Method and system for providing a modified timed division multiple access (TDMA) for reduced delay

• US 7,835,383 B2
• Filed: 09/30/2005
• Issued: 11/16/2010
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Herrmann, Falk, Manjeshwar, Arati
• Primary Examiner(s): Moe; Aung S
• Assistant Examiner(s): Rose; Kerri M
• Application Number:
  US11/241,639
• Publication Number:
  US 20070076655A1
• Time in Patent Office: 1,873 Days
• Field of Search: 370/431, 370/438, 370/439, 370/445, 370/447, 370/448, 370/458, 370/461, 370/462
• US Class Current: 370/445
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 12/40156 by using dedicated slots associated with a priority level
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

A method for shared access of a communication channel is provided, which includes dividing access to the communication channel into a plurality of time slots, and allocating the time slots, at least partially, based on a priority of use of the communication channel.

Claims

1. A method for shared access of a communication channel, the method comprising:

dividing access to the communication channel into a plurality of time slots;

for at least some of the time slots, allocating the time slots, with respect to accessing the communication channel, to use of the communication channel exclusively for performing particular corresponding activities;

allocating a subset of the time slots, with respect to accessing the communication channel, as exclusive to particular corresponding nodes; and

resolving a contention for one of the at least some of the time slots using a Carrier Sense Multiple Access (CSMA) communications protocol, for only those nodes that are waiting to perform the corresponding activity for which the time slot has been allocated.

2. The method of claim 1, wherein the corresponding activities include transmitting one of a high priority message and low priority message.

3. The method of claim 1, wherein the corresponding activities include transmitting a supervision message.

4. The method of claim 3, wherein the supervision message is sent by a base station to poll a status of one of the nodes.

5. The method of claim 4, wherein different ones of the at least some of the time slots are used for supervision messages sent to poll different ones of the nodes.

6. The method of claim 1, wherein the corresponding activities include transmitting an alarm message.

7. The method of claim 6, wherein the alarm message is sent by a node to a base station for alerting the base station of a condition that requires attention.

8. The method of claim 1, wherein the allocation of the at least some of the time slots allocated, with respect to accessing of the communication channel, to use of the communication channel exclusively for performing particular corresponding activities is according to a modified Time Division Multiple Access communications protocol.

9. A network comprising:

at least two node elements configured to;

communicate on a shared communication channel a message of a predefined activity in a time slot predefined as exclusive, with respect to accessing of the communication channel, for allocation of performance of the predefined activity;

refrain from accessing the shared communication channel during a time slot exclusively reserved for a node; and

resolve a contention for the time slot predefined as exclusive, with respect to accessing of the communication channel, for allocation of performance of the predefined activity using a Carrier Sense Multiple Access (CSMA) communications protocol for only those nodes that are waiting to perform the predefined activity for which the time slot had been previously allocated.

10. The network of claim 9, wherein the predefined activity is to transmit one of a high priority message and a low priority message.

11. The network of claim 9, wherein the predefined activity is to transmit a supervision message.

12. The network of claim 9, wherein the predefined activity is to transmit an alarm message.

13. The network of claim 9, wherein the time slot predefined as exclusive, with respect to accessing of the communication channel, for allocation of performance of the predefined activity is allocated, at least partially, based on a priority of use of the shared communication channel.

14. A method for shared access of a communication channel, the method comprising:

dividing access to the communication channel into a plurality of time slots;

for a first subset of the time slots, allocating the time slots, with respect to accessing of the communication channel, to use of the communication channel exclusively for performing particular corresponding activities;

allocating a second subset of the time slots, with respect to accessing of the communication channel, as exclusive to particular corresponding nodes; and

resolving a contention for one of the first subset of the time slots using a multiple access communications protocol, for only those nodes that are waiting to perform the corresponding activity for which the time slot has been allocated.

15. The method of claim 14, wherein the second subset of the time slots are allocated using a Time Division Multiplex Access (TDMA) communications protocol.

16. The method of claim 14, wherein the multiple access communications protocol is a Carrier Sense Multiple Access (CSMA) communications protocol.

17. The method of claim 14, wherein the second subset of the time slots are allocated using a Time Division Multiplex Access (TDMA) communications protocol and the multiple access communications protocol is a Carrier Sense Multiple Access (CSMA) communications protocol.

18. The method claim 17, wherein the time slots are configurable in size.

19. The method of claim 18, wherein the size is configurable according to the priority of use of the communication channel.

20. The method of claim 14, wherein the activities include transmission by a base station of a message to one of the nodes for the one of the nodes to forward to other nodes within a subtree of the one of the nodes.

21. The method of claim 14, wherein a respective one of the first subset of the time slots is allocated between each pair of sequentially scheduled ones of the second subset of the time slots.

22. The method of claim 14, wherein, for each of at least one of the activities, a time slot allocated, with respect to accessing the communication channel, to use of the communication channel exclusively for performing the respective activity is smaller than a time required for performing the activity.

23. The method of claim 22, wherein, once the time slot allocated, with respect to accessing the communication channel, to use of the communication channel exclusively for performing the respective activity is accessed for performing the activity, performance of the activity is continued into a following time slot.

24. The method of claim 23, wherein the following time slot is treated as busy, blocking accessing of the following time slot for its allocated activity.

25. The method of claim 14, wherein the communication channel is a wireline communication channel.

26. The method of claim 14, wherein the communication channel is a wireless communication channel.

27. The method of claim 14, wherein multiple ones of the second subset of time slots are scheduled between each pair of sequentially scheduled ones of the first subset of time slots.

28. The method of claim 14, wherein:

each of the activities is classified according to a respective priority level; and

for each of the activities, a number of the firs subset of the time slots allocated to the respective activity depends on its respective classified priority level.

29. A method for sharing access of a communication channel among a plurality of nodes of a network, the method comprising:

dividing, by a hardware system, access to the communication channel into a plurality of time slots;

for at least some of the time slots, allocating, by the hardware system and with respect to accessing of the communication channel, the time slots to use of the communication channel exclusively for performing particular corresponding activities; and

for each of the at least some of the time slots, providing, by the hardware system, access to the time slot, using a contention-based protocol, to only those nodes that are waiting to perform the corresponding activity for which the time slot has been allocated.

30. The method of claim 29, wherein the at least some of the time slots are not assigned to any node when no nodes are waiting to perform said corresponding activities, even if one or more nodes are waiting to use the communication channel for performance of another activity.

31. A method for shared access of a communication channel, the method comprising:

dividing access to the communication channel into a plurality of time slots;

for at least some of the time slots, allocating the time slots, with respect to accessing of the communication channel, to use of the communication channel exclusively for performing particular corresponding activities;

allocating a subset of the time slots, with respect to accessing of the communication channel, as exclusive to particular corresponding devices; and

resolving a contention using a multiple access communications protocol, wherein the contention arises if more than one device attempts to access a particular one of the at least some of the time slots.