Communications session management

• US 8,135,003 B2
• Filed: 05/11/2005
• Issued: 03/13/2012
• Est. Priority Date: 05/11/2005
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Axnäs, Johan
• Primary Examiner(s): Rao, Seema S
• Assistant Examiner(s): Baron, Henry
• Application Number:
  US11/919,800
• Publication Number:
  US 20100075685A1
• Time in Patent Office: 2,498 Days
• Field of Search: 370/436, 370/441, 370/468, 714/748
• US Class Current: 370/366
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections

Abstract

A scheduling algorithm is disclosed that allows mobile units, participating in an ongoing communications session, to temporary perform channel-demanding communications operations without ending the session and that is useful in the case of no free radio channels. The algorithm is based on selecting a radio channel for transmitting a radio block based on information of a previous radio channel, no which a previous radio block has been transmitted. The radio block and the previous radio block are based on common information. A mobile unit participating in the communications session selects whether to perform any channel-demanding communications operations on the selected radio channel. By limiting any such other channel-demanding operations to only the selected radio channel, the probability of loss of useful data for the mobile unit during the communications session is minimized.

Claims

1. A method of enabling, during an ongoing communications session involving transmission of radio blocks to a mobile unit on a set of multiple available time slots, other temporary channel-demanding communications for said mobile unit, said method comprising:

selecting a time slot from said time slot set for transmitting a radio block in a subsequent time slot frame containing information of a previous time slot on which a previous radio block has been transmitted to and received at said mobile unit in a previous time slot frame,

wherein the information contained in the radio block in the subsequent time slot frame is the same as or is derivable from the information contained in the radio block in the previous time slot frame, and

wherein said mobile unit performs said other temporary channel-demanding communications on said selected time slot in the subsequent time slot frame with reduced probability of loss of data for said communications session.

2. The method according to claim 1, further comprising transmitting said radio block on said selected time slot.

3. The method according to claim 1, wherein said selecting step comprises selecting said time slot based on said information and based on quality data representing the quality of a communications link between said mobile unit and a network node transmitting said radio blocks.

4. The method according to claim 3, further comprising:

organizing said multiple radio channels of said set into at least a first time slot subset and a second time slot subset, wherein said previous time slot belongs to said first subset; and

comparing said quality data with a minimum quality threshold,

wherein said selecting step comprises i) selecting said time slot from said second subset based on said information if said quality data exceeds said minimum quality threshold and ii) selecting said time slot from said first subset based on said information if said quality data is smaller than said minimum quality threshold.

5. The method according to claim 1, further comprising organizing said multiple time slots of said set into at least a first time slot subset and a second time slot subset, wherein said previous time slot belongs to said first subset, and said selecting step comprises selecting said time slot from said second subset based on said information.

6. The method according to claim 1, further comprising organizing said multiple time slots of said set into at least a first time slot subset and a second time slot subset, wherein said previous time slot belongs to said first subset, and said selecting step comprises selecting said time slot from said first subset based on said information.

7. The method according to claim 6, wherein radio blocks are grouped into block frames, each block frame comprises multiple radio blocks and is assigned a time slot subset selected from said at least first and second subset, said selecting step comprises the steps of:

identifying a time slot subset assigned to a block frame to which said radio block belongs based on said information; and

selecting said time slot from said identified radio channel subset.

11. The method according to claim 1, wherein said temporary communications comprise at least one of:

said mobile unit setting up a temporary block flow;

said mobile unit listening to a control channel time slot; and

said mobile unit performing neighbor cell signal measurements.

12. The method according to claim 11, wherein said temporary block flow comprises at least one of:

said mobile unit sending a data message; and

said mobile unit performing a wireless application protocol interaction.

13. The method according to claim 1, wherein said ongoing communications session is a multimedia broadcast multicast communications session.

14. The method according to claim 1, wherein said radio block comprises the same information bits as said previous radio block.

8. A method of managing a communications session involving reception of radio blocks by a mobile unit on a set of multiple available time slots, said method comprising:

said mobile unit performing other time slot-demanding communications, during said communications session, on a time slot in a subsequent time slot frame on which a radio block is expected to be received, where said time slot is selected based on information contained in a previous time slot on which a previous radio block has been received in a previous time slot frame in order to reduce the probability of loss of data for said communications session,

wherein information contained in the radio block in the subsequent time slot frame is the same as or is derivable from the information contained in the radio block in the previous time slot frame.

9. The method according to claim 8, further comprising said mobile unit receiving said information from a network node transmitting said radio blocks.

10. The method according to claim 8, wherein said previous radio block has been successfully received by said mobile unit.

15. A system for enabling, during an ongoing communications session involving transmission of radio blocks to a mobile unit on a set of multiple available time slots, other temporary channel-demanding communications for said mobile unit, said system comprising one or more processing units configured to:

select a time slot from said time slot set for transmitting a radio block based on information contained in a previous time slot on which a previous radio block has been transmitted to and received at said mobile unit in a previous time slot frame, said information contained in the radio block is the same as or is derivable from the information contained in the previous radio block to enable said mobile unit to perform said other temporary channel-demanding communications on said selected time slot with reduced probability of loss of data for said communications session.

16. The system according to claim 15, wherein said one or more processing units is configured for selecting said time slot based on said information and based on quality data representing the quality of a communications link between said mobile unit and a network node transmitting said radio blocks.

17. The system according to claim 16, wherein the one or more processing units are configured to:

organize said multiple time slots of said set into at least a first time slot subset and a second time slot subset, wherein said previous time slot belongs to said first subset; and

compare said quality data with a minimum quality threshold,

i) select said time slot from said second subset based on said information if said quality data exceeds said minimum quality threshold and ii) select said time slot from said first subset based on said information if said quality data is smaller than said minimum quality threshold.

18. The system according to claim 15, wherein the one or more processing units is configured to organize said multiple time slots of said set into at least a first time slot subset and a second time slot subset, wherein said previous time slot belongs to said first subset, and select said time slot from said second subset based on said information.

19. The system according to claim 15, wherein the one or more processing units is configured to organize said multiple time slots of said set into at least a first time slot subset and a time slot subset, wherein said previous time slot belongs to said first subset, and to select said time slot from said first subset based on said information.

20. The system according to claim 19, wherein radio blocks are grouped into block frames, each block frame comprises multiple radio blocks and is assigned a time slot subset selected from said at least first and second subset, wherein the one or more processing units is configured to:

identify a time slot subset assigned to a block frame to which said radio block belongs based on said information; and

select said time slot from said identified time slot subset.

21. A network node comprising:

a system for enabling, during an ongoing communications session, other temporary channel-demanding communications for a mobile unit according to claim 15; and

a transmitter for transmitting said radio block on said selected time slot.

22. A mobile unit arranged for conducting a communications service, involving reception of radio blocks on a set of multiple available time slots, with a network node in a communications system, said mobile unit comprising:

a receiver for receiving a previous radio block from said network node on a previous time slot of said time slot set; and

one or more processing units configured to perform other channel-demanding communications, during said communications session, on a time slot on which a radio block is expected to be received from said network node in a subsequent time frame, where said time slot is selected based on information contained in said previous time slot on which said previous radio block has been received by said receiver in a previous time slot frame in order to reduce the probability of loss of data for said communications session,

wherein information contained in the radio block in the subsequent time slot frame is the same as or is derivable from the information contained in the radio block in the previous time slot frame.

23. The mobile unit according to claim 22, wherein said previously radio block has been successfully received by said receiver.

24. The mobile unit according to claim 22, wherein said radio block is a retransmitted version of said previous radio block.

25. The mobile unit according to claim 22, wherein said receiver is configured for receiving a notification of said time slot from said network node.

26. The mobile unit according to claim 22, further comprising means for selecting said time slot based on said information.