Wireless communication system and method of reducing power consumption thereof

• US 20050083902A1
• Filed: 09/02/2004
• Published: 04/21/2005
• Est. Priority Date: 10/09/2003
• Status: Abandoned Application

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Hashimoto, Tatsushi
• Application Number:
  US10/931,989
• Publication Number:
  US 20050083902A1
• Time in Patent Office: Days
• US Class Current: 370/349
• CPC Class Codes: H04M 2250/02 including a Bluetooth interface
• CPC Class Codes: H04W 52/029 reducing the clock frequency of the controller
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In a wireless communication system capable of reducing power consumption in accordance with an actual transmission/reception status of each time slot even in an active mode, a wireless transmitter/receiver on a master side selects a high speed clock, supplies this clock to a CPU at the start of a reception time slot and reliably processes a reception packet. When a transmission packet to be transmitted in a next transmission time slot does not exist after completion of the processing of the reception packet, a clock signal is switched to a low speed clock. A wireless transmission/reception on a slave side surely supplies a high speed clock to the CPU at an intermediate part of the transmission time slot and prepares for the processing of the reception packet in the next reception time slot. When the effective reception packet is not detected in the reception time slot, the clock signal is switched to the low speed clock.

Claims

1. A wireless communication system for executing packet communication between a transmitter/receiver on a master side and a transmitter/receiver on a slave side by using a wireless channel in which transmission time slots and reception time slots are alternately repeated in a predetermined time interval, wherein:

said transmitter/receiver on the master side includes;

a central processing unit for controlling said transmitter/receiver as a whole;

a high speed clock oscillator for generating a high speed clock to be supplied to said central processing unit in an operation mode in which said transmitter/receiver is under communication; and

a low speed clock oscillator for generating a low speed clock to be supplied to said central processing unit in a standby mode in which said transmission/receiver does not execute communication; and

wherein;

said high speed clock is always selected at the start of the reception time slot of said wireless channel and is supplied to said central processing unit, and when an effective reception packet is not detected in said reception time slot and a transmission packet to be transmitted in a next transmission time slot does not exist, or when the effective reception packet is received in the reception time slot but the transmission packet to be transmitted in the next transmission slot does not exist, said low speed clock is selected and is supplied to said central processing unit.

2. A wireless communication system for executing packet communication between a transmitter/receiver on a master side and a transmitter/receiver on a slave side by using a wireless channel in which transmission time slots and reception time slots are alternately repeated in a predetermined time interval, wherein:

said transmitter/receiver on the slave side includes;

a central processing unit for controlling said transmitter/receiver as a whole;

a high speed clock oscillator for generating a high speed clock to be supplied to said central processing unit in an operation mode in which said transmitter/receiver is under communication; and

a low speed clock oscillator for generating a low speed clock to be supplied to said central processing unit in a standby mode in which said transmission/receiver does not execute communication; and

wherein;

when the transmission packet is not transmitted at an intermediate part of the transmission time slot of said wireless channel, said high speed clock is selected and is supplied to said central processing unit and when an effective reception packet is not detected in said reception time slot, said low speed clock is selected and is supplied to said central processing unit.

3. A method for reducing power consumption in a wireless communication system for executing packet communication between a transmitter/receiver on a master side and a transmitter/receiver on a slave side by using a wireless channel in which transmission time slots and reception time slots are alternately repeated in a predetermined time interval, wherein:

said transmitter/receiver on the master side always supplies a high speed clock to a central processing unit for control at the start of the reception time slot of said wireless channel, and when an effective reception packet is not detected in said reception time slot and a transmission packet to be transmitted in a next transmission time slot does not exist, or when the effective reception packet is received in the reception time slot but the transmission packet to be transmitted in the next transmission slot does not exist, said low speed clock is selected and is supplied to said central processing unit.

4. A method for reducing power consumption in a wireless communication system for executing packet communication between a transmitter/receiver on a master side and a transmitter/receiver on a slave side by using a wireless channel in which transmission time slots and reception time slots are alternately repeated in a predetermined time interval, wherein:

said transmitter/receiver on the slave side selects said high speed clock and supplies it to a central processing unit for control when the transmission packet is not transmitted at an intermediate part of the transmission time slot of said wireless channel, and selects said low speed clock and supplies it to said central processing unit when an effective reception packet is not detected in said reception time slot.