JP2006345449A - Wireless communication system, wireless communication device, and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, in time division multiplexing communication when a local station cannot receive communication from other wireless station in the time allocated for communication with the other wireless station belonging to the same group to which the local station belongs, the time allocated for communication with the other wireless station becomes useless time and sufficient communication channels cannot be secured. <P>SOLUTION: When a first wireless station (102) cannot receive communication from a second wireless station (104) in the time allocated for communication with the second wireless station (104), it sends Send Data Request to a third wireless station (103) which needs to extend the communication time with the local station (102) to ask the station (103) to send data to it. In response to the Send Data Request from the first wireless station (102), the third wireless station (103) responds to the Send Data Request from the first wireless station (102), sends data to the first wireless station (102) in the communication time allocated for communication with the second wireless station (104). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to the field of wireless communication, and in particular, to a communication technique using a time division communication method.

  In recent years, Bluetooth and ultra-wide band (UWB) communication have attracted attention as personal area networks as short-range wireless communication. In particular, in UWB capable of high-speed wireless communication, IEEE 802.15.3 MAC is basically used, and in the time division multiplexing system defined by IEEE 802.15.3 MAC, how much data is stored. The issue is whether to send and receive.

  A method of time division communication in IEEE 802.15.3 MAC will be described with reference to FIGS. In FIG. 7A, a DEV (wireless station) 1 indicated by 101 functions as a PNC (Piconet Controller), and DEV2 and DEV3 indicated by 102 and 103, respectively, communicate with each other in the same piconet 100 as the PNC 101. It is. Since the PNC 101 itself is a radio station, a channel time allocation (allocation time for each radio station to communicate with a beacon so that the other radio stations 102 and 103 can communicate with each other is assigned to the channel time allocation ( Thereafter, CTA) is broadcast. Each of the wireless stations 101 to 103 communicates with other stations in a CTA assigned to the own station. An example of communication time allocation in this time division communication is shown in FIG.

  In FIG. 8A, cta1 indicates a CTA transmitted by the wireless station 101 (DEV1), cta2 indicates a CTA transmitted by the wireless station 102 (DEV2), and cta3 indicates a CTA transmitted by the wireless station 103 (DEV3). Furthermore, each cta is divided for each receiving radio station.

  Here, as shown in FIG. 7B, when another wireless station 104 (DEV4) and wireless station 105 (DEV5) try to communicate near the piconet 100, the wireless stations 104 and 105 are The PNC 101 detects a beacon, transmits an association request to the PNC 101, and participates in the piconet 100. After joining the piconet, the wireless stations 104 and 105 transmit a channel time request to the PNC 101 to secure time for the wireless station 104 and the wireless station 105 to communicate. FIG. 8B shows the CTA assignment after the wireless stations 104 and 105 have joined the piconet 100.

JP-A-10-155181

  Here, comparing (a) and (b) of FIG. 8, when the radio station 104 (DEV4) and the radio station 105 (DEV5) are added to the piconet 100, the CTAs of the other radio stations (DEV1 to DEV3) are It turns out that it becomes short. Here, if the wireless station 102 cannot intercept the communication in the CTA of the wireless station 104, there will be time to waste the channel for the wireless station that cannot intercept the communication.

  In addition, when the wireless stations 103 to 105 cannot intercept the communication in the CTA of other wireless stations, it is possible to waste time for the wireless station that cannot similarly intercept the communication.

  In short, in conventional time division multiplex communication, if communication cannot be intercepted in the time allocated to another wireless station belonging to the same wireless group, the time is allocated to the other wireless station that cannot communicate. As a result, there has been a problem that a sufficient communication channel cannot be secured.

  Therefore, an object of the present invention is to avoid wasting a channel for a radio station that cannot intercept communication and to improve communication efficiency.

  One aspect of the present invention relates to a wireless communication system that includes first to third wireless stations grouped by broadcast notification, and performs time division communication between the first to third wireless stations, When the first radio station (102) cannot intercept the communication of the second radio station (104) in the time allocated to the second radio station (104), the communication time to the own station (102) The third wireless station (103) transmits a transmission request to its own station (102) to the third wireless station (103) that needs to expand the range, and the third wireless station (103) In response to the transmission request, data is transmitted to the first radio station during a communication time allocated to the second radio station (104).

  Reference numerals in the accompanying drawings cited herein do not limit the scope of the invention.

  According to the present invention, since the time allocated to a radio station that cannot intercept communication is used as the data transmission time of another radio station, a channel is not wasted for a radio station that cannot intercept communication, which is efficient. Communication is possible.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. In addition, not all combinations of features described in the following embodiments are essential as the problem solving means of the present invention.
(First embodiment)

  First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is one of the basic configuration diagrams of the present invention. In the figure, a wireless station 101 functions as a PNC (Paging Network Controller). Reference numerals 102 to 105 denote wireless stations that communicate within the same piconet 100 as the PNC 101. In this example, the wireless station 102 as the first wireless station is a wireless station that cannot intercept the communication of the wireless station 104 as the second wireless station.

  In time-division communication, in order to prevent a decrease in the time in which a local station cannot be intercepted and a time for which the local station can communicate is reduced for a wireless station that the local station cannot intercept, the channel time allocated to the wireless station that the local station cannot intercept is reduced. The local station may communicate with another wireless station.

  Therefore, a communication permission to the local station is transmitted to another wireless station that needs to extend the communication time with the local station, and the wireless station communicates with another wireless station at the communication time allocated to the wireless station that cannot intercept the communication.

  By the way, in a radio station that is normally assigned and received time, a transmission request is received from a radio station that cannot normally intercept transmission data of a radio station that is regularly assigned and transmitted and communication of a radio station that is normally assigned and transmitted. There is a possibility that transmission data of wireless stations collide.

  Therefore, in this embodiment, another wireless station that has received a transmission request at the communication time of another wireless station transmits a probe request to a wireless station that should be normally received at the communication time, and only when there is no reply. Data is transmitted to the wireless station that has requested transmission.

  FIG. 2 shows a sequence chart of the wireless stations 102 to 105. As shown in FIG. 1, when the wireless station 102 cannot intercept the communication of the wireless station 104, the wireless station 102 transmits a probe request to the wireless station 104.

  When there is no probe response from the wireless station 104, the wireless station 102 is a wireless station 103 as a third wireless station that wants to take a longer transmission channel time to the wireless station 102 in communication with the wireless station 102. Send request (Send data Requst).

  The wireless station 103 transmits a probe request to the wireless station 105 because the wireless station 104 wants to transmit data using a channel time for transmitting data to the wireless station 105 as the fourth wireless station.

  When a probe response is not returned from the wireless station 105, the transmission signal of the wireless station 103 is unlikely to become an interference signal when the wireless station 104 transmits data to the wireless station 105. Data is transmitted using a channel time for transmitting data to the station 105.

  In FIG. 2, the probe request and the probe response are used only for checking the communication environment of each wireless station. If each communication environment of each wireless station is checked in advance as shown in FIG. Data can be transmitted immediately when a data transmission request is received at the channel time.

When performing communication at the channel time of another radio station as shown in FIG. 2 or FIG. 3, as shown in FIG. 4, the radio station 103 communicates not only at its own channel time cta3 but also at the channel time cta4. It becomes possible.
(Second Embodiment)

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a basic configuration of the piconet 100 in the present embodiment. In the figure, 101 is a PNC, and 102 to 106 are radio stations that communicate within the same piconet 100 as the PNC 101. Each wireless station has previously examined the communication environment between itself and another wireless station by a probe request or the like. In FIG. 5, the wireless station 102 is the wireless station 104, the wireless station 103 is the wireless station 105, the wireless station Reference numeral 104 denotes a wireless station 102 and a wireless station 106, wireless station 105 cannot communicate with the wireless station 103 and wireless station 106, and wireless station 106 cannot communicate with the wireless station 104 and wireless station 105.

  FIG. 6 shows combinations of radio stations that can be transmitted, radio stations that can be received, and radio stations that can communicate with each CTA. In addition to the CTA assigned to the own station in FIG. 6, each radio station stores a radio station that can be transmitted by the own station and its timing, and a radio station that can be received by the own station and its timing.

  In time-division communication, each wireless station normally does not turn on the transmitter / receiver in order to save power other than the CTA assigned to itself. In the present invention, since communication is performed using a CTA that is not assigned to the own station, communication must be performed using a CTA that is not assigned to the own station.

  If there is a wireless station that needs to expand the communication time to the local station among the wireless stations that can be received by the local station other than the CTA assigned to the local station, the communication time to the local station By transmitting a transmission request to a wireless station that needs to be expanded, it is possible to notify that the local station can receive without being in the power saving mode, and it is possible to receive data other than the CTA assigned to the local station. become.

  In addition to the CTA assigned to the local station, if there is a radio station that needs to increase the communication time from the local station among the wireless stations that can be transmitted by the local station, the local station extends the communication time. Allocate to your own station by transmitting data at the time allotted to the radio station you need and telling when to send data to the same radio station according to the stored memory to which period it can send When transmitting data other than the received CTA, the receiving station does not enter the power saving mode.

  In addition, when transmitting data other than the CTA assigned to the own station under the control of the transmitting side, the CTA assigned to the own station notifies the timing of transmitting data other than the CTA assigned to the own station. However, redundant communication such as a transmission request in the case of control on the receiving side is not required.

In the 1st Embodiment of this invention, it is a figure which shows communicating by CTA other than an own station. It is the sequence chart between the radio stations in the 1st Embodiment of this invention. It is another sequence chart between the radio stations in the 1st Embodiment of this invention. It is a figure which shows the channel arrangement | positioning in the 1st Embodiment of this invention. It is a figure which shows having confirmed the communication state in the 2nd Embodiment of this invention. It is a figure which shows the example of the combination of the radio station which can transmit in each CTA in the 2nd Embodiment of this invention, the radio station which can be received, and the radio station which can communicate. It is a figure which shows that the radio stations 104 and 105 are added to the piconet 100 by the conventional method. It is a figure which shows channel arrangement | positioning when the radio stations 104 and 105 are added to the piconet 100 by the conventional method.

Claims (5)

A wireless communication system including first to third wireless stations grouped by broadcast notification and performing time-division communication between the first to third wireless stations,
If the first radio station cannot intercept the communication of the second radio station at the time allotted to the second radio station, the first radio station is assigned to a third radio station that needs to increase the communication time to itself. Send a transmission request to your station,
In response to the transmission request from the first wireless station, the third wireless station transmits data to the first wireless station during a communication time allocated to the second wireless station. A wireless communication system. The wireless communication system further includes a fourth wireless station belonging to the same wireless group as the first to third wireless stations,
In response to the transmission request from the first wireless station, the third wireless station is a communication destination of the second wireless station in a communication time allocated to the second wireless station. The probe request (Probe Request) is transmitted to the fourth wireless station, and data is transmitted to the first wireless station when a response to the probe request is not obtained. Wireless communication system. A communication method in a wireless communication system including first to third wireless stations grouped by broadcast notification and performing time division communication between the first to third wireless stations,
If the first radio station cannot intercept the communication of the second radio station at the time allocated to the second radio station, the third radio station needs to increase the communication time to the own station. A step of transmitting a transmission request to the own station;
In the third radio station, in response to the transmission request from the first radio station, transmitting data to the first radio station during a communication time allocated to the second radio station; A communication method characterized by comprising: A wireless communication device that performs time division communication with a plurality of wireless stations in a wireless network,
Means for holding communication environment information with each of the plurality of radio stations;
Means for holding information on which radio station can receive data from which radio station in which period, in addition to the time allotted for the radio communication device to receive;
A wireless communication apparatus comprising: In addition to the time allocated for reception by the wireless communication device, the first wireless device that needs to extend the communication time to the wireless communication device among the wireless stations stored as wireless stations that can receive data If there is a station, transmission means for transmitting a transmission request to the first wireless station;
Receiving means for receiving data from a third wireless station during a communication time assigned by the wireless communication apparatus to the second wireless station;
The wireless communication apparatus according to claim 4, further comprising:

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