JP2013005179A - Radio communication system, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay transmission technology enabling a plurality of radio stations located around a transmission source radio station and a destination radio station to perform multi-hop relay of radio packets in a coordinated manner.SOLUTION: A radio station comprises: region information acquisition means for acquiring identifier information of a divided region in which its own station is located, where the divided region is one of regions obtained by dividing a communication area in which the retransmission relay is performed, and identifier information of a reception region in which a radio station performing retransmission relay of a received radio packet is located; region agreement determination means for determining whether or not an identifier showing the reception region of the received radio packet agrees with an identifier of the divided region in which its own station is located; base station identifier acquisition means; identifier agreement determination means; retransmission relay implementation determination means; and radio packet transmission means for describing a next reception region in the received radio packet and transmitting the radio packet, when any of identifiers showing a transmission source or destination agrees with an identifier of a base station, the identifier showing the reception region agrees with the identifier of the divided region in which its own station is located, and it is determined that the retransmission relay should be performed.

Description

  The present invention relates to a wireless communication system in which a transmission source wireless station transmits and receives a wireless packet to and from a destination wireless station, and the distance between the transmission source wireless station and the destination wireless station is long or out of sight. The present invention relates to a wireless communication system and a wireless communication method for performing stable wireless communication even in an environment including a case where direct wireless communication is difficult.

  In particular, when direct communication between the source radio station and the destination radio station becomes difficult, when a plurality of radio stations located around the source radio station and the destination radio station have successfully received radio packets. In addition, the present invention relates to a relay transmission technique for these radio stations to perform multi-hop relay cooperatively.

  In recent years, the spread of wireless communication has been remarkable. From mobile communications such as mobile phones, provision of spot wireless LAN services in quasi-stationary environments, provision of FWA (Fixed Wireless Access) services that provide wireless lines to homes as an alternative to wired lines such as optical fibers, etc. Services utilizing the advantages of wireless communication are being developed in various forms. At this time, from a business standpoint, it is desirable to cover a wide area with a small number of base station facilities and accommodate more user terminals. However, in general, the area area that can be covered by a single base station varies depending on conditions specific to the system (for example, frequency, transmission output, antenna gain, antenna installation location, modulation method, etc.) and propagation environment. For example, when a high-power transmission amplifier is provided as a function on the transmission side of a radio station, a wider area can be set as a service area. In general, a lower frequency is transmitted farther away.

  However, using a high-function, high-power transmission amplifier with high linearity will increase the price of the equipment, and there is also an upper limit on the transmission output according to regulations such as the Radio Law, so a transmission amplifier with too much power will be used. It is not desirable to expand the service area by using it. On the other hand, low frequency microwave bands are being used in many systems as easy-to-use frequency bands, so the frequency resources are already being depleted and it is expected that licenses will be allocated to new systems. Can not.

  As a result, when providing a service to a wide service area using a relatively high frequency band, the service area area obtained from the circuit design is often not sufficient from the viewpoint of business profitability. As a countermeasure in this case, it is conceivable to construct a wireless multi-hop network using many wireless stations in the area and perform relay transmission. As an example of such a multi-hop network, for example, a meshwork in a wireless LAN standard called IEEE802.11s is famous (see Non-Patent Document 1). Here, data arrives from a source radio station to a destination radio station. A routing method such as AODV has been proposed.

FIG. 11 shows an overview of routing in a prior art wireless multi-hop network.
In FIG. 11, reference numeral 100 denotes a network, 101 to 104 are wireless stations (specifically, 101 is a transmission source wireless station, 102 is a destination wireless station, and 103 to 104 are relay nodes). Represents a radio metric value. For example, when data is transferred from the network 100 to the wireless station 103, the wireless station 101 and the wireless station 103 can simply cope with each other by directly communicating via a wireless line. On the other hand, when data is transferred to the wireless station 102 that cannot directly communicate with the wireless station 101, the route of the transmission source wireless station 101 → the relay node 103 → the destination wireless station 102 and the transmission source wireless As in the route of the station 101 → the relay node 104 → the destination wireless station 102, a routing process for searching for an optimum route from routes having a plurality of options is required.

  In this routing process, first, a wireless metric defined as an index indicating the state of a wireless line such as a transmission speed, a traffic amount, and an interference amount that can be operated between wireless stations is used. In order to simplify the description, it is assumed here that the state of the wireless line is preferable when the wireless metric value is small. For example, in FIG. 11, the wireless metric value between the transmission source wireless station 101 and the relay node 103 is “12”, the wireless metric value between the transmission source wireless station 101 and the relay node 104 is “10”, and the relay node The radio metric value between 103 and the destination radio station 102 is “20”, and the radio metric value between the relay node 104 and the destination radio station 102 is “12”. Processing for performing routing under these conditions is shown below.

(Step 1) Each radio station exchanges radio metrics with neighboring radio stations.
(Step 2) The source wireless station 101 broadcasts a request packet in the multihop network. Specifically, a request packet containing a radio metric value is sent from the transmission source radio station 101 to neighboring relay nodes 103 to 104.

(Step 3) Each relay node 103 to 104 further adds a request packet obtained by adding (accumulating or adding) a radio metric value to the next radio station to the radio metric value in the received request packet. Send to. In FIG. 11, since both the relay node 103 and the relay node 104 have only the destination wireless station 102 as a relay destination, a request packet is transmitted to this station.

(Step 4) The destination radio station 102 refers to the radio metric value accommodated in the received request packet, and selects the one with the minimum radio metric value accumulated or added over the entire route. In FIG. 11, the route of the transmission source radio station 101 → the relay node 103 → the destination radio station 102 is the integrated (or addition) value of the radio metric values “12” and “20”, and the transmission source radio station 101 → the relay node as a route. Since the route of 104 → destination wireless station 102 is an integrated (or added) value of the radio metric values “10” and “12”, the route of the source wireless station 101 → relay node 104 → destination wireless station 102 is the route. It is judged preferable.

(Step 5) The destination wireless station 102 notifies the relay node of the route selected using the response packet. In FIG. 11, a response packet is sent to the relay node 104.

(Step 6) The relay node 104 that has received the response packet transfers the response packet to the previous wireless station on this route. Specifically, a response packet is transmitted to the transmission source radio station 101, and in the multi-hop network, the route of the transmission source radio station 101, the relay node 104, and the destination radio station 102 is selected and communication is determined.

  The above is an outline of routing in a multi-hop network. In general, when a large number of radio stations coexist, the number of logical routes becomes enormous, and it takes time to select an optimum route from among them. Therefore, in order to appropriately perform such routing processing, there is no change in the topology of the multi-hop network for a certain period, or the state of the individual link of each route is constant for a certain period and the change is small. This assumption is necessary.

FIG. 12 shows a configuration example of a radio station apparatus in the prior art.
In FIG. 12, 121 is a radio station apparatus, 122 is a radio unit, 123 is a baseband signal processing unit, 124 is a radio packet termination unit, 125 is an interface unit, 126 is an antenna, 127 is a communication control unit, and 128 is an identifier acquisition unit. Reference numeral 129 denotes an identifier match determination unit, 130 denotes a radio metric management unit, and 131 denotes the entire control unit. The radio station apparatus here is a general radio station apparatus including a base station and a terminal station, and the basic operation is as described below. In addition, if it is a base station, the function for managing the subordinate terminal station etc. will be added, For example, these functions can be seen as a part of function of the communication control part 127. FIG.

  The radio station apparatus 121 receives a signal via a radio line by an antenna 126, and performs filtering of an out-of-band signal by the radio unit 122, signal amplification by a low-noise amplifier, frequency conversion from an RF frequency to a baseband, and analog signal to digital Processing such as A / D conversion to a signal is performed. The digitized baseband signal is input to the baseband signal processing unit 123 and subjected to a series of baseband signal processing such as timing detection, termination of header information related to the physical layer, demodulation processing, and error correction. The specific processing content here depends on the radio system provided in the radio station apparatus, but the basic operation described below does not depend on the radio system.

  The demodulated signal output from the baseband signal processing unit 123 is input to the wireless packet termination unit 124, where the format of the packet communicated on the wired network such as Ethernet (registered trademark) from the wireless communication format. Is converted to This wireless packet includes overhead such as a so-called header area, and terminates various control information and error detection bits. For example, for a wireless packet determined to have no error by the error detection function, an identifier indicating a destination, a transmission source, or the like is extracted from the header information and transferred to the communication control unit 127. The communication control unit 127 manages the header information. The identifier acquisition unit 128 extracts the destination identifier from the header information, and the identifier match determination unit 129 determines match / mismatch with the own station identifier. This result is fed back to the communication control unit 127, and when it is determined that the destination is the local station, the communication control unit 127 instructs the wireless packet termination unit 124 to output data, and the format-converted packet The interface unit 125 adjusts electrical conditions and the like and outputs them to the outside.

  Conversely, when a packet is input from the outside, it is input to the wireless packet termination unit 124 via the interface unit 125, where header information is added according to an instruction from the communication control unit 124, and further an error detection code, etc. Is added to generate a wireless packet. Here, in addition to the identifier of the destination wireless station, the identifier of the own station is given as the identifier of the transmission source. This signal is input to the baseband signal processing unit 123, where various modulation processes are performed in addition to the addition of header information related to the physical layer and the encoding for error correction, and the preamble signal is added to the base of the radio packet. Generate a band signal. This signal is input to the wireless unit 122, performs D / A conversion for converting a digital signal into an analog signal, frequency conversion, filtering of out-of-band signals, signal amplification, and the like, and is transmitted from the antenna 126.

  When the above routing process is performed, the communication control unit 127 generates and terminates a request packet and a response packet, and manages a wireless metric value that is a communication state with surrounding wireless stations at that time. The necessary information is stored in a database through the wireless metric management means 130 for management.

  The series of signal processing described above is an overview of the entire process, and details include more detailed processing. For example, various timings such as management of a time division switch corresponding to switching between transmission and reception in the radio unit The communication control unit 127 performs control mainly from management to generation / termination of various control information. Further, here, the identifier acquisition unit 128, the identifier match determination unit 129, and the wireless metric management unit 130 have been described separately from the communication control unit 127, but it is also possible to regard all of these as one control unit 131. is there. In other words, it is not necessary to configure as a separate circuit different in hardware, and the entire control unit 131 exists as one circuit that performs software processing, and it is considered that logical functions are separated in its internal processing. It is possible.

Hidenori Aoki et al. “IEEE802.11s Wireless LAN Mesh Network Technology” NTT DoCoMo Technical Journal Vol.14 No.2 pp.14-pp.22, July 2006

The following problems exist in the multi-hop relay with the above routing.
(1) Since the routing processing of the prior art takes time from the start to the completion, frequent rerouting is necessary when the topology of each radio station that can be a relay node and the communication state of each link change rapidly. It becomes. This frequent rerouting overhead reduces communication efficiency.

  (2) Since the communication selected by routing is a combination of multiple stages of one-to-one communication, if an unstable ring exists somewhere on the path, the link is the communication characteristic of all paths. There is a risk of becoming a bottleneck that affects

  Regarding the above problem (1), for example, consider a multi-hop network composed of radio stations mounted in a large number of vehicles moving at high speed. In this case, each car is moving at a high speed, and in particular, in a network in which cars traveling in opposite directions are mixed, the topology changes rapidly. When a large number of vehicles can serve as relay nodes, it takes time to search for an optimum route when searching for various routes. For example, assume that routing takes about 1 second. If each car is moving at 60 km / h, the relative speed of cars traveling in opposite directions will be 120 km / h. Since the distance moved per second at this speed is about 33 m, the topology changes greatly with the movement of this distance. That is, the radio metric value obtained in the above (step 1) at the start of routing changes to a completely different value at the completion of routing, and if communication is continued for 1 second in that state, the accumulated car is about 67 m. It has moved. During this time, another car may enter the link where the line of sight should have been secured, and the line of sight may be interrupted. That is, the time required for routing must be small enough to be negligible with respect to the time scale in which the communication state is considered to be stable. However, this condition cannot be satisfied in the above-described wireless multi-hop network between automobiles.

  Regarding the above problem (2), consider a case where a base station connected to a network provides an FWA service to neighboring households. In this case, the base station has an antenna installed at a relatively high place, and it is highly likely that each user's home can be seen. However, since propagation attenuation with distance is inevitable, the reception level decreases as the distance increases, and as a result, the area where direct communication is possible is limited. Consider a case where an FWA terminal station in which a multi-hop network is set in the user's home is used as a relay node in such a state.

  Since each relay node is installed at a low place with respect to the base station, it is unlikely that a line of sight can be secured between the relay nodes. Furthermore, when there is an area where the density of radio stations that can locally become relay nodes is very low, the quality of communication between the relay nodes and the relay nodes deteriorates, and any of the selected routes If the link is unstable, the communication quality as a whole also becomes unstable. In the first place, the reason why such a problem occurs is that the conditions and installation environment of the base station and the general terminal station are asymmetric, and the communication between the base station and each terminal station is relatively good. However, communication between terminal stations is generally inferior in communication quality compared to communication with base stations, so if there is no element to compensate for the asymmetry, the efficiency of relaying in a multihop network Will decline.

  As described above, when the topology of the multi-hop network changes abruptly or when there is a non-target between the base station and the terminal station in the multi-hop network, the above (1), (2) New technology to solve this problem will be required.

  The present invention enables stable communication by suppressing the influence of the topology change even when the topology of the multi-hop network rapidly changes, and even when an unstable link exists somewhere on the route, An object of the present invention is to provide a wireless communication system and a wireless communication method that enable stable communication while avoiding the risk that the unstable link becomes a bottleneck that affects the communication characteristics of all paths.

  A first aspect of the invention is a wireless packet that includes one base station and a plurality of wireless stations, and describes identifier information indicating a transmission source and a destination between the base station and a wireless station of a communication partner in the wireless station. In a wireless communication system that performs retransmission relaying in multihop, a wireless station receives, from a plurality of divided areas obtained by dividing a communication area to be subjected to retransmission relay, identifier information of a divided area in which the local station is located, and reception An area information acquisition unit that acquires identifier information of a reception area that is a divided area where a radio station that retransmits the received wireless packet at the next transmission opportunity, and an identifier indicating the reception area acquired from the received wireless packet are An area match determination means for determining whether or not the identifier of the divided area where the station is located, a base station identifier acquisition means for acquiring an identifier of the base station to which the station is connected, An identifier match judging means for judging whether or not the identifier indicating the source or destination acquired from the packet matches the identifier of the base station or the identifier of the own station, and the retransmission relay termination condition described in the wireless packet Alternatively, according to any of the retransmission relay termination conditions defined on the system, the retransmission relay execution determining means for determining whether or not to perform retransmission relay of the received wireless packet, and the identifier match determining means for the source or destination It is determined that any of the identifiers indicating the base station identifier matches, and the region match determination unit determines that the identifier indicating the reception region matches the identifier of the divided region where the own station is located, and the retransmission relay execution determination unit Wireless packet transmission means for transmitting the next reception area in the received wireless packet when it is determined that retransmission relay should be performed in When an identifier indicating a destination with an identifier match determining means is determined to match the identifier indicating the own station, and a wireless packet terminal means for terminating the wireless packet received extracted data.

  In the wireless communication system of the first invention, the wireless packet transmitting means determines that the received wireless packet is a downlink wireless packet if the identifier indicating the transmission source acquired from the received wireless packet matches the identifier of the base station. If the identifier indicating the destination acquired from the base station matches the identifier of the base station, it is determined as an uplink radio packet, the next reception area of the radio packet is specified according to whether it is a downlink or uplink, and the radio packet to be transmitted This is the configuration to be described.

  In the wireless communication system of the first invention, the base station and the wireless packet transmission means of the wireless station describe identifiers indicating a plurality of reception areas in a wireless packet to be transmitted or retransmitted, and the area match determination means includes a plurality of reception In this configuration, it is determined whether or not an identifier indicating one reception area in the area matches the identifier of the divided area where the local station is located.

  In the wireless communication system of the first invention, the region information acquisition means is configured to acquire identifier information of a destination region that is a divided region where a wireless station that is a destination of a wireless packet is located. The identifier indicating the destination area acquired from the wireless packet is configured to determine whether or not the identifier of the divided area where the own station is located, and the retransmission relay execution determining unit indicates the destination area by the area matching determining unit. When it is determined that the identifier matches the identifier of the divided area where the local station is located, it is determined that the retransmission relay of the wireless packet should be terminated.

  A second invention is a wireless packet that includes one base station and a plurality of wireless stations, and describes identifier information indicating a transmission source and a destination between the base station and a wireless station of a communication partner in the wireless station. In the wireless communication method for performing relay relay in a multi-hop manner, the wireless station is located in a plurality of divided regions obtained by dividing the communication area to be subjected to retransmission relay using the region information acquisition means. The step of obtaining the identifier information of the divided area, the identifier information of the receiving area that is the divided area where the radio station that repeats and relays the received wireless packet at the next transmission opportunity, and the area matching determination means The step of determining whether or not the identifier indicating the reception area acquired from the wireless packet matches the identifier of the divided area where the local station is located, and the base station identifier acquisition means is used to connect the local station. Whether the identifier indicating the source or destination acquired from the received wireless packet matches the identifier of the base station or the own station using the identifier matching determination means. Using the retransmission relay execution determination means, and according to either the retransmission relay termination condition described in the wireless packet or the retransmission relay termination condition defined in the system, Determining whether retransmission relay should be performed or terminated, and using wireless packet transmission means, it is determined by the identifier match determination means that either the identifier indicating the source or destination matches the identifier of the base station, and The area matching determination means determines that the identifier indicating the reception area matches the identifier of the divided area where the local station is located and When it is determined that retransmission relay should be performed in step (b), the step of transmitting the next reception area in the received wireless packet and transmitting the received packet and the identifier indicating the destination by the identifier match determination unit using the wireless packet termination unit A step of terminating the received wireless packet and extracting data when it is determined that the identifier matches the identifier indicating the own station.

  In the wireless communication method of the second invention, the wireless packet transmitting means determines that the received wireless packet is a downlink wireless packet if the identifier indicating the transmission source acquired from the received wireless packet matches the identifier of the base station. If the identifier indicating the destination acquired from the base station matches the identifier of the base station, it is determined as an uplink radio packet, the next reception area of the radio packet is specified according to whether it is a downlink or uplink, and the radio packet to be transmitted is determined. Describe.

  In the wireless communication method of the second invention, the base station and the wireless packet transmission means of the wireless station describe identifiers indicating a plurality of reception areas in a wireless packet to be transmitted or retransmitted, and the area match determination means includes a plurality of reception It is determined whether or not the identifier indicating one reception region in the region matches the identifier of the divided region where the own station is located.

  In the wireless communication method of the second invention, the region information acquisition means acquires identifier information of a destination region that is a divided region where the wireless station that is the destination of the wireless packet is located. It is determined whether or not the identifier indicating the acquired destination area matches the identifier of the divided area where the own station is located, and the retransmission relay execution determining means determines that the identifier indicating the destination area is the position of the own station by the area matching determining means. When it is determined that it matches the identifier of the divided area to be determined, it is determined that the retransmission relay of the wireless packet should be terminated.

  The wireless communication system and the wireless communication method of the present invention enable the transmission source wireless station and the destination wireless station to perform relay relaying in multihop in a situation where it is difficult for the transmission source wireless station and the destination wireless station to directly perform data communication. When communication between stations is realized, it is possible to realize without requiring a routing process for optimizing a route in which one-to-one communication is combined in multiple stages. As a result, even when the topology of the multi-hop network changes abruptly, it becomes possible to provide stable communication while suppressing the influence of the topology change.

  Also, instead of combining one-to-one communication in multiple stages, a plurality of wireless stations are involved in retransmission relay, so even if there is an unstable ring somewhere on the route, many other Since routes are operated in parallel, it is possible to avoid the risk that unstable local links become a bottleneck that affects the communication characteristics of all routes.

It is a figure which shows the system configuration example to which the retransmission relay in this invention is applied. It is a figure which shows the basic operation example of the retransmission relay in this invention. It is a figure which shows the basic structural example of the radio station apparatus in this invention. It is a figure which shows the basic processing flow of the retransmission relay in this invention. It is a figure which shows the operation example 1 of the retransmission relay in Example 1 of this invention. It is a figure which shows the operation example 2 of the retransmission relay in Example 1 of this invention. It is a figure which shows the structural example of the radio station apparatus in Example 1 of this invention. It is a figure which shows the processing flow of the retransmission relay in Example 1 of this invention. It is a figure which shows the operation example of the retransmission relay in Example 2 of this invention. It is a figure which shows the processing flow of the retransmission relay in Example 2 of this invention. It is a figure which shows the outline | summary of the routing in the radio | wireless multihop network of a prior art. It is a figure which shows the structural example of the radio station apparatus in a prior art.

  Embodiments of a wireless communication system according to the present invention will be described below with reference to the drawings. First, the overall basic operation will be described before the description of the individual embodiments. In this specification, the term “retransmission relay” is used, but this is different from communication in which one-to-one communication at the time of multi-hop relay is combined in multiple stages, and the transmission source described in the header area It is intended to relay without rewriting the identifier of the destination wireless station, and does not mean so-called retransmission for error correction (ARQ: Automatic Repeat reQest).

FIG. 1 shows a system configuration example to which the retransmission relay according to the present invention is applied.
In FIG. 1, 1-1 to 1-2 are base stations, 2-1 to 2-7 and 3-1 to 3-7 are radio stations, 4-1 to 4-2 are radio packets, 5-1 to 5 -2 represents the service area of each base station, and 100 represents a network.

  Base stations 1-1 and 1-2 connected to the network 100 form service areas 5-1 and 5-2, respectively. The service area 5-1 is an area managed by the base station 1-1, and the service area 5-2 is an area managed by the base station 1-2. Radio stations 2-1 to 2-7 exist in the service area 5-1, and radio stations 3-1 to 3-7 exist in the service area 5-2. The radio stations 2-1 to 2-3 can communicate with the base station 1-1, but the other radio stations 2-4 to 2-7 cannot directly communicate with the base station 1-1. The service area here refers to an area that is expanded as a multi-hop network by a radio station managed by the base station 1-1 and in which the radio station can communicate with the base station 1-1. Each of the base stations 1-1 to 1-2 and each of the wireless stations 2-1 to 3-7 is assigned an identifier. For example, the base station 1-1 has “A”, and the base station 1-2 has The identifier of “B”, “a” for the wireless station 2-1, “b” for the wireless station 2-2,..., “N” for the wireless station 3-7.

  Assume that the radio stations 2-1 to 3-7 belonging to each service area 5-1 to 5-2 know the identifier of the base station that manages the service area. This grasping method may be any method. For example, in the case of an FWA service, base station information for each service area may be set at the time of service contract. If the position of the wireless station is known, it is provided on the network or the wireless station. The identifier of the base station may be grasped by referring to the database and the position information. Furthermore, the base station may notify the users in the area. In this way, for example, the wireless stations 2-1 to 2-7 in the service area 5-1 recognize in advance that the identifier of the base station 1-1 that manages the own station is “A”. .

  Next, consider a case where there is data to be transmitted from the network 100 to the radio station 2-7. This data is input from the network 100 to the base station 1-1, and the base station 1-1 generates a wireless packet 4-1 including a transmission source identifier “A” and a destination identifier “g” in the header area. Send. This wireless packet 4-1 is received by wireless stations 2-1 to 2-3 in the vicinity of the base station 1-1. For example, when the wireless station 2-1 receives the wireless packet 4-1, the wireless station 2-1 recognizes the transmission source identifier “A” and the destination identifier “g” given to the header area. Here, since the identifier of the base station 1-1 that manages the own station is “A”, it can be recognized that the transmission source is the base station 1-1 that manages the own station. Assume that the wireless stations 2-1 to 2-3 that have received the wireless packet 4-1 under such conditions retransmit the wireless packet and the wireless stations 2-4 to 2-6 have received it. Similarly, these wireless stations 2-4 to 2-6 receive the wireless packet equivalent to the wireless packet 4-1, and recognize the transmission source identifier “A” and the destination identifier “g” given to the header area thereof. To do.

  Here, since the identifier of the base station 1-1 that manages the wireless station 2-4 to 2-6 is "A", the transmission source is the base station 1-1 that manages the local station. Can be recognized. Similarly, the radio packet is retransmitted and received by the radio station 2-7. The wireless station 2-7 recognizes the transmission source identifier “A” and the destination identifier “g” given to the header area of the received wireless packet, and recognizes that the destination identifier matches the identifier of the own station. As a result, it is possible to recognize that this wireless packet is addressed to the own station, terminate this wireless packet, and take out the data contained therein. In this way, communication from the base station 1-1 to the radio station 2-7 is realized.

  Next, uplink communication from the downstream to the upstream of the multihop network will be described. For example, consider a case where there is data to be transmitted from the wireless station 3-7 to the network 100 side. The wireless station 3-7 generates a wireless packet 4-2 including a transmission source identifier “n” and a destination identifier “B” in the header area, and transmits this. This wireless packet is received by wireless stations 3-4 to 3-6 in the vicinity of the wireless station 3-7. For example, when receiving the wireless packet 4-2, the wireless station 3-4 recognizes the transmission source identifier “n” and the destination identifier “B” given to the header area. Here, since the identifier of the base station 1-2 that manages the own station is “B”, it can be recognized that the destination is the base station 1-2 that manages the own station. Assume that the wireless stations 3-4 to 3-6 that have received the wireless packet 4-2 under such conditions retransmit the wireless packet and that the wireless stations 3-1 to 3-3 have received it. Similarly, these wireless stations 3-1 to 3-3 receive a wireless packet equivalent to the wireless packet 4-2 and recognize the transmission source identifier “n” and the destination identifier “B” given to the header area. To do.

  Here, since the identifier of the base station 1-2 that manages its own station is “B”, the wireless stations 3-1 to 3-3 also recognize that the destination is the base station 1-2 that manages its own station. can do. Similarly, the wireless packet is retransmitted and received by the base station 1-2. The base station 1-2 recognizes the transmission source identifier “n” and the destination identifier “B” given to the header area of the received wireless packet, and recognizes that the destination identifier matches the identifier of the own station. As a result, it is possible to recognize that this wireless packet is addressed to the own station, terminate this wireless packet, take out the data accommodated therein, and transfer it to the network 100. In this way, communication from the radio station 3-7 to the base station 1-2 is realized.

  It should be noted here that, for example, a signal equivalent to the wireless packet 4-2 retransmitted by the wireless station 3-4 due to leakage of radio waves from a nearby service area is transmitted to the base station 1-1. It is assumed that, for example, the radio station 2-3 or the radio station 2-6 (which means that the radio station 2-3 exists in the service area 5-1 of the base station 1-1) has been received. At this time, the wireless station 2-3 or 2-6 can recognize the transmission source identifier “n” and the destination identifier “B” given to the header area of the received wireless packet. Since it does not match the identifier “A” of the base station 1-1 that manages the retransmission, retransmission relay is not performed.

  The above is the basic operation. The feature is that there are a plurality of radio stations that perform retransmission relay, and all of them transmit signals of the same content at the same frequency and at the same timing. When the frequency error of each radio station can be ignored, even if there is a slight timing error, it can be regarded as a signal equivalent to a multipath signal. In addition, in FIG. 1, since three radio stations transmit at the same time, the total transmission power is tripled, and a diversity effect is also obtained because the signals are from physically different places. On the receiving side, signals from multiple radio stations are combined and received, so it is expected that the characteristics will vary from radio station to radio station, but the gain is improved by the number of relay stations with respect to the average received power. Therefore, it is expected that the line gain of the entire system is greatly improved. In particular, even if there is a locally unrecognizable link, signals can be received from a plurality of radio stations, and a plurality of candidates exist on the receiving side, so the diversity effect is very large. Furthermore, since the one-to-one communication is not configured in multiple stages, a routing process for selecting an optimum route is unnecessary, and it is possible to flexibly cope with a sudden change in topology.

FIG. 2 shows a basic operation example of retransmission relay in the present invention.
In FIG. 2, 11 is a base station, 12-1 to 12-9 are radio stations that perform retransmission relay, and 13 is a destination radio station. 2 (1) shows the positional relationship between the base station 11, the radio stations 12-1 to 12-9, and the destination radio station 13, and FIG. 2 (2) shows the transmission of each radio station in the time slots # 1 to # 8. Or a reception state is shown and a horizontal axis shows time.

  In time slot # 1, when the base station 11 transmits a radio packet to the radio station 13, the radio stations 12-1 to 12-3 receive this signal. In the next time slot # 2, the base station 11 transmitting in the previous time slot # 1 and the receiving radio stations 12-1 to 12-3 perform retransmission relaying, and the radio stations 12-4 to 12-12. -6 receives this radio packet. In the next time slot # 3, the base station 11 and the radio stations 12-1 to 12-3 transmitting in the previous time slot # 2 and the receiving radio stations 12-4 to 12-6 repeat retransmission The wireless stations 12-7 to 12-9 receive this wireless packet. In the next time slot # 4, the base station 11 and the radio stations 12-1 to 12-6 that have been transmitting in the previous time slot # 3 and the radio stations 12-7 to 12-9 that have received the transmission operation The destination wireless station 13 receives this wireless packet. Thereby, the wireless packet transmitted by the base station 11 can be received by the destination wireless station 13.

  Similarly, when the wireless station 13 transmits a wireless packet addressed to the base station 11, when the wireless station 13 transmits the wireless packet in time slot # 5, the wireless stations 12-7 to 12-9 receive this wireless packet. . In the next time slot # 6, the wireless station 13 transmitting in the previous time slot # 5 and the receiving wireless stations 12-7 to 12-9 perform retransmission relaying, and the wireless stations 12-4 to 12-12. -6 receives this radio packet. In the next time slot # 7, the radio station 13 and radio stations 12-7 to 12-9 transmitting in the previous time slot # 6 and the receiving radio stations 12-4 to 12-6 repeat retransmission The wireless stations 12-1 to 12-3 receive this wireless packet. In the next time slot # 8, the radio station 13 and radio stations 12-4 to 12-9 that were transmitting in the previous time slot # 7 and the radio stations 12-1 to 12-3 that were received are retransmitted. The destination base station 11 receives this wireless packet. As a result, the radio packet transmitted by the radio station 13 can be received by the base station 11.

  Here, until a predetermined time slot, each wireless station continues to repeatedly transmit the received wireless packet. In this manner, the final radio packet delivery can be ensured by increasing the total transmission power.

FIG. 3 shows a basic configuration example of a radio station apparatus according to the present invention.
In FIG. 3, 21 is a radio station device, 22 is a radio unit, 23 is a baseband signal processing unit, 24 is a radio packet termination unit, 25 is an interface unit, 26 is an antenna, 27 is a communication control unit, and 28 is an identifier acquisition unit. , 29 is an identifier match determination unit, 30 is a base station identifier acquisition unit, 31 is a retransmission relay execution determination unit, and 32 is an entire control unit. As described in the description of the prior art, the wireless station device here is a general wireless station device including a base station and a terminal station. If it is a base station, a function for managing a terminal station under its control, etc. However, since these functions can be regarded as a part of the functions of the communication control unit 27, it is basically possible to understand including the base station and the terminal station in the following description. .

  The basic operation is the same as that of the prior art, but the operation in the case of retransmitting a packet other than the wireless packet addressed to the own station is different. Therefore, only this point will be described here. A signal via a wireless line is received by the antenna 26, and the signal processed by the wireless unit 22 and the baseband signal processing unit 23 is input to the wireless packet terminator 24. Is converted to a typical packet format. Here, the header information attached to the wireless packet is taken out and transferred to the communication control unit 27. The communication control unit 27 manages the header information. The identifier acquisition unit 28 extracts the source identifier and the destination identifier from the header information, and the identifier match determination unit 29 connects the local station identifier and the local station to which the local station is connected. A match / mismatch determination with the identifier is performed. This result is fed back to the communication control unit 27, and when it is determined that the destination is the local station, the communication control unit 27 instructs the wireless packet termination unit 24 to output data, and the format-converted packet Is output to the outside by adjusting the electrical conditions and the like in the interface unit 25.

  On the other hand, when the identifier match determining unit 29 determines that the source identifier or the destination identifier is not addressed to the own station but matches the identifier of the base station to which the own station is connected, this result is used as the retransmission relay execution determining unit 31. The retransmission relay execution determination means 31 determines whether or not the retransmission relay can be performed in consideration of various determination conditions described later, and notifies the communication control unit 27 of the result. When the communication control unit 27 receives an instruction to perform retransmission relay, the wireless packet termination unit 24 receives the wireless packet as it is or changes the header information according to a predetermined rule, and performs processing such as error detection coding. The wireless packet is updated, and this is transmitted to the wireless line via the baseband signal processing unit 23, the wireless unit 22, and the antenna 26. In this way, retransmission relay is performed.

  In addition, although the change rule of the header information of a radio | wireless packet, the judgment conditions of retransmission relay implementation judgment, etc. are demonstrated in the following examples, it is not limited to these examples. Also, the base station identifier acquisition means 30 is a base station to which the own station is to be connected when the communication control unit 27 acquires the base station identifier notified by the base station or from various information provided by itself. Get identifier information. That is, the identifier of the base station may be acquired from a radio packet received from the base station, or may be referred to from a database held by the own station. In this case, if the wireless station can acquire the position information of its own station such as GPS, an identifier corresponding to the nearest base station is acquired based on the position information and the position of the base station on the database, etc. It is also possible to acquire based on other information. In the case of an FWA service or the like, it may be set at the time of contracting or at the time of equipment installation. As described above, the purpose of “acquisition of identifier” by the base station identifier acquisition means 30 is not necessarily active acquisition, but is processing of reading setting values in the apparatus and searching from a database. Also good. Thus, the base station identifier acquisition means 30 manages the identifier information acquired in various forms, and responds to the inquiry of the identifier match determination means 29. The communication control unit 27, the identifier acquisition unit 28, the identifier match determination unit 29, the base station identifier acquisition unit 30, and the retransmission relay execution determination unit 31 have been described separately from the communication control unit 27. It can also be regarded as the entire control unit 32 of the above. That is, it is not necessary to configure as a separate circuit different in hardware, and the entire control unit 32 exists as one circuit that performs software processing, and the logical functions are considered to be separated in its internal processing. It is also possible.

  The above is the operation when a wireless packet is received through a wireless line, but when a packet is input from the outside, naturally the reference such as the identifier is omitted and the transmission operation similar to the conventional technique is performed. . However, in the prior art, the operation for routing is specified, but here, since the wireless packet is transferred without performing routing, these functions are not necessary.

  The series of signal processing described above is an overview of the entire process, and details include more detailed processing. For example, various timings such as management of a time division switch corresponding to switching between transmission and reception in the radio unit The communication control unit 27 performs control mainly from management to generation / termination of various control information.

FIG. 4 shows a basic processing flow of retransmission relay in the present invention.
In FIG. 4, when each wireless station receives a wireless packet (S1), it acquires a transmission source identifier and a destination identifier from predetermined fields of the received wireless packet (S2), and the destination identifier matches the identifier of its own station. Whether or not (S3). If they match, the wireless packet is terminated and data output processing is performed (S6), and the processing is terminated as "no retransmission relay" (S7).

  On the other hand, if they do not match in step S3, it is determined whether or not the source identifier or destination identifier matches the identifier of the base station that manages the own station (S4). The process is terminated as “none” (S7). On the other hand, if they match, it is determined whether or not the retransmission relay execution conditions are met (S5). If the retransmission execution conditions are met, retransmission relay is performed (S9). If they do not match, retransmission relay is performed. Is finished (S8). When retransmission relay is performed in step S9, the process returns to step S5 again after the retransmission relay is performed, and it is continuously determined whether or not the conditions for retransmission relay are met. If the repeated retransmission execution condition is met, the retransmission relay is continued a plurality of times, and the retransmission relay is terminated when the condition is not met. Note that the retransmission relay execution condition here is a specific example in the following embodiment. For example, to what time slot the retransmission relay is continued, and how many times the retransmission relay is repeated until the retransmission relay is finished. It means conditions such as.

  The above description does not involve any routing processing as described in the prior art. When a base station or a terminal station is a transmitting station, it is necessary to ensure consistency such as setting header information of radio packets as needed or adapting frame conditions and broadcast information to retransmission relay conditions as necessary. There is. Further, after the new transmission of the wireless packet (S10), the transmitting station proceeds to the process S5 in the same manner as when receiving the wireless packet, and the subsequent processing is the same as when receiving the wireless packet and matches the retransmission execution condition. Whether or not retransmission relay is completed (S8) or retransmission relay execution (S9) is executed according to the determination result.

  Here, the retransmission relay implementation condition in which the wireless station repeats the retransmission relay will be described. When the number of retransmissions at each radio station is specified as a retransmission execution condition, the following is performed. For example, the retransmission relay may be performed only once in the next time slot after receiving the wireless packet. Similarly, the number of times may be limited to twice, such as the next time slot after receiving the wireless packet and the next time slot only. In any case, retransmission relay is repeated at the previous wireless station, but the number of retransmissions at each wireless station is limited.

  Further, when a time slot (hop count) in which retransmission relaying is continued is defined as a retransmission execution condition, it is as follows. As a condition for grasping the remaining number of retransmissions in a wireless packet, for example, a retransmission counter is recorded, and when there is a remaining number of retransmission counters when a wireless packet is received, retransmission relay is performed only for the remaining period. carry out. If the retransmission counter (hereinafter referred to as “RC”) indicates the remaining number of retransmissions, when RC = 2 is received, the counter value is subtracted by 1 at the time of the first retransmission relay, and RC = 1, the next retransmission At the time of relaying, RC = 0 is set, the counter value is updated, accommodated in a radio packet, and transmitted. The radio station that has received the radio packet with RC = 0 does not perform the next retransmission relay. That is, it is limited to retransmission relays up to the time slot (hop count) set in the retransmission counter by the wireless station that first transmitted the wireless packet. In this operation, the contents of the radio packet are changed every time the relay is retransmitted. However, since all the radio stations update the contents of the radio packet with the same rule, the same radio packet is eventually transmitted. It is possible to send.

  The basic concept of retransmission relay described above is a technical feature of the invention described in the prior application (Japanese Patent Application No. 2011-082022).

  The re-transmission condition here is to perform re-transmission relay when each radio station that has received a radio packet satisfies conditions such as the number of retransmissions. Can not do it. Therefore, the range of wireless stations that perform retransmission relay simultaneously may extend over an unnecessarily wide area, and may cause unnecessary interference in the transmission of other wireless packets. In the present invention, by using the location information of each radio station, radio stations that perform retransmission relays simultaneously are restricted, thereby preventing unnecessary retransmission relays and facilitating interference control.

FIG. 5 shows an operation example 1 of retransmission relay according to the first embodiment of the present invention.
In FIG. 5, 11 is a base station (A), 12-1 to 12-15 are radio stations, and 13 is a destination radio station (Z). The divided areas a1 to a8 are areas managed by the base station (A) 11, and the base station (A) 11 is an area in which the base station (A) 11 communicates with each wireless station by direct communication or multihop communication. This divided area is obtained by virtually dividing the entire communication area into a plurality of areas.

  Each wireless station has configuration information of these divided areas (hereinafter, divided area configuration information), and each divided area and boundary information between the areas are managed by coordinates and the like. Each wireless station can grasp the information by receiving the divided region configuration information created and broadcasted by the base station (A) 11. Alternatively, each wireless station may be provided with a database in which divided region configuration information is stored in advance. In addition to being fixedly set in the wireless station, this database may be configured to set information by accessing the network at another opportunity and downloading from a predetermined site. In addition, each wireless station has a means for grasping the position information of the own station, and by comparing the position information with the divided region configuration information, the wireless station can determine which divided region from among the divided regions. It is possible to grasp whether it is located in. When the radio station is a mobile station, the position information of the own station is generally grasped by acquiring coordinate values by GPS. When the station is a fixed station or does not involve movement during communication in a quasi-stationary environment, the position information may be grasped by inputting address information where the wireless station is located.

  A radio packet transmitted and received by each radio station is composed of a header area and a data area. In the header area, a reception area identifier indicating a “reception area” is included in addition to a transmission source identifier and a destination identifier. The “reception area” indicates a divided area where a radio station that retransmits a received radio packet is located, and is updated every retransmission relay. That is, a radio station that has received a radio packet determines that it is a radio station that is responsible for relay relay when the divided area in which the station is located matches the "reception area" of the received radio packet, and determines the next "reception area" Is specified, the reception area of the wireless packet is updated and reconfigured, and retransmission relay is performed.

  The next method of identifying the “reception area” is that each radio station knows the transmission direction of downlink if the source of the received radio packet is a base station and uplink if the destination is a base station. With reference to the divided region configuration information to be performed, a divided region located in the transmission direction is selected from the divided region where the own station is located.

  The base station (A) 11 transmits a radio packet destined for the radio station (Z) 13. The source identifier of the wireless packet is “A”, the destination identifier is “Z”, and the reception area identifier is “a1”. Here, since the transmission source identifier is “A”, the radio station in any area that has received this radio packet can recognize that this communication is communication in the downlink direction. Further, the wireless stations 12-1 to 12-3 located in the divided area a1 match the received area identifier in the header area of the wireless packet received in the time slot # 1 with the identifier of the divided area in which the own station is located. And grasping that retransmission relay is performed in the next time slot # 2. On the other hand, the wireless station 12-4 in the divided area a2 that receives the same wireless packet does not perform retransmission relay in the next time slot # 2 because the received area identifier does not match the identifier of the divided area in which the own station is located.

  The radio stations 12-1 to 12-3 in the divided area a1 specify that the next “reception area” is a3 because the radio packet received in the time slot # 1 is in the downlink direction. The radio packet reconstructed by updating the reception area identifier of the radio packet to “a3” is retransmitted in time slot # 2. The wireless stations 12-5 to 12-7 located in the divided area a3 have the following information because the reception area identifier of the header area of the wireless packet received in the time slot # 2 matches the identifier of the divided area where the own station is located. It is grasped that retransmission relay is performed in time slot # 3. On the other hand, the wireless station 12-8 in the divided region a4 that receives the same wireless packet does not perform retransmission relay in the next time slot # 3 because the received region identifier does not match the identifier of the divided region in which the own station is located.

  The radio stations 12-5 to 12-7 in the divided area a3 specify that the next "reception area" is a5 because the radio packet received in the time slot # 2 is in the downlink direction, and received The wireless packet reconfigured by updating the reception area identifier of the wireless packet to “a5” is retransmitted in time slot # 3. The wireless stations 12-9 to 12-10 located in the divided area a5 have the same reception area identifier in the header area of the wireless packet received in time slot # 3 and the identifier of the divided area in which the own station is located. It is understood that retransmission relay is performed at the transmission opportunity. The destination radio station 13 located in the divided area a5 terminates the radio packet because the destination identifier of the radio packet received in time slot # 3 matches the identifier of the own station. On the other hand, the wireless station 12-11 in the divided area a6 that receives the same wireless packet in the time slot # 3 retransmits in the next time slot # 4 because the received area identifier does not match the identifier of the divided area in which the own station is located. Do not relay.

  The radio stations 12-9 to 12-10 in the divided area a5 specify that the next "reception area" is a7 because the radio packet received in the time slot # 3 is in the downlink direction, and received The radio packet reconfigured by updating the reception area identifier of the radio packet to “a7” is retransmitted in time slot # 4. The radio stations 12-12 to 12-14 located in the divided area a7 receive the radio packet in time slot # 4. However, this retransmission relay is useless if the base station 13 in the same divided area a5 has already received the wireless packet. Therefore, the wireless station 13 that has received the wireless packet addressed to itself transmits, for example, ACK in time slot # 4, and this is received by the wireless stations 12-9 to 12-10 located in the same divided area a5, The retransmission relay in time slot # 4 can be stopped. On the other hand, when the destination wireless station 13 cannot receive the wireless packet in time slot # 3, the wireless station 12-9 to 12-10 in the divided area a5 receives the wireless packet to be retransmitted in time slot # 4. Can be, and not necessarily wasted. Further, if the wireless stations 12-12 to 12-14 located in the divided area a7 receive the ACK transmitted by the wireless station 13 in the time slot # 5, the subsequent retransmission relay can be stopped.

  Similarly, wireless packets transmitted from the wireless station 13 to the base station 11 are sequentially transmitted to the divided areas a5, a3, and a1, and the wireless stations 12-1 to 12-3 in the divided area a1 receive the received wireless packets. Is the uplink direction, the next “reception area” is updated to the identifier “A” of the base station, and the reconstructed radio packet is relayed again.

  In addition, the information defining the area as the “reception area” does not have to be global area information that is unique in a vast service area, but in the service area of the base station described in “destination” or “source”. It may be local region information corresponding to where. For example, when the area managed by the base station is a one-dimensional area, the area is defined so that the distance from the base station is approximately equal, and the local identifiers are “0” and “1” in order from the nearest. , “2”, “3”,... May be ordered to indicate the number of hops from the base station. In the case of a two-dimensional area, a direction may be specified in the direction in addition to the distance, and a 360-degree direction around the base station may be fixedly divided into N areas. Further, the designated direction may be a 0 degree direction, and the area may be dynamically changed during operation so as to indicate the center direction and a range of ± α degrees before and after the center direction. Furthermore, it is also possible to define complex area information on the aforementioned database.

  In addition, although the operation example of FIG. 5 shows the case where the wireless packet received by each wireless station is retransmitted only once, the number of retransmission relays of each wireless station may be two or more. FIG. 6 shows operation example 2 when the number of retransmission relays at each radio station is two.

  In FIG. 6, a base station (A) 11 transmits a wireless packet destined for the wireless station (Z) 13. The source identifier of the wireless packet is “A”, the destination identifier is “Z”, and the reception area identifier is “a1”. Here, since the transmission source identifier is “A”, the radio station in any area that has received this radio packet can recognize that this communication is communication in the downlink direction. Further, the wireless stations 12-1 to 12-3 located in the divided area a1 match the received area identifier in the header area of the wireless packet received in the time slot # 1 with the identifier of the divided area in which the own station is located. And grasping that retransmission relay is performed in the next time slot # 2.

  The radio stations 12-1 to 12-3 in the divided area a1 specify that the next “reception area” is a3, update the reception area identifier of the radio packet to “a3”, and reconfigure the radio packet. Repeat retransmission in time slot # 2. In addition, the base station 11 retransmits the wireless packet reconstructed by updating the reception area identifier of the wireless packet transmitted in the time slot # 1 to “a3” in the time slot # 2 (second time). The wireless stations 12-5 to 12-7 located in the divided area a3 have the following information because the reception area identifier of the header area of the wireless packet received in the time slot # 2 matches the identifier of the divided area where the own station is located. It is grasped that retransmission relay is performed in time slot # 3.

  The radio stations 12-5 to 12-7 in the divided area a3 specify that the next “reception area” is a5, update the reception area identifier of the radio packet to “a5”, and reconfigure the radio packet. Retransmission is performed at time slot # 3. Also, the wireless stations 12-1 to 12-3 in the divided area a1 retransmit the wireless packet reconstructed by updating the reception area identifier of the wireless packet transmitted in the time slot # 2 to “a5” in the time slot # 3. Relay (second time). The wireless stations 12-9 to 12-10 located in the divided area a5 have the same reception area identifier in the header area of the wireless packet received in time slot # 3 and the identifier of the divided area in which the own station is located. It is grasped that retransmission relay is performed in time slot # 4. The destination radio station 13 located in the divided area a5 terminates the radio packet because the destination identifier of the radio packet received in time slot # 3 matches the identifier of the own station.

  The radio stations 12-9 to 12-10 in the divided area a5 specify that the next “reception area” is a7, update the reception area identifier of the received radio packet to “a7”, and reconfigure the radio. The packet is retransmitted in time slot # 4. Also, the radio stations 12-5 to 12-7 in the divided area a3 retransmit the reconstructed radio packet in the time slot # 4 by updating the reception area identifier of the radio packet transmitted in the time slot # 3 to “a7”. Relay (second time). Here, as described above, the respective retransmission relays may be stopped by receiving the ACK transmitted by the destination wireless station 13 in the time slot # 4.

  In the example of FIGS. 5 and 6, one reception area is specified at the time of retransmission relay. However, a plurality of reception areas may be specified. In this case, a rule for updating the reception area for each retransmission relay may be specified in advance. For example, if the reception area is “a1 and a3”, the next retransmission relay will overlap the reception area so that the reception area is “a3 and a5” and then the reception area is “a5 and a7”. By repeating the retransmission relay, the reliability of the retransmission relay can be improved. In the example of FIG. 5, if the reception area of the wireless packet transmitted by the base station 11 in time slot # 1 is “a1 / a3”, the wireless stations 12-1 to 12-3, 12-5 in the divided areas a1 and a3. Among ˜12-7, the wireless station that has received the wireless station packet in time slot # 1 will retransmit the wireless packet having the reception area “a3 / a5” in time slot # 2. Therefore, of the radio stations 12-5 to 12-7 in the divided area a3, the radio stations that could not be received in the time slot # 1 are retransmitted in the time slot # 2 from the radio stations in the divided area a1 and the same divided area a3. Therefore, the reliability of retransmission relay is improved.

FIG. 7 shows a configuration example of a radio station apparatus according to Embodiment 1 of the present invention.
In FIG. 7, the radio station apparatus according to the first embodiment is different from the basic configuration example of the radio station apparatus illustrated in FIG. 3 in that the position information acquisition unit 35, the divided region configuration information management unit 36, the region information acquisition unit 37, and the region matching In this configuration, a determination unit 38 is added. The position information acquisition means 35 may be a means for acquiring position information by a GPS device, or may be a storage means for address information in the case of a fixed station. In the latter case, a configuration with a user interface for input may be used. The divided area configuration information management unit 36 stores divided area identifiers and boundary information between divided areas.

  In the present configuration example, the case where the divided region configuration information is acquired via a wireless line has been illustrated. However, when information is acquired via a network, the information may be acquired via the interface unit 25. The communication control unit 27 transfers the current position information grasped by the position information obtaining unit 35 and the information of the divided region configuration information managing unit 36 to the region information obtaining unit 37, and the region information obtaining unit 37 receives the information (coordinates). By comparing the value), the identifier of the divided area where the local station is located is grasped. The communication control unit 27 also transfers the identifier of each region described in the header region of the wireless packet to the region information acquisition unit 37. The area information acquisition means 37 outputs the identifier of the divided area where the local station is located and the identifier of the area described in the header area to the area matching judgment means 38. The area matching judgment means 38 judges from the output identifier whether the divided area where the station is located matches the area described in the header area, and the result is the retransmission relay execution judgment means 31. Output to. Similarly to the configuration example of FIG. 3, the communication control unit 27 transfers the destination identifier and the transmission source identifier from the control information given to the received wireless packet to the identifier acquisition unit 28 and further to the identifier match determination unit 29. Then, it is determined whether the destination identifier or the transmission source identifier matches the identifier of the base station to which the own station belongs, and the result is output to the retransmission relay execution determining means 31.

  In the operation examples shown in FIGS. 5 and 6, as a retransmission relay execution condition, each wireless station performs a fixed number of retransmission relays after receiving a wireless packet, but this is not necessarily limited thereto. . For example, the transmission source estimates the number of retransmissions until the wireless packet reaches the destination wireless station in advance, and stores this in the wireless packet as a retransmission counter. The retransmission counter is updated to a value obtained by subtracting 1 each time retransmission is performed. As retransmission relay implementation conditions, retransmission relay is performed until the retransmission counter of a received or retransmitted wireless packet reaches a predetermined value (for example, until the retransmission counter reaches zero). Note that the retransmission counter value can be added one by one, and retransmission relaying can be performed until the retransmission counter reaches a predetermined value. The retransmission relay execution determining unit 31 determines whether or not retransmission relay is necessary based on the output coincidence information.

FIG. 8 shows a processing flow of retransmission relay in Embodiment 1 of the present invention.
In FIG. 8, when each wireless station receives a wireless packet (S101), it acquires a transmission source identifier, a destination identifier, and a reception area identifier from predetermined fields of the received wireless packet (S102), and the destination identifier is its own station. It is determined whether or not the identifier matches (S103). If they match (Yes in S103), the wireless packet is terminated and data output processing is performed (S104), and the processing ends as “no retransmission relay” (S105). On the other hand, when the identifier of the own station does not match the destination identifier (No in S103), it is determined whether the source identifier or the destination identifier matches the identifier of the base station that manages the own station (S106). If they do not match (No in S106), the processing is terminated as “no retransmission relay” (S105). If they match (Yes in S106), it is determined whether or not the reception area identifier matches the divided area where the station is located (S107). If they do not match (No in S107), the processing is terminated as “no retransmission relay” (S105). If they match (Yes in S107), it is determined whether or not the retransmission execution conditions are met (S108), and retransmission relaying is performed as long as they match (Yes in S108) (S111).

  The retransmission execution condition here may be that the retransmission is repeated once after the packet is received as shown in FIG. 5, or the retransmission is repeated a predetermined number of times after the packet is received as shown in FIG. You may set to implementation conditions. Alternatively, the retransmission counter value may be subtracted for each retransmission relay using a retransmission counter accommodated in the wireless packet, and the retransmission counter value may be a predetermined value (eg, 0). Note that the retransmission counter value can be added one by one, and retransmission relaying can be performed until the retransmission counter reaches a predetermined value. Alternatively, the retransmission relay may be terminated when an ACK transmitted when the destination wireless station 13 receives a wireless packet addressed to itself is received.

  In the first embodiment, the division area in which the radio station that performs the next retransmission relay is designated as the “reception area” prevents the radio stations that perform the retransmission relay from spreading. By designating the divided area where the wireless station is located as the “destination area”, the retransmission relay is terminated when the wireless packet reaches the destination area by the retransmission relay. By describing the “reception area” and “destination area” in the header area of the wireless packet, it is possible to prevent the number and position of wireless stations involved in retransmission relay from being unnecessarily expanded.

  In this embodiment, it is necessary for the transmission source (base station) to know the information of the “destination area”, which is a divided area where the destination wireless station is located. It is possible to identify the divided area where the destination wireless station is located from the notified position information by notifying the location information where the own station is located in the belonging process performed in the normal communication.

FIG. 9 shows an example of retransmission relay operation in Embodiment 2 of the present invention.
In FIG. 9, a base station (A) 11 transmits a radio packet destined for the radio station (Z) 13. The source identifier of the wireless packet is “A”, the destination identifier is “Z”, the reception area identifier is “a1”, and the destination area identifier is “a5”. Here, since the transmission source identifier is “A”, the radio station in any area that has received this radio packet can recognize that this communication is communication in the downlink direction. Further, the wireless stations 12-1 to 12-3 in the divided area a1 match the reception area identifier in the header area of the wireless packet received in time slot # 1 with the identifier of the divided area in which the own station is located, and the destination area identifier Since the identifiers of the divided areas in which the own station is located do not match, it is understood that retransmission relay is performed in the next time slot # 2.

  The radio stations 12-1 to 12-3 in the divided area a1 specify that the next “reception area” is a3, update the reception area identifier of the radio packet to “a3”, and reconfigure the radio packet. Repeat retransmission in time slot # 2. The wireless stations 12-5 to 12-7 located in the divided area a3 match the received area identifier in the header area of the wireless packet received in time slot # 2 with the identifier of the divided area in which the own station is located. Since the identifiers of the divided areas in which the own station is located do not match, it is understood that retransmission relay is performed in the next time slot # 3.

  The radio stations 12-5 to 12-7 in the divided area a3 specify that the next “reception area” is a5, update the reception area identifier of the radio packet to “a5”, and reconfigure the radio packet. Retransmission is performed at time slot # 3. The wireless stations 12-9 to 12-10 located in the divided area a5 match the received area identifier in the header area of the wireless packet received in the time slot # 3 with the identifier of the divided area in which the own station is located. Since the identifiers of the divided areas where the own station is located coincide with each other, retransmission relay is terminated here. The destination radio station 13 located in the divided area a5 terminates the radio packet because the destination identifier of the radio packet received in time slot # 3 matches the identifier of the own station.

  In the above example, when the local station is the destination area, the wireless station has finished the retransmission relay. However, even if some of the radio stations in the destination area receive the radio packet, the destination radio station may not receive the radio packet. Therefore, in order to improve the reliability of communication, even when the local station is in the destination area, the retransmission relay may not be terminated immediately, but may be terminated after performing the retransmission relay once. In any case, in the present embodiment, it is possible to determine whether the area is a “destination area” in units of divided areas, and to prevent unnecessary retransmission relays after the radio station located in the destination area.

  The configuration of the radio station apparatus in the present embodiment is the same as that of the first embodiment shown in FIG. This is because the area information acquisition means 37 can grasp the divided area where the station is located, and the area match determination means 38 can determine the match with the “reception area” and “destination area” described in the wireless packet. . Information relating to the match with the destination information is input from the area match determination unit 38 to the retransmission relay execution determination unit 31, and the retransmission relay execution determination is determined based on the input information.

  FIG. 10 shows an operation flow of retransmission relay in the present embodiment. The difference from the first embodiment is that, after step S107, it is determined whether or not the destination area identifier matches the divided area where the own station is located (S112). The processing is terminated as “none” (S105). If they match (Yes in S112), it is determined whether or not the retransmission execution conditions are met (S108). As long as they match (Yes in S108), retransmission relay is performed (S111).

1-1 to 1-2 Base station 2-1 to 2-7, 3-1 to 3-7 Radio station 4-1 to 4-2 Radio packet 5-1 to 5-2 Service area of each base station 100 Network DESCRIPTION OF SYMBOLS 11 Base station 12-1-12-11 Radio station which performs resending relay 13 Destination radio station 21 Radio station apparatus 22 Radio | wireless part 23 Baseband signal processing part 24 Radio | wireless packet termination means 25 Interface part 26 Antenna 27 Communication control part 28 Identifier Acquisition means 29 Identifier match determination means 30 Base station identifier acquisition means 31 Retransmission relay execution determination means 32 Overall control unit 35 Location information acquisition means 36 Divided area configuration information management means 37 Area information acquisition means 38 Area match determination means

Claims (8)

A wireless packet that includes one base station and a plurality of wireless stations, and that describes identifier information indicating a transmission source and a destination in a multi-hop manner between the base station and a wireless station of a communication partner in the wireless station. In a wireless communication system that relays retransmissions,
The radio station is
A wireless station that repeats and relays the received wireless packet at the next transmission opportunity, and identifier information of the divided area where the local station is located among a plurality of divided areas obtained by dividing the communication area to be subjected to retransmission relay Area information acquisition means for acquiring identifier information of a reception area that is a divided area in which
An area matching determination means for determining whether or not an identifier indicating the reception area acquired from the received wireless packet matches an identifier of a divided area where the local station is located;
Base station identifier acquisition means for acquiring an identifier of a base station to which the local station is connected;
Identifier matching judgment means for judging whether or not an identifier indicating a transmission source or a destination acquired from the received wireless packet matches an identifier of the base station or an identifier indicating the own station;
Retransmission relay for determining whether or not to perform retransmission relay of the received wireless packet according to either a retransmission relay termination condition described in the wireless packet or a retransmission relay termination condition defined on the system Implementation decision means;
The divided region where the identifier matching judgment unit determines that either the identifier indicating the transmission source or the destination matches the identifier of the base station, and the region matching judgment unit determines that the identifier indicating the reception region is located in the own station And when the retransmission relay execution determining means determines that retransmission relay should be performed, the received wireless packet includes an identifier indicating the next reception area and is transmitted. A transmission means;
Radio packet termination means for terminating the received radio packet and extracting data when it is determined by the identifier match judgment means that the identifier indicating the destination matches the identifier indicating the own station. Wireless communication system. The wireless communication system according to claim 1, wherein
The wireless packet transmitting means determines a downlink wireless packet if the identifier indicating the transmission source acquired from the received wireless packet matches the identifier of the base station, and indicates a destination acquired from the received wireless packet If the identifier matches the identifier of the base station, it is determined as an uplink radio packet, the next reception area of the radio packet is specified according to whether it is a downlink or uplink, and is described in the radio packet to be transmitted There is a wireless communication system characterized by that. The wireless communication system according to claim 1, wherein
The wireless packet transmission means of the base station and the wireless station describes an identifier indicating a plurality of the reception areas in a wireless packet to be transmitted or retransmitted,
The region match determination means is configured to determine whether or not an identifier indicating one reception region of the plurality of reception regions matches an identifier of a divided region where the own station is located. Wireless communication system. The wireless communication system according to claim 1, wherein
The area information acquisition means is configured to acquire identifier information of a destination area that is a divided area where a destination radio station of the radio packet is located,
The area match determination means is configured to determine whether or not an identifier indicating the destination area acquired from the received wireless packet matches an identifier of a divided area where the own station is located,
The retransmission relay execution determining means should end the retransmission relay of the radio packet when the area matching determining means determines that the identifier indicating the destination area matches the identifier of the divided area where the local station is located. A wireless communication system, characterized in that the configuration is determined. A wireless packet that includes one base station and a plurality of wireless stations, and that describes identifier information indicating a transmission source and a destination in a multi-hop manner between the base station and a wireless station of a communication partner in the wireless station. In a wireless communication method for relay retransmission,
The radio station is
Using area information acquisition means, among the plurality of divided areas obtained by dividing the communication area to be subjected to retransmission relay, the identifier information of the divided area where the own station is located, and the received wireless packet Obtaining identifier information of a reception area which is a divided area where a radio station to be retransmitted at a transmission opportunity is located;
Determining whether or not an identifier indicating the reception area acquired from the received wireless packet matches an identifier of a divided area where the own station is located using an area matching determination unit;
Using the base station identifier acquisition means to acquire the identifier of the base station to which the local station is connected;
Determining whether an identifier indicating a transmission source or destination acquired from the received wireless packet matches an identifier indicating the base station or an identifier indicating the own station, using an identifier match determination unit;
Retransmission relay execution determination means is used to perform retransmission relay of the received wireless packet in accordance with either the retransmission relay termination condition described in the wireless packet or the retransmission relay termination condition defined in the system. A step of determining whether to finish or
Using the wireless packet transmission means, it is determined that either the identifier indicating the transmission source or the destination matches with the identifier of the base station by the identifier match determination means, and the identifier indicating the reception area is determined by the area match determination means. An identifier that indicates the next reception area in the received radio packet when it is determined that it matches the identifier of the divided area in which the local station is located and the retransmission relay execution determination means determines that retransmission relay should be performed And sending
Using the wireless packet termination means, and terminating the received wireless packet and extracting data when the identifier matching judgment means judges that the identifier indicating the destination matches the identifier indicating its own station. A wireless communication method characterized by the above. The wireless communication method according to claim 5, wherein
The wireless packet transmitting means determines a downlink wireless packet if the identifier indicating the transmission source acquired from the received wireless packet matches the identifier of the base station, and indicates a destination acquired from the received wireless packet If the identifier matches the identifier of the base station, it is determined as an uplink radio packet, the next reception area of the radio packet is specified according to whether it is a downlink or an uplink, and is described in the radio packet to be transmitted. A wireless communication method. The wireless communication method according to claim 5, wherein
The wireless packet transmission means of the base station and the wireless station describes an identifier indicating a plurality of the reception areas in a wireless packet to be transmitted or retransmitted,
The area matching determination means determines whether or not an identifier indicating one reception area of the plurality of reception areas matches an identifier of a divided area where the own station is located. . The wireless communication method according to claim 5, wherein
The area information acquisition means acquires identifier information of a destination area that is a divided area where a radio station of a destination of the radio packet is located,
The area match determination means determines whether or not an identifier indicating the destination area acquired from the received wireless packet matches an identifier of a divided area where the own station is located,
The retransmission relay execution determining means should end the retransmission relay of the radio packet when the area matching determining means determines that the identifier indicating the destination area matches the identifier of the divided area where the local station is located. A wireless communication method, characterized in that

Images