Method and apparatus employing a mediation device to facilitate communication among devices in an asynchronous communications network

• US 6,816,493 B2
• Filed: 03/09/2001
• Issued: 11/09/2004
• Est. Priority Date: 03/09/2001
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Shi, Qicai, Callaway, Jr., Edgar H., Huang, Jian
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): ODLAND, DAVID E
• Application Number:
  US09/803,322
• Publication Number:
  US 20020126627A1
• Time in Patent Office: 1,341 Days
• Field of Search: 370/236.1, 370/310, 370/311, 370/313, 370/342, 370/344, 370/349, 370/350, 370/389, 370/395.1, 370/395.2, 370/395.21, 370/395.4, 370/428, 370/429, 455/412, 455/500, 455/507, 455/514, 455/515, 455/517, 455/522, 379/67.1, 379/88.12, 340/7.23, 340/7.32, 340/7.35, 340/7.36, 340/7.38
• US Class Current: 370/395.4
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• 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 low power consumption protocol for low power communication devices attached to an asynchronous network is described. In this protocol, a communication device is used as a high communication duty cycle Mediation Device (MD), thus permitting other communication devices to use a low communication duty cycle framing structure. The MD functions as a storage and retrieval service for messages between two devices when one device is not able to communicate. When the previously unavailable device becomes available, it can check in with the MD to retrieve any missed messages and respond to these messages accordingly. In a communication network, each of the low power communication devices can be configured to behave as MD'"'"'s for a small amount of time. Sharing this responsibility among all communication devices in the network allows each device to maintain an low average communication duty cycle. This technique is applicable to a low power, low cost, zero-configuring, self-organizing, asynchronous network.

Claims

1. A first communication device of a plurality of communication devices operable to mediate communications between the plurality of communication devices in an asynchronous network, comprising:

a processing element;

a receiver, coupled to and controlled by the processing element, that receives during a mediation communication period of the first communication device a communication request from a second communication device of the plurality of communication devices when a message transmitted by the second communication device is not received by a third communication device of the plurality of communication devices, wherein the communication request comprises contact information from the second communication device useful for facilitating communication between the second and third communication devices;

a transmitter, coupled to the processing element, that in response to the receiver receiving a query from the third communication device transmits the contact information to the third communication device;

wherein the first communication device operates to mediate communications between the second and third communication devices during the mediation communication period in a mediation mode and does not operate to mediate communications between the second and third communication devices in a normal operating mode; and

wherein the processing element of the first communication device randomly sets a duration of a communication cycle of a plurality of communication cycles comprising the mediation communication period during the mediation mode, and a plurality of normal communication periods and a plurality of sleep periods during the normal operating mode.

2. The device of claim 1, wherein the plurality of normal communication periods are separated by the plurality of sleep periods.

3. The device of claim 1, wherein a duration of each of the plurality of communication cycles is randomly set by the processing element.

4. A method of a first communication device mediating communications between second and third communication devices of a plurality of communication devices of an asynchronous network, comprising:

randomly setting a duration of a communication cycle of a plurality of communication cycles of the first communication device comprising a mediation communication period during a mediation mode of the first communication device and a plurality of normal communication periods and a plurality of sleep periods during a normal operating mode of the first communication device;

the first communication device receiving a communication request, during a receive portion of the mediation communication period representative that a message sent by a second communication device was not received by the third communication device, wherein the communication request comprises contact information useful for facilitating communication between the second and third communication devices;

in response to receiving the communication request, the first communication device transmitting an acknowledge message;

the first communication device receiving a query about whether messages intended for the third communication device have been missed; and

in response to receiving the query, the first communication device transmitting a replay message containing the contact information.

5. The method of claim 4, wherein the duration of the communication cycle is randomly set by a processing element of the first communication device.

6. The method of claim 4, wherein the plurality of normal communication periods are separated by the plurality of sleep periods.

7. The method of claim 4, wherein a duration of each of the plurality of communication cycles is randomly set by the processing element.

8. The method of claim 4, further comprising:

upon the first communication device powering-up, randomly setting an initial timing offset of the first communication device.

9. The method of claim 8, wherein the initial timing offset is set with respect to a clock phase of the first communication device.

10. The method of claim 4, further comprising:

the first communication device transmitting an announcement message at the beginning of the mediation communication period.

11. The method of claim 4, further comprising:

if the first communication device receives an announcement message during the mediation communication period, the first communication device transmitting an alarm message in response.

12. An asynchronous communications network, comprising:

a plurality of communications devices each having a plurality of communication cycles and each operable to mediate communications between the plurality of communication devices during a mediation communication period in a mediation mode and each not operable to mediate communications between the plurality of communication devices in a normal operating mode, wherein each communication cycle of the plurality of communication cycles comprises a mediation communication period during the mediation mode and a plurality of normal communication periods and a plurality of sleep periods during the normal operating mode;

wherein upon entering the mediation mode, a first communication device of the plurality of communication devices randomly sets a duration of a first communication cycle of the plurality of communication cycles of the first communication device and transmits an announcement message at the beginning of the mediation communication period of the first communication cycle in the mediation mode;

wherein if a message transmitted by a second communication device of the plurality of communication devices is not received by a third communication device of the plurality of communication devices the second communication device transmits a communication request to the first communication device, the first communication device in response to the communication request transmits an acknowledge message to the second communication device, the third communication device upon waking from a sleep period transmits a query to the first communication device, in response to the query the first communication device transmits to the third communication device a replay message containing contact information that facilitates communication between the second and third communication devices, and during a synchronized communication period in which communication of the second and third communication devices is synchronized the second communication device transmits the message to the third communication device.

13. The network of claim 12, wherein after the synchronized communication period a duration of a subsequent communication cycle of the second communication device is randomly set and a duration of a subsequent communication cycle of the third communication device is randomly set.

14. The network of claim 12, wherein in response to a fourth communication device of the plurality of communication devices receiving the announcement message during a second communication cycle of the fourth communication device, the fourth communication device transmitting an alarm message during a transmission portion of the mediation communication period of the fourth communication device that causes the first communication device to delay transmission during the mediation communication period of the first communication device until after the fourth communication device has completed transmission.

15. The network of claim 12, wherein upon the first communication device powering-up, an initial timing offset of the first communication device is randomly set.

16. The network of claim 15, wherein the initial timing offset is set with respect to a clock phase of the first communication device.

17. The network of claim 12, wherein the plurality of normal communication periods are separated by the plurality of sleep periods.

18. The network of claim 12, wherein a duration of each of the plurality of communication cycles is randomly set by a processing element of the first communication device.

19. The network of claim 12, wherein the mediation communication period of the communication cycle of each of the communication devices of the plurality of communication devices are within Tw seconds of one another.

20. The network of claim 19, wherein the duration of Tw is determined by the number of communication devices of the plurality of communication devices in the asynchronous network.

21. The network of claim 12, wherein each mediation communication period of one or more communication devices of the plurality of communication devices comprises a plurality of mediation communication sub-periods of varying duration periodically arranged during one or more corresponding communication cycles.

22. A method of mediating communications between a plurality of communication devices of an asynchronous communications network, comprising:

upon entering a mediation mode, a first communication device of the plurality of communication devices randomly setting a duration of a first communication cycle of a plurality of communication cycles of the first communication device and transmitting an announcement message at the beginning of a mediation communication period of the mediation mode of the first communication device;

if a message transmitted by a second communication device of the plurality of communication devices is not received by a third communication device of the plurality of communication devices, the second communication device transmitting a communication request to the first communication device during the mediation communication period of the first communication device;

in response to receiving the communication request, the first communication device transmitting an acknowledge message to the second communication device during the mediation communication period of the first communication device;

the third communication device upon waking from a sleep period transmitting a query to the first communication device;

in response to the query the first communication device transmitting to the third communication device a replay message containing contact information that facilitates communication between the second and third communication devices; and

during a synchronized communication period in which communication of the second and third communication devices is synchronized, the second communication device transmitting the message to the third communication device.

23. The method of claim 22, further comprising:

in response to a fourth communication device of the plurality of communication devices receiving the announcement message during a second communication cycle of the fourth communication device, the fourth communication device transmitting an alarm message during a transmission portion of the mediation communication period of the fourth communication device that causes the first communication device to delay transmission during the mediation communication period of the first communication device until after the fourth communication device has completed transmission.