And a means for setting a relay flag only when a packet is transmitted to the packet and a means for copying and transferring the packet according to a preset copy transfer condition only when the relay flag is set. .

In the mobile wireless data transmission system according to the invention of claim 8, each terminal according to claim 1 manages time and adjusts it to a certain reference time, and a packet transmitted and received in the system. A means for storing the transmission time of the corresponding packet transmitted in the header part in time synchronization with the reference time, and recognizing the transmission time from the header part of the received packet and recognizing the difference between the current time and the transmission time. Means to recognize time,
The present invention is characterized by comprising means for copying and transferring a packet received within a specified elapsed time, and means for discarding a packet received for a specified elapsed time or more.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 of the Invention 1 shows a communication network used in a mobile wireless data transmission system according to a first embodiment of the invention. In FIG. 1, six terminals 1
Radio waves of the same frequency are used for communication among a, 1b, 1c, 1d, 1e and 1f. Since it is necessary for each of the terminals 1a to 1f to be capable of bidirectional data transmission,
A multi-access system that allows data transmission by sharing one frequency among a plurality of terminals 1a to 1f is used. The multiple access method includes, for example, a TDMA method in which a transmission slot J1 for each terminal is determined as shown in FIG.

Returning to FIG. 1, A1a is a radio wave communication area (communication range) of the terminal la, and the terminals 1b and 1c are present in the radio wave communication area A1a and can directly communicate with the terminal 1a. It is assumed that the terminals ld, le, and 1f are outside the radio wave notification area A1a and cannot directly communicate with the terminal 1a. Although not shown, the terminals 1b to 1f have respective radio wave notification areas, and the terminals 1a and 1f are included in the radio wave notification area of the terminal 1b.
1c, 1d exist, terminals 1a, 1b, 1d, 1e exist in the radio wave notification area of terminal 1c, and terminals 1d, 1c, 1f exist in the radio wave notification area of terminal 1e. Then, for example, when data is transmitted from the terminal 1a to the terminal 1f, the data transmitted from the terminal 1a is transmitted from the terminals 1b and 1c in the radio wave notification area A1a to the radio wave notification area A1.
Copying and transferring to the terminals 1d, 1e, and 1f outside the area a eliminates the processing time of the route selection, and data can be transmitted to the terminals outside the wide radio wave communication area.

That is, when data is transmitted from the terminal la as the source terminal to the terminal if as the destination terminal, first, the terminal la includes the source information and the destination terminal for identifying the source terminal in the packet B. The packet B is transmitted by setting the destination information for identifying Then, the terminals lb and lc within the radio wave notification area A1a receive the packet B from the terminal 1a. Since the destination information of the received packet B is not addressed to these terminals 1b and 1c, these terminals 1b and 1c check whether or not the packet B can be transferred based on the copy transfer condition decided in advance, The received packet B is copied and transferred as the first copy packet C without changing the destination information. The first copy packet C includes terminals 1a, 1 adjacent to the terminals 1b, 1c.
It is received at d and 1e. Then, the terminal la recognizes that its own terminal is the transmission source from the transmission source information of the received first copy packet C, and discards the first copy packet C.
Further, since the destination information of the received first copy packet C is not addressed to itself, the terminals ld and le check whether or not the first copy packet C can be transferred based on the above-mentioned copy transfer condition, and then transmit the same. The first copy packet C is copied and transferred as the second copy packet D without changing the original information and the destination information. The second copy packet D is sent to the terminal 1
It is received by the terminals 1b, 1c, 1d and 1f adjacent to d and 1e. Then, the terminals lb, lc, and ld receive the second
The second copy packet D is discarded by recognizing that the copy transfer has been completed based on the source information and the destination information of the copy packet D. The terminal lf recognizes that the second copy packet D is addressed to itself based on the destination information of the received second copy packet D, and then takes in the second copy packet D.

FIG. 3 shows a wireless communication device 10 mounted on each of the terminals 1a-1f. In FIG. 3, the wireless communication device 10
Is a data terminal interface 12 that connects the data terminal 11, a CPU 13 that performs device control and data transmission control,
An application S / W (not shown) and a memory 14 for storing various data, a timer 15 for various time management, a reception history memory 18 for storing packet reception history, and a radio interface for connecting to a radio 17 connected to the outside. 16 and.

FIG. 4 shows a transmission process inside the wireless communication device 10. In FIG. 4, when a packet transmission request is issued from the data terminal 11 (S1), the packet corresponding to the packet transmission request is temporarily stored in the memory 14 via the data terminal interface 12 (S2). A transmission format is created in which transfer information, which is information for determining copy transfer conditions, is additionally set in the packet in the header portion of the packet (S3), and the packet is transmitted from the wireless device 17 to the wireless space via the wireless device interface 16. (S4).

FIG. 5 shows a receiving process inside the wireless communication device 10. In FIG. 5, when the wireless device 17 receives a packet from the wireless space (S5), it is checked whether the packet is normally received (S6), and the packet is stored in the memory 14 when the packet is normally received. (S7). C
After detecting an error in the received packet (S8), the PU 13 analyzes the inside of the received packet (S9), checks the destination information of the received packet (S1O), and checks the copy transfer condition (S11). If the destination information is not the own terminal, the packet transfer information is updated after checking the copy transfer conditions (S12) and retransmitted to the wireless space (S1).
3). If the destination information is its own terminal, the received packet is compared with the storage of the reception history memory 18 (S14, S15), and if the received packet is the same as the already received packet, the received packet is discarded (S17), If the received packet is a new received packet, the received packet is received and transmitted to the data terminal 11 (S16).

As in the first embodiment of the present invention, each of the terminals 1a to 1f realizes the packet relay function by copying and transferring the packet, and the source terminal is aware of the data transmission path to the destination terminal. Since a plurality of copy transfer packets arrive, it is possible to improve the accuracy of data delivery in the wireless network.

Second Embodiment of the Invention FIG. 6 shows a format of a packet transmitted / received in the communication network according to the second embodiment of the invention. In FIG. 6, the packet E1 is
SYNC pattern e1 indicating the beginning of the packet, data length e2 indicating the length of the packet, header portion e3, packet E
Has a data part e4 which is internal data of and a CRCe5 for detecting a packet error. The header part e3 is
Packet transfer count e3 that stores the packet transfer count
1, a terminal transfer flag e3-2 that stores the information of the transferred terminal of the packet, a packet type e that indicates the type of the packet
3-3, a transmission source terminal number e3-4 indicating a transmission source, a transmission destination terminal number e3-5 indicating a transmission destination, a sequence number e3-6 indicating a series of transmission numbers of packets, and 1 configured in units of a plurality of packets Data IDe3 representing significant data of lump
-7, and packet IDe 3-8. The packet ID e3-8 is the transmission packet number e3 in all the packets.
-8a and the total number of packets e3-8b for the data ID.

FIG. 7 shows a flowchart of the packet transfer processing according to the second embodiment of the invention. In FIG. 7, after the CPU of the wireless communication device of each terminal checks the error detection of the packet received from the wireless space, if it is normal, the packet is taken out to the memory of the wireless communication device and the header portion of the packet is analyzed. Yes (S18). Then, the source terminal number is checked (S19), and if the source terminal number matches its own terminal number, the packet is discarded (S29). If the source terminal number does not match the own terminal number, then it is checked whether the destination terminal number matches the own terminal number (S2
0) If they do not match, the number of packet transfers is equal to or less than a predetermined value specified in advance (S21), and the received packet is copied and transferred only when the own terminal is an untransferred packet in the terminal transfer flag (S22). (S23, S24).
If the destination terminal number matches the own terminal number, it is checked whether or not there is a packet with the same content in the reception history memory of the wireless communication device (S25, 26), and if the received packet is a new received packet, the received packet concerned. Is received (S
27). Furthermore, it is checked whether another terminal is set as the destination for the destination terminal number of the received packet (S
28) If another terminal is set as the destination, copy transfer is realized if the transfer conditions are matched based on the packet transfer count and the terminal transfer flag (S21 to S24).

FIG. 8 shows the positional relationship between the three terminals 1, 2, 3 according to the second embodiment of the invention. In FIG. 8, a part of the radio wave communication area A1 of the terminal 1 and a part of the radio wave communication area A3 of the terminal 3 overlap each other, and the terminal 2 exists in the overlapping portion.

FIG. 9 shows a schematic sequence diagram in the terminal positional relationship of FIG. FIG. 9 shows that the wireless communication device 10 of the terminal 1 transmits a packet to the terminal 2 by receiving a data transmission request from the data terminal 11, and then the packet is copied and transferred from the terminal 2 to the terminal 3. .

By limiting the number of packet transfers as the copy transfer condition as in the second embodiment of the present invention, it is possible to suppress the increase in the number of copy packets in the wireless network to a certain value or less, and to move. Copy transfer can be realized according to the degree of variation in the positional relationship between terminals.

Third Embodiment of the Invention FIG. 10 shows a grouped wireless communication network according to a third embodiment of the invention. In FIG. 10, 3 depending on the types of the terminals 21a to 21g, the terminals 22a to 22h, and the terminals 23a to 23g.
Assuming that the terminals are divided into two layers, the terminals 21a to 21g are the first layer terminals, the terminals 22a to 22h are the second layer terminals, and the terminal 2
3a to 23g are defined as the third layer terminals. Terminal 21a-
In the radio wave notification areas A21a to A21g for every 21 g, the radio wave notification area A21a partially overlaps the radio wave notification areas A21b and A21d, and the radio wave notification area A21b is the radio wave notification area A21.
a, A21c, A21d partially overlap with each other, and the radio communication area A
21c partially overlaps the radio wave notification areas A21b, A21d, and A21f, and the radio wave notification area A21d overlaps the radio wave notification area A2.
1a, A21b, A21c, A21e, A21f are partially overlapped with each other, and the radio communication area A21e is the radio communication area A21.
d, A21f, and the radio wave notification area A21f partially overlaps with the radio wave notification areas A21c, A21d, A21e, A21g, and the radio wave notification area A21g is the radio wave notification area A2.
It partially overlaps with 1f. Further, reference numerals 24a to 24 denote copy transfer paths capable of copy transfer when the copy transfer of the terminals 22a to 22h and 23a to 23g of the second and third layers is realized.
It is indicated by t.

That is, in general, realizing copy transfer in the entire wireless network leads to an increase in the number of copy packets in the network and an increase in the processing load of the wireless communication device of each terminal. Therefore, as shown in FIG. 10, when a set of terminals can be grouped according to the type of terminal and the class of each terminal 21a to 21g, 22a to 22h, and 23a to 23g, the positional relationship of terminals and information sharing should be performed. In the case where the range is determined to some extent and a set of terminals can be configured, by performing copy transfer only within that range, wasteful copy transfer can be eliminated and efficient data transmission can be realized.

FIG. 11A shows a packet format according to the third embodiment of the invention. In FIG. 11A, FIG.
The packet E2 transmitted / received in the network of 0 has the layer information e3-9 added to the source terminal information e3-4 and the destination terminal information e3-5 of the packet E1 of FIG. 6, and the packet type of the packet E1 of FIG. A retransmit flag e3-10 is added to the vacant portion of e3-3, and a transfer hierarchy flag e3-11 indicating in which group the copy transfer is performed in the vacant portion of the packet transfer count e3-1 of the packet E1 of FIG. Is provided, and packet copy transfer is performed based on these areas, and the group to be copy transferred is limited. The group setting is preliminarily agreed between the terminals before the system operation is started, and the transmission source terminal sets and transmits the transfer layer flag e3-11 according to the contents of the packet. Transfer layer flag e3-
As shown in FIG. 11B, reference numeral 11 denotes a first transfer instruction e3-11a indicating transfer on the first layer, a second transfer instruction e3-11b indicating transfer on the second layer, and an n-th layer. The n th transfer
It has a layer instruction e3-11n, and can be set to a form in which transfer settings of a plurality of layers can be set.

Fourth Embodiment of the Invention FIG. 12 shows a priority information table H set in each terminal according to the fourth embodiment of the invention. Each terminal in the system arranges a priority information table H as shown in FIG. 12 before the operation starts, and sets it in the memory of the wireless communication device of each terminal. That is,
The packet transmission source terminal stores the priority information in the packet header according to the importance of the packet to be transmitted. The basic processing is the same as the flowchart of FIG. 7, but is characterized in that the specified value of the maximum transfer count is changed according to the priority of the packet when checking the packet transfer count. Therefore, if the number of copy transfers is increased as in the second embodiment of the invention, the number of packets in the system is increased, but according to the fourth embodiment of the present invention, the certainty delivery rate of the corresponding packet is improved. , The reachability to the terminal outside the radio communication area is also improved. Further, the number of packets in the network can be suppressed by copy transfer according to the importance of information.

Fifth Embodiment of the Invention FIG. 13 shows a packet format transmitted / received in the network according to the fifth embodiment of the invention. In FIG. 13, the packet E3 is shown in FIG.
Of the packet type e3-3 of the packet E1 is added with a retransmission flag e3-10 and a retransmission request flag e3-12 that expects a packet retransmission request, and CRCe3-13 is added to the header part e3. is there.

FIG. 14 shows a flowchart of the transmission process in the retransmission control according to the fifth embodiment of the invention. In FIG. 14, the packet transmission source terminal checks the reception of a response packet to the transmission packet (S30), and if a data transmission request from the data terminal is received, stores it in the memory 14 (S31). A head section is created (S32). When the retransmission request is made, the retransmission request flag is set and the timer is set after the packet is transmitted (S33 to S35, S42). If the data transmission request from the data terminal is not received by the reception check of the response packet for the transmission packet, it is determined whether all the response reception packets have been prepared for the transmission packet (S36). If not, check the timeout according to the number of transmitted packets and the maximum number of transfers (S3
7) After the time-out, a packet for which a retransmission request is made is reconstructed and transmitted based on the reception amount of the normal reception packet and the retransmission request packet (S38 to S39). If no normally received packet is received, all previously transmitted packets are retransmitted (S40). The response packet until the time-out is stored in the internal memory of the device (S4
1).

FIG. 15 shows a flowchart of the receiving process in the retransmission control according to the fifth embodiment of the invention. In FIG. 15, the destination terminal of the packet carries out an error check of the header section information at the same time as receiving the packet (S43, S4).
4). If normal, it is stored in the memory 14 and the header portion of the received packet is analyzed (S45, S46). If the resend request flag is set, an error check is performed on the data part (S47, S48), and if there is an error, resend prompting the resend request to the source terminal based on the header part information of the received packet. A request packet is transmitted (S49, S50). If it can be normally received without error, it is checked whether the destination terminal number and the own terminal number match (S51). If they do not match, the copy transfer condition is checked, and then copy transfer is performed if possible (S52-). S54). If the destination terminal number is its own terminal, a normal reception packet indicating normal reception is created and transmitted (S55, S56), and whether or not the reception packet is a new reception packet is compared and searched with the contents of the reception history memory. Yes (S57). If it is a newly received packet, the packet is received and transmitted to the data terminal (S58, S
60), it is checked whether another terminal number is set as the destination terminal number (S61). If another terminal is set, the packet copy transfer condition is checked and transferred (S52 to S54). If it is a received packet, the received packet is discarded (S62). The retransmission request packet and the normal transmission packet have only the header section, and can be recognized by changing the packet type.

As in the fifth embodiment of the present invention, by performing the retransmission control by the retransmission request flag e3-12 set in the source terminal, it is possible to suppress the increase of packets in the network.

Sixth Embodiment of the Invention FIG. 16 shows a packet format transmitted and received in a network according to the sixth embodiment of the invention. In FIG. 16, the packet E4 is shown in FIG.
The maximum transfer count flag e3-13 is added to the vacant portion of the packet type e3-3 of the packet E3 of No. 3.

FIG. 17 shows a maximum transfer number table G capable of controlling the maximum transfer number in several stages based on the maximum transfer number flag according to the sixth embodiment of the invention. Before starting operation, each terminal sets a maximum transfer count table G that defines the flag value and the maximum transfer count. When the packet retransmission control is performed, the transmission source terminal receives a response packet for confirming delivery to the transmission destination terminal. When the response packet is received, first, the terminal transfer flag e3- in the header section e3 is received. Count the number of terminals set to 2. Terminal transfer flag e3-
Since the number of terminals set to 2 is the same as the number of times the response packet has been copied and transferred, this information is stored. The terminal transfer flag e3 of the accumulated response packet when the retransmission packet is transmitted after a fixed time-out
-2, referring to the maximum transfer count table G, the optimum maximum transfer count flag e3 shown in FIG.
Set 13. In the retransmitted packet of a packet that has no response, a flag having a larger number of one-step transfer counts than the previous transmission is set as the optimum maximum transfer count flag e3-13 from the maximum transfer count table G and transmitted.

The sixth embodiment of the present invention is directed to the case where the data does not reach the destination terminal with the preset maximum transfer count of the packet or the copy transfer count is too large compared to the positional relationship of the terminals. By automatically controlling the number of transfers for each retry, a wide range of data transmission and an increase in copy transfer packets can be suppressed, and optimization is possible.

Seventh Embodiment of the Invention FIG. 18 shows a format of a packet broadcast from each terminal according to the seventh embodiment of the invention. In FIG. 18, the packet H is a SYNC pattern h1, a data length h2, a packet transfer count h3, a terminal transfer flag h4, a packet type h5, link information h6,
It is composed of CRCh7. Each bit of the link information h6 sets the own terminal number and the terminal number in the linked state. Therefore, by receiving the packet H transmitted from the own terminal and the terminal in the radio communication area, the link information h6 of the adjacent terminal is obtained at that time. It is possible to know which terminal is in the link state.

FIG. 19 shows the network configuration of the six terminals 31 to 36 according to the seventh embodiment of the invention. In the case of FIG. 19, it is the terminal 3 that can confirm the link state from the terminal 35.
2 and the terminal 36, and the terminal 31 and the terminal 34 beyond that.
The link status with and cannot be recognized (it is undefined).

FIG. 20 shows a link status table I according to the seventh embodiment of the invention. In FIG. 20, the information from the own terminal to the terminal at the second link destination can be recognized. Further, the link state table I can be created by considering the reversibility of the link state.

As in the seventh embodiment of the present invention, based on the link status table I, copy transfer is realized for the terminal itself and the terminals outside the radio wave communication area. A relay flag is added to the header of the packet to be transmitted / received in the system, which indicates whether or not the copy transfer of the corresponding packet can be executed, and the transmission source terminal transmits the packet to the terminal outside the radio communication area based on the link status table. Only when the relay flag is set. As a result, when packets are sent to a destination terminal that is within the radio wave notification area, copy transfer is not performed, but only the terminals outside the radio wave notification area are realized, thereby reducing the number of packets to be copied and transferred. It is possible to realize the optimum transfer function.

Eighth Embodiment of the Invention In the seventh embodiment of the invention, an example of the packet H having the link information h6 is given. However, when the slot transmitted by each terminal of the TDMA system shown in FIG. 2 can be uniquely set, as shown in FIG.
By providing the link information area K for constantly transmitting the link information to the TDMA slot J2, the link status of each terminal can be collected regardless of the transmission / reception of the packet, and more efficient information collection is possible and the delay of the collection is possible. Absent.

Ninth Embodiment of the Invention 22 shows a packet format transmitted and received in the system according to the ninth embodiment of the invention. 22, a packet E5 is provided with communication time information e3-14 in place of the packet transfer count e3-1 and the terminal transfer flag e3-2 of the packet E1 of FIG.
Each terminal of the system manages the time and synchronizes the time by adjusting all the terminals in the system to a certain reference time. For example, this is because each terminal is equipped with a GPS receiver, and in the case of the TDMA method shown in FIG. 2, the master station for synchronization puts time information in the NCS area in the slot.
It is possible for the slave station to synchronize the time in the device with the time of the master station based on the time information. Therefore, as shown in FIG. 22, transmission time information e3-1 that stores the time when the packet is transmitted is stored in the header portion e3 of the packet E5 that is transmitted and received.
4 is provided, and the transmission source terminal sets a transmission time that is time-synchronized at the time of packet transmission and transmits the packet. When performing the copy transfer of the packet E5, each terminal calculates the difference between the transmission time of the packet E5 and the current time as the elapsed time, and determines whether or not the preset value of the preset elapsed time is exceeded. If the specified time has elapsed, the packet E5 is discarded without being copied and transferred. If it is within the specified time, the packet E5 is copied and transferred. Therefore, by judging the copy transfer condition of the packet E5 as the elapsed time from the transmission time of the packet E5, each terminal can realize a simple copy transfer process.

[0047]

As described above, according to the first aspect of the invention, data transmission between a plurality of moving terminals,
In mobile wireless data transmission that transmits data to terminals outside the coverage area , the data may arrive at the final destination terminal by copying and transmitting the packet to be transmitted at each terminal in the system. Since it is possible, there is no need to store or update the transmission route from the transmission source terminal to the transmission destination terminal in each terminal and select it. This is effective when the positional relationship of the mobile body changes frequently, and it is not necessary to perform transmission route selection for each movement, and it is possible to reduce data non-delivery due to route selection delay. Further, when the plurality of packets that have been copy-transferred reach the destination terminal, it is equivalent to receiving a packet from a plurality of routes, and there is an effect of improving the certainty delivery rate of the packet.

According to the second aspect of the present invention, by limiting the number of packet transfers as a copy transfer condition, it is possible to suppress the increase in the number of copy packets in the wireless network to a fixed value or less, and to reduce the number of moving terminals. Copy transfer can be realized according to the degree of variation in the positional relationship. As a result, the transmission capacity of the wireless line for realizing data transmission and the processing load of the terminal can be suppressed, which is effective in suppressing the hardware cost of the wireless communication device of each terminal including the wireless device.

According to the invention of claim 3, when a set of terminals can be grouped according to the type of terminal or the class of the terminal, the positional relationship of the terminals and the range to share the information are determined to some extent. In the case where several sets can be configured, by implementing copy transfer only within that range, wasteful copy transfer can be eliminated and efficient data transmission can be realized. As a result, the transmission capacity of the wireless line for realizing data transmission and the processing load of the terminal can be suppressed, which is effective in suppressing the hardware cost of the wireless communication device of each terminal including the wireless device.

According to the fourth aspect of the present invention, when the packet transfer count is checked, the specified value of the maximum transfer count is changed according to the priority of the packet, so that the certainty delivery rate of the corresponding packet is improved and the radio wave notification is transmitted. The reachability to terminals outside the area is improved, and the number of packets in the network can be suppressed by copy transfer according to the importance of information. As a result, the transmission capacity of the wireless line for realizing data transmission and the processing load of the terminal can be suppressed, which is effective in suppressing the hardware cost of the wireless communication device of each terminal including the wireless device.

According to the fifth aspect of the present invention, the increase of packets in the network can be suppressed by performing the retransmission control by the retransmission request flag set in the transmission source terminal. As a result, it is possible to suppress the transmission capacity of the wireless line and the processing load of the terminal for realizing data transmission,
It is effective in suppressing the hardware cost of the wireless communication device of each terminal including the wireless device.

According to the sixth aspect of the present invention, when the data does not reach the destination terminal with the preset maximum transfer count of the packet, or when the copy transfer count is too large compared to the terminal positional relationship. By automatically controlling the number of transfers for each retry, it is possible to suppress a wide range of data transmission and an increase in copy transfer packets, and optimization is possible. As a result, the transmission capacity of the wireless line for realizing data transmission and the processing load of the terminal can be suppressed, which is effective in suppressing the hardware cost of the wireless communication device of each terminal including the wireless device.

According to the invention described in claim 7, while monitoring the link status of each terminal at a constant cycle, it is determined whether the source terminal and the destination terminal are within the radio communication area, and the copy transfer is performed at the time of packet transmission. By controlling the availability, it is possible to reduce the number of useless copy packets in the wireless network, and it is effective in suppressing the cost of the wireless communication device including the wireless device.

According to the eighth aspect of the present invention, each terminal judges the packet copy transfer condition based on the elapsed time from the packet transmission time, thereby reducing complicated processing in packet copy transfer. It is possible to reduce the cost of the wireless communication device.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a mobile wireless data transmission system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a transmission slot for multiple access according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a wireless communication device according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a transmission process according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a receiving process according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a transmitted / received packet format according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing copy transfer processing according to the second embodiment of the present invention.

FIG. 8 is a diagram showing a positional relationship of terminals according to the second embodiment of the present invention.

FIG. 9 is a diagram showing a sequence between terminals according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a layered network and its copy transfer according to the third embodiment of the present invention.

FIG. 11 is a diagram showing a packet format to be transmitted / received according to the third embodiment of the present invention.

FIG. 12 is a diagram showing a priority information table according to the fourth embodiment of the present invention.

FIG. 13 is a diagram showing a transmitted / received packet format according to a fifth embodiment of the present invention.

FIG. 14 is a flowchart showing a transmission process according to the fifth embodiment of the present invention.

FIG. 15 is a flowchart showing a receiving process according to the fifth embodiment of the present invention.

FIG. 16 is a diagram showing a packet format to be transmitted / received according to the sixth embodiment of the present invention.

FIG. 17 is a diagram showing a maximum transfer count table according to the sixth embodiment of the present invention.

FIG. 18 is a diagram showing a packet format for transmitting link information according to the seventh embodiment of the present invention.

FIG. 19 is a diagram showing a positional relationship of terminals according to the seventh embodiment of the present invention.

FIG. 20 is a diagram showing a link status table according to the seventh embodiment of the present invention.

FIG. 21 is a diagram showing link information according to the eighth embodiment of the present invention.

FIG. 22 is a diagram showing a packet format to be transmitted / received according to the ninth embodiment of the present invention.

FIG. 23 is an explanatory diagram of conventional mobile wireless communication.

FIG. 24 is an explanatory diagram of different conventional mobile wireless communication.

FIG. 25 is an explanatory diagram of still another conventional mobile wireless communication.

FIG. 26 is an explanatory diagram of the conventional mobile wireless communication.

[Explanation of symbols]

10 wireless communication device, 11 data terminal, 12 data terminal interface, 13 CPU, 14 memory, 1
5 timer, 16 radio interface, 17 radio, 18 reception history memory.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-2-5653 (JP, A) JP-A-8-32596 (JP, A) JP-A-59-103442 (JP, A) JP-A-3- 9637 (JP, A) JP-A-4-368034 (JP, A) JP-A-9-83528 (JP, A) JP-A-8-37531 (JP, A) JP-A-9-181772 (JP, A) JP 63-203035 (JP, A) JP 7-183911 (JP, A) JP 2-2757 (JP, A) JP 1-135154 (JP, A) JP 1-120928 (JP, A) JP-A-4-354225 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/56 H04L 12/28 300

Claims (8)

(57) [Claims] 1. Data transmission between a plurality of mobile terminals.
Therefore, data transmission to terminals outside the radio communication area is performed.
In the mobile wireless data transmission method, each terminal receives the packet, receives the packet, detects whether the received packet is normal, and discards the packet if the received packet is an incorrect packet. Means for determining whether or not the packet meets a copy transfer condition preset in each terminal by identifying the header part of the packet when the received packet is normal; Transfer means for copying and transferring the packet when the header part of the received packet satisfies the copy transfer condition, and the determining means is provided for the packet provided in the header part of the normally received packet. Is provided with a means for determining whether or not the transmission source terminal number representing the transmission source of the Mobile wireless data transmission system Xinyuan terminal number characterized by comprising means for discarding packets the received If a match with the own terminal number. 2. The determining means includes means for determining whether or not a destination terminal number, which is provided in a header portion of a packet that is normally received and represents a destination of the packet, matches the own terminal number, If the destination terminal number of the normally received packet does not match the own terminal number, the transfer means stores the number of times the packet is transferred, which is provided in the header section of the packet, and which terminal Refer to the terminal transfer flag indicating whether the packet has already been transferred, and if it is less than or equal to the maximum transfer count preset for each terminal and if the packet is not transferred at the local terminal, it is normally received. A packet which is normally received when the destination terminal number matches its own terminal number, and a packet which is newly received according to its history. 2. The mobile radio data transmission system according to claim 1, further comprising means for receiving the case of 3. The transfer means includes address information including a source terminal number and a destination terminal number provided in a header portion of a normally received packet, and hierarchical information indicating a classification of each terminal into a hierarchical structure. 3. The mobile wireless data transmission system according to claim 1, further comprising means for copying and transferring the packet only in the closed area of the address information of the hierarchical structure based on the above. 4. The header of the packet received based on the packet priority provided in the header of the normally received packet, the copy transfer permission / prohibition of the packet, and the maximum transfer count for the packet priority. The mobile radio data transmission system according to claim 1 or 2, further comprising means for identifying a unit, and said transfer means having means for copying and transferring a packet based on a packet priority. 5. Each of the terminals detects the error in the received packet when the destination number of the received packet is its own terminal, and requests retransmission of the packet, and a packet corresponding to the retransmission request. And a means for adding a retransmission request flag that expects a retransmission request for the corresponding data to the header portion of the packet transmitted and received within the system,
Means to analyze the header of the received packet, check the retransmission request flag preset by the source terminal and perform retransmission control, and the packet cannot be received normally based on the information in the header of the received packet. If the packet is recognized, a means for returning a resend request packet to prompt a resend request, a means for resending the corresponding packet when the resend request packet is received, and a means for indicating that the packet has been normally received The mobile wireless data transmission system according to claim 1 or 2, further comprising: means for returning a normal reception packet to a transmission source terminal. 6. Each of the terminals sets a resend request flag that expects a resend request of the corresponding data in a header part of a normally received packet, and sends the packet, and a resend request within a fixed time. 6. The mobile radio data according to claim 1, further comprising means for automatically changing the number of packet transfers unless a packet or a normally received packet is received again. Transmission method. 7. Each of the terminals recognizes and judges a terminal within a radio communication area of the terminal, a link state recognition means, a means for broadcasting the link information to another terminal at a constant cycle, and a link other than the own terminal. Means for receiving information from another terminal to create a link status table, means for adding a relay flag indicating execution of copy transfer of the packet to the header portion of the packet transmitted / received in the system, and the link status A means for setting a relay flag only when a packet is transmitted to a terminal outside the radio wave communication area based on the table, and a packet is copied and transferred according to a preset copy transfer condition only when the relay flag is set. The mobile wireless data transmission system according to claim 1 or 2, further comprising: 8. Each of the terminals manages time and adjusts the time to a certain reference time, and a header of a packet transmitted / received in the system is time-synchronized with the reference time to transmit the corresponding packet. A means for storing the transmission time, a means for recognizing the transmission time from the header of the received packet and recognizing the elapsed time from the difference between the current time and the transmission time, and a packet received within the specified elapsed time. The mobile wireless data transmission system according to claim 1, further comprising: a unit for copying and transferring, and a unit for discarding a packet received after a lapse of a specified elapsed time.