Method and apparatus for selective reading of system information in a mobile wireless device

• US 8,630,216 B2
• Filed: 09/30/2010
• Issued: 01/14/2014
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Deivasigamani, Giri Prassad, Ramasamy, Venkatasubramanian, Garg, Sharad, Vasudevan, Srinivasan
• Primary Examiner(s): Sam, Phirin
• Application Number:
  US12/895,398
• Publication Number:
  US 20110320856A1
• Time in Patent Office: 1,202 Days
• Field of Search: None
• US Class Current: 370/311
• CPC Class Codes: H04L 1/0053 specially adapted for power saving
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence

Abstract

A method to read selectively system information messages in a mobile wireless communication device. The mobile wireless device receives a first transmission of a multiple segment message through a radio frequency receiver. The mobile wireless device detects decoding errors in at least one of the received segments of the first transmission. In response to detecting decoding errors, the mobile wireless device selectively receives a first subset of segments in a second transmission of the multiple segment message. The mobile wireless device powers down at least a portion of the radio frequency receiver during receive time intervals for a second subset of segments in the second transmission. The first subset of segments in the second transmission corresponds to segments in the first transmission received with decoding errors. The second subset of segments in the second transmission corresponds to segments in the first transmission received without decoding errors.

Claims

1. A method, comprising:

in a mobile wireless communication device connected to a wireless communication network;

receiving a first transmission of a multiple segment message from the wireless communication network through a radio frequency receiver;

detecting at least one decoding error in at least one received segment of the first transmission;

powering down at least a portion of the radio frequency receiver during receive time intervals for a first subset of segments in a second transmission of the multiple segment message from the wireless communication network;

selectively receiving a second subset of segments in the second transmission of the multiple segment message; and

powering up at least the portion of the radio frequency receiver previously powered down prior to selectively receiving the second subset of segments in the second transmission of the multiple segment message;

wherein the first subset of segments in the second transmission corresponds to one or more segments in the first transmission received without decoding errors, and the second subset of segments in the second transmission corresponds to the at least one received segment in the first transmission received with decoding errors.

2. The method as recited in claim 1, further comprising:

repeating the detecting, powering down, powering up and selectively receiving steps until each segment of the multiple segment message has been received correctly.

3. The method as recited in claim 2, wherein each segment includes one or more system frames, and the second subset of segments in the first transmission of the multiple segment message includes at least two segments separated by one or more system frames that are not part of the multiple segment message.

4. The method as recited in claim 3, wherein the multiple segment message comprises a system information block message.

5. The method as recited in claim 4, further comprising:

receiving a master information block message broadcast by the wireless communication network that specifies when the system information block message can be received.

6. The method as recited in claim 5, wherein the master information block includes a tag indicating when values contained in the system information block change.

7. A method, comprising:

in a mobile wireless communication device connected to a wireless communication network;

receiving multiple repeated copies of a system information message transmitted by a radio network subsystem in the wireless communication network;

assembling and decoding the system information message from multiple segments correctly received in the multiple repeated copies; and

controlling a receiver, by a control processor in the mobile wireless communication device, to power up and receive segments of the system information message received incorrectly previously;

wherein at least a portion of the receiver in the mobile wireless communication device powers down during time intervals in which one or more later copies, corresponding to segments received correctly in one or more earlier copies, of the system information message are transmitted.

8. The method as recited in claim 7, further comprising:

detecting by the receiver at least one error in at least one segment of at least one received copy of the system information message.

9. The method as recited in claim 7, further comprising:

receiving a master information message broadcast by the radio network subsystem in the wireless communication network;

wherein the master information message contains information about when the segments of each copy of the system information message are transmitted.

10. The method as recited in claim 9, wherein the master information message contains an indication when values in the system information message change.

11. A mobile wireless communication device, comprising:

a control processor, and

a transceiver coupled to the control processor, the transceiver including a receiver configured to receive wireless transmissions from a radio network subsystem in a wireless communication network;

wherein the mobile wireless communication device is configured to receive a system information message, the mobile wireless communication device comprising;

logic configured to determine a first copy of the system information message contains changed values, wherein each copy of the system information message contains segments spaced apart in an identical pattern;

logic configured to receive all segments of the first copy of the system information message;

logic configured to detect an error in at least one received segment of the first copy of the system information message;

logic configured to discard first segments of the first copy received with an error;

logic configured to retain second segments of the first copy received without error;

logic configured to receive one or more segments of subsequent copies of the system information message that correspond to the first segments of the first copy received with an error; and

logic configured to assemble the system information message from the retained second segments of the first copy and the one or more received segments of subsequent copies.

12. The mobile wireless communication device as recited in claim 11, wherein before each segment of the system information has been correctly received, the control processor is configured to power down at least a part of the receiver during time intervals in subsequent copies of the system information message that correspond to segments of the system information message received correctly in a prior copy.

13. The mobile wireless communication device as recited in claim 11, wherein the receiver is configured to receive a master information message;

and the control processor is configured to determine the pattern of the segments in the system information message based on information contained in the master information message.

14. The mobile wireless communication device as recited in claim 13, wherein the control processor is configured to determine the first copy of the system information message contains changed values based on information contained in the master information message.

15. A non-transitory computer readable medium having at least one program to control a mobile wireless communication device connected to a radio access system in a wireless communication network stored thereon, the at least one program configured to, when executed, cause the mobile wireless communication device to:

receive a first transmission of a message comprising multiple segments from the wireless communication network through a radio frequency receiver;

detect at least one decoding error in at least one segment received in the first transmission;

power down at least a portion of the radio frequency receiver during receive time intervals for a first subset of segments in a second transmission of the message from the wireless communication network, the first subset of segments in the second transmission corresponding to segments in the first transmission received without decoding errors;

selectively receive a second subset of segments in the second transmission of the message, the second subset of segments in the second transmission corresponding to segments in the first transmission received with decoding errors; and

power up the portion of the radio frequency receiver previously powered down prior to reception of the second subset of segments in the second transmission of the message.

16. The non-transitory computer readable medium as recited in claim 15, wherein the at least one program is further configured to, when executed, cause the mobile wireless communication device to:

repeatedly detect, power down, power up and selectively receive one or more segments of the message until each segment of the message has been received correctly.

17. The non-transitory computer readable medium as recited in claim 16, wherein the message comprises a system information block message.

18. The non-transitory computer readable medium as recited in claim 17, wherein the at least one program is further configured to, when executed, cause the mobile wireless communication device to:

receive a master information block message broadcast by the wireless communication network that specifies when the system information block message can be received.

19. The computer readable medium as recited in claim 18, wherein the master information block message includes a tag that indicates when values contained in the system information block message change.