JP2007043435A - Wireless multihop network, communication terminal apparatus, and channel reservation method and program to be used for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a high-quality wireless communication line occupying time slots without consuming time slots to be wireless resources correspondingly to the number of hops. <P>SOLUTION: In the case of transmitting data from a communication terminal 11 to a communication terminal 15, time slots of a time-division multiplexing system are reserved on a wireless link of a communication route from the communication terminal 11 up to the communication terminal 15 via communication terminals 12 to 14 by signaling followed by control information from the communication terminal 11. Time slots to be used for transmitting data from the communication terminal 11 to the communication terminal 12 are reused for a wireless link from the communication terminal 14 to the communication terminal 15 which is separated from the communication terminals 12 by a plurality of hops to secure a communication route to the communication terminal 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless multi-hop network, a communication terminal apparatus, a channel reservation method used therefor, and a program therefor, and more particularly to time slot (channel) allocation to a wireless communication apparatus in a wireless multi-hop network.

  In order to configure a local area network by radio, a method is generally used in which a control station called an access point or coordinator is provided in the area, and the control station centrally controls communication within the area to form a network. ing. In order to accommodate a plurality of communications at the same time using this network forming method, a system reserves a band before the terminal starts communications, and controls so that the access point does not interfere with other communications. Is widely adopted.

  However, in this method of reserving the bandwidth, it is necessary that terminals in the wireless local area network can always communicate directly with the access point. There are cases where communication cannot be performed, access point control cannot be received, and bandwidth reservation cannot be performed.

  In order to solve this, ad-hoc communication has been devised in which terminals directly perform wireless communication without using a control device to form a network. In this ad hoc communication, a proactive method that notifies a neighboring terminal of the presence using a beacon indicating the location of the terminal and a reactive method that searches for a route by a broadcast method at the start of communication are devised.

  These methods can form a network in an autonomous and distributed manner even when there is no control station, so that communication can be performed. For example, when a communication path to the control station is secured, time slots are assigned from the control station. By reserving the bandwidth, the bandwidth can be secured and high-quality communication can be performed.

  Or, by broadcasting a time slot request, it is possible to make a bandwidth reservation without a control station, but since it is necessary to wait for a response from all wireless terminals, not only does it take time, but multiple bandwidth reservation requests If this occurs, duplication of slots will occur. This method is difficult to adapt in an autonomous distributed system in which the wireless communication environment changes due to movement.

  In a wireless multi-hop network using a conventional time-division multiplex wireless communication system, each wireless terminal is assigned a time slot with a transmission right in advance to avoid interference between the wireless terminals, and each wireless designated as a relay The terminal performs communication by selecting a time slot necessary for relaying (see, for example, Patent Document 1).

JP 2004-186935 A

  In the above-described conventional wireless multi-hop network, each wireless terminal pre-assigns a time slot with a transmission right, and each wireless terminal designated for relay performs communication by selecting a time slot necessary for relay, Since the allocated slot is used, interference between the radio terminals can be avoided, but there is a problem that radio resources are wasted.

  Also, in a conventional wireless multi-hop network, each wireless terminal uniquely assigns a relay time slot, so communication is continued without knowing whether or not the transmission source can occupy the time slot. ing. In other words, when the time slot is shared with other communication and the time slot is not occupied in the communication path, the communication speed and delay time from the transmission source to the transmission destination in communication that requires real-time characteristics Is significantly reduced, and there is a problem that it is used without satisfying the desired quality.

  Due to the above problems, in a wireless multi-hop network that consumes a pre-assigned time slot for each relay, not only the radio resources cannot be effectively used, but also the reliability of the line is impaired.

  Accordingly, an object of the present invention is to solve the above-described problems and to realize a high-quality wireless communication line that occupies a time slot or channel without wasting a time slot or channel that is a radio resource by the number of hops. An object of the present invention is to provide a wireless multi-hop network, a communication terminal apparatus, a channel reservation method used therefor, and a program thereof.

The wireless multi-hop network according to the present invention wirelessly exchanges control information between a plurality of communication terminal devices to form a network autonomously distributed, selects a route from a transmission source to a transmission destination, and the communication terminal device A wireless multi-hop network that performs signaling for reserving channels each with transmission rights,
Each of the plurality of communication terminal devices includes means for transmitting the signaling information by adding channel information allocated in the channel reservation process in addition to band reservation information, and transmission of the channel assigned to the signaling information. And means for reusing the channel when the information indicates a channel in a communication terminal apparatus separated by a plurality of hops.

A communication terminal device according to the present invention wirelessly exchanges control information between a plurality of communication terminal devices to form a network in an autonomous distributed manner, selects a route from a transmission source to a transmission destination, and each of the communication terminal devices Is a communication terminal device used in a wireless multi-hop network that performs signaling for reserving a channel having a transmission right,
Means for adding the channel information assigned in the channel reservation process in addition to bandwidth reservation information to the signaling information for transmission; and a communication terminal apparatus in which the channel information assigned to the signaling information is separated by a plurality of hops Means for reusing the channel when indicating the channel assigned to.

In the channel reservation method according to the present invention, control information is exchanged wirelessly between a plurality of communication terminal devices to form a network in an autonomous distributed manner, a route from a transmission source to a transmission destination is selected, and each of the communication terminal devices Is a channel reservation method used in a wireless multi-hop network that performs signaling for reserving a channel having a transmission right,
Each of the plurality of communication terminal devices transmits the signaling information by adding channel information allocated in the channel reservation process in addition to the bandwidth reservation information, and transmitting the channel information added to the signaling information. When the information indicates a channel in a communication terminal apparatus separated by a plurality of hops, processing for reusing the channel is executed.

  The program of the channel reservation method according to the present invention exchanges control information between a plurality of communication terminal devices wirelessly to form a network autonomously distributed, selects a route from a transmission source to a transmission destination, and the communication terminal A program of a channel reservation method used in a wireless multi-hop network that performs signaling for reserving a channel for which each device has a transmission right, wherein each of the plurality of communication terminal devices includes a bandwidth reservation information in the signaling information. In addition to the process of assigning and transmitting information on the channel assigned in the channel reservation process, and when the channel information assigned to the signaling information indicates a channel in a communication terminal device that is separated by multiple hops, the channel The process of reusing is executed.

  That is, the wireless multi-hop network of the present invention is a wireless multi-hop network in which control information is exchanged wirelessly between a plurality of communication terminals using a time division multiplexing wireless communication method, and the network is autonomously distributed. When selecting a route from the transmission source to the transmission destination and performing signaling for reserving a time slot or channel for which each communication terminal has a transmission right, in addition to bandwidth reservation information, the time slot allocated in the reservation process Alternatively, it is possible to realize a network that effectively uses radio resources by reusing time slots or channels by communication terminals that are separated by a plurality of hops by adding channel information and transmitting.

  More specifically, in the wireless multi-hop network of the present invention, when data is transmitted from the first communication terminal to the fifth communication terminal, the first communication terminal to the second to fourth communication as communication paths. In a wireless link on the route from the first communication terminal to the fifth communication terminal via the terminal, time division multiplexing is performed on the wireless links of the first to fifth communication terminals by signaling with control information from the first communication terminal. A time slot of a system (which can be expressed as a channel including a frequency multiplexing system) is reserved.

  The time slot used when transmitting data from the first communication terminal to the second communication terminal is reused in the radio link of the fifth communication terminal from the fourth communication terminal separated by a plurality of hops, and the fifth communication Secure a communication path to the terminal. Therefore, in the wireless multi-hop network of the present invention, it is possible to minimize the consumption of the time slot to which each of the first to fifth communication terminals has a transmission right by reusing the time slot. Effective use is possible.

  Further, in the wireless multi-hop network of the present invention, a node ID and a reserved slot number of a communication terminal to which a message is sent are assigned in a signaling message sent from a transmission source to a transmission destination. By adding to the message, it becomes possible to grasp the slot number in which each communication terminal that performs relay is used. As a result, in the wireless multi-hop network of the present invention, it is possible to avoid interference between communication terminals and reuse time slots in multiple hops of 3 hops or more.

  As described above, in the wireless multi-hop network of the present invention, even in the case where a large number of communications that require reservation of time slots occur in the wireless multi-hop network when the number of relay hops is large, the time slot that is a radio resource is hopped. A high-quality wireless communication line that occupies a time slot can be realized without wasting a few minutes.

  The present invention is configured and operated as described below to realize a high-quality wireless communication line that occupies a time slot or channel without wasting a time slot or channel that is a radio resource by the number of hops. The effect that it can be obtained.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a wireless multi-hop network according to an embodiment of the present invention. In FIG. 1, a wireless multi-hop network 1 according to an embodiment of the present invention is configured by communication terminals 11 to 15 in each of the communicable areas A11 to A15. In the following description, a case where the time division multiplexing method is used will be described. Therefore, a time slot is used for the description. However, a channel can be described in consideration of a case where the frequency multiplexing method is used.

  FIG. 2 is a diagram showing the structure of a signaling message used in one embodiment of the present invention. In FIG. 2, the signaling message used in one embodiment of the present invention is a message type, an expiration date, a message size, a transmission terminal ID (identification information), a sequence number, a hop count, a required slot number, and a usage. It is formed of a slot number, reserved information for the number of communication terminals constituting the route, transit node IDs, and reserved slot numbers.

  FIG. 3 is a block diagram showing the configuration of a communication terminal according to an embodiment of the present invention. In FIG. 3, each of the communication terminals 11 and 12 includes wireless communication devices 21 and 31, resource management units 22 and 32, time slot use management tables 23 and 33, and transmission right possessed time slot tables 24 and 34, respectively. Has been. Although not shown, the other communication terminals 13 to 15 have the same configuration as the communication terminals 11 and 12 described above.

  4 and 5 are flowcharts showing operations of the communication terminals 11 to 15 in FIG. The operation of the communication terminals 11 to 15 according to one embodiment of the present invention will be described with reference to FIGS. In the following description, the operation between the communication terminals 11 and 12 will be described. 4 and 5 is realized by a CPU (central processing unit) (not shown) of the communication terminals 11 to 15 executing a program (a program executable by a computer).

  In the wireless multi-hop network 1 according to the present embodiment, the signaling message shown in FIG. 2 is transmitted on the route from the communication terminal 11 to the communication terminal 15. In this case, the resource management unit 22 generates a signaling message so that the communication terminal 11 as a transmission source reserves a network time slot in advance before transmitting data (steps S1 and S2 in FIG. 4).

  The resource management unit 22 selects an available slot from the transmission right possessed time slot table 24 (step S3 in FIG. 4), and outputs and records the selected time slot number to the time slot use management table 23 (step S4 in FIG. 4). ). The resource manager 22 outputs the selected time slot number and the generated signaling message to the wireless communication device 21. The wireless communication device 21 adjusts the transmission timing based on the time slot number input from the resource management unit 22, and outputs the input signaling message wirelessly (step S5 in FIG. 4).

  The communication terminal 12 that has received the signaling message transmitted by the communication terminal 11 outputs the signaling message received by the wireless communication device 31 to the resource management unit 32 (step S6 in FIG. 5). The resource management unit 32 analyzes the signaling message received from the communication terminal 11 (step S7 in FIG. 5). It is determined whether the number of hops is exceeded (step S9 in FIG. 5).

  The resource management unit 32 selects the time slot number when the number of hops exceeds 3 hops or more (steps S10 and S11 in FIG. 5), and does not exceed the number of hops of 3 hops or more. In this case, an available slot is selected from the transmission right possessing time slot table 34 (steps S10 and S12 in FIG. 5), and is output and recorded in the time slot use management table 33 (step S13 in FIG. 5). Generate (step S14 in FIG. 5).

  Further, the resource management unit 32 outputs the time slot number output to the time slot usage management table 33 and the newly generated signaling message to the wireless communication device 31. The wireless communication device 31 adjusts the transmission timing based on the time slot number input from the resource management unit 32, and outputs the input signaling message wirelessly (step S15 in FIG. 5).

  FIG. 6 is a diagram showing an example of time slot transition according to one embodiment of the present description. The operation of the wireless multi-hop network according to the embodiment of the present description will be described with reference to FIGS. 1 to 3 and FIG.

  When transmitting data from the communication terminal 11 to the communication terminal 15, the communication terminal 11 transmits a signaling message in advance before transmitting data. When the communication terminal 12 receives the signaling message from the communication terminal 11, the resource management unit 32 counts the number of hops, and the number of hops is 2 hops or less. To obtain a slot according to the required number of slots.

  After acquiring the slot, the communication terminal 12 outputs and records the acquired slot number in the time slot use management table 33, and records a flag indicating that the acquired slot number is in use in the transmission right possessed time slot table 34. . Next, the resource management unit 32 outputs the acquired slot number to the wireless communication device 31, newly generates a signaling message in which the acquired slot information is added, and outputs it to the wireless communication device 31. The wireless communication device 31 adjusts the output timing based on the indicated slot information, and outputs a signaling message wirelessly.

  Subsequently, when the communication terminal 13 receives a message from the communication terminal 12, the communication terminal 13 performs the same processing as the communication terminal 12 described above, and the communication terminal 12 and the communication terminal 13 consumes a time slot with the transmission right. Relayed to.

  The communication terminal 14 is 3 hops away from the communication terminal 11, and the communicable area A 14 of the communication terminal 14 is at a distance that does not reach the communication terminal 11 and the communication terminal 12. Therefore, the communication terminal 14 reuses the time slot used for transmission by the communication terminal 11 and does not use the slot having the transmission right of the communication terminal 14 in the signaling message to the communication terminal 15 that becomes the next hop. Add the slot number and output.

  Time slot transition by the above operation will be described with reference to FIG. First, signaling to the communication terminal 12 is performed by the time slot TS1 used by the communication terminal 11. In response to this, the communication terminal 12 relays the signaling message to the communication terminal 13 using the time slot TS2 for which the communication terminal 12 has the transmission right.

  As with the communication terminal 12 described above, the communication terminal 13 newly uses a time slot TS3 to which the communication terminal 13 has a transmission right, and relays a signaling message to the communication terminal 14 through the time slot TS3. Since the communication terminal 14 is three hops away from the communication terminal 11, the time slot TS1 used by the communication terminal 11 is reused and the signaling message is relayed to the communication terminal 15 in the time slot TS1.

  After completion of the signaling, the communication terminal 15 transmits a message indicating the completion of reservation to the communication terminal 11, and thereafter, data transmission / reception is performed from the communication terminal 11 to the communication terminal 15 using the time slot reserved in the above-described processing. Is called.

  As described above, in this embodiment, in a wireless multi-hop network in which the number of relay hops is large, even when a lot of communication that requires time slot reservation occurs, the time slot that is a radio resource is wasted for the number of hops. In addition, a high-quality wireless communication line occupying a time slot can be realized.

  The present invention is not limited to the above-described embodiments, and is also applied to an apparatus that effectively uses frequency in relaying in a frequency division multiplexing system that relays by changing the frequency, for example, instead of time division multiplexing in a radio line can do.

1 is a block diagram illustrating a configuration of a wireless multi-hop network according to an embodiment of the present invention. FIG. It is a figure which shows the structure of the signaling message used in one Example of this invention. It is a block diagram which shows the structure of the communication terminal by one Example of this invention. It is a flowchart which shows operation | movement of the communication terminal of FIG. It is a flowchart which shows operation | movement of the communication terminal of FIG. It is a figure which shows an example of the time slot transition by one Example of this description.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wireless multi-hop network 11-15 Communication terminal 21,31 Wireless communication apparatus 22,32 Resource management part 23,33 Time slot use management table 24,34 Transmission right possession time slot table A11-A15 Communication area TS1-TS3 Time slot

Claims (13)

Exchange control information between multiple communication terminal devices wirelessly to form a network in an autonomous distributed manner, select a route from the transmission source to the transmission destination, and reserve a channel each of which has a transmission right A wireless multi-hop network that performs signaling to
Each of the plurality of communication terminal devices includes means for transmitting the signaling information by adding channel information allocated in the channel reservation process in addition to band reservation information, and transmission of the channel assigned to the signaling information. A wireless multi-hop network comprising means for reusing a channel when information indicates a channel in a communication terminal apparatus separated by a plurality of hops.   The means for reusing the channel adds the channel information assigned to the signaling information without adding the channel information assigned to the relay device to the signaling information when relaying the signaling information. 2. The wireless multi-hop network according to claim 1, wherein the wireless multi-hop network is directly added to signaling information to be relayed.   In the signaling information transmitted from the transmission source to the transmission destination, the node identification information and the channel information of the communication terminal device to which it passes are given, and the node identification information and The wireless multi-hop network according to claim 2, wherein the channel information is added to the signaling information.   The wireless multi-hop network according to any one of claims 1 to 3, wherein the wireless multi-hop network is used for relaying in at least one of time division multiplexing and frequency division multiplexing. Exchange control information between multiple communication terminal devices wirelessly to form a network in an autonomous distributed manner, select a route from the transmission source to the transmission destination, and reserve a channel each of which has a transmission right A communication terminal device used in a wireless multi-hop network that performs signaling for
Means for adding the channel information assigned in the channel reservation process in addition to bandwidth reservation information to the signaling information for transmission; and a communication terminal apparatus in which the channel information assigned to the signaling information is separated by a plurality of hops And a means for reusing the channel when indicating the channel assigned to the communication terminal device.   The means for reusing the channel relays the channel information assigned to the signaling information without giving the channel assigned to the device itself to the signaling information when relaying the signaling information. 6. The communication terminal apparatus according to claim 5, wherein the communication terminal apparatus adds the signal information as it is.   In the signaling information transmitted from the transmission source to the transmission destination, the node identification information and the channel information of the device that passes through are added, and the node identification information and the information of the channel that pass through the device each time. The communication terminal apparatus according to claim 6, wherein: is added to the signaling information.   The communication terminal apparatus according to any one of claims 5 to 7, wherein the communication terminal apparatus is used for relaying in at least one of time division multiplexing and frequency division multiplexing. Exchange control information between multiple communication terminal devices wirelessly to form a network in an autonomous distributed manner, select a route from the transmission source to the transmission destination, and reserve a channel each of which has a transmission right A channel reservation method used for a wireless multi-hop network that performs signaling for
Each of the plurality of communication terminal devices transmits the signaling information by adding channel information allocated in the channel reservation process in addition to the bandwidth reservation information, and transmitting the channel information added to the signaling information. And a process of reusing the channel when the information indicates a channel in a communication terminal apparatus separated by a plurality of hops.   In the process of reusing the channel, the information on the channel assigned to the signaling information is added to the signaling information without adding the information on the channel assigned to the relay apparatus when relaying the signaling information. The channel reservation method according to claim 9, wherein the channel reservation method is added to the signaling information to be relayed as it is.   In the signaling information transmitted from the transmission source to the transmission destination, the node identification information and the channel information of the communication terminal device that passes through are given, and the node identification information that passes through the communication terminal device The channel reservation method according to claim 10, wherein the channel information is added to the signaling information.   The channel reservation method according to any one of claims 9 to 11, wherein the channel reservation method is used for relaying in at least one of time division multiplexing and frequency division multiplexing.   Exchange control information between multiple communication terminal devices wirelessly to form a network in an autonomous distributed manner, select a route from the transmission source to the transmission destination, and reserve a channel each of which has a transmission right A channel reservation method program for use in a wireless multi-hop network for performing signaling, wherein the signaling information is assigned to each of the plurality of communication terminal apparatuses in the channel reservation process in addition to bandwidth reservation information. For performing transmission processing with the added channel information, and for reusing the channel information when the channel information added to the signaling information indicates a channel in a communication terminal device separated by a plurality of hops. Program.

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