Cognitive wireless communication system

• US 20080182605A1
• Filed: 01/07/2008
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamaoka, Ryouji, Yoshizawa, Satoshi, Morishige, Takehiro, Suzuki, Toshiaki, Yano, Masashi, Wakayama, Koji, Hanaoka, Seishi, Yamamoto, Junji
• Granted Patent: US 8,219,131 B2
• Time in Patent Office: Days
• US Class Current: 455/507
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

To prevent a hung-up of communications due to changes in a radio wave condition resulting from frequent displacement of the terminals and changes in a number of the terminals, and to realize switching of the radio systems adapting to the radio condition. A radio communication system comprising: a base station for providing a plurality of radio systems, and terminals for communicating with the base station through the plurality of radio systems. The base station decides a priority of the radio system on which the each terminal will communicate thereafter and transmits paging signals of one of the plurality of radio systems which includes information on the decided priority to the each terminal.

Claims

1. A radio communication system comprising:

a base station for providing a plurality of radio systems, and

terminals for communicating with the base station through the plurality of radio systems, wherein

the base station decides a priority of the radio system on which the each terminal will communicate thereafter and transmits paging signals of one of the plurality of radio systems which includes information on the decided priority to the each terminal.

2. The radio communication system according to claim 1 further comprising a monitoring node coupled with the base station,

wherein the base station comprises access points for each of the radio systems, gateways terminate the each radio system, and a control node for controlling the gateways.

wherein the monitoring node obtains states of the radio systems, and

wherein the control node decides the priority of the radio system on which the each terminal will communicate thereafter based on the state of the each radio system obtained by the monitoring nodes, information on the radio systems available for the each terminal, and the information on a radio system that the terminal requests to use.

3. The radio communication system according claim 2,

wherein the monitoring node obtains at least a piece of information on RSSI, packet loss, transmission rate of the each terminal, number of the terminals coupled with each of the access points, and processing load of each of the access points, and

wherein the control node converts the information obtained from the radio systems at different timing into comparable forms, and decides the priority of the radio system on which the each terminal will communicate thereafter based on the converted information by taking into account the position and the direction of movement of the each terminals.

4. The radio communication system according to claim 2 wherein,

the control node selects the radio systems to be used to transmit the decided priority based on the information obtained by the monitoring node and the information obtained from the terminals, and

instructs the gateway to send the paging signal including information on the priority from the access points.

5. The radio communication system according to claim 4 wherein,

wherein the base station provide a first radio system having a wide communication area and a second communication system having a narrower communication area than the first radio system,

wherein the control node controls to transmit the information on the decided priority of the radio system on which the each terminal will communicate thereafter by the paging signal of the first radio system if the first radio system is available, and

wherein the control node controls to transmit the information on the decided priority of the radio system on which the each terminal will communicate thereafter by the paging signal of the second radio system if the first radio system is not available.

6. The radio communication system according to claim 1 wherein,

the terminal comprises a plurality of transmitters and a plurality of receivers each corresponding to a plurality of radio systems, and a controller for controlling the transmitters and the receivers, and

the controller decides the radio systems to be used for communication based on the priority information included in the paging signals transmitted from the base station, the obtained information on the available radio system, and information on the radio system that the terminal requests to use.

7. The radio communication system according to claim 6 wherein, the controller obtains information on the available radio system by referring the beacon signal of the radio systems, and stores the obtained information on the available radio system and information on a radio system that the terminal requests to use.

8. The radio communication system according to claim 6 wherein, the controller sets the receiver of the radio system decided to be used for communication in an active state.

9. The radio communication system according to claim 6 wherein, the controller sets the receiver of the radio system not decided to be used for communication in a sleep state.

10. The radio communication system according to claim 9 wherein, the receiver of the radio system which is set in the sleep state changes the time interval of receiving paging signals depending on the radio system of which the receiver is in the active state.

11. The radio communication system according to claim 9 wherein, the receiver of the radio system which is set in the sleep state does not wake up even if the paging signal is detected.

12. A radio communication terminal for communicating with the base station providing a plurality of radio systems by means of the plurality of radio systems comprising:

a plurality of transmitters and a plurality of receivers each corresponding to the plurality of radio systems, and

a controller for controlling the transmitters and the receivers,

wherein the each receiver receives the paging signals sent from the base station,

wherein the controller obtains the priority information of the radio systems of which the terminal will communicate thereafter from the received paging signals,

obtains information on the available radio system, and

decides a radio system used for communication based on the obtained priority information, the obtained information on the available radio system, and information on a radio system that the terminal requests to use.

13. The radio communication terminal according to claim 12 wherein, the controller obtains information on the available radio system by referring the beacon signals of the radio systems, and stores the obtained information on the available radio system, and information on a radio system that the terminal requests to use.

14. The radio communication terminal according to claim 12 wherein, the controller sets the receiver of the radio system decided to be used for communication in an active state.

15. The radio communication terminal according to claim 12 wherein, the controller sets the receiver of the radio system no decided to be used for communication in a sleep state.

16. The radio communication terminal according to claim 15 wherein, the receiver of the radio system which is set in the sleep state changes the time interval of receiving paging signals depending on the radio system of which the receiver is in the active state.

17. The radio communication terminal according to claim 15 wherein, the receiver of the radio system which is set in the sleep state does not wake up even if paging signal is detected.