Media access control and distributed data processing using mediation devices in an asynchronous network

• US 7,492,773 B2
• Filed: 05/22/2003
• Issued: 02/17/2009
• Est. Priority Date: 05/23/2002
• Status: Expired due to Fees

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hester, Lance Eric, Callaway, Edgar Herbert Jr., Huang, Jian, Shi, Qicai
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Mui; Gary
• Application Number:
  US10/443,428
• Publication Number:
  US 20040042501A1
• Time in Patent Office: 2,098 Days
• Field of Search: 370/311, 370/236.1, 370/313, 370/342, 370/395.4, 370/428, 370/429, 370/304, 370/297, 370/324, 370/350, 370/395.62, 370/503, 370/507, 370/510, 370/401
• US Class Current: 370/401
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• 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, one or more mediation devices (MDs) facilitate data processing capabilities in the network, whether in a dedicated MD or distributed MD network environment. These capabilities may be provided by the functions of packet caching, removal of replicated packets, and multiple communication types performed by the one or more MDs in accordance with a common synchronization schedule (2510) managed by the one or more MDs and communicated to other devices in the network (2530).

Claims

1. A method of facilitating communications between one or more of a plurality of communication devices of an asynchronous network, comprising:

determining a first communication schedule of a first communication device of the plurality of communication devices and a second communication schedule of one or more of the plurality of communication devices;

a mediation device of the asynchronous network establishing a common synchronization schedule from the first and second communication schedules, further comprising;

the mediation device transmitting a synchronization message to the plurality of communication devices when the mediation device knows the plurality of communication devices will be able to receive the synchronization message; and

the mediation device transmitting the common synchronization schedule to the plurality of communication devices in accordance with the synchronization message,

wherein the common synchronization schedule provides information needed by the first and second communication devices to be available to receive messages sent to them via the mediation device; and

upon receiving a communication request from the first communication device, the mediation device initiating transmittal of and transmitting a message received from the first communication device of the plurality of communication devices to the one or more of the plurality of communication devices when the one or more of the plurality of communication devices are available to receive the message in accordance with the common synchronization schedule.

2. The method of claim 1, further comprising:

each of the plurality of communication devices acknowledging receipt of the common synchronization schedule if the common synchronization schedule is received.

3. The method of claim 2, wherein acknowledging receipt of the common synchronization schedule comprises:

each of the plurality of communication devices that received the common synchronization schedule transmitting an acknowledge message at a random time during a receive period of the mediation device that follows the transmission of the common synchronization schedule by the mediation device.

4. The method of claim 2, wherein acknowledging receipt of the common synchronization schedule comprises:

each of the plurality of communication devices that received the common synchronization schedule transmitting an acknowledge message to the mediation device at a predetermined beacon transmission slot.

5. The method of claim 2, wherein acknowledging receipt of the common synchronization schedule comprises:

each of the plurality of communication devices that received the common synchronization schedule transmitting a regularly scheduled beacon transmission of the communication device following receipt of the common synchronization schedule.

6. The method of claim 1, further comprising:

if data of the message has been previously cached in memory, the mediation device discarding the message and sending the cached data to the one or more of the plurality of communication devices.

7. The method of claim 1, wherein the mediation device transmits the message received from the first communication device to a second communication device in accordance with the common synchronization schedule and a unicast communication request received from the first communication device.

8. The method of claim 1, wherein the mediation devices transmits the message received from the first communication device to multiple communication devices of the plurality of communication devices in accordance with the common synchronization schedule and a multicast communication request received from the first communication device.

9. The method of claim 8, wherein the multiple communication devices are of a group identified by a group address in the multicast communication request from the first communication device and the MD transmits the message to the group address.

10. The method of claim 1, wherein the mediation devices transmits the message received from the first communication device to the plurality of communication devices in accordance with the common synchronization schedule and a broadcast communication request received from the first communication device.

11. An asynchronous communications network, comprising:

a plurality of communication devices of the asynchronous communications network;

a mediation device (MD) of the asynchronous communications network operable to facilitate communications between a first communication device and one or more communication devices of the plurality of communication devices;

wherein the MD facilitates communications between the first communication device and the one or more communication devices in accordance with a common synchronization schedule managed by the MD and wherein the MD establishes the common synchronization schedule from a first communication schedule of the first communication device and a second communication schedule of the one or more communication devices, wherein to establish the common synchronization schedule the MD further;

transmits a synchronization message to the plurality of communication devices when, the mediation device knows the plurality of communication devices will be able to receive the synchronization messages; and

transmits the common synchronization schedule to the plurality of communication devices in accordance with the synchronization message,

wherein the common synchronization, schedule provides information needed by the first and second communication devices to be available to receive messages sent to them via the mediation device; and

wherein upon receipt of a communication request to transmit a message received from the first communication device, the MD initiates transmittal of and transmits the message to the one or more communication devices when the MD knows that the one or more communication devices are available to receive the message in accordance with the common synchronization schedule.

12. The network of claim 11, wherein the MD transmits a message received from the first communication device to the one or more communication devices in accordance with the common synchronization schedule and a communication request received by the MD from the first communication device.

13. The network of claim 12, wherein the communication request is a unicast communication request from the first communication device to transmit the message to a second communication device of the plurality of communication devices and the MD transmits the message to the second communication device in accordance with the common synchronization schedule.

14. The network of claim 12, wherein the communication request is a multicast communication request from the first communication device to transmit the message to multiple communication devices of the plurality of communication devices and the MD transmits the message to the multiple communication devices in accordance with the common synchronization schedule.

15. The network of claim 14, wherein the multiple communication devices are of a group identified by a group address in the multicast communication request from the first communication device and the MD transmits the message to the group address.

16. The network of claim 12, wherein the communication request is a broadcast communication request from the first communication device to transmit the message to the plurality of communication devices and the MD transmits the message to the plurality of communication devices in accordance with the common synchronization schedule.

17. The network of claim 11, wherein the asynchronous network operates in one of a distributed mode with the MD being a second communication device of the plurality of communication devices and a dedicated mode with the MD being a dedicated mediation device in the asynchronous network.

18. The network of claim 11, wherein the common synchronization schedule is established and communicated to the plurality of communication devices by the MD.

19. The network of claim 11, wherein the MD establishes the common synchronization schedule in response to a communication request received from the first communication device.

20. The network of claim 11, wherein the MD establishes the common synchronization schedule upon becoming the mediation device.

21. The network of claim 11, wherein if data from the first communication device to be transmitted to a second communication device of the plurality of communication devices has been cached in a memory element, the mediation device discards the data from the first communication device.

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

a processing and control element that establishes and manages a common synchronization schedule based upon a communication schedule of one or more of the plurality of communication devices of the asynchronous network;

a receiver, coupled to and controlled by the processing and control element, that receives a communication request to send a message to the one or more of the plurality of communication devices; and

a transmitter, coupled to and controlled by the processing and control element, that in response to the receiver receiving the communication request initiating transmittal of and transmitting the message to the one or more communication devices in accordance with the common synchronization schedule,

wherein the common synchronization schedule provides information needed by the first and second communication, devices to be available to receive messages sent to them via the mediation device, and

wherein the common synchronization schedule is established by the processing and control element causing the transmitter to transmit a synchronization message to the plurality of communication devices when the first communication device knows the plurality of communication devices will be able to receive the synchronization message and causing the transmitter to transmit the common synchronization schedule to the plurality of communication devices in accordance with the synchronization message.

23. The device of claim 22, wherein the receiver further receives one or more acknowledgements from one or more of the plurality of communication devices that received the common synchronization schedule.

24. The device of claim 22, wherein the processing and control element establishes the common synchronization schedule in response to a communication request received from a second communication device.

25. The device of claim 22, wherein the communication request is a unicast communication request and the transmitter transmits the message to a second communication device in accordance with the unicast communication request and the common synchronization schedule.

26. The device of claim 22, wherein the communication request is a multicast communication request and the transmitter transmits the message to multiple communication devices of the plurality of communication devices in accordance with the multicast communication request and the common synchronization schedule.

27. The device of claim 22, wherein the communication request is a broadcast communication request and the transmitter transmits the message to the plurality of communication devices in accordance with the broadcast communication request and the common synchronization schedule.

28. The device of claim 22, wherein the first communication device facilitates communications between the plurality of communication devices during one or a distributed mode of operation and a dedicated mode of operation.

29. The device of claim 22, further comprising:

a memory element of the first communication device, wherein if data of the message has been previously cached in the memory element, the processing and control element discards the message and causes the transmitter to transmit the cached data to one or more of the plurality of communication devices.

30. The device of claim 22, wherein the processing and control element causes the transmitter to transmit the common synchronization schedule to the plurality of communication devices by the MD.

31. A method for facilitating communications between one or more of a plurality of communication devices of an asynchronous network, comprising:

a first communication device of the plurality of communication devices transmitting a communication request to a mediation device to transmit a message to one or more of the one or more communication devices;

the mediation device receiving the communication request from the first communication device; and

the mediation device initiating transmittal of and transmitting the message to the one or more communication devices when the one or more communication devices are available to receive the message in accordance with a common synchronization schedule managed by the mediation device, wherein the common synchronization schedule provides formation needed, by the plurality of communication devices to be available to receive messages sent to them via the mediation device, wherein the common synchronous schedule is determined from a first communication schedule of the first communication device of the plurality of communication devices and a second communication schedule of the one or more communication devices and wherein establishing the common synchronization, schedule further comprises;

the mediation device transmitting a synchronization message to the plurality of, communication devices when the, mediation device knows the plurality of communication devices will be able to receive the synchronization message; and

the mediation device transmitting the common synchronization schedule to the plurality of communication devices in accordance with the synchronization message.

32. The method of claim 31, further comprising:

each of the plurality of communication devices that receives the common synchronization schedule transmitting an acknowledge message at a random time during a receive period of the mediation device that follows the transmission of the common synchronization schedule by the mediation device.

33. The method of claim 31, further comprising:

each of the plurality of communication devices that receives the common synchronization schedule transmitting an acknowledge message to the mediation device during a predetermined transmission slot.

34. The method of claim 31, further comprising:

each of the plurality of communication devices that receives the common synchronization schedule transmitting a regularly scheduled transmission following receipt of the common synchronization schedule.

35. The method of claim 31, wherein the communication request is a unicast communication request and further comprising:

the mediation device transmitting the message to a second communication device in accordance with the common synchronization schedule.

36. The method of claim 31, wherein the communication request is a multicast communication request and further comprising:

the mediation device transmitting the message to multiple communication devices in accordance with the common synchronization schedule.

37. The method of claim 31, wherein the communication request is a broadcast communication request and further comprising:

the mediation device transmitting the message to the plurality of communication devices in accordance with the common synchronization schedule.

38. Computer-readable media tangibly embodying a program of instructions executable by a computer to facilitate communications between one or more of a plurality of communication devices of an asynchronous network, the method comprising:

determining a first communication schedule of a first communication device of the plurality of communication devices and a second communication schedule of one or more of the plurality of communication devices;

a mediation device of the asynchronous network establishing a common synchronization schedule from the first and second communication schedules;

further comprising;

the mediation device transmitting a synchronization message to the plurality of communication devices when the mediation device knows the plurality of communication devices will be able to receive the synchronization message, and

the mediation device transmitting the common synchronization schedule to the plurality of communication devices in accordance, with the synchronization message,

wherein the common synchronization schedule provides information needed by the first and second communication devices to be available to receive messages sent to them via the mediation device; and

upon receiving a communication request from the first communication device, the mediation device initiating transmittal of and transmitting a message received from the first communication device of the plurality of communication devices to the one or more of the plurality of communication devices when the one or more of the plurality of communication devices are available to receive the message in accordance with the common synchronization schedule.

39. Computer-readable media tangibly embodying a program of instructions executable by a computer to facilitate communications between one or more of a plurality of communication devices of an asynchronous network, comprising:

a first communication device of the plurality of communication devices transmitting a communication request to a mediation device to transmit a message to one or more of the one or more communication devices;

the mediation device receiving the communication request from the first communication device; and

the mediation device initiating transmittal of and transmitting the message to the one or more communication devices when the one or more communication devices are available to receive the message in accordance with a common synchronization schedule managed by the mediation device, wherein the common synchronous schedule provides information needed by the plurality of communication devices to be available to receive messages sent to them via the mediation device, wherein the common synchronous schedule is determined from a first communication schedule of the first communication device of the plurality of communication devices and a second communication schedule of the one or more communication devices and wherein establishing the common synchronization schedule further comprises;

the mediation device transmitting a synchronization message to the plurality of communication devices when the mediation device knows the plurality of communication devices will be able to receive the synchronization message; and

the mediation device transmitting the common synchronization schedule to the plurality of communication devices in accordance with the synchronization message.