Method and system to provide increased data throughput in a wireless multi-hop network

• US 20060215605A1
• Filed: 03/01/2006
• Published: 09/28/2006
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: Hitachi Energy Switzerland AG (Hitachi, Ltd.)
• Original Assignee: Amalavoyal Chari, Cyrus Behroozi, Devabhaktuni Srikrishna
• Inventors: Behroozi, Cyrus, Srikrishna, Devabhaktuni, Chari, Amalavoyal
• Granted Patent: US 7,668,137 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04K 2203/18 for wireless local area networks or WLAN
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

It is the object of this invention to provide a method of increasing the data throughput of a multi-hop wireless link. A method is provided which mitigates self-interference, without precluding the use of omni-directional transceivers. Distributed protocols for channel allocations in a multi-hop wireless communication system are described. These protocols result in channel allocations that increase the capacity utilization of the network and render the system robust to localized interferers and jammers.

Claims

1-18. -18. (canceled)

19. A method to determine a quality of a link comprising:

sending a predetermined number of packets to an originating node in response to a reservation packet; and

deducing, at the originating node, a packet error rate based on a number of packets received without error; and

assigning best quality channel to the downstream connection from the originating node based on the packet error rate.

20. The method of claim 19, wherein the best quality channel comprises a plurality of downlink channels, and each downstream connection to a downstream node uses one of the plurality of downlink channels.

21. A method to determine a quality of a link comprising:

sending a predetermined number of packets to an originating node in response to a reservation packet; and

deducing, at the originating node, a throughput rate based on the packets received without error; and

assigning a best quality channel to the downstream connection from the originating node based on the observed throughput.

22. The method of claim 21, wherein the best quality channel comprises plurality of downlink channels, and each downstream connection to a downstream node uses one of the plurality of downlink channels.

23. The method of claim 22, wherein the determination is performed periodically, and on all downstream links from a given node and on all available channels in order to determine the choice of channel or channels for the downlink for which the best link quality is achieved.

24. A method to allocate communication channels that results in enhanced resistance to external interferers in a wireless mesh network comprising:

periodically evaluating a downstream channel by receiving a plurality of packets from each downstream node for each of a plurality of channels; and

selecting as the downstream channel a best of the plurality of channels based on link-quality.

25. The method of claim 24, wherein the method results in a channel allocation for the system that eliminates interference between adjacent links or next-to-adjacent links.

26. The method of claim 24, wherein the communications channel to be used on a link (connecting two nodes) is assigned by the node that is at a smaller number of hops to the access point.

27. The method of claim 24, wherein all the links comprising the downlink from a given node are assigned to the same channel.

28. The method of claim 24, wherein the links comprising the downlink from a given node may be assigned to different channels.

29. The method of claim 24, wherein the channel allocations for the system may change in response to the presence of an interferer or jammer transmitting on one or more of the channels used by the system.

30. The method of claim 24 wherein the presence of an interferer or a jammer is inferred based on the link quality observed on each link.