Methods and Apparatus For Uplink Macro-Diversity in Packet-Switched Cellular Networks

• US 20110228690A1
• Filed: 05/27/2011
• Published: 09/22/2011
• Est. Priority Date: 05/06/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Park, Vincent, Corson, M. Scott, Kapoor, Samir, Laroia, Rajiv
• Granted Patent: US 8,670,341 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/185 using make before break
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method and apparatus for providing uplink macro-diversity in packet-switched networks that allows packets and/or portions of packets, e.g., frames, to be selectively sent from an end node, e.g., wireless communication device or mobile terminal, over a set of multiple communication connections, e.g., physical-layer or link-layer connections, to one or more access nodes, e.g., base stations. Uplink macro-diversity is achieved in part through intelligent selective forwarding over multiple communication connections, where the forwarding decision is controlled by the end node based on a variety of factors, e.g., physical-layer channel conditions and/or higher layer policy. The forwarding decision is executed on a rapid timescale, e.g., on a per packet basis, to adapt to the dynamically varying conditions of the set of communication connections.

Claims

1. A method of operating a wireless terminal, comprising:

maintaining a plurality of communications connections between the wireless terminal and at least two different receivers;

monitoring channel conditions on the communications connections;

selecting one of the plurality of communications connections based on the monitored channel conditions;

transmitting at least a portion of a packet using the selected communications connection; and

repeating the monitoring, selecting and transmitting steps, wherein multiple communications connections are selected for uplink transmissions during a period of time in which a single communications connection is used for downlink transmissions to the wireless terminal.

2. The method of claim 1, wherein each transmitted portion of a packet is directed over a single one of the communications connections to a single one of the receivers.

3. The method of claim 1, wherein the communications connections are physical layer connections.

4. The method of claim 1, wherein the communications connections are link layer connections.

5. The method of claim 2, wherein portions of packets transmitted over a first selected communications connection are transmitted using a first communications protocol and wherein portions of packets transmitted over a second selected communications connection are transmitted using a second communications protocol that is different than the first communications protocol.

6. The method of claim 5, wherein the first communications protocol is compatible with the Institute of Electrical and Electronics Engineers (IEEE) 802.11b protocol and the second communications protocol is an orthogonal frequency-division multiplexing (OFDM) based communications protocol.

7. The method of claim 2, wherein the selecting comprises selecting a new connection after transmitting an entire packet, wherein a next packet is transmitted on the selected new connection.

8. The method of claim 7, wherein the receivers are located at different access nodes.

9. The method of claim 7, wherein the receivers are located at a same access node.

10. The method of claim 2, wherein a frame corresponds to a portion of a packet, the selecting step being performed to correspond to frame boundaries such that a new connection is selected after transmitting a frame, wherein a next frame is transmitted on the selected new connection.

11. The method of claim 10, wherein the receivers are located at different access nodes.

12. The method of claim 10, wherein the receivers are located at a same access node.

13. The method of claim 12, wherein different portions of a first packet are transmitted over different communications connections.

14. The method of claim 13, further comprising:

operating the access node to combine the different portions of the first packet transmitted over different communications channels to reassemble the first packet; and

operating the access node to transmit the reassembled first packet to another node.

15. The method of claim 14, wherein the access node is a base station.

16. The method of claim 1, further comprising controlling packet size as a function of the measured channel conditions.

17. The method of claim 16, wherein the controlling comprises controlling a transmission packet length by fragmenting packets to be transmitted into smaller packets.

18. The method of claim 16, wherein the controlling comprises controlling a transmission packet length by signaling a source of the packets to generate packets of a different size.

19. The method of claim 1, wherein the selecting is performed independent of handoff between access nodes.

20. The method of claim 1, wherein the selecting is based on physical layer channel conditions.

21. The method of claim 1, wherein the selecting is based on link layer channel conditions.

22. The method of claim 1, wherein the selecting is based on layer characteristics other than physical layer characteristics or link layer characteristics.

23. The method of claim 1, wherein the selecting is based on at least one of packet content, packet size, packet type, higher layer policy and a communications protocol to which the packet corresponds.

24. The method of claim 23, wherein the selecting comprises:

selecting a same communications connection to transmit portions of packets corresponding to a specific communications protocol during the period of time; and

selecting between different communications connections during portions of the period of time used for transmitting portions of packets which do not correspond to the specific communications protocol.

25. A wireless terminal, comprising:

a processor;

memory in electronic communication with the processor;

instructions stored in the memory, the instructions being executable by the processor to;

maintain a plurality of communications connections between the wireless terminal and at least two different receivers;

monitor channel conditions on the communications connections;

select one of the plurality of communications connections based on the monitored channel conditions;

transmit at least a portion of a packet using the selected communications connection; and

repeat the monitoring, selecting and transmitting, wherein multiple communications connections are selected for uplink transmissions during a period of time in which a single communications connection is used for downlink transmissions to the wireless terminal.

26. The wireless terminal of claim 25, wherein each transmitted portion of a packet is directed over a single one of the communications connections to a single one of the receivers.

27. The wireless terminal of claim 25, wherein the communications connections are physical layer connections.

28. The wireless terminal of claim 25, wherein the communications connections are link layer connections.

29. The wireless terminal of claim 26, wherein the instructions executable to select comprise instructions executable to select a new connection after transmitting an entire packet, wherein a next packet is transmitted on the selected new connection.

30. The wireless terminal of claim 25, wherein the instructions executable to select comprise instructions executable to select independent of handoff between access nodes.

31. The wireless terminal of claim 25, wherein the instructions executable to select comprise instructions executable to select based on physical layer channel conditions.

32. The wireless terminal of claim 25, wherein the instructions executable to select comprise instructions executable to select based on link layer channel conditions.

33. The wireless terminal of claim 25, wherein the instructions executable to select comprise instructions executable to select based on layer characteristics other than physical layer characteristics or link layer characteristics.

34. A wireless terminal, comprising:

means for maintaining a plurality of communications connections between the wireless terminal and at least two different receivers;

means for monitoring channel conditions on the communications connections;

means for selecting one of the plurality of communications connections based on the monitored channel conditions;

means for transmitting at least a portion of a packet using the selected communications connection; and

means for repeating the monitoring, selecting and transmitting steps, wherein multiple communications connections are selected for uplink transmissions during a period of time in which a single communications connection is used for downlink transmissions to the wireless terminal.

35. The wireless terminal of claim 34, wherein each transmitted portion of a packet is directed over a single one of the communications connections to a single one of the receivers.

36. The wireless terminal of claim 35, wherein the means for selecting selects a new connection after transmitting an entire packet, wherein a next packet is transmitted on the selected new connection.

37. The wireless terminal of claim 34, wherein the means for selecting operates independent of handoff between access nodes.

38. A non-transitory computer-readable medium having instructions thereon, the instructions being executable to:

maintain a plurality of communications connections between a wireless terminal and at least two different receivers;

monitor channel conditions on the communications connections;

select one of the plurality of communications connections based on the monitored channel conditions;

transmit at least a portion of a packet using the selected communications connection; and

repeat the monitoring, selecting and transmitting, wherein multiple communications connections are selected for uplink transmissions during a period of time in which a single communications connection is used for downlink transmissions to the wireless terminal.

39. The computer-readable medium of claim 38, wherein each transmitted portion of a packet is directed over a single one of the communications connections to a single one of the receivers.

40. The computer-readable medium of claim 39, wherein the instructions executable to select comprise instructions executable to select a new connection after transmitting an entire packet, wherein a next packet is transmitted on the selected new connection.

41. The computer-readable medium of claim 38, wherein the instructions executable to select comprise instructions executable to select independent of handoff between access nodes.