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

• US 7,668,137 B2
• Filed: 03/01/2006
• Issued: 02/23/2010
• Est. Priority Date: 03/26/2001
• Status: Expired due to Term

• Current Assignee: Hitachi Energy Switzerland AG (Hitachi, Ltd.)
• Original Assignee: Tropos Networks Incorporated (ABB Limited)
• Inventors: Behroozi, Cyrus, Srikrishna, Devabhaktuni, Chari, Amalavoyal
• Primary Examiner(s): Sheikh; Ayaz R
• Assistant Examiner(s): Wong; Blanche
• Application Number:
  US11/366,707
• Publication Number:
  US 20060215605A1
• Time in Patent Office: 1,455 Days
• Field of Search: 370/229, 370/231, 370/232, 370/329
• 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. A method to allocate a downlink channel for a plurality of nodes in a wireless network, wherein one of the plurality of nodes is an originating node and the remaining of the plurality of nodes are downstream nodes, comprising:

sending, by the originating node, a reservation packet to the plurality of downstream nodes, wherein the reservation packet specifies a plurality of channels;

responding, by each of the downstream nodes that are one hop away from the originating node, to the reservation packet;

sending, by each of the responding downstream nodes, a predetermined number of packets to the originating node for each of the plurality of channels;

deducing, by the originating node, a packet error rate for each of the plurality of channels for each of the responding downstream node, wherein the packet error rate is based on a number of packets without error received by the originating node compared to the predetermined number of packets sent by the corresponding downstream node to the originating node;

determining, by the originating node, a best quality channel based on the packet error rates;

sending, by the originating node, a message with the best quality channel to each of the responding downstream nodes; and

changing, by each of the responding downstream nodes, an uplink to the best quality channel in the message.

2. The method of claim 1, wherein when the determining a best quality channel results in a plurality of best quality channels, the originating node sends a different message to at least two of the responding downstream nodes and each of the responding downstream nodes changes an uplink to the best quality channel in the corresponding message.

3. A method to allocate a downlink channel for a plurality of nodes in a wireless network, wherein one of the plurality of nodes is an originating node and the remaining of the plurality of nodes are downstream nodes, comprising:

sending, by the originating node, a reservation packet to the plurality of downstream nodes, wherein the reservation packet specifies a plurality of channels;

responding, by each of the downstream nodes that are one hop away from the originating node, to the reservation packet;

sending, by each of the responding downstream nodes, a predetermined number of packets to the originating node for each of the plurality of channels;

deducing, by the originating node, a throughput rate for each of the plurality of channels for each of the responding downstream node, wherein the throughput rate is based on a number of packets without error received by the originating node compared to the predetermined number of packets sent by the corresponding downstream node to the originating node;

determining, by the originating node, a best quality channel based on the throughput rates;

sending, by the originating node, a message with the best quality channel to each of the responding downstream nodes; and

changing, by each of the responding downstream nodes, an uplink to the best quality channel in the message.

4. The method of claim 3, wherein when the determining a best quality channel results in a plurality of best quality channels, the originating node sends a different message to at least two of the responding downstream nodes and each of the responding downstream nodes changes an uplink to the best quality channel in the corresponding message.

5. The method of claim 4, wherein the allocation is performed periodically, for all downstream nodes one hop away from the originating node and on all available channels in order to determine the best quality channel or channels to link the originating node to each downstream node one hop away from the originating node.

6. A method to discover a downlink channels to eliminates interference between adjacent channels or next-to-adjacent channels, comprising:

periodically evaluating, by an originating node, a quality of each of a plurality of channels linking the originating node to a downstream node, wherein the originating node receives a predetermined number of packets from the downstream node for each of the plurality of channels, and wherein the downstream node is one hop away from the originating node; and

selecting, by the originating node, a best quality channel as a downlink channel based on the quality of each of the plurality of channels, wherein the downlink channel links the originating node to the downstream node, and wherein the downstream node becomes a new originating node to discover a downlink channel linking the new originating node to a new downstream node.

7. The method of claim 6, wherein the downlink channel may change in response to a presence of an interferer or jammer transmitting on the downlink channel.

8. The method of claim 6, wherein a presence of an interferer or a jammer is inferred based on the quality observed on the downlink channel.