Radio Communication Device and Radio Communication Method

• US 20100062773A1
• Filed: 03/14/2008
• Published: 03/11/2010
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Yokota, Tomoyoshi
• Granted Patent: US 8,260,299 B2
• Time in Patent Office: Days
• US Class Current: 455/437
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

When communication quality exceeds the first threshold, the radio communication terminal 300 starts connection with the radio communication system 120 and establishes the radio link L2 to the radio communication system 120. Further, a handover from the radio link L1 to the radio link L2 is performed when the communication quality exceeds the second threshold after the establishment of the radio link L2, the second threshold corresponding to communication quality degraded than that indicated by the first threshold.

Claims

1. A radio communication device including:

a radio communication unit configured to perform radio communication by connecting to a first radio communication system and to a second radio communication system different from the first radio communication system; and

a mobility manager configured to manage mobility from the first radio communication system to the second radio communication system,

the radio communication device comprising;

a communication quality acquirer configured to acquire communication quality of a first radio link established with the first radio communication system;

a communication quality determination unit configured to determine whether or not the communication quality acquired by the communication quality acquirer exceeds a first threshold or a second threshold corresponding to the communication quality degraded than that indicated by the first threshold; and

a handover controller configured to control a handover from the first radio communication system to the second radio communication system, wherein

when the communication quality determination unit determines that the communication quality exceeds the first threshold, the handover controller starts connection with the second radio communication system and establishes a second radio link with the second radio communication system, and

when the communication quality determination unit determines that the communication quality exceeds the second threshold after the second radio link has been established, the handover controller performs a handover from the first radio link to the second radio link.

2. The radio communication device according to claim 1, wherein

the handover controller causes the radio communication unit to transmit the same packets simultaneously via the first radio link and the second radio link, and

when the radio communication unit has received a packet via to the second radio link, the handover controller disconnects the first radio link.

3. The radio communication device according to any one of claims 1 and 2, wherein

the handover controller includes a media independent handover function not depending on a configuration of a physical layer of each of the first radio communication system and the second radio communication system, and

the media independent handover function performs the handover based on an instruction from a protocol positioned in a layer higher than the media independent handover function.

4. A radio communication method of performing radio communication by connecting to a first radio communication system and to a second radio communication system different from the first radio communication system, the radio communication method comprising the steps of:

acquiring communication quality of a first radio link established with the first radio communication system;

determining whether or not the communication quality acquired exceeds a first threshold; and

when it is determined that the communication quality exceeds the first threshold, starting connection with the second radio communication system and establishing a second radio link with the second radio communication system;

determining whether or not the communication quality exceeds a second threshold corresponding to the communication quality degraded than that indicated by the first threshold; and

when it is determined that the communication quality exceeds the second threshold after the second radio link has been established, performing a handover from the first radio link to the second radio link.