Radio communication method, radio communication system and wireless terminal

• US 20050163088A1
• Filed: 01/27/2005
• Published: 07/28/2005
• Est. Priority Date: 01/27/2004
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yamano, Satoru, Arai, Masanobu
• Granted Patent: US 8,379,608 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0261 managing power supply demand, e.g. depending on battery level
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A radio communication method, a radio communication system and a wireless terminal by which low power consumption and the flexibility of a network can be realized. A base station and wireless terminals change an intermittent receive period and the preamble length of data on the basis of characteristics of the multihop radio network to carry out the intermittent receiving of data. Thus, a wireless terminal relaying data can receive the data reliably and a useless boot-up of a receiving part and standby time can be largely reduced to achieve low power consumption.

Claims

1. A radio communication method of a mutlihop radio network including a plurality of wireless terminals, wherein a receiving side wireless terminal changes an intermittent receive period and a sending side wireless terminal changes the preamble length of data on the basis of characteristics of the multihop radio network to carry out the intermittent receiving of the data.

2. The radio communication method claimed in claim 1, wherein the characteristics depend on a change in traffic, network topology, time, battery remaining power of the wireless terminals or occurrence of an event.

3. The radio communication method claimed in claim 2, wherein one wireless terminal as a base station monitors the traffic, and when the volume of traffic is larger than a predetermined upper limit value, the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network are extended.

4. The radio communication method claimed in claim 2, wherein when the volume of traffic received by the receiving side wireless terminal is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

5. The radio communication method claimed in claim 2, wherein when the volume of traffic sent from the sending side wireless terminal is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

6. The radio communication method claimed in claim 2, wherein one wireless terminal as a base station detects a topology change, and when the volume of traffic expected by the topology change is larger than a predetermined upper limit value, the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network are extended.

7. The radio communication method claimed in claim 2, wherein when the expected volume of traffic received by the receiving side wireless terminal which varies according to a topology change of the multihop radio network is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

8. The radio communication method claimed in claim 2, wherein when the expected volume of traffic sent from the sending side wireless terminal which varies according to a topology change of the multihop radio network is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

9. The radio communication method claimed in claim 2, wherein one wireless terminal as a base station detects the time and, at a predetermined time, the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network are changed.

10. The radio communication method claimed in claim 2, wherein the wireless terminals constituting the multihop radio network detect the time and, at a predetermined time, and change the intermittent receive period and the preamble length of data.

11. The radio communication method claimed in claim 2, wherein when the expected volume of traffic received by the receiving side wireless terminal which varies according to the time is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

12. The radio communication method claimed in claim 2, wherein when the expected volume of traffic sent from the sending side wireless terminal which varies according to the time is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

13. The radio communication method claimed in claim 2, wherein the sending side wireless terminal detects the occurrence of an event, and when the volume of traffic sent from the sending side wireless terminal which is expected by the occurrence of an event detected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

14. The radio communication method claimed in claim 2, wherein the wireless terminals inform one wireless terminal as a base station of their battery remaining power, and the base station changes the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network according to the battery remaining power informed.

15. The radio communication method claimed in claim 2, wherein the receiving side wireless terminal detects the battery remaining power, and when the battery remaining power is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the battery remaining power is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

16. The radio communication method claimed in claim 2, wherein one wireless terminal monitors at least one of the time, a topology change of the multihop radio network and the received traffic, transmitted traffic, occurrence of an event and battery remaining power of one or more wireless terminals constituting the multihop radio network, and determines the intermittent receive period and the preamble length of data of each wireless terminal on the basis of the monitoring.

17. A radio communication system of a multihop radio network including a plurality of wireless terminals, comprising:

a receiving side wireless terminal including network characteristics detecting means for detecting characteristics of the multihop radio network and intermittent receive period setting means; and

a sending side wireless terminal including preamble length changing means, wherein when the network characteristics detecting means detects a change of the characteristics of the network, the intermittent receive period setting means changes an intermittent receive period, and the preamble length changing means changes the preamble length of data.

18. The radio communication system claimed in claim 17, wherein the characteristics depend on a change in traffic, network topology, time, battery remaining power of the wireless terminals or occurrence of an event.

19. The radio communication system claimed in claim 18, wherein one wireless terminal as a base station further includes:

monitoring means for monitoring the traffic of the multihop radio network;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the traffic monitored by the monitoring means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means;

and wherein each of the wireless terminals constituting the multihop radio network includes receiving means for receiving the information on the intermittent receive period and the preamble length of data from the base station, and the wireless terminals constituting the multihop radio network change the intermittent receive period and the preamble length of data on the basis of the information received by the receiving means.

20. The radio communication system claimed in claim 18, wherein the receiving side wireless terminal further includes measuring means for measuring the volume of traffic of received data, and when the volume of traffic measured is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

21. The radio communication system claimed in claim 18, wherein the sending side wireless terminal further includes measuring means for measuring the volume of traffic of sending data, and when the volume of traffic measured is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

22. The radio communication system claimed in claim 18, wherein one wireless terminal as a base station further includes:

detecting means for detecting a topology change of the multihop radio network;

expecting means for expecting the traffic from the topology change detected by the detecting means;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the traffic expected by the expecting means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means;

and wherein each of the wireless terminals constituting the multihop radio network includes receiving means for receiving the information on the intermittent receive period and the preamble length of data from the base station, and the wireless terminals constituting the multihop radio network change the intermittent receive period and the preamble length on the basis of the information received by the receiving means.

23. The radio communication system claimed in claim 18, wherein the receiving side wireless terminal further includes:

detecting means for detecting a topology change of the multihop radio network; and

expecting means for expecting the volume of traffic received by the receiving side wireless terminal from the topology change detected by the detecting means, and when the volume of traffic expected by the expecting means is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

24. The radio communication system claimed in claim 18, wherein the sending side wireless terminal further includes:

detecting means for detecting a topology change of the multihop radio network; and

expecting means for expecting the volume of traffic sent from the sending side wireless terminal from the topology change detected by the detecting means, and when the volume of traffic expected by the expecting means is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

25. The radio communication system claimed in claim 18, wherein one wireless terminal as a base station further includes:

clock means for clocking the time;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the time obtained by the clock means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means;

and wherein each of the wireless terminals constituting the multihop radio network includes receiving means for receiving the information on the intermittent receive period and the preamble length of data from the base station, and the wireless terminals constituting the multihop radio network change the intermittent receive period and the preamble length on the basis of the change information received by the receiving means.

26. The radio communication system claimed in claim 18, wherein each of the wireless terminals constituting the multihop radio network further include:

clock means for clocking the time; and

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminal on the basis of the time obtained by the clock means.

27. The radio communication system claimed in claim 18, wherein the receiving side wireless terminal further includes:

a clock;

expecting means for expecting the volume of traffic received by the receiving side wireless terminal which varies according to the time; and

expecting means for expecting the volume of traffic received by the receiving side wireless terminal from the present time, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

28. The radio communication system claimed in claim 18, wherein the sending side wireless terminal further includes:

a clock;

expecting means for expecting the volume of traffic sent from the sending side wireless terminal which varies according to the time; and

expecting means for expecting the volume of traffic sent from the sending side wireless terminal from the present time, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

29. The radio communication system claimed in claim 18, wherein the sending side wireless terminal further includes:

detecting means for detecting the occurrence of an event; and

expecting means for expecting the volume of traffic sent from the sending side wireless terminal from the occurrence of an event detected, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

30. The radio communication system claimed in claim 18, wherein the wireless terminal further includes:

detecting means for detecting the battery remaining power; and

determining means for determining the intermittent receive period and the preamble length of the wireless terminals according to the battery remaining power detected.

31. The radio communication system claimed in claim 18, wherein the receiving side wireless terminal further includes detecting means for detecting the battery remaining power, and when the battery remaining power detected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the battery remaining power is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

32. The radio communication system claimed in claim 18, wherein each wireless terminal further includes:

monitoring means for monitoring at least one of the time, a topology change of the multihop radio network and the received traffic, transmitted traffic, occurrence of an event and battery remaining power of one or more wireless terminals constituting the multihop radio network;

monitor information sending means for sending information monitored by the monitoring means to a specific wireless terminal in the multihop radio network; and

setting information receiving means for receiving setting information on at least one of the intermittent receive period and the preamble length of data from the specific wireless terminal;

and wherein the specific wireless terminal includes;

change information receiving means for receiving change information from each wireless terminal;

determining means for determining setting information on at least one of the intermittent receive period and the preamble length of data of each wireless terminal on the basis of the change information; and

setting information sending means for sending the setting information to each wireless terminal, and sets the intermittent receive period and the preamble length of data of each wireless terminal on the basis of the setting information.

33. A wireless terminal constituting a radio communication system of a multihop radio network including a plurality of wireless terminals, comprising:

network characteristics detecting means for detecting characteristics of the multihop radio network;

intermittent receive period setting means; and

preamble length changing means;

wherein when the network characteristics detecting means detects a change of the characteristics of the network, the intermittent receive period setting means changes the intermittent receive period, and the preamble changing means changes the preamble length of data.

34. The wireless terminal claimed in claim 33, wherein the characteristics depend on a change in traffic, network topology, time, battery remaining power of the wireless terminals or occurrence of an event.

35. The wireless terminal claimed in claim 34 further comprising:

monitoring means for monitoring the traffic of the multihop radio network;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the traffic monitored by the monitoring means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means.

36. The wireless terminal claimed in claim 35 further comprising:

detecting means for detecting a topology change of the multihop radio network;

expecting means for expecting the traffic from the topology change detected by the detecting means;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the traffic expected by the expecting means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means.

37. The wireless terminal claimed in claim 36 further comprising:

clock means for clocking the time;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the time obtained by the clock means; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means.

38. The wireless terminal claimed in claim 36 further comprising:

receiving means for receiving information on the battery remaining power from another wireless terminal;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the battery remaining power of another wireless terminal; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means.

39. The wireless terminal claimed in claim 36 further comprising:

receiving means for receiving information on the occurrence of an event from another wireless terminal;

determining means for determining the intermittent receive period and the preamble length of data of the wireless terminals constituting the multihop radio network on the basis of the occurrence of an event informed by another wireless terminal; and

informing means for informing the wireless terminals constituting the multihop radio network of the intermittent receive period and the preamble length of data determined by the determining means.

40. The wireless terminal claimed in claim 36 further comprising receiving means for receiving setting information on the intermittent receive period and the preamble length of data from another wireless terminal, wherein the wireless terminals constituting the multihop radio network change the intermittent receive period and the preamble length on the basis of the setting information received.

41. The wireless terminal claimed in claim 40 further comprising detecting means for detecting at least one of the traffic, the topology change, the battery remaining power and the occurrence of an event, and informing the other wireless terminals of the information detected by the detecting means.

42. The wireless terminal claimed in claim 36 further comprising preamble length change requesting means for requesting the other wireless terminals to change the preamble length of data according to the change of the intermittent receive period.

43. The wireless terminal claimed in claim 36 further comprising intermittent receive period change requesting means for requesting the other wireless terminals to change the intermittent receive period according to the change of the preamble length of data.

44. The wireless terminal claimed in claim 36 further comprising receiving means for receiving a preamble length change request from another wireless terminal, and changes the preamble length of data on the basis of the preamble length change request received.

45. The wireless terminal claimed in claim 36 further comprising receiving means for receiving an intermittent receive period change request from another wireless terminal, and changes the intermittent receive period on the basis of the intermittent receive period change request received.

46. The wireless terminal claimed in claim 36 further comprising measuring means for measuring the volume of traffic received, and when the volume of traffic received is larger than a predetermined upper limit value, the intermittent receive period is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period is extended.

47. The wireless terminal claimed in claim 36 further comprising measuring means for measuring the volume of traffic transmitted, and when the volume of traffic transmitted is larger than a predetermined upper limit value, the preamble length of data is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the preamble length of data is extended.

48. The wireless terminal claimed in claim 36 further comprising detecting means for detecting a topology change and expecting means for expecting the volume of traffic received according to the topology change, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period is extended.

49. The wireless terminal claimed in claim 36 further comprising detecting means for detecting a topology change and expecting means for expecting the volume of traffic transmitted according to the topology change, and when the volume of traffic expected is larger than a predetermined upper limit value, the preamble length of data is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the preamble length of data is extended.

50. The wireless terminal claimed in claim 36 further comprising clock means for clocking the time and expecting means for expecting the volume of traffic received according to the time change, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period is extended.

51. The wireless terminal claimed in claim 36 further comprising clock means for clocking the time and expecting means for expecting the volume of traffic transmitted according to the time change, and when the volume of traffic expected is larger than a predetermined upper limit value, the preamble length of data is shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the preamble length of data is extended.

52. The wireless terminal claimed in claim 36 further comprising detecting means for detecting the occurrence of an event and expecting means for expecting the volume of traffic sent from the sending side wireless terminal from the occurrence of an event detected, and when the volume of traffic expected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the volume of traffic is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

53. The wireless terminal claimed in claim 36 further comprising detecting means for detecting the battery remaining power, and when the battery remaining power detected is larger than a predetermined upper limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are shortened and, when the battery remaining power is smaller than a predetermined lower limit value, the intermittent receive period of the receiving side wireless terminal and the preamble length of data of the sending side wireless terminal are extended.

54. The wireless terminal claimed in claim 36 further comprising receiving means for receiving setting information on at least one of the intermittent receive period and the preamble length from a specific wireless terminal, and changes at least one of the intermittent receive period and the preamble length on the basis of the setting information received from the specific wireless terminal.

55. The wireless terminal claimed in claim 54 further comprising monitoring means for monitoring at least one of the time, the topology change of the multihop radio network and the received traffic, transmitted traffic, occurrence of an event and battery remaining power of one or more wireless terminals constituting the multihop radio network, and sending means for sending the information monitored by the monitoring means to the specific wireless terminal in the multihop radio network.

56. The wireless terminal claimed in claim 36 further comprising determining means for determining setting information on at least one of the intermittent receive period and the preamble length of the wireless terminals except the wireless terminal itself and sending means for sending the setting information to the wireless terminals except the wireless terminal itself.

57. The wireless terminal claimed in claim 36 further comprising receiving means for receiving information on the change of at least one selected from the topology of the multihop radio network, received traffic, transmitted traffic, the occurrence of an event and battery remaining power from the wireless terminals except the wireless terminal itself;

determining means for determining setting information on at least one of the intermittent receive period and the preamble length of data of each wireless terminal on the basis of the change information; and

sending means for sending the setting information to the respective wireless terminals.