Method for data transfer with a mobile station while in discontinuous reception state

• US 7,684,799 B2
• Filed: 03/28/2006
• Issued: 03/23/2010
• Est. Priority Date: 03/28/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Love, Robert T., Stewart, Kenneth A., Kuchibhotla, Ravi
• Primary Examiner(s): RAMPURIA, SHARAD K
• Application Number:
  US11/391,112
• Publication Number:
  US 20070230400A1
• Time in Patent Office: 1,456 Days
• Field of Search: 455436-437, 455572-574, 455/525, 455/522, 455/69, 370/311, 370/332, 370/335
• US Class Current: 455/436
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for sleep mode during an impending handover is disclosed. The method comprises receiving (104) from a network a handover threshold value. Then once in sleep mode, monitoring (128) a channel condition of a handover candidate cell and determining that the handover threshold value of the handover candidate cell has been exceeded. After receiving a pending data indicator, remaining awake (134) to receive a data set associated with the pending data indicator. The network re-schedules (216) transmission of the data set to the mobile station.

Claims

1. A method performed by a mobile wireless device to expedite acquisition of data from a serving cell prior to handover, the serving cell providing wireless communication service to the wireless device, the wireless device being capable of operating in a discontinuous reception mode, the method comprising:

receiving a measurement report configuration from the serving cell, the measurement report configuration including at least one measurement report configuration parameter based upon which the wireless device is to determine whether to send a measurement report;

monitoring at least one channel condition of at least one handover candidate cell while in a sleep cycle of the discontinuous reception mode;

determining whether a handover may be necessary based on the at least one channel condition of the at least one handover candidate cell;

awaking from the sleep cycle in accordance with the discontinuous reception mode;

while awake from the sleep cycle,

transmitting the measurement report to the serving cell in response to a determination that the measurement report is to be sent, the determination being based upon the at least one measurement report configuration parameter and the measurement report including the at least one channel condition of the at least one handover candidate, and

receiving a pending data indicator from the serving cell after transmission of the measurement report, the pending data indicator indicating that the serving cell has data to send to the wireless device, wherein the data was received by the serving cell for the wireless device and was originally to be delivered to the wireless device after a time at which the wireless device would be handed off to a handover candidate cell; and

responsive to receipt of the pending data indicator and determination that the handover may be necessary, remaining awake to receive the data from the serving cell prior to a handover of the wireless device to the handover candidate cell such that delivery of the data is expedited when compared to a time at which the data was originally to be delivered to the wireless device.

2. The method of claim 1, further comprising:

receiving a serving cell channel condition threshold value from the serving cell; and

monitoring a channel condition of the serving cell while in a sleep cycle of the discontinuous reception mode.

3. The method of claim 1, further comprising:

receiving a handover threshold value from the serving cell.

4. The method of claim 1, further comprising:

receiving, from a network, a handover threshold that includes an upper threshold limit and a lower threshold limit such that the wireless device can adjust the threshold within the threshold limits.

5. The method of claim 1, further comprising:

receiving a serving cell condition threshold value that is related to a received signal to noise ratio.

6. The method of claim 3, wherein transmitting the measurement report includes:

determining that the channel condition of the handover candidate cell has exceeded the handover threshold value.

7. The method of claim 2, further comprising:

determining that the serving cell channel condition threshold value has not been met.

8. The method of claim 1, further comprising:

receiving a timer value that indicates a maximum time the wireless device is to remain in the sleep cycle.

9. The method of claim 1, further comprising:

receiving a timer value that indicates a minimum interval between sending measurement reports to the serving cell.

10. A method in a wireless communication device, the method comprising:

entering a sleep cycle of a discontinuous reception mode while receiving wireless communication service from a serving cell;

while in the sleep cycle, determining channel conditions for a plurality of handover candidates;

awaking from the sleep cycle in accordance with the discontinuous reception mode;

while awake from the sleep cycle, determining whether the serving cell has data to send to the wireless communication device, wherein the data was received by the serving cell for the wireless communication device and was originally to be delivered to the wireless communication device after a time at which the wireless communication device would be handed off to one of the plurality of handover candidates;

responsive to determining that the serving cell has data to send to the wireless communication device, remaining awake from the sleep cycle if at least a channel condition of a handover candidate is greater than a handover threshold value; and

while remaining awake from the sleep cycle, receiving the data from the serving cell prior to a handover to the handover candidate such that delivery of the data is expedited when compared to a time at which the data was originally to be delivered to the wireless communication device.

11. The method of claim 10, further comprising:

prior to entering the sleep cycle, receiving, from the serving cell, a channel condition threshold for the serving cell; and

determining whether a channel condition of the serving cell is below the channel condition threshold;

wherein the wireless communication device remains awake from the sleep cycle if a channel condition of a handover candidate is greater than the handover threshold, the channel condition of the serving cell is below the channel condition threshold, and the serving cell has data to send to the wireless communication device such that delivery of the data is expedited when compared to the time at which the data was originally to be delivered to the wireless communication device.

12. A method in a current serving cell of a communication network that is providing wireless communication service to a mobile station, the method comprising:

receiving data that is to be sent to the mobile station and storing the data in a buffer;

receiving a message from the mobile station that includes a channel condition measurement report for a neighboring cell and the current serving cell, the channel condition measurement report indicating that a channel condition of the current serving cell is below a channel condition threshold and a channel condition of the neighboring cell exceeds a handover threshold;

determining, based on the channel condition measurement report, that a handover of the mobile station to the neighboring cell is to occur;

determining that the data is scheduled to be transmitted to the mobile station after the handoff is to occur; and

re-scheduling transmission of the data to the mobile station such that transmission of the data occurs prior to the handoff.

13. The method of claim 12, further comprising:

determining that the mobile station is in sleep mode and scheduling the data for transmission to the mobile station after the mobile station has exited sleep mode.

14. The method of claim 13, further comprising:

sending a pending data indicator to the mobile station after the mobile station has exited the sleep mode and before the handoff to the neighboring cell to inform the mobile station that the current serving cell has the data to send to the mobile station before the handoff.

15. The method of claim 12, further comprising:

re-scheduling transmission of the data to the mobile station at a time after a first timer has expired, the first timer corresponding to a time period in which the mobile station is in a sleep mode.

16. A method in a wireless communication device, the method comprising:

checking channel conditions of a serving cell and a plurality of handover candidates while the wireless communication device is in a sleep cycle of a discontinuous reception mode and receiving communication service from the serving cell;

transmitting a measurement report to the serving cell when the channel conditions of the serving cell and the plurality of handover candidates indicate a need to execute a handover of the communication service to at least one of the plurality of handover candidates, the measurement report indicating the need to execute the handover;

receiving, after the wireless communication device has awoken from the sleep cycle and entered an active state, a pending downlink transmission status from the serving cell in response to transmission of the measurement report, the pending downlink transmission status indicating that the serving cell has data to send to the wireless communication device, wherein the data was received by the serving cell for the wireless communication device and was originally to be delivered to the wireless communication device after a time at which the wireless communication device would be handed off to the at least one of the plurality of handover candidates; and

responsive to receiving the pending downlink transmission status, remaining in the active state, instead of returning to the sleep cycle, to allow the serving cell to send the data to the wireless communication device prior to the handover such that delivery of the data is expedited when compared to a time at which the data was originally to be delivered to the wireless communication device.

17. A method for pre-handover data transfer from a serving cell to a mobile station, the serving cell providing wireless communication service to the mobile station, the method comprising:

receiving, by the mobile station from the serving cell, a channel condition threshold, a handover threshold, and a timer value;

entering, by the mobile station, a sleep cycle of a discontinuous reception mode after receiving the channel condition threshold, the handover threshold, and the timer value, wherein the timer value defines a duration of the sleep cycle;

while in the sleep cycle, determining, by the mobile station, channel conditions for the serving cell and at least one handover candidate cell;

awaking, by the mobile station, upon expiration of the sleep cycle;

while awake from the sleep cycle, determining, by the mobile station, whether the serving cell has data to send to the mobile station, wherein the data was received by the serving cell for the mobile station and was to be delivered to the mobile station after a time at which the mobile station would be handed off to the at least one handover candidate cell;

remaining awake, by the mobile station, from the sleep cycle if the channel conditions for the serving cell and the at least one handover candidate cell, when respectively compared to the channel condition threshold and the handover threshold, indicate that a handover of the mobile station to a handover candidate cell is necessary and the serving cell has data to send to the mobile station; and

while remaining awake from the sleep cycle, receiving, by the mobile station, the data from the serving cell prior to the handover to the handover candidate cell such that delivery of the data is expedited when compared to a time at which the data was originally to be delivered to the mobile station.

18. The method of claim 17, further comprising:

transmitting, by the mobile station, a measurement report including the channel conditions for the serving cell and the at least one handover candidate cell;

receiving, by the serving cell, the measurement report;

determining, by the serving cell, whether the mobile station is to be handed over to the at least one handover candidate cell based on the measurement report;

transmitting, by the serving cell, a pending data indicator to the mobile station when the measurement report indicates that the mobile station is to be handed over to the at least one handover candidate cell and the serving cell has data to send to the mobile station, the transmission of the pending data indicator occurring during a period of time when the mobile station is awake from the sleep cycle; and

determining, by the serving cell, that the data is scheduled to be transmitted to the mobile station after the handover is to occur;

re-scheduling, by the serving cell, transmission of the data to the mobile station such that transmission of the data occurs prior to the handover;

wherein the mobile station determines that the serving cell has data to send based upon receipt of the pending data indicator.