WO2011111864A1 - Radio communication device and radio communication method - Google Patents
Radio communication device and radio communication method Download PDFInfo
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- WO2011111864A1 WO2011111864A1 PCT/JP2011/056130 JP2011056130W WO2011111864A1 WO 2011111864 A1 WO2011111864 A1 WO 2011111864A1 JP 2011056130 W JP2011056130 W JP 2011056130W WO 2011111864 A1 WO2011111864 A1 WO 2011111864A1
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- WIPO (PCT)
- Prior art keywords
- radio communication
- communication device
- beacon
- packet
- time slot
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- 238000004891 communication Methods 0.000 title claims abstract description 549
- 238000000034 method Methods 0.000 title claims description 16
- 230000005540 biological transmission Effects 0.000 claims abstract description 50
- 238000006243 chemical reaction Methods 0.000 claims description 23
- 230000008859 change Effects 0.000 claims description 6
- 238000012545 processing Methods 0.000 description 38
- 238000010586 diagram Methods 0.000 description 14
- 230000004048 modification Effects 0.000 description 9
- 238000012986 modification Methods 0.000 description 9
- 125000004122 cyclic group Chemical group 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 101100172132 Mus musculus Eif3a gene Proteins 0.000 description 4
- 238000012937 correction Methods 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 108700026140 MAC combination Proteins 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/20—Control channels or signalling for resource management
- H04W72/27—Control channels or signalling for resource management between access points
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/04—Scheduled access
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2643—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA]
- H04B7/2656—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA] for structure of frame, burst
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/14—Spectrum sharing arrangements between different networks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
Definitions
- the present invention relates to a radio
- the radio communication network has fewer physical limitations compared to a cable network. Therefore, necessity and demands for the radio communication technology are increasing more and more in recent years. In addition, speed- up of the communication speed is highly required in the radio communication technology.
- radio communication techniques such as wireless LAN based on IEEE (The Institute of Electrical and Electronics Engineers) 802.11, ultra wide band (UWB)
- CSMA/CA Carrier Sense Multiple Access / Collision Avoidance
- TDMA Time Division Multiple Access
- a CSMA/CA access control scheme is used.
- packet communication is performed after checking network use status by using carrier sense.
- radio communication is performed using a ultra wideband.
- carrier detection is difficult. The reason is that the frequency band to be scanned is wide.
- the radio communication device for performing UWB radio communication uses the time division multiple access (TDMA) scheme.
- TDMA time division multiple access
- the CSMA/CA access control scheme is not used.
- a predetermined period is set as a superframe period, and a plurality of time slots are arranged in the superframe period.
- the superframe period is defined by a standard for example.
- a radio node participating in a network is assigned - - a time slot.
- the radio node can perform packet transmission in the time slot period.
- the superframe period is determined by a network coordinator.
- since communication available period is set for each radio node data to be transmitted to the network by each radio node do not contend with each other.
- time division multiple access scheme includes a request time slot assignment scheme and a cyclic time slot assignment scheme.
- the radio node transmits a time slot request packet each time when performing packet transmission.
- the time period of time slots occupied by radio nodes becomes minimum.
- use efficiency of the time slots is good.
- the radio node since the radio node transmits the time slot request packet each time when performing packet transmission, the transmission delay time from the
- the radio node that requested a time slot occupies time slots in a plurality of superframe periods.
- the radio node does not need to transmit a - - time slot request packet until the assigned time slot is released. Since it is not necessary to transmit the time slot request packet for each packet transmission, the transmission delay time is short. In addition, contention of request packets with other radio nodes is hard to occur. However, the time period during which one radio node occupies becomes long. For example, there may be a case where all time .slots of one superframe are occupied. When all time slots in one
- the number of time slots in the superframe are preset. Therefore, there is a possibility that idle time slots occur depending on the amount of data to be transmitted by the radio node. The use efficiency of time slots deteriorates when idle time slots occur, which is not preferable. Following techniques have been disclosed for reducing idle time slots so far.
- priorities are determined for each kind of packets to be transmitted. Then, packets to be transmitted are selected from those having higher priority according to the number of idle time slots and the number of time slots necessary for packet transmission. Accordingly, the number of idle time slots per one superframe can be reduced. Since the number of idle time slots per one superframe can be reduced, use efficiency of time slots can be improved. As a result, throughput improves.
- an idle time slot occurs in a superframe. When an idle time slot occurs in a superframe, other radio nodes miss packet
- Patent document, 1 Japanese Laid-Open Patent Application No. 2003-318852
- the present invention is contrived in view of the above-mentioned circumstances, and an object of the present invention is to provide a radio communication device and a radio communication method that can reduce waiting time for transmitting a packet even when the number of radio nodes participating in the radio network is large, and that can improve use efficiency of time slots even when the number of radio nodes participating in the radio network is small.
- the radio communication device is a radio communication device including:
- a beacon cycle determination unit configured to determine a beacon cycle for transmitting a beacon based on a sum of a number of time slots that is included in a beacon transmitted by another radio communication device and that the other radio communication device requests for transmitting data and a number of time slots to be requested by the radio communication device for transmitting data;
- the beacon cycle determination unit determines whether transmit a packet at a time slot and to receive a packet from another radio communication device at a time slot different from the time slot for transmission.
- the radio communication method is a radio
- radio communication method performed by a radio communication device including:
- a beacon cycle determination step of determining a beacon cycle for transmitting a beacon based on a sum of a number of time slots that is included in a beacon transmitted by another radio communication device and that the other radio communication device requests for transmitting data and a number of time slots to be requested by the radio
- waiting time for transmitting a packet can be reduced even when the number of radio nodes participating in the radio network is large, and use efficiency of time slots can be improved even when the number of radio nodes participating in the radio network is small.
- Fig. 1 is a schematic diagram showing a radio communication system according to an embodiment of the present invention
- Fig. 2 is a functional block diagram showing a radio communication device according to an embodiment of the present invention.
- Fig. 3 is a functional block diagram showing a radio communication device according to an embodiment of the present invention.
- Fig. 4 is an explanatory diagram (1) showing an example of a superframe in a radio communication system according to an embodiment of the present invention
- Fig. 5 is an explanatory diagram (2) showing an example of a superframe in a radio communication system according to an embodiment of the present invention
- Fig. 6 is an explanatory diagram (3) showing an example of a superframe in a radio communication system according to an embodiment of the present invention
- Fig. 7 is a flowchart showing operation of a radio communication system according to an embodiment of the present invention.
- Fig. 8 is a flowchart showing operation of a radio communication system according to an embodiment of the present invention.
- Fig. 9 is a functional block diagram showing a radio communication device according to an embodiment of the present invention.
- Fig. 10 is a schematic diagram showing a radio communication system according to an embodiment of the present invention.
- Fig. 11 is a functional block diagram showing a radio communication device according to an embodiment of the present invention.
- Fig. 12 is a functional block diagram showing a radio communication device according to an embodiment of the present invention.
- radio communication device 102 radio data processing unit
- CPU central processing unit
- Fig. 1 shows a radio communication system according to the present embodiment.
- the radio communication includes a plurality of radio communication devices 100 n (n is an integer greater than 0) .
- the radio communication device 100 n may be a note PC or a mobile terminal or the like as long as the radio communication device 100 n includes a radio interface (I/F) .
- the radio communication device may be called a radio node.
- Fig. 1 shows 9 radio communication devices as an example, the number may be less than 9 or greater than 9.
- the radio communication devices form a mesh network. In the mesh network, the radio communication devices perform radio communication mutually with each other so as to form a radio communication network 150 like a mesh. For example, radio communication devices connected by a solid line indicates that they can perform radio communication with each other. In the radio communication network 150, there is no device that becomes a base unit, so that the radio communication devices perform distributed control. In Fig. 1, the radio
- the radio communication network 150 is shown using a dotted line circle. For example, a distance by which radio communication is available in the radio communication network 150 may be represented as an approximate circle of the dotted line.
- the radio communication network 150 may be called a subnet.
- the subnet is a small radio communication network that is a management unit when a large radio communication network is divided into a plurality of small radio communication networks. It is not necessary to limit the radio communication network 150 to the mesh network. It may be configured as a network configuration, such as a star type network, different from the mesh network.
- each radio communication device 100 n can perform near field radio
- each radio communication device 100 n may perform near field radio communication by using IrDA, Bluetooth (BT) , Ultra Wide Band (UWB) , Z-Wave or ZigBee, for example.
- the radio communication devices 100 n perform near field communication so that a wireless personal area network (WPAN) may be formed.
- wireless personal area network near field radio communication of about 10m can be realized, for example. More specifically, the wireless personal area network can be applied to radio
- the technique can realize about 10m as a radio communication distance, the technique can be applied to various places in addition to an office and a room.
- the radio communication devices 100 n share a communication band available for the radio communication network 150 by dividing the communication band. Also, the radio communication devices 100 n transmit packets using a time division multiplexing scheme. When transmitting packets using the time division multiplexing scheme, the radio communication devices 100 n dynamically change the number of time slots to be included in one superframe according to the number of radio communication devices belonging to the radio communication network. By changing the number of time slots to be included in one superframe according to the number of radio
- the change of the number of time slots may be performed by controlling the protocol of the data link layer in OSI (Open Systems
- a beacon period during which control information is to be transmitted is defined at the head of the superframe.
- the control information includes information such as radio communication network synchronization.
- a beacon packet to be transmitted from each radio communication device is assigned to a beacon slot in the beacon period.
- the number of time slots requested by the radio communication devices participating in the radio communication network 150 may be dynamically set as the number of time slots to be included in one superframe. For example, in the case when a plurality of applications are implemented in a radio communication device and the applications transmit and receive data almost at the same time, time slots more than the number of radio communication devices are required. By dynamically setting the number of time slots to be included in one superframe as the number of time slots requested by the radio communication devices, requested time slots can be set even when applications implemented in radio communication devices transmit and receive data almost at the same time. In addition, by dynamically setting the number of time slots included in one superframe to be the number of time slots requested by the radio communication devices participating in the radio communication network 150, a state where there is no idle time slot can be made.
- the radio communication network 150 By making the state where there is no idle time slot, reduction of throughput can be avoided. Also, even when the radio communication network 150 is congested, any radio communication device can participate in the radio communication network 150. The reason is that, the number of time slots included in one superframe can be dynamically set to be the number of time slots requested by the radio communication devices participating in the radio communication network 150. Since the radio communication device can participate in the radio communication network 150, it becomes unnecessary to wait until a time slot is released.
- Fig. 2 shows an example of the radio communication device 100 n according to the present embodiment. Since each radio communication device has the same configuration, Fig. 2 shows the radio communication device 100 n as an example.
- the radio communication device 100 n includes a central processing unit (CPU) 104.
- the CPU 104 controls each functional block of the radio communication device 100 n .
- the radio communication device 100 n includes a RAM 106.
- the RAM stores radio data, management information and the like.
- the radio communication device 100 n includes a radio data processing unit 102.
- the radio data processing unit 102 performs manipulation and processing on the radio data.
- the CPU 104, the RAM 106 and the radio data processing unit 102 are connected by a bus 140.
- the radio data processing unit 102 includes a protocol control unit 1022.
- the protocol control unit 1022 manages superframe period, the number of time slots and the like. Also, the protocol control unit 1022 issues a data transmission instruction at a time when data should be transmitted. In the present embodiment, as an example, a case is described where protocol control is performed according to Wi edia ALLIANCE as an example. But, other protocol may be applied.
- the superframe includes a plurality of time slots.
- the first several time slots in the plurality of time slots are set as a beacon period (BP) .
- a length of the beacon period becomes longer as the number of radio communication devices belonging to the radio communication network 150 increases. Also, the length of the beacon period becomes shorter as the number of radio communication devices belonging to the radio communication network 150 decreases.
- Each time slot included in the beacon period may include a plurality of beacon slots.
- the beacon slot may include an ID of a radio communication device requesting transmission in the superframe period and the number of time slots requested by the radio communication device.
- Fig. 3 shows a functional block diagram showing the protocol control unit 1022.
- the protocol control unit 1022 includes a timer 302.
- the timer 302 is a timer for managing the superframe period.
- the protocol control unit 1022 includes a beacon transmit and receive control unit 304.
- the beacon transmit and receive control unit 304 is connected to a signal
- the beacon transmit and receive control unit 304 controls transmit and receive of a beacon to be broadcasted to the radio communication network 150 to which the radio communication device belongs. More specifically, control is performed such that, the radio communication device transmits a beacon to another radio communication device in a time slot for transmitting a beacon, and that the radio communication device receives a beacon at a time slot other than the time slot by which the radio
- the protocol control unit 1022 includes a time slot number determination unit 306.
- the time slot number determination unit 306 is connected to the beacon transmit and receive control unit 304 and the signal processing unit 1024.
- the time slot number determination unit 306 receives the number of time slots to be requested by the radio
- the time slot number determination unit 306 determines the number of time slots to be included in one superframe based on the number of time slots requested by other radio communication devices, that is supplied by the signal processing unit 1024, and based on the number of time slots to be requested by the radio communication device for - - transmitting data to another radio communication device. For example, a total value of the number of time slots is obtained by adding the number of time slots requested by the other communication devices and the number of time slots requested by the radio communication device for transmitting data to the other radio communication device.
- the time slot number is obtained by adding the number of time slots requested by the other communication devices and the number of time slots requested by the radio communication device for transmitting data to the other radio communication device.
- determination unit 306 determines whether the total value is 0. In other words, it is determined whether no radio
- the time slot number determination unit 306 reports, to a power save mode control unit 308, that the total number is 0.
- the time slot number determination unit 306 supplies the total value to the superframe setting unit 310.
- the protocol control unit 1022 includes the power save mode control unit 308. When it is reported that the total value of time slots is 0 from the time slot number determination unit 306, the power save mode control unit 308 determines whether a power save (PS) count value is a
- the predetermined value is set as a value common to radio communication devices belonging to the radio communication network.
- the power save count value is a threshold used for determining whether to cause the radio communication device belonging to the radio communication network to change to a power save mode.
- the power save count value is increased by a predetermined value which may be 1, for example.
- the power save mode control unit 308 determines that the power save count value is the predetermined value, the power save mode control unit 308 causes the radio communication device to change to a power save mode. In other words, when a
- a power down period until changing to the power save mode is represented as a product of the beacon period and the predetermined number of times .
- the power save mode control unit 308 determines that the power save count value is not the predetermined value, the power save mode control unit 308 increases the power save count value by a predetermined value.
- the power save mode control unit 308 supplies, to the
- superframe setting unit 310 information indicating that the total value of time slots is 0.
- the protocol control unit 1022 includes the superframe setting unit 310.
- the superframe setting unit 310 is connected to the time slot number determination unit 306 and the power save mode control unit 308.
- the superframe setting unit 310 sets a superframe based on the number of time slots supplied from the time slot number determination unit 306 or based on the information indicating that the number of time slots is 0 supplied from the power save mode control unit 308. For example, the superframe setting unit 310 sets a beacon period and a packet transmission period as time slots for transmitting data other than the beacon period. In other words, the superframe setting unit 310 sets a cycle (beacon cycle) for transmitting the beacon.
- the packet transmission period is used by each radio communication device sequentially for transmitting packets.
- the beacon period depends on the number of radio communication devices belonging to the radio communication network
- the packet transmission period depends on the number of time slots requested by radio communication devices.
- the length of the packet transmission period other than the beacon period becomes longer as the number of time slots requested by the radio communication devices belonging to the radio communication network 150 increases, and the length of the packet transmission period other than the beacon period becomes shorter as the number of time slots requested by the radio communication devices belonging to the radio communication network 15 decreases.
- Fig. 4 shows an example (1) of the superframe.
- the number of radio communication devices belonging to the radio communication network 150 is 5.
- Fig. 5 shows an example (2) of the superframe.
- the number of radio communication devices belonging to the radio communication network 150 is 3.
- Fig. 6 shows an example (3) of the superframe.
- the number of radio communication devices belonging to the radio communication network 150 is 2.
- the superframe period becomes longer than that of the case shown in Fig. 5.
- beacon periods are shown to be the same length among Figs. 4-6, beacon periods may be different. For example, since the beacon period depends on the number of radio communication devices requesting transmission, the beacon period of Fig. 4 may be greater than the beacon period of Fig. 5, and the beacon period of Fig. 5 may be greater than the beacon period of Fig. 6.
- the superframe setting unit 310 sets a superframe including only the beacon period.
- the protocol control unit 1022 includes the packet transmit and receive control unit 312.
- the packet transmit and receive control unit 312 is connected to the timer 302, - - the beacon transmit and receive control unit 304, the
- the packet transmit and receive control unit 312 instructs the beacon transmit and receive control unit 304 to transmit a request signal for requesting time slot(s) when the radio communication device has data to be transmitted.
- the communication device may include data whose transmission source is the radio communication device, and data, whose transmission source is another radio communication device, to be transmitted to the other radio communication device via the radio communication device.
- the packet transmit and receive control unit 312 controls transmit and receive of packets of the radio communication device based on a timer value supplied from the timer 302 according to the superframe supplied from the superframe setting unit 310. For example, the packet transmit and receive control unit 312 controls for transmitting transmission data supplied from the ROM 106 or transmitting a packet addressed to another radio communication device received from another radio communication device at a time slot where the radio communication device perform transmission. For example, the packet transmit and receive control unit 312 supplies transmission data to the signal processing unit 1024.
- the packet transmit and receive control unit 312 performs control for receiving data that is transmitted by another radio communication device and that is addressed to the radio communication device. Also, for example, the packet transmit and receive control unit 312 performs control for receiving data that is transmitted by another radio communication device and that is addressed to another radio communication device via the radio communication device.
- the radio data processing unit 102 includes the signal processing unit 1024.
- the signal processing unit 1024 performs modulation and demodulation for a radio packet. Also, the signal processing unit 1024 performs error correction and the like as necessary.
- the radio data processing unit 102 includes an AD/DA conversion unit 1026.
- the AD/DA conversion unit 1026 converts digital data into analog data or converts analog data into digital data.
- the radio data processing unit 102 includes an RF (Radio Frequency) unit 1028.
- the RF unit 1028 controls analog high frequency signal so as to transmit and receive a radio packet from an antenna.
- Fig. 7 shows a flowchart showing an example of operation of the radio communication device 100 n according to the present embodiment.
- Each radio communication device 100 n participates in the radio communication network 150 by - - performing processing shown in Fig. 7. In other words, each radio communication device 100 n performs processing shown in Fig. 7 so that the radio communication network 150 is formed.
- a radio communication device 100 n that is not participating in the radio communication network 150 performs scan in step S702.
- the scan may include electric field scan, active scan, and passive scan.
- scan is performed by using electric field measurement.
- active scan a beacon request command is issued to search neighboring nodes.
- passive scan a beacon from a neighboring node is received without transmitting a beacon.
- the protocol control unit 1022 of the radio communication device 100 n performs active scan.
- the radio communication device 100 n determines whether there is the radio communication network 150 based on the scan result in step S702 (step S704) .
- the protocol control unit 1022 determines whether there is the radio communication network 150 based on the scan result in step S702. For example, it may be determined that the radio communication network 150 exists when an electronic field strength greater than a predetermined electronic field strength is detected a predetermined number of times. For example, in the case of active scan, it may be determined that the radio communication network 150 exists when receiving a beacon response. For example, in the case of passive scan, it may be determined that the radio communication network 150 exists when receiving a neighboring beacon.
- the radio communication device 100 n synchronizes with the radio communication network 150 and transmits a connection request (step S706) .
- the protocol control unit 1022 transmits a connection request to the radio communication network 150 according to a predetermined protocol.
- the protocol control unit 1022 may transmit a participation request.
- the radio communication device 100 n After transmitting the connection request in step S706, the radio communication device 100 n performs
- the protocol control unit 1022 transmits an authentication request to the radio communication network 150 according to a predetermined protocol.
- the radio communication device 100 n participates in the radio communication network 150 (step S710) .
- step S704 determines that the radio communication network 150 does not exist in step S704 (step S704:NO).
- the radio communication device 100 n generates the radio communication network 150.
- the radio communication device 100 n that
- the radio communication device 100 n waits for receiving a participation request from another radio communication device (step S712) .
- the protocol control unit 1022 waits for receiving a participation request from another radio communication device according to a
- the other radio communication device ascertains the existence of the radio communication network 150 by receiving the beacon packet.
- radio communication device that recognized the existence of the radio communication network 150 synchronizes with the radio communication network 150, and transmits a participation request when participating in the radio communication network 150.
- the radio communication device 100 n determines whether a participation request is received (step S714) .
- the radio communication device 100 n When the radio communication device 100 n receives the participation request (step S714:YES), the radio communication device 100 n permits connection for the other radio
- step S716 the protocol control unit 1022 performs connection permission when the radio communication device 100 n causes the other radio communication device to participate in the radio communication network 150 generated by the radio communication device 100 n .
- step S714 when the radio communication device 100 n does not receive a participation request in step S714 (step S714:NO), the process returns to step S712.
- the radio communication device 100 n waits for receiving a
- step S712 participation request from another radio communication device.
- the radio communication device 100 n After permitting connection for the other radio communication device that transmitted a participation request in step S716, the radio communication device 100 n permits authentication for the other radio communication device that transmitted the participation request (step S718) .
- the protocol control unit 1022 performs
- the radio communication device 100 n participating in the radio communication network 150 requests a time slot (or time slots) from the next superframe when it - - has data to be transmitted.
- the radio communication device 100 n requests a time slot (or time slots) from the next superframe when it - - has data to be transmitted.
- Each radio communication device 100 n included in the radio communication network 150 broadcasts a beacon for requesting a time slot.
- Each radio communication device 100 n receives a beacon
- Each radio communication device 100 n transmits a superframe to other radio communication devices .
- Fig. 8 shows a flowchart showing an example (2) of operation of the radio communication device 100 n according to the present embodiment.
- Fig. 8 shows processing of one superframe period. It is assumed that radio communication devices 100 n belonging to the radio communication network 150 synchronize with each other.
- Each radio communication device 100 n waits until a beacon period (BP) starts (step S802) .
- the beacon transmit and receive control unit 304 waits until a beacon period starts.
- Each radio communication device 100 n determines whether a beacon period is going to start (step S804) .
- the beacon transmit and receive control unit 304 determines whether a beacon period is going to start. Whether the beacon period is going to start is determined until a time right before the beacon period starts.
- step S804:NO When it is not determined that the beacon period is going to start (step S804:NO), the process returns to step S802.
- the beacon transmit and receive control unit 304 waits until a time when beacon period is going to start.
- each radio communication device 100 n determines whether a beacon slot (a time slot for transmitting a beacon) of the radio communication device is going to start. For example, when the beacon transmit and receive control unit 304 determines that the beacon period is going to start, the beacon transmit and receive control unit 304 determines whether a beacon slot of the radio
- the radio communication device 100 n transmits a beacon at the beacon slot (step S808) .
- the beacon transmit and receive control unit 304 determines that a beacon slot of the radio communication device is going to start
- the beacon transmit and receive control unit 304 controls the radio communication device such that the radio communication device transmits a beacon at the beacon slot.
- the beacon may include an ID of the radio communication device and the number of time slots to be requested.
- modulation processing is performed by the signal processing unit 1024, and error correction processing is performed as necessary.
- the beacon on which modulation processing has been performed is converted to an analog signal by the AD/DA conversion unit 1026, and the signal is converted to a radio signal by the RF unit 1028, and the signal is transmitted from the antenna.
- the radio communication device 100 n receives a beacon transmitted from another radio communication device (step S810) .
- the beacon transmit and receive control unit 304 performs control to receive a beacon transmitted from the other radio communication device.
- the beacon transmitted from the other radio communication device is supplied to the RF unit 1028.
- the radio signal is converted into a signal of intermediate frequency, and the converted signal is supplied to the AD/DA conversion unit 1026.
- the AD/DA conversion unit 1026 the signal of the intermediate frequency is converted into a digital signal.
- the digital signal is demodulated by the signal processing unit 1024, and error correction is performed as necessary.
- the demodulated - - signal is supplied to the time slot number determination unit 306.
- Each radio communication device 100 n determines whether the beacon period ends (step S812) .
- the beacon transmit and receive control unit 304 determines whether the beacon period ends.
- the radio communication device waits until a next beacon slot. For example, when the beacon transmit and receive control unit 304 does not determine that the beacon period ends, the beacon transmit and receive control unit 304 waits until a next beacon slot starts.
- each radio communication device 100 n determines the number of time slots in the superframe (step S814) .
- the time slot number determination unit 306 determines the number of time slots in the superframe based on the beacon received from the other radio communication device in step S810. More specifically, the time slot number determination unit 306 adds the number of time slots to be requested by the radio communication device for transmitting data to another radio communication device and the number of time slots requested by other radio communication device (s) for transmitting data so as to determine the total value to be the number of time slots of the superframe other than the beacon period.
- Each radio communication device determines whether there is one or more time slot use requests (step S818) .
- the time slot number determination unit 306 determines whether there is one or more time slot use requests. For example, the time slot number determination unit 306
- step S814 determines whether the number of time slots determined in step S814 is equal to or greater than 1.
- each radio communication device 100 n sets the superframe (step S820) .
- the superframe setting unit 310 sets the packet transmission period in the superframe other than the beacon period.
- a beacon cycle is set.
- the beacon cycle is set such that, according to priorities that are predetermined for the radio communication devices, packet transmission is performed from a radio communication device having high priority.
- Each radio communication device sets a power save count value to be 0 (step S822) .
- the power save mode control unit sets the power save count value to be 0. The reason is that, the power save mode is set when a superframe having no data continues a predetermined number of times.
- Each radio communication device 100 n determines whether the radio communication device performed time slot request (step S824) .
- the packet transmit and receive control unit 312 determines whether the radio
- the radio communication device transmits a packet at a time slot at which the radio communication device should transmit data (step S826) .
- the packet transmit and receive control unit 312 transmits a packet at a time slot at which the radio communication device should transmit data.
- step S824:NO when it is not determined that the radio communication device performed time slot request (step S824:NO), and when the radio communication device transmitted a packet in step S826, the radio communication device waits until the superframe ends (step S828) .
- the packet transmit and receive control unit 312 waits until the superframe ends. While waiting, a radio communication device that is a destination of a packet transmitted by another radio communication device, or a radio communication device that relays a packet to be transmitted to - - another radio communication device receives the packet
- the packet transmit and receive control unit 312 performs control such that the radio
- the communication device is a destination of the packet
- radio communication device is a radio communication device that relays the packet to be transmitted to another radio communication device.
- the wireless communicating device 100 n determines whether the power save count value is N (step S830) .
- N indicates the number of superframes for changing to the power save mode, and it is preset. It may be set by a user. For example, when it is not determined that the number of time slots is equal to or greater than 1, in other words, when every radio communication device belonging to the radio communication network does not have data to be transmitted, the power save mode control unit 308 determines whether the power save count value is N.
- the radio communication device 100 n changes to a power save mode (step S832) .
- the power save mode control unit 308 changes to the power save mode .
- the radio communication device 100 n adds 1 to the power save count value (step S834) .
- the power save mode control unit 308 adds 1 to the power save count value (step S834) .
- a piconet may be formed, so that a piconet coordinator (PNC) may control each radio communication device to assign time slots.
- PNC piconet coordinator
- every radio communication device included in the radio communication network 150 has functions shown in Fig. 3, and it is only necessary that at least one radio communication device has the functions shown in Fig. 3.
- Fig. 9 shows a functional block diagram showing a protocol control unit 1022 of a radio communication device other than the piconet coordinator.
- the protocol control unit 1022 includes a timer 302.
- the timer 302 is a timer for managing the superframe period.
- the protocol control unit 1022 includes a beacon transmit and receive control unit 304.
- the beacon transmit and receive control unit 304 is connected to a signal
- the beacon transmit and receive control unit 304 controls transmit and receive of a beacon to be broadcasted to the radio communication network 150 to which the radio communication device belongs. More specifically, control is performed such that, the radio communication device transmits a beacon to the other radio communication devices in a time slot for transmitting a beacon from the radio communication device, and that the radio communication device receives a beacon at a time slot other than the time slot by which the radio communication device transmits a beacon to the other radio communication devices.
- the protocol control unit 1022 includes a power save mode control unit 308.
- the power save mode control unit 308 changes to a power saving mode.
- the protocol control unit 1022 includes a packet transmit and receive control unit 312.
- the packet transmit and receive control unit 312 is connected to the timer 302, the beacon transmit and receive control unit 304, the ROM 106 and the signal processing unit 1024.
- the packet transmit and receive control unit 312 instructs the beacon transmit and receive control unit 304 to transmit a request signal for requesting time slots when the radio communication device has data to be transmitted.
- the data to be transmitted by the radio communication device may include data whose transmission source is the radio communication device, and data, whose transmission source is another radio communication device, to be transmitted to another radio communication device via the radio communication device.
- the packet transmit and receive control unit 312 controls transmit and receive of packets of the radio communication device based on a timer value supplied from the timer 302 according to the superframe reported from the piconet coordinator. For example, the packet transmit and receive control unit 312 controls for transmitting transmission data supplied from the ROM 106 or a packet addressed to another radio communication device
- the packet transmit and receive control unit 312 supplies transmission data to the signal processing unit 1024. Also, for example, the packet transmit and receive control unit 312 performs control for receiving data that is
- the packet transmit and receive control unit 312 performs control for receiving data that is transmitted by - - another radio communication device and that is addressed to another radio communication device via the radio communication device .
- the number of time slots included in a superframe in each radio communication network is independent of each other. In other words, the number of time slots included in the superframe may be different among radio communication networks.
- Fig. 10 is a schematic diagram showing that communication is performed between radio communication devices belonging to different radio communication networks .
- a radio communication network 150i includes radio communication devices IOO1-IOO9
- a radio communication network 150 2 includes radio communication devices ⁇ - ⁇
- a radio communication network 150 3 includes radio communication devices 100i 7 -100 2 i.
- the number of radio communication devices belonging to a radio communication network may be different among the radio communication networks 150 ⁇ -15 ⁇ 3 . Also, the number of time slots requested by the radio communication device in a superframe period may be different for each of the radio communication networks 150i-150 3 . Therefore, when a
- a start time of a beacon period for the radio communication device of the radio communication network is different from a start time of a beacon period for the radio communication device of the different radio communication network.
- At least one radio communication device belonging to a first radio communication network performs communication with another radio communication device
- Fig. 11 shows a radio communication device (1) according to the modification example.
- the radio
- the radio communication device includes a protocol conversion unit 314 in the radio communication device
- the protocol conversion unit 314 is connected to the packet transmit and receive control unit 312 and the signal processing unit 1024.
- the protocol conversion unit 314 converts the communication protocol used in the radio
- the communication network 150 to a communication protocol commonly used in the radio communication network and another radio communication network.
- the protocol conversion unit 314 performs protocol conversion from UWB to Ethernet.
- the protocol- converted data is transmitted to a radio communication device in the other radio communication network.
- a packet transmitted by the Ethernet from the other radio communication network is protocol-converted to UWB by the protocol
- the packet protocol-converted into 1MB is modulated by the signal processing unit 1024, and is converted to a radio signal by the RF unit 1028, so that the signal is transmitted.
- Fig. 12 shows a radio communication device (2) according to the modification example.
- the base unit may be configured as a configuration shown in Fig. 11.
- Each radio communication device other than the base unit includes a protocol conversion unit 314 in the radio communication device described with reference to Fig. 9.
- the protocol conversion unit 314 is connected to the packet transmit and receive control unit 312 and the signal processing unit 1024.
- the protocol conversion unit 314 converts the communication protocol used in the radio
- the communication network 150 to a communication protocol commonly used in the radio communication network and another radio communication network.
- the protocol conversion unit 314 performs protocol conversion from UWB to Ethernet.
- the protocol- converted data is transmitted to a radio communication device in the other radio communication network.
- a packet transmitted by the Ethernet from the other radio communication network is protocol-converted to UWB by the protocol
- the packet protocol-converted into UWB is modulated by the signal processing unit 1024, and is converted to a radio signal by the RF unit 1028, so that the signal is transmitted.
- Ethernet is used as an example of the communication protocol commonly used by radio communication networks, the protocol is not limited to the Ethernet. Other protocols may be used. For example, wireless LAN may be used.
- the at least one radio communication device includes at least two network interfaces .
- the radio communication device performs transmission request in units of time slots.
- the time unit of the time slot is preset. But, each radio communication device may be configured to be able to arbitrarily set a period of time slot for request.
- the beacon transmit and receive control unit 304 may specify a period of a time slot when there is data to be transmitted.
- a radio communication device is provided.
- the radio communication device includes:
- a beacon cycle determination unit configured to determine a beacon cycle for transmitting a beacon based on a sum of a number of time slots that is included in a beacon transmitted by another radio communication device and that the other radio communication device requests for transmitting data and a number of time slots to be requested by the radio communication device for transmitting data;
- a packet transmit and receive control unit configured to control the radio communication device
- the beacon cycle determination unit determines whether transmit a packet at a time slot and to receive a packet from another radio communication device at a time slot different from the time slot for transmission.
- the radio communication device may further includes: a beacon transmit and receive control unit configured to control the radio communication device to transmit a beacon at a time slot for transmission of a beacon among a plurality of time slots included in the beacon cycle, and to receive a beacon from another radio communication device at a different time slot for receiving a beacon.
- a beacon transmit and receive control unit configured to control the radio communication device to transmit a beacon at a time slot for transmission of a beacon among a plurality of time slots included in the beacon cycle, and to receive a beacon from another radio communication device at a different time slot for receiving a beacon.
- all of the radio communication devices participating in the radio communication network can perform packet transmission in one superframe period. In other words, a period in which packet transmission is not performed does not occur. Since the period in which packet transmission is not performed does not occur, packet transfer efficiency in the whole radio network improves .
- the radio communication device may include: a power save mode control unit configured to cause the radio
- the radio communication device changes to a power save mode during a period in which packet communication is not performed.
- power consumption of each radio communication device can be reduced. Therefore, power consumption of the whole radio communication network can be reduced.
- the beacon cycle determination unit may determines the beacon cycle such that the beacon cycle is different from a beacon cycle set in another radio communication network.
- the radio communication device may include: a protocol conversion unit configured to convert a communication protocol of a packet to be transmitted from a communication protocol used by the radio communication network to which the radio communication device belongs into a communication protocol commonly used in the radio
- the packet transmit and receive control unit transmits a packet that is protocol-converted by the protocol conversion unit to the other radio communication network.
- radio communication device packet transmit and receive between radio subnetworks becomes available, so that the communication network range can be enlarged.
- a period of the time slot can be changed.
- a radio communication method performed by a radio communication device is provided.
- the radio communication method performed by a radio communication device includes:
- a beacon cycle determination step of determining a beacon cycle for transmitting a beacon based on a sum of a number of time slots that is included in a beacon transmitted by another radio communication device and that the other radio communication device requests for transmitting data and a number of time slots to be requested by the radio
- the present application is based on Japanese
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Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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CN201180012918.2A CN102792730B (en) | 2010-03-10 | 2011-03-09 | Radio communications set and radio communication method |
KR1020127023126A KR101353109B1 (en) | 2010-03-10 | 2011-03-09 | Radio communication device and radio communication method |
EP11753519.5A EP2545728B1 (en) | 2010-03-10 | 2011-03-09 | Radio communication device and radio communication method |
US13/579,214 US20120314639A1 (en) | 2010-03-10 | 2011-03-09 | Radio communication device and radio communication method |
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JP2010-052572 | 2010-03-10 | ||
JP2010052572A JP5488062B2 (en) | 2010-03-10 | 2010-03-10 | Wireless communication apparatus and wireless communication method |
Publications (1)
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WO2011111864A1 true WO2011111864A1 (en) | 2011-09-15 |
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Family Applications (1)
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PCT/JP2011/056130 WO2011111864A1 (en) | 2010-03-10 | 2011-03-09 | Radio communication device and radio communication method |
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US (1) | US20120314639A1 (en) |
EP (1) | EP2545728B1 (en) |
JP (1) | JP5488062B2 (en) |
KR (1) | KR101353109B1 (en) |
CN (1) | CN102792730B (en) |
WO (1) | WO2011111864A1 (en) |
Families Citing this family (8)
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JP6232870B2 (en) | 2013-09-11 | 2017-11-22 | 株式会社リコー | Wireless communication system, wireless communication method, program, and recording medium |
JP2015104072A (en) | 2013-11-27 | 2015-06-04 | 株式会社リコー | Communication apparatus, signal process program, and recording medium |
JP2016154299A (en) | 2015-02-20 | 2016-08-25 | 株式会社リコー | Communication system, communication apparatus, and communication method |
US11101933B2 (en) * | 2016-09-30 | 2021-08-24 | Inplay, Inc. | Methods and systems for low latency wireless communication with a scalable hierarchial architecture |
CN106879060A (en) * | 2017-03-29 | 2017-06-20 | 武汉米风通信技术有限公司 | A kind of broadcasting and TV frequency spectrum ultra-narrow band many base station beacon recognition methods of Internet of Things |
CN111405534B (en) * | 2020-03-11 | 2023-08-25 | 锐迪科微电子(上海)有限公司 | Information transmission method, first terminal and computer storage medium |
CN112492565B (en) * | 2020-12-13 | 2021-10-29 | 同济大学 | Self-adaptive wireless sensor network based on ZigBee and BLE mixed protocol |
JP7237263B2 (en) * | 2021-02-08 | 2023-03-10 | 三菱電機株式会社 | Wireless communication terminal, wireless communication method and wireless communication program |
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Also Published As
Publication number | Publication date |
---|---|
KR20120123537A (en) | 2012-11-08 |
JP2011188324A (en) | 2011-09-22 |
EP2545728A4 (en) | 2016-12-28 |
JP5488062B2 (en) | 2014-05-14 |
KR101353109B1 (en) | 2014-01-17 |
EP2545728B1 (en) | 2018-05-02 |
CN102792730B (en) | 2015-11-25 |
EP2545728A1 (en) | 2013-01-16 |
US20120314639A1 (en) | 2012-12-13 |
CN102792730A (en) | 2012-11-21 |
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