Communication channel establishing method, communication system, and communication apparatus

• US 20070232363A1
• Filed: 03/30/2007
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Inventors: Sukegawa, Katsuhiko, Kimura, Youichi, Hiketa, Hitoshi, Seike, Yohoko
• Granted Patent: US 8,014,441 B2
• Time in Patent Office: Days
• US Class Current: 455/572
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication channel establishing method is provided that is used in a communication system including a base station that transmits a beacon on a predetermined communication channel and a communication apparatus that receives the beacon from the base station and establishes communication with the base station using the predetermined communication channel. The method involves detecting at the base station whether a main power supply has been shut off, driving the base station by a backup power supply and transmitting a power supply shutoff notification signal from the base station to the communication apparatus upon detecting that the main power supply has been shut off, storing a current communication channel of the communication apparatus when the power supply shutoff notification signal from the base station is received by the communication unit, and reestablishing communication with the base station at the communication apparatus using the stored current communication channel upon recovery of the main power supply.

Claims

1. A communication channel establishing method used in a communication system including a base station that transmits a beacon on a predetermined communication channel and a communication apparatus that receives the beacon from the base station and establishes communication with the base station using the predetermined communication channel, the method comprising the steps of:

detecting at the base station whether a main power supply has been shut off;

driving the base station by a backup power supply and transmitting a power supply shutoff notification signal from the base station to the communication apparatus upon detecting that the main power supply has been shut off;

storing a current communication channel of the communication apparatus when the power supply shutoff notification signal from the base station is received by the communication unit; and

reestablishing communication with the base station at the communication apparatus using the stored current communication channel upon recovery of the main power supply.

2. The communication channel establishing method as claimed in claim 1, wherein

the communication apparatus stores current status information upon receiving the main power supply shutoff notification signal from the base station.

3. The communication channel establishing method as claimed in claim 1, wherein

the communication apparatus intermittently performs communication channel search after receiving the main power supply shutoff notification signal from the base station.

4. The communication channel establishing method as claimed in claim 1, wherein

the base station transmits a main power supply recovery notification signal to the communication apparatus when the main power supply is turned on after being shut off;

and

the communication apparatus receives the main power supply recovery notification signal from the base station and reestablishes communication with the base station using the stored current communication channel.

5. A communication system comprising:

a base station that transmits a beacon on a predetermined communication channel; and

a communication apparatus that receives the beacon from the base station and establishes communication with the base station using the predetermined communication channel;

wherein

the base station detects whether a main power supply has been shut off, receives drive power from a backup power supply when the main power supply is shut off, and transmits a main power shutoff notification signal to the communication apparatus; and

the communication apparatus stores a current communication channel upon receiving the main power shutoff notification signal from the base station, and reestablishes communication with the base station using the stored current communication channel upon recovery of the main power supply.

6. A communication apparatus that receives a beacon from a base station and establishes communication using a communication channel according to the received beacon, the communication apparatus comprising:

a communications unit that establishes communication with the base station; and

a control unit that stores a current communication channel upon receiving a main power supply shutoff notification signal from the base station via the communications unit, and searches subsequent beacons transmitted from the base station using the stored current communication channel.