Batched fair exhaustive polling scheduler

• US 6,480,505 B1
• Filed: 12/06/1999
• Issued: 11/12/2002
• Est. Priority Date: 12/06/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johansson, Niklas, Johansson, Per
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US09/455,172
• Time in Patent Office: 1,072 Days
• Field of Search: 370/431, 370/449, 370/329, 370/346, 455/450
• US Class Current: 370/449
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method and apparatus for improving channel utilization and throughput in an ad-hoc wireless communication system is provided. A master unit and one or more slave units are coupled to a shared communication channel having at least an uplink (UL) channel and a downlink channel (DL) for each master unit-slave unit pair. A group of active nodes is established corresponding to slave units having UL and/or DL data associated therewith for transfer. The group of active nodes may be polled according to Fair Exhaustive Polling (FEP) and information alternately transferred on a TDD. Accumulated information may be transferred in a batch and feedback information collected and used to adjust polling. One or more links may be identified as lossy links due to increased Bit Error Rate (BER) and accompanying information loss resulting in lower throughput. Virtual active nodes added to the group of active nodes to compensate therefor. A transmission parameter such as number of retransmissions may be evaluated against a predetermined threshold to identify lossy links. If lossy links improve, virtual active nodes may be removed from the group of active nodes. Information associated with the one or more slaves units may be circuit switched synchronous information or non-circuit switched asynchronous information. Feedback information such as timeout information associated with the slave units may be evaluated. If a time out signal associated with a slave unite is received the slave unit may be scheduled for polling responsive to the time out signal.

Claims

1. A method for improving channel utilization and throughput in an ad-hoc wireless communication system having a master unit and one or more slave units coupled with a shared communication channel having at least an uplink (UL) channel and a downlink channel (DL) for each master unit-slave unit pair, the method comprising the steps of:

establishing a group of active nodes corresponding to one or more of the one or more slave units having UL and/or DL data associated therewith for transfer;

polling the group of active nodes according to Fair Exhaustive Polling (FEP); and

alternately transferring information between the master and a next slave unit as polled according to FEP.

2. The method of claim 1, further comprising the steps of:

accumulating information to be transferred to the next slave unit and one or more subsequently polled slave units in a batch; and

alternately transferring respective portions the batch of information between the next slave unit and the one or more subsequently polled slave units during a polling interval associated with each of the next slave unit and the one or more subsequently polled slave units.

3. The method of claim 2, further comprising the steps of:

collecting feedback information from the next slave unit and the one or more subsequently polled slave units related to the alternately transferred portions of the batch; and

adjusting the polling according to the feedback information.

4. The method of claim 1, further comprising the steps of:

identifying one or more links associated with the one or more slave units as lossy links;

adding one or more virtual active nodes to the group of active nodes, wherein one or more of the one or more virtual active nodes is associated with the each of the identified one or more lossy links.

5. The method of claim 4, wherein the step of identifying further includes evaluating a transmission parameter against a predetermined threshold for each of the one or more links and wherein if the threshold is exceeded the link is identified as lossy, and wherein if the threshold is not exceeded the link is not identified as lossy.

6. The method of claim 4, further including the steps of:

identifying one or more links associated with the one or more slave units as no longer lossy links;

removing one or more virtual active nodes from the group of active nodes, wherein one or more of the one or more removed virtual active nodes is associated with the each of the identified one or more no longer lossy links.

7. The method of claim 1, wherein the information is associated with one or more of circuit switched synchronous information and non-circuit switched asynchronous information.

8. The method of claim 1, wherein the step of polling further includes the step of evaluating feedback information associated with the one or more slave units.

9. The method of claim 1, wherein the step of polling further includes the steps of:

receiving a time out signal associated with one or more of the one or more slave units; and

scheduling;

the one or more timed out slave units for polling responsive to the time out signal.

10. An apparatus for improving channel utilization and throughput in an ad-hoc wireless communication system, the apparatus comprising:

a master unit;

one or more slave units; and

a shared communication channel having at least an uplink (UL) channel and a downlink channel (DL) for each master unit-slave unit pair;

the master unit and the one or more slave units coupled to the shared communication channel, the master device having at least a transceiver, a memory, and a processor, the processor configured to;

establish a group of active nodes corresponding to one or more of the one or more slave units having UL and/or DL data associated therewith for transfer;

poll the group of active nodes according to Fair Exhaustive Polling (FEP); and

alternately transfer information between the master and a next slave unit as polled according to FEP.

11. The apparatus of claim 10, wherein the processor is further configured to:

accumulate information to be transferred to the next slave unit and one or more subsequently polled slave units in a batch; and

alternately transfer respective portions the batch of information between the next slave unit and the one or more subsequently polled slave units during a polling interval associated with each of the next slave unit and the one or more subsequently polled slave units.

12. The apparatus of claim 11, wherein the processor is further configured to:

collect feedback information from the next slave unit and the one or more subsequently polled slave units related to the alternately transferred portions of the batch; and

adjust the polling according to the feedback information.

13. The apparatus of claim 10, wherein the processor is further configured to:

identify one or more links associated with the one or more slave units as lossy links;

add one or more virtual active nodes to the group of active nodes, wherein one or more of the one or more virtual active nodes is associated with the each of the identified one or more lossy links.

14. The apparatus of claim 13, wherein the processor, in identifying is further configured to evaluate a transmission parameter against a predetermined threshold for each of the one or more links and wherein if the threshold is exceeded the link is identified as lossy, and wherein if the threshold is not exceeded the link is not identified as lossy.

15. The apparatus of claim 13, wherein the processor is further configured to:

identify one or more links associated with the one or more slave units as no longer lossy links;

remove one or more virtual active nodes from the group of active nodes, wherein one or more of the one or more removed virtual active nodes is associated with the each of the identified one or more no longer lossy links.

16. The apparatus of claim 10, wherein the information is associated with one or more of circuit switched synchronous information and non-circuit switched asynchronous information.

17. The apparatus of claim 10, wherein the processor, in polling, is further configured to evaluate feedback information associated with the one or more slave units.

18. The apparatus of claim 10, wherein the processor, in polling, is further configured to:

receive a time out signal associated with one or more of the one or more slave units; and

schedule;

the one or more timed out slave units for polling responsive to the time out signal.