RADIO COMMUNICATION TERMINAL AND NETWORK SIDE COMMUNICATION APPARATUS

• US 20090135759A1
• Filed: 09/08/2006
• Published: 05/28/2009
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Benjamin, Tien Ming, Ng, Chan Wah, Tan, Pek Yew, Hirano, Jun, Aramaki, Takashi
• Granted Patent: US 8,270,368 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 36/008375 based on historical data
• CPC Class Codes: H04W 36/142 over the same radio air interface technology
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A technology is disclosed for achieving fast and reliable handover. According to this technology, in the network composition where a network coverage area of the cellular base station 105 and network coverage areas of plural WLAN AP (Wireless LAN access point) 110, 115, 120 and 130 overlaps, the roaming mobile node (mobile terminal) 100 stores the listened beacon information from each WLAN AP. The mobile node can promptly perform the handover procedures without waiting for listening to the next beacon by acquiring the beacon information of WLAN AP which is a handover target from the stored information at the instant of determining to do handover to a new WLAN AP. Furthermore, the mobile node can store information on stability of the network connection if it would be connected to each WLAN AP, and determine which WLAN AP is suitable for a handover target by considering the stability.

Claims

1. A radio communication terminal comprising:

plural radio communication interface means, each of plural radio communication interface means being capable of connecting to one or plural base stations,

a beacon information storing means for storing information which is included in a beacon signal, the beacon signal being periodically sent from the base station and being received by each of the plural radio communication interface means,

a beacon information retrieving means for retrieving information included in the beacon signal from the beacon information storing means, the beacon signal being received by the radio communication interface means which corresponds to a predetermined trigger according the predetermined trigger, and

a communication control means for controlling to start communication on the radio communication interface means by using information included in the beacon signal, the beacon signal being retrieved by the beacon information retrieving means.

2. The radio communication terminal according to claim 1 comprising a communication switch controlling means for providing the predetermined trigger to the beacon information retrieving means upon initiating to communicate on any one of the plural radio communication interface means or upon switching a point of attachment on any one of the plural radio communication interface means, the predetermined trigger corresponding to the radio communication interface means which initiates to communicate or switches the base station to be connected.

3. The radio communication terminal according to claim 1 comprising an information storage controlling means for controlling to listen the beacon signal on the radio communication interface or to store information included in the beacon signal into the beacon information storing means, based on any one of initiation timing of communication on the radio communication interface, switch timing of connection to the base station on the radio communication interface, and a policy about electric power.

4. The radio communication terminal according to claim 1 comprising:

a stability information storing means for storing information about stability of communication with the base station which each of the plural radio communication interface means can connect to, and

a stability determining means for determining whether the base station can be selected as a candidate for communication or not, based on the information about stability stored in the stability information storing means.

5. The radio communication terminal according to claim 4 comprising a stability evaluating means for evaluating stability of communication between each of the plural radio communication interface means and the base station based on the beacon signal received from the base station by each of the plural radio communication interface means, or based on information about stability of communication between other radio communication terminals and the base station, the information being informed from the other radio communication terminals.

6. The radio communication terminal according to claim 5 wherein the stability evaluating means is arranged to rank the base stations based on a time-variable pattern of the information about stability of communication or a frequency of detecting the beacon signals.

7. The radio communication terminal according to claim 1 comprising:

a stability information storing means for storing information about stability of communication with the base station which each of the plural radio communication interface means can connect to, and

a message sending means for sending a message requesting to improve the stability of communication to the base station whose stability becomes below a predetermined threshold level, referring the information about stability stored in the stability information storing means.

8. The radio communication terminal according to claim 7 wherein the message comprises at least an identification information of the base station, an identification information of the radio communication terminal, and communication characteristics information about communication with the base station.

9. The radio communication terminal according to claim 7 comprising a stability evaluating means for evaluating stability of communication between each of the plural radio communication interface means and the base station based on the beacon signal received from the base station by each of the plural radio communication interface means, or based on information about stability of communication between other radio communication terminals and the base station, the information being informed from the other radio communication terminals.

10. The radio communication terminal according to claim 9 wherein the stability evaluating means is arranged to rank the base stations based on a time-variable pattern of the information about stability of communication or a frequency of detecting the beacon signals.

11. A radio communication terminal comprising:

plural radio communication interface means, each of plural radio communication interface means being capable of connecting to one or plural base stations,

a stability information storing means for storing information about stability of communication with the base station which each of the plural radio communication interface means can connect to, and

a stability determining means for determining whether communication starts or not between the radio communication interface means and the base station, based on the information about stability stored in the stability information storing means.

12. The radio communication terminal according to claim 11 comprising a stability evaluating means for evaluating stability of communication between each of the plural radio communication interface means and the base station based on the beacon signal received from the base station by each of the plural radio communication interface means, or based on information about stability of communication between other radio communication terminals and the base station, the information being informed from the other radio communication terminals.

13. The radio communication terminal according to claim 12 wherein the stability evaluating means is arranged to rank the base stations based on a time-variable pattern of the information about stability of communication or a frequency of detecting the beacon signals.

14. A radio communication terminal comprising:

plural radio communication interface means, each of plural radio communication interface means being capable of connecting to one or plural base stations,

a stability information storing means for storing information about stability of communication with the base station which each of the plural radio communication interface means can connect to, and

a message sending means for sending a message requesting to improve the stability of communication to the base station whose stability becomes below a predetermined threshold level, referring the information about stability stored in the stability information storing means.

15. The radio communication terminal according to claim 14 wherein the message comprises at least an identification information of the base station, an identification information of the radio communication terminal, and communication characteristics information about communication with the base station.

16. A network side communication apparatus accommodating a radio communication terminal, comprising:

a radio communication interface means for communicating the radio communication terminal,

a message receiving means for receiving a message requesting to improve stability of communication with the radio communication terminal from the radio communication terminal via the radio communication interface means, and

a communication stability improving means for improving the stability of communication with the radio communication terminal which is the source of the message by controlling operation of the radio communication interface means.

17. The network side communication apparatus according to claim 16 wherein the communication stability improving means is arranged to increase transmitting power or adjust directional characteristics toward the radio communication terminal as the controlled operation of the radio communication interface means.