Beaconless communication system

• US 8,175,109 B2
• Filed: 11/14/2005
• Issued: 05/08/2012
• Est. Priority Date: 11/15/2004
• Status: Active Grant

• Current Assignee: Sony Deutschland GmbH (Sony Group Corp.)
• Original Assignee: Sony Deutschland GmbH (Sony Group Corp.)
• Inventors: Nogueira-Nine, Juan, Böhnke, Ralf
• Primary Examiner(s): Edouard, Patrick
• Assistant Examiner(s): HEIBER, SHANTELL LAKETA
• Application Number:
  US11/273,656
• Publication Number:
  US 20060133408A1
• Time in Patent Office: 2,367 Days
• Field of Search: 455/522, 455/434, 455/574, 455/13.4, 455/127.5, 455/127.1, 370/447, 370/461
• US Class Current: 370/447
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention relates to an energy efficient mechanism for establishing and maintaining a communication between nodes (A . . . F) in a wireless communication system. In particular, it relates to a distributed low power medium access control (MAC) mechanism for sharing the communication means in a wireless communication system. According to the present invention a destination node (A) listens to a communication channel periodically. For requesting services from the destination node (A), a wake-up signal (WU) is transmitted from a source node (B) to the destination node (A) via the communication channel, wherein the wake-up signal (WU) is formed by a preamble (WP) and an information for controlling the communication between nodes (A . . . F). The WU signal duration and content is adapted depending on the system operation context to reduce either idle times, power consumption, latency or network blocking (collision avoidance).

Claims

1. A beaconless communication method between nodes in a communication system, said communication system comprising at least two nodes, the method comprising:

listening to a communication channel by a destination node periodically during reception slots using a receiver of the destination node, wherein a listen duration is T_L and a listen periodicity is T_PL and T_L<

<

T_PL; and

transmitting a wake-up signal before a payload data transmission from a source node to said destination node via said communication channel using a transmitter of the source node, wherein

said wake-up signal contains a preamble and a control information,

a duration of a signal block formed by said preamble and said control information is T_SB and 2·

T_SB<

T_L,

in said communication system, the communication between said nodes is controlled based on said control information,

said control information indicates a subsequent time point at which said source node starts the payload data transmission and said destination node receiving said control information starts the listening to the communication channel,

the transmitter of the source node does not transmit signals between a last bit of the payload data transmission and a next wake-up signal subsequent to the last bit of the payload data transmission, and

the receiver of the destination node does not listen to the communication channel between a reception slot and the subsequent time point, the subsequent time point indicated in the control information of the wake-up signal received by the destination node during the reception slot and the subsequent time point identifying a time at which the destination node starts the listening to the communication channel for reception of the payload data transmission.

2. The communication method according to claim 1, wherein said communication system is a wireless communication system.

3. The communication method according to claim 1, wherein the listen periodicity is T_PL and 2·

T_L<

<

T_PL.

4. The communication method according to claim 1, wherein said communication system comprises a plurality of nodes forming a network and said control information indicates that said source node wants to join said network.

5. The communication method according to claim 1, wherein said communication system comprises a plurality of nodes-forming a network and said control information indicates that said source node is still present in said network.

6. The communication method according to claim 1, wherein said communication system comprises a plurality of nodes forming a network and said control information indicates an address of a predetermined node.

7. The communication method according to claim 6, wherein, when said nodes receive said wake-up signal via said communication channel and are not addressed by said control information, said nodes do not listen to said communication channel and/or transmit any data via said communication channel for a predetermined period of time.

8. The communication method according to claim 7, wherein said control information indicates the duration of a subsequent payload data transmission and said predetermined period of time is the duration of said subsequent payload data transmission time indicated by said control information.

9. The communication method according to claim 1, wherein said control information indicates a period between a time point at which the control information is transmitted and said time point at which said source node starts the payload data transmission.

10. The communication method according to claim 9, wherein said wake-up signal comprises a repetition of said signal block, wherein, for each of the successive signal blocks, the period between the time point at which the control information is transmitted and said time point at which said source node starts the payload data transmission is calculated.

11. The communication method according to claim 1, wherein said control information indicates a selection of a predetermined communication channel.

12. The communication method according to claim 1, wherein said communication system comprises a plurality of nodes and said nodes interchange timing information of listen timing and each node accumulates said timing information wherein said source node calculates a start of said wake-up signal based on said timing information.

13. The communication method according to claim 12, wherein each node calculates a clock drift with respect to any other peer node based on said timing information, wherein said source node calculates the start and/or a duration of said wake-up signal based on said clock drift.

14. A beaconless communication system constituted by at least two nodes, the system comprising:

means for listening, on a destination node, to a communication channel periodically during reception slots, wherein a listen duration is T_L and a listen periodicity is T_PL and T_L(<

<

T_PL; and

means for transmitting a wake-up signal before a payload data transmission from a source node to said destination node via said communication channel, said wake-up signal containing a preamble and a control information, wherein

a duration of a signal block formed by said preamble and said control information is T_SB, and 2·

T_SB<

T_L,

in said communication system, the communication between said nodes is controlled based on said control information,

said destination node is configured to detect whether said control information indicates a subsequent time point at which said source node starts the payload data transmission and to listen to a communication channel at said time point,

the transmitter of the source node does not transmit signals between a last bit of the payload data transmission and a next wake-up signal subsequent to the last bit of the payload data transmission, and

the means for listening of the destination node does not listen to the communication channel between a reception slot and the subsequent time point, the subsequent time point indicated in the control information of the wake-up signal received by the destination node during the reception slot and the subsequent time point identifying a time at which the destination node starts the listening to the communication channel for reception of the payload data transmission.

15. The communication system according to claim 14, wherein said communication system is a wireless communication system.

16. The communication system according to claim 14, wherein the listen periodicity is T_PL and 2·

T_L<

<

T_PL.

17. The communication system according to claim 14, wherein said communication system comprises a plurality of nodes forming a network and said destination node is adapted to detect whether said control information indicates that said source node wants to join said network.

18. The communication system according to claim 14, wherein said communication system comprises a plurality of nodes forming a network and said destination node is adapted to detect whether said control information indicates that said source node is still present in said network.

19. The communication system according to claim 14, wherein said communication system comprises a plurality of nodes forming a network and said destination node is adapted to detect whether said control information indicates an address of a predetermined node.

20. The communication system according to claim 19, wherein said destination node is adapted to stop the listening to said communication channel and/or the transmission of any data via said communication channel for a predetermined period of time when said destination node is not addressed by said control information.

21. The communication system according to claim 20, wherein said destination node is adapted to detect whether said control information indicates the duration of a subsequent payload data transmission and said predetermined period of time is the duration of said subsequent payload data transmission time indicated by said control information.

22. The communication system according to claim 14, wherein said control information indicates a period between a time point at which the control information is transmitted and said time point at which said source node starts the payload data transmission.

23. The communication system according to claim 22, wherein said source node is adapted to generate a wake-up signal comprising a repetition of said signal block, wherein said source node comprises means for calculating, for each of the successive signal blocks in said wake-up signal, the period between the time point at which the control information is transmitted and the time point at which said source node starts the payload data transmission.

24. The communication system according to claim 14, wherein said destination node is adapted to detect whether said control information indicates a predetermined communication channel.

25. The communication system according to claim 14, further comprising a plurality of nodes, wherein said nodes are configured to interchange timing information of listen timing and each node is configured to accumulate said timing information, wherein said source node is configured to calculate a start of said wake-up signal based on said timing information.

26. The communication system according to claim 25, wherein each node is configured to calculate a clock drift with respect to any other peer node based on said timing information, wherein said source node is configured to calculate the start and/or a duration of said wake-up signal based on said clock drift.

27. Apparatus for requesting services from a remote apparatus, said remote apparatus listens to a communication channel periodically during reception slots, wherein a listen duration is T_L and a listen periodicity is T_PL and T_L<

<

T_PL, the requesting apparatus comprising;

wake-up signal generating means for generating a wake-up signal;

control means for controlling said wake-up signal generating means to generate said wake-up signal when a service is requested from said remote apparatus; and

transmitting means for transmitting the wake-up signal generated by said wake-up signal generating means to said remote apparatus via said communication channel, said wake-up signal containing a preamble and a control information, wherein

a duration of a signal block formed by said preamble and said control information is T_SB and 2·

T_SB<

T_L,

said wake-up signal generating means adds control information indicating a subsequent time point at which the transmitting means starts a payload data transmission to said wake-up signal,

the transmitting means does not transmit signals between a last bit of the payload data transmission and a next wake-up signal subsequent to the last bit of the payload data transmission, and

the remote apparatus does not listen to the communication channel between a reception slot and the subsequent time point, the subsequent time point indicated in the control information of the wake-up signal received by the remote apparatus during the reception slot and the subsequent time point identifying a time at which the remote apparatus starts listening to the communication channel for reception of the payload data transmission.

28. The apparatus according to claim 27, wherein the listen periodicity is T_PL and 2·

T_L<

<

T_PL.

29. The apparatus according to claim 27, wherein said wake-up signal generating means adds a control information including a network join request to said wake-up signal.

30. The apparatus according to claim 27, wherein said wake-up signal generating means adds a control information including a presence notice to said wake-up signal.

31. The apparatus according to claim 27, wherein said wake-up signal generating means adds a control information indicating the address of a remote apparatus from which a service has to be requested to said wake-up signal.

32. The apparatus according to claim 27, wherein said wake-up signal generating means adds a control information indicating a duration of a subsequent payload data transmission to said wake-up signal.

33. The apparatus according to claim 27, wherein said control information indicates a period between a time point at which the control information is transmitted and said time point at which said transmitting means starts the payload data transmission.

34. The apparatus according to claim 33, wherein said wake-up signal generating means generates a wake-up signal comprising a repetition of said signal block, wherein said wake-up signal generating means comprises means for calculating, for each of the successive signal blocks in said wake-up signal, a period between the time point at which the control information is transmitted by said transmitting means and the time point at which said transmitting means starts the payload data transmission.

35. The apparatus according to claim 27, wherein said wake-up signal generating means adds a control information indicating a predetermined communication channel to said wake-up signal.

36. The apparatus according to claim 27, further comprising means for receiving timing information of listen timing from a remote apparatus, wherein said control means calculates a start of said wake-up signal based on said timing information.

37. The apparatus according to claim 36, wherein said control means calculates a clock drift with respect to said remote apparatus based on said timing information and, wherein said control means calculates the start and/or a duration of said wake-up signal based on said clock drift.

38. Apparatus for providing services requested from a remote apparatus, the apparatus comprising:

receiving means for receiving a wake-up signal sent from said remote apparatus via a communication channel;

control means for controlling said receiving means to listen to said communication channel periodically during reception slots, wherein a listen duration is T_L and a listen periodicity is T_PL and T_L<

<

T_PL, said control means providing a service when said wake-up signal is received by said receiving means, said wake-up signal contains a preamble and a control information, and a duration of a signal block formed by said preamble and said control information is T_SB and 2·

T_SB<

T_L; and

a separating means for separating said control information from said wake-up signal, wherein

said control means controls said receiving means based on said control data separated by said separating means,

said control means detects whether said control information indicates a subsequent time point at which said remote apparatus starts a payload data transmission and controls said receiving means to listen to a communication channel at said subsequent time point,

said receiving means does not receive a signal from said remote apparatus between a last bit of the payload data transmission and a next wake-up subsequent to the last bit of the payload data transmission, and

said receiving means does not listen to the communication channel between a reception slot and the subsequent time point, the subsequent time point indicated in the control information of the wake-up signal received from said remote apparatus during the reception slot and the subsequent time point identifying a time at which said receiving means starts the listening to the communication channel for reception of the payload data transmission.

39. The apparatus according to claim 38, wherein the listen periodicity is T_PL and 2·

T_L<

<

T_PL.

40. The apparatus according to claim 38, wherein said control means detects whether said control information includes a network join request.

41. The apparatus according to claim 38, wherein said control means detects whether said control information includes a presence notice.

42. The apparatus according to claim 38, wherein said control means detects whether said control information includes an apparatus address.

43. The apparatus according to claim 42, wherein said control means controls said receiving means to stop the listening to said communication channel and/or the transmission of any data via said communication channel for a predetermined period of time when said service providing apparatus is not addressed by said control information.

44. The apparatus according to claim 43, wherein said control means detects whether said control information indicates the duration of a subsequent payload data transmission of said remote apparatus, and wherein said predetermined period of time is a duration of said subsequent payload data transmission time indicated by said control information.

45. The apparatus according to claim 38, wherein said control information indicates a period between a time point at which the control information is transmitted and said time point at which said transmitting means starts the payload data transmission.

46. The apparatus according to claim 38, wherein said control means detects whether said control information indicates a selection of a predetermined communication channel.

47. The apparatus according to claim 38, wherein said control means detects timing information of listen timing of a remote apparatus received by said receiving means, wherein said control means calculates a start of said wake-up signal based on said timing information.

48. The apparatus according to claim 47, wherein said control means calculates a clock drift with respect to said remote apparatus based on said timing information, and wherein said control means calculates the start and/or a duration of said wake-up signal based on said clock drift.