Reducing power consumption of a wireless device

• US 7,656,853 B2
• Filed: 12/27/2004
• Issued: 02/02/2010
• Est. Priority Date: 12/27/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Albulet, Mihai
• Primary Examiner(s): Pérez-Gutiérrez; Rafael
• Assistant Examiner(s): Kasraian; Allahyar
• Application Number:
  US11/020,234
• Publication Number:
  US 20060140166A1
• Time in Patent Office: 1,863 Days
• Field of Search: 370/346, 370/449, 370/498, 455/574, 455/343.2, 455/127.5, 713/320
• US Class Current: 370/346
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• CPC Class Codes: G06F 1/3271 Power saving in keyboard
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The present invention provides a system and method for conserving power consumption of a wireless device such as a BLUETOOTH slave device. A master device polls a slave device in a polling period. The slave responds by transmitting a data packet. If there is an error in transmission of the data, the master device may transmit an ARQ (Automatic Repeat Request) to the slave device in a TIMEOUT period to indicate that the data packet was not received. The slave device may reduce power consumption or power off during that TIMEOUT and receive a retransmit ARQ in a subsequent polling period.

Claims

1. A method for operating a first device in wireless communication with a second device using a communication protocol having polling periods, each polling period having an associated subsequent supplemental period, each supplemental period being at least reserved for reduction of power consumption of the first device or retransmission of data transmitted during a previous polling period, the method comprising the steps of:

receiving at the first device a first transmission in a first time slot of a first polling period;

transmitting a first response in a second time slot of the first polling period, the first response being responsive to receiving the first transmission;

reducing power consumption of the first device during a first supplemental period associated with and subsequent to the first polling period, substantially following transmitting the first response;

receiving a second transmission in a first time slot of a second polling period, the second transmission indicating that the first response was not properly received;

transmitting a second response during a second time slot of the second polling period, the second response being responsive to receiving the second transmission;

receiving a third transmission in a first time slot of a third polling period, the third transmission indicating that a prior response was not properly received;

transmitting a third response in a second time slot of the third polling period, the third response being responsive to receiving the third transmission;

maintaining power during a third supplemental period associated with the third polling period if each of a predetermined number of prior consecutive transmissions indicated that a response was not properly received; and

reducing power consumption in a supplemental period after another predetermined number of polling period transmissions indicating that a prior response was properly received.

2. The method of claim 1 wherein transmitting the second response during the second time slot of the second polling period comprises retransmitting the first response.

3. The method of claim 2 wherein the second response comprises a data packet having user data.

4. The method of claim 2 wherein the second response comprises a packet indicating a lack of user data to be transmitted.

5. The method of claim 4 wherein the packet indicating the lack of user data to be transmitted is a NULL packet.

6. The method of claim 1 wherein the step of reducing power consumption comprises powering off a transceiver.

7. The method of claim 6 wherein the step of reducing power consumption comprises powering off a transceiver such that a transmission indicating that the first response was not properly received cannot be received during the first supplemental period.

8. The method of claim 1 wherein the second transmission is also transmitted during the first supplemental period and the step of reducing power consumption comprises powering off a transceiver such that the second transmission is not received during the first supplemental period.

9. The method of claim 1 wherein the communication protocol is the BLUETOOTH protocol, each polling period is a SNIFF period and the associated subsequent supplemental period is a TIMEOUT period.

10. A wireless device comprising

a battery power source;

a radio transceiver powered by the battery;

a memory having instructions stored thereon; and

a controller coupled to the radio transceiver and to the memory and configured to execute instructions for operating a first device in wireless communication with a second device using a communication protocol having polling periods, each polling period having an associated subsequent supplemental period, each supplemental period being at least reserved for reduction of power consumption of the first device or retransmission of data transmitted during a previous polling period, so as to;

receive at the first device a first transmission in a first time slot of a first polling period;

transmit a first response in a second time slot of the first polling period, the first response being responsive to receiving the first transmission;

reduce power consumption of the first device during a first supplemental period associated with and subsequent to the first polling period, substantially following transmitting the first response;

receive a second transmission in a first time slot of a second polling period, the second transmission indicating that the first response was not properly received;

transmit a second response during a second time slot of the second polling period, the second response being responsive to receiving the second transmission;

receive a third transmission in a first time slot of a third polling period, the third transmission indicating that a prior response was not properly received;

transmit a third response in a second time slot of the third polling period, the third response being responsive to receiving the third transmission;

maintain power during a third supplemental period associated with the third polling period if each of a predetermined number of prior consecutive transmissions indicated that a response was not properly received; and

reduce power consumption in a supplemental period after another predetermined number of transmissions indicating that a prior response was properly received.

11. The wireless device of claim 10 wherein the controller retransmits the first response when the controller transmits the second response during the second time slot of the second polling period.

12. The wireless device of claim 11 wherein the second response comprises one of a data packet and a packet indicating the lack of data to be transmitted.

13. The wireless device of claim 10 wherein the wireless device is selected from the group consisting of a mouse and a keyboard.

14. A computer-readable medium having stored thereon data representing sequences of instructions for operating a first device in wireless communication with a second device using a communication protocol having polling periods, each polling period having an associated subsequent supplemental period, each supplemental period being at least reserved for reduction of power consumption of the first device or retransmission of data transmitted during a previous polling period, the sequences of instructions, when executed by a processor, cause the processor to perform steps comprising:

receiving at the first device a first transmission in a first time slot of a first polling period;

transmitting a first response in a second time slot of the first polling period, the first response being responsive to receiving the first transmission;

reducing power consumption of the first device during a first supplemental period associated with and subsequent to the first polling period, substantially following transmitting the first response;

receiving a second transmission in a first time slot of a second polling period, the second transmission indicating that the first response was not properly received;

transmitting a second response during a second time slot of the second polling period, the second response being responsive to receiving the second transmission;

receiving a third transmission in a first time slot of a third polling period, the third transmission indicating that a prior response was not properly received;

transmitting a third response in a second time slot of the third polling period, the third response being responsive to receiving the third transmission;

maintaining power during a third supplemental period associated with the third polling period if each of a predetermined number of prior consecutive transmissions indicated that a response was not properly received; and

reducing power consumption in a supplemental period after another predetermined number of transmissions indicating that a prior response was properly received.

15. The computer-readable medium of claim 14 wherein transmitting the second response during the second time slot of the second polling period comprises retransmitting the first response.

16. The computer-readable medium of claim 15 wherein the second response comprises a data packet.

17. The computer-readable medium of claim 15 wherein the second response comprises a packet indicating the lack of data to be transmitted.

18. The computer-readable medium of claim 14 wherein the step of reducing power consumption comprises powering off a transceiver such that a transmission indicating that the first response was not properly received cannot be received during the first supplemental period.

19. A method for operating a slave device in wireless communication with a master device using a communication protocol having a plurality of sniff periods associated respectively with timeout periods, each timeout period being subsequent to each respective sniff period, comprising:

polling the slave device during a first time slot of a first sniff period by transmitting a first poll packet from the master device to the slave device;

transmitting a first transmission of a first data packet from the slave device to the master device during a second time slot of the first sniff period in response to the slave device receiving the first poll packet during the first time slot of the first sniff period;

reducing power consumption of the slave device substantially following the first transmission of the first data packet, the reduced power consumption being sustained at least during a first timeout period subsequent to the first sniff period;

restoring power consumption of the slave device after the first timeout period;

receiving at the slave device a transmission error indication from the master device during a first time slot of a second sniff period indicating that the first data packet was not properly received by the master device;

transmitting a second transmission of the first data packet from the slave device to the master device during a second time slot of the second sniff period in response to the received transmission error indication;

reducing power consumption of the slave device substantially following the second transmission of the first data packet, the reduced power consumption being sustained at least during a second timeout period;

for each subsequent sniff period, receiving at the slave device from the master device either a poll packet polling the slave device for data or a transmission error indication indicating that a previously transmitted data packet was not properly received by the master device, wherein;

when a slave device receives a predetermined number of transmission error indications in a predetermined number of consecutive sniff periods, the slave device maintains power during subsequent sniff and timeout periods such that user data acquired by the slave device during the consecutive sniff and timeout periods can be transmitted in substantially consecutive data packets to the master device.

20. The method according to claim 19, wherein if the second transmission of the first data packet is properly received by the master device, the slave device transmits a second data packet to the master device substantially following the second transmission of the first data packet during a second timeout period subsequent to the second time slot of the second sniff period.

21. The method according to claim 19, wherein if the first data packet was a null data packet indicating a lack of user data to be transmitted and the slave device has acquired user data between an end of the first sniff period and a beginning of the second sniff period, the second transmission of the first data packet comprises transmission of the user data.