JP2009055350A - Radio communication system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system, in which a time for facing the antenna of a control terminal to a dependent terminal is shortened when there is a communication request whereby communication between the control terminal and the dependent terminal can be started in a short time. <P>SOLUTION: The control terminal transmits beacon at a predetermined time to respective predetermined directions and the dependent terminal transmits a member registering demand to the control terminal upon receiving the beacon at the predetermined time in the predetermined direction while the control terminal receives the member registering request and determines an orientation capable of communicating to register in a terminal registration table and, thereafter, when there is the communication request from the dependent terminal, communication is effected between the dependent terminal based on an inclination information registered in the terminal registration table of the control terminal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  According to the present invention, in wireless communication, particularly in a wireless PAN, a control terminal registers antenna pointing information for directing the direction of a subordinate terminal in advance in a terminal registration table based on a member registration request from the subordinate terminal. The present invention relates to a wireless communication system and method for performing data communication by automatically matching the antenna directivity directions of a control terminal and a subordinate terminal when requested.

  Development of a wireless communication system of a millimeter wave WPAN (Wireless Personal Area Network) that uses millimeter waves to perform high-speed communication between wireless terminals is underway. In such a wireless communication system, an ultra wide band of 7 GHz to 9 GHz in the 60 GHz band is used, and ultra high speed communication of several Gbps is possible. Such a wireless communication system is expected to be used for transmission of uncompressed video signals and kiosk downloading type file transfer.

  As such a wireless communication system, there is one whose standardization is being studied as IEEE 802.15.3 (see Non-Patent Document 1). The wireless communication system will be described below.

  FIG. 9 shows the configuration of an IEEE 802.15.3 wireless communication system. In the IEEE 802.15.3 wireless communication system, a wireless terminal is called a device (DEV). Among the wireless terminals of these devices, only one device becomes a control terminal called a piconet coordinator (PNC), and the other device (DEV) becomes a subordinate terminal. In FIG. 9, one control terminal (PNC) and four subordinate terminals (DEV) are shown. Note that the number of dependent terminals is not limited to this. The control terminal (PNC) can also function as a subordinate terminal.

  When receiving a command from an upper layer, the control terminal bundles peripheral subordinate terminals to form one piconet. A piconet is a network configured by connecting a plurality of slaves (here, subordinate terminals) to one master (here, a control terminal). Here, the subordinate terminals can freely join and leave the network.

  The control terminal has a function of sending out a beacon and adjusting the timing of the network. Each subordinate terminal receives a beacon from a wireless terminal (PNC), and transmits and receives data at a designated timing.

  The control terminal forms a communication path between the control terminal and each subordinate terminal by managing the time resources allocated to each subordinate terminal, so that a point-to-point communication path is established between the control terminal and any subordinate terminal. Formed and data transferred.

  FIG. 10 shows the structure of a superframe used in IEEE802.15.3. As shown in FIG. 10, one superframe is composed of three parts: a beacon period, a contention access period (CAP), and a channel time allocation period (CTAP).

  The start of each super frame is a beacon period, and the beacon is broadcast from the control terminal during this beacon period. This beacon instructs the start of each superframe, and provides time allocation and management information from the control terminal to each subordinate terminal.

  The contention access period (CAP) is allocated next to the beacon period in the superframe. The contention access period (CAP) is a period in which all wireless terminals can access by CSMA / CA (Carrier Sense Multiple Access With Collision Avoidance). In this contention access period (CAP), a signal such as ACK that does not depend on time is transferred.

  The channel time allocation (CTAP) period is a period in which the control terminal permits communication only to a specific subordinate terminal. The channel time allocation period (CTAP) is composed of time slots (CTA1, CTA2,...) In which communication is performed between wireless terminals. In this channel time allocation (CTAP) period, time-dependent data (isochronous data) is transferred.

As described above, the control terminal transmits a beacon frame in a predetermined direction, and after matching the antenna pointing direction with each subordinate terminal, performs communication with the subordinate terminal during the CTAP period of the superframe. It was.
IEEE 802.15, Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Wireless Personal Area Networks (WPAN) Amendment 1: MAC Sublayer, IEEE Std. 802.15.3b, 2005

However, in the conventional method as described above, when there are a large number of beams that cover the omnidirectional range of the antenna in order to obtain a high antenna gain, scanning is performed by sequentially transmitting a beacon with each of the many beams. Therefore, it takes a long time to match only this, but if the beams of the control terminal and the subordinate terminal do not match each other in the first round, the same operation must be repeated until the beams match each other. There was a problem that it took too much time for the subordinate terminals to be matched.
In addition, when a communication request is made from a subordinate terminal, it is necessary to determine the antenna directivity direction between the control terminal and the subordinate terminal each time, so that communication cannot be started immediately when a communication request is made. was there.

In order to solve the above-described problem, a wireless communication system according to the present invention includes a control terminal and a plurality of subordinate terminals, and includes a superframe including a beacon period, a contention access period, and a channel time allocation period. In a wireless communication system that transmits and receives data using
The control terminal includes an antenna that can transmit and receive information in a predetermined direction, an antenna control unit that performs antenna directivity control, a function determination unit that determines whether or not it has a network controller function, and a subordinate terminal that has requested registration A terminal registration table in which information is recorded, a timer that manages system time, a network control unit that performs communication control using a superframe, a beacon transmission unit that transmits a beacon, and a member registration request from a subordinate terminal A member registration request detecting unit for detecting ACK, and an ACK sending unit for sending ACK to a subordinate terminal,
The belonging terminal has an antenna unit that can transmit and receive information in a predetermined direction, an antenna control unit that performs antenna directivity control, a function determination unit that determines whether or not it has a network controller function, and system time management. A timer to perform, a network control unit that performs communication control using a superframe, a beacon detection unit that detects a beacon received from the control terminal, a member registration request generation unit that generates a member registration request to be sent to the control terminal, An ACK detector for detecting an ACK from the control terminal;
The control terminal transmits a beacon at a predetermined time for each predetermined direction, and the subordinate terminal transmits a member registration request to the control terminal when the beacon is received in the predetermined direction at the predetermined time. The control terminal receives the member registration request, determines the directivity direction in which communication is possible, registers it in the terminal registration table, and when there is a communication request from the subordinate terminal thereafter, directs registered in the terminal registration table of the control terminal It communicates with a subordinate terminal based on information, It is characterized by the above-mentioned.

  In the wireless communication system of the present invention, when there is a communication request from a subordinate terminal registered in the terminal registration table of the control terminal, the network control unit reserves a communication time performed between the control terminal and the subordinate terminal, and makes a reservation The antenna pointing control unit communicates with the subordinate terminal that has made a communication request for the antenna pointing direction based on the pointing information registered in the terminal registration table.

  In the wireless communication system of the present invention, the terminal registration table includes the ID of the subordinate terminal that has requested member registration, and the antenna pointing direction of the control terminal that points to the antenna of the subordinate terminal that has requested the member registration. Is recorded.

According to the radio communication system of the present invention, data is transmitted / received using a superframe that is composed of a control terminal and a plurality of subordinate terminals and includes a beacon period, a contention access period, and a channel time allocation period. In a wireless communication system,
The control terminal transmits a beacon at a predetermined time for each predetermined direction, and the subordinate terminal transmits a member registration request to the control terminal when the beacon is received in the predetermined direction at the predetermined time. The control terminal receives the member registration request, determines the directivity direction in which communication is possible, registers it in the terminal registration table, and when there is a communication request from the subordinate terminal thereafter, directs registered in the terminal registration table of the control terminal Since communication with the subordinate terminal is performed based on the information, the beacon transmission period is shortened, and the time for blocking the communication between the control terminal and the subordinate terminal is reduced.

  Further, according to the wireless communication system of the present invention, when there is a communication request from a subordinate terminal registered in the terminal registration table of the control terminal, the network control unit sets the communication time performed between the control terminal and the subordinate terminal. When the reserved time comes, the antenna pointing control unit communicates the antenna pointing direction with the subordinate terminal that requested the communication based on the pointing information registered in the terminal registration table. Control for directing the antenna of the terminal toward the subordinate terminal is facilitated, so that communication between the control terminal and the subordinate terminal can be started in a short time.

  Further, according to the wireless communication system of the present invention, the terminal registration table includes the ID of the subordinate terminal that has requested member registration and the antenna orientation of the control terminal that is directed to the antenna of the subordinate terminal that has requested member registration. Since the direction is recorded, when there is a communication request, the time for directing the antenna of the control terminal to the subordinate terminal is shortened, so that communication between the control terminal and the subordinate terminal can be started in a short time.

  FIG. 1 is a diagram showing a control terminal 10 in the wireless communication system of the present invention. In this wireless communication system, a wireless terminal having a network controller function is called a control terminal 10. In FIG. 1, a control terminal 10 determines whether an antenna 11 that transmits and receives beacons and data in a predetermined direction, an antenna directing control unit 12 that controls the directivity of the antenna 11, and whether the wireless terminal has a network controller function. A function determination unit 13, a timer 14 for managing the time of the system, a network control unit 15 for controlling communication in units of superframes, a terminal ID of one or more subordinate terminals, and a control terminal directed to the subordinate terminal A terminal registration table 17 that records the antenna directivity direction, a terminal registration table control unit 16 that controls the terminal registration table 17, a beacon sending unit 18 that sends out beacons, and a member request detection that detects member registration requests from subordinate terminals A unit 19 and an ACK sending unit 20 are included.

  In FIG. 1, the function determining unit 13 determines whether or not the wireless terminal has a network controller function. If the wireless terminal has a network controller function, the function determining unit 13 sets the wireless terminal to operate as the control terminal 10 and If the wireless terminal does not have the function, the wireless terminal is set to operate as the subordinate terminal 30. The following describes the control terminal 10 that operates as a control terminal when it is determined that the wireless terminal has a network controller function. The timer 14 of the control terminal 10 sends a system clock to the network control unit 15 that manages the system time. The network control unit 15 sends the superframe time information to the antenna directivity control unit 12, and the antenna directivity control unit 12 changes the antenna directivity direction Si of the antenna 11 based on the superframe time information, as will be described later. .

  FIG. 2 is a diagram illustrating S1 to S8, which are directing directions of the antenna 11 of the control terminal 10. In FIG. 2, the directivity direction (S1 to S8, generally referred to as Si hereinafter) when the total directivity range (2π) of the antenna 11 of the control terminal 10 is divided into eight, for example, is shown. The directivity direction Si is a direction in which communication with the antenna of the subordinate terminal 30 is possible as viewed from the antenna 11 of the control terminal 10. As shown in FIG. 1, the antenna 11 is set in one of the directivity directions Si by the antenna directivity control unit 12, a beacon is transmitted in that direction, and a member registration request is received from the subordinate terminal 30 in that direction. At the same time, subsequent communication is performed.

  FIG. 3 is a diagram illustrating a data arrangement configuration example of the terminal registration table 17 of the control terminal 10. The terminal registration table 17 includes a table number that is numbered in descending order, the ID of the subordinate terminal that has requested member registration, and the control terminal 10 that is directed to the antenna of the subordinate terminal that has requested member registration. The arrangement configuration records the antenna directivity direction. The terminal registration table 17 is configured with a hard memory, a flash memory, or the like. As will be described later, when there is a member registration request from the subordinate terminal 30 in the system to the control terminal 10, the terminal registration table control unit 16 of the control terminal 10 determines the table number, the subordinate terminal ID, and the control terminal 10 antenna. The pointing direction is registered in the terminal registration table 17. Returning to FIG. 1, the member registration request processing is performed as follows. That is, first, when the control terminal 10 sends a beacon from the beacon sending unit 18, when the subordinate terminal 30 receiving the beacon makes a member registration request, the subordinate terminal 30 sends a beacon of the member registration request to the control terminal 10. The terminal registration table control unit 16 of the control terminal 10 that has received this beacon registers the ID and the directivity direction Si of the subordinate terminal 30 in the terminal registration table 17 and sends an ACK from the ACK transmission unit 20 to the subordinate terminal 30. This completes the member registration request process.

  FIG. 4 is a diagram showing an outline of the configuration of the slave terminal according to the present invention. In general, the subordinate terminal 30 is generally manufactured so as to have the same configuration as that of the control terminal 10. However, as described above, the function determination unit 33 of the subordinate terminal 30 determines that the wireless terminal has a network controller function. Therefore, the wireless terminal is set to operate as the subordinate terminal 30. In FIG. 4, only the components used in the subordinate terminal 30 are displayed, and the other components provided in FIG. 1 are omitted.

  In FIG. 4, the subordinate terminal 30 performs a function determination unit 33 that determines whether the wireless terminal has a network controller function, an antenna 31 that transmits and receives beacons and information in a predetermined direction, and directivity control of the antenna 31. An antenna directing control unit 32, a timer 34 for managing system time, a beacon detection unit 36 for detecting a beacon from the control terminal 10, and a member for generating a member registration request corresponding to the beacon from the control terminal 10 The registration request generator 37 and an ACK detector 38 that receives an ACK from the control terminal 10 are included. In this wireless system, as described above, each wireless terminal can freely select whether to become the control terminal 10 or the subordinate terminal 30, but in the following, a wireless terminal having no network controller function is selected. This is called the subordinate terminal 30.

  Below, operation | movement of the control terminal 10 is demonstrated using FIG.1 and FIG.5. FIG. 5 is a flowchart showing an outline of a communication control procedure in the control terminal. When the wireless terminal is determined to have a network controller function by the function determination of the function determination unit 13 of the wireless terminal 10 after the wireless terminal 10 is started, the wireless terminal is controlled by the control terminal 10 (network controller wireless terminal PNC). (Step S1). When the wireless terminal 10 is determined to be the control terminal 1, the control terminal 10 transmits a beacon to all antenna directivity (S1 to S8) as shown in FIG. 2 (step S2). Thereafter, when there is a member registration request from one or more subordinate terminals 30 that do not have the network controller function in the system to the control terminal 10, the control terminal performs member registration of the subordinate terminal (step S3). Thereafter, when there is a data transfer request from the subordinate terminal 30, the control terminal 10 communicates with the subordinate terminal 30 (step S4). The communication is repeated until the control terminal 10 finishes the management function as the PNC (step S5).

  FIG. 6 is a flowchart showing a beacon pointing control procedure in the control terminal of the present invention, and shows details of step S2 in FIG. A beacon pointing control procedure in the control terminal will be described with reference to FIGS. 6 and 1. In FIG. 6, after the control terminal 10 is started, the antenna directivity control unit 12 of the control terminal 10 sets the beam directivity direction Si of the antenna 11 to S1 (step S11), and the network control unit 15 performs the superframe clock. Is reset to the first super frame, the terminal registration table control unit 16 of the control terminal 10 resets the table number to the initial value (step S12), and the timer 14 instructs the network control unit 15 to start the super frame. (Step S13).

  The terminal registration table control unit 16 confirms whether or not there is a subordinate terminal 30 registered in the terminal registration table 17 or whether or not the table number of the terminal registration table 17 is the last (step S14). If there is a terminal 30 and it is the last number, the antenna 11 of the control terminal transmits a beacon in the antenna pointing direction Si of the registered subordinate terminal 30 (step S15). If there is no registered terminal or the table number of the terminal registration table 17 is the last number, the antenna control unit 12 determines whether or not the antenna directivity direction Si is the last directivity direction Sm of the antenna (step S16) If not the last, the antenna control unit 12 advances (increases by 1) the antenna directing direction (step S17), and returns to step S14. When the antenna directivity control unit 12 determines that the antenna directivity direction Si is the last directivity direction of the antenna (step S16), the antenna control unit 12 determines whether or not the superframe is the last superframe. Judgment is made (step S18), and if the superframe is the last superframe, the processing of the beacon directing control procedure is terminated. If the superframe is not the last superframe, the superframe is incremented (step S19), the process returns to step S13, the timer 14 starts the next superframe, and the processing is continued.

  FIG. 7 is a flowchart showing the registration control procedure of the slave terminal in the control terminal, and shows details of step S3 in FIG. The member registration control procedure of the subordinate terminal 2 will be described with reference to FIGS. In FIG. 7, when receiving an ACK from the subordinate terminal 2 (step S31), the control terminal 1 determines whether there is a registration request from the subordinate terminal 2 (step S32). When there is a member registration request from the subordinate terminal 2, the terminal registration table control unit 16 registers the terminal ID and the antenna directivity direction Si in the terminal registration table 17 shown in FIG. 3 (step S33). It is determined whether or not the member registration process has been completed for all the dependent terminals 2 (step S34). If registration has not been completed for all the dependent terminals, the process proceeds to step S31, and an ACK is received for the next dependent terminal 2. The same process is continued. On the other hand, if there is no member registration request from the subordinate terminal 2 in step S32, it is determined whether or not registration has been completed for all subordinate terminals (step S34), and the same processing as described above is performed.

  FIG. 8 is a diagram showing a superframe configuration used in the beacon pointing control procedure (FIG. 6) in the control terminal of the present invention. In the present invention, beacon directivity control is performed using superframes SF # 1 to SF # n. Each super frame is incremented (incremented) by the value of i as in SF # 1 to SF # n, and sequentially as in superframe SF # 1, superframe SF # 2, ..., superframe SF # n. Process each superframe. Hereinafter, superframe SF # k will be described as a general description. First, the control terminal 1 transmits the directional beacon Si toward the subordinate terminal 2 (step S15 in FIG. 15). The subordinate terminal 2 transmits to the control terminal 1 whether or not a registration request is desired by using the registration request beacons 1, 2,..., M (steps S31 and S32 in FIG. 7). With this registration request beacon from the subordinate terminal 2, the control terminal 1 registers the subordinate terminal in the terminal registration table 17 (step S33 in FIG. 7). Communication is performed between the control terminal 1 and the subordinate terminal 2 in a later superframe based on the registered ID of the subordinate terminal (step S4 in FIG. 5).

  The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the gist of the present invention.

  Although not shown, as an example of the communication system, a personal computer system including a plurality of personal computers (hereinafter referred to as personal computers) in which the terminal device shown in FIG. 6 is arranged within a narrow range is conceivable. One of the plurality of personal computers operates as having the function of the control terminal 1 shown in FIG. 1, and the other personal computer has the same function as the subordinate terminal shown in FIG. In such a system, the personal computer can be moved to any location within a narrow range, and no matter where the personal computer is moved, it is possible to immediately communicate between the personal computers and freely transmit and receive data. It can be performed. Of course, the personal computer may be a digital signal processor or an FPGA (Field Programmable Gate Array).

  The present invention can be applied to a communication system that performs communication with a predetermined subordinate terminal only when there is a subordinate terminal registered in the terminal registration table of the control terminal in the wireless PAN.

It is a figure which shows schematic structure of the control terminal which has a network controller function. It is a figure which shows an example of the directivity direction of the antenna in a control terminal. It is a figure which shows the example of registration of the terminal registration table in a control terminal. It is a figure which shows an example of a structure of a subordinate terminal. It is a flowchart which shows the outline | summary of the communication control procedure in a control terminal. It is a flowchart which shows the directivity control procedure of a beacon. It is a flowchart which shows the procedure which member-registers a subordinate terminal in a control terminal. It is a figure which shows the mode of the registration request | requirement in the super frame in this invention. It is explanatory drawing of the radio | wireless communications system of IEEE802.15.3. It is explanatory drawing of the super frame in the radio | wireless communications system of IEEE802.15.3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control terminal 11 Antenna 12 Antenna orientation control part 13 Function judgment part 14 Timer 15 Network control part 16 Terminal registration table control part 17 Terminal registration table 18 Beacon transmission part 19 Member registration request detection part 20 ACK transmission part 30 Subordinate terminal 31 Antenna 32 Antenna orientation control unit 33 Function determination unit 34 Timer 35 Network control unit 36 Beacon detection unit 37 Member registration request generation unit 38 ACK detection unit

Claims (3)

In a wireless communication system that includes a control terminal and a plurality of subordinate terminals, and transmits and receives data using a superframe consisting of a beacon period, a contention access period, and a channel time allocation period,
The control terminal has a registration request, an antenna that can transmit and receive information in a predetermined direction, an antenna control unit that performs directivity control of the antenna, a function determination unit that determines whether or not it has a network controller function, and the like A terminal registration table in which information of subordinate terminals is recorded, a timer for managing time of the system, a network control unit for performing communication control using superframes, a beacon transmitting unit for transmitting beacons, and members from subordinate terminals A member registration request detecting unit for detecting a registration request, and an ACK sending unit for sending an ACK to a subordinate terminal,
The slave terminal includes an antenna unit that can transmit and receive information in a predetermined direction, an antenna control unit that performs directivity control of the antenna, a function determination unit that determines whether it has a network controller function, and a system time A timer that performs management, a network control unit that performs communication control using a superframe, a beacon detection unit that detects a beacon received from a control terminal, and a member registration request generation unit that generates a member registration request to be sent to the control terminal And an ACK detection unit for detecting ACK from the control terminal,
The control terminal transmits a beacon at a predetermined time in each predetermined direction, and the subordinate terminal requests a member registration to the control terminal when the beacon is received in the predetermined direction at a predetermined time. The control terminal receives the member registration request, determines the directivity direction in which communication is possible and registers it in the terminal registration table. Thereafter, when there is a communication request from a subordinate terminal, the terminal registration of the control terminal A wireless communication system, wherein communication is performed with the subordinate terminal based on directional information registered in a table.   When there is a communication request from the subordinate terminal registered in the terminal registration table of the control terminal, the network control unit reserves a communication time performed between the control terminal and the subordinate terminal, and the reserved time 2. The communication according to claim 1, wherein the antenna pointing control unit communicates with the subordinate terminal that has requested communication of the antenna pointing direction based on the pointing information registered in the terminal registration table. system. The terminal registration table records an ID of a subordinate terminal that has requested member registration and an antenna pointing direction of a control terminal that points to the antenna of the subordinate terminal that has requested the member registration. Item 3. The wireless communication system according to Item 1 or 2.

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