Multi-radio unification protocol
First Claim
1. In a wireless network comprising a plurality of nodes, a method for selecting, by a first node, a channel for communicating with a second node, the first node having at least two network interfaces with radios tuned to orthogonal channels, the method comprising:
- discovering network interfaces of the second node available for communicating with the first node;
with respect to each available network interface of the second node, periodically making a channel quality estimate; and
making a channel selection,wherein discovering available network interfaces comprises;
broadcasting an address resolution protocol request;
receiving on a first channel a first address resolution protocol response from the second node;
recording medium access control address information contained in the first address resolution protocol response;
initially selecting the first channel for communicating with the second node; and
for each additional address resolution protocol response received from the second node, recording medium access control address information contained in the additional address resolution protocol response.
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Accused Products
Abstract
An invention is disclosed whereby a wireless network node, equipped with two or more radio transceivers statically tuned to non-interfering frequency channels, can make decisions regarding which channel to use when communicating with a neighboring wireless node. A multi-radio unification protocol implemented in a wireless node coordinates the use of multiple wireless network interface cards and provides a virtual layer that hides the multiple physical network interfaces from higher layers of a node'"'"'s network protocol stack. The invention is applicable to wireless networks generally, including those in which some nodes do not have multiple radios or do not recognize the multi-radio unification protocol. The invention makes possible simultaneous transmissions using available channels, thereby reducing interference and delay while increasing the overall capacity of the network.
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Citations
7 Claims
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1. In a wireless network comprising a plurality of nodes, a method for selecting, by a first node, a channel for communicating with a second node, the first node having at least two network interfaces with radios tuned to orthogonal channels, the method comprising:
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discovering network interfaces of the second node available for communicating with the first node; with respect to each available network interface of the second node, periodically making a channel quality estimate; and making a channel selection, wherein discovering available network interfaces comprises; broadcasting an address resolution protocol request; receiving on a first channel a first address resolution protocol response from the second node; recording medium access control address information contained in the first address resolution protocol response; initially selecting the first channel for communicating with the second node; and for each additional address resolution protocol response received from the second node, recording medium access control address information contained in the additional address resolution protocol response.
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2. In a wireless network comprising a plurality of nodes, a method for selecting, by a first node, a channel for communicating with a second node, the first node having at least two network interfaces with radios tuned to orthogonal channels, the method comprising:
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discovering network interfaces of the second node available for communicating with the first node; with respect to each available network interface of the second node, periodically making a channel quality estimate; and making a channel selection, wherein discovering available network interfaces is in accordance with a protocol, and wherein discovering available network interfaces further comprises discovering whether the second node is capable of operating in accordance with the protocol, wherein discovering whether the second node is capable of operating in accordance with the protocol comprises; sending a channel select message along each known network interface of the second node; if a channel select acknowledgment response is received from each known network interface of the second node, classifying the second node as being capable of operating in accordance with the protocol; if no channel select acknowledgment response is received from a known network interface after expiration of a timeout period, and if a maximum number of unacknowledged retransmissions has not been exceeded, retransmitting a channel select message along the interface; and if a maximum number of unacknowledged retransmissions has been exceeded, classifying the second node as not being capable of operating in accordance with the protocol. - View Dependent Claims (3)
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4. In a wireless network comprising a plurality of nodes, a method for selecting, by a first node, a channel for communicating with a second node, the first node having at least two network interfaces with radios tuned to orthogonal channels, the method comprising:
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discovering network interfaces of the second node available for communicating with the first node; with respect to each available network interface of the second node, periodically making a channel quality estimate; and making a channel selection, wherein making a channel quality estimate comprises; sending a probe message along the network interface; receiving a response to the probe message from the second node; and calculating a round-trip latency time associated with sending the probe message and receiving the response, further comprising; computing a smoothed round-trip time (SRTT) value according to a formula;
SRTT=α
*RTTnew+(1−
α
)*SRTToldwherein α
is a parameter chosen with a range from 0 to 1, wherein RTTnew is a most recent round-trip latency time measurement, and wherein SRTTold is a previously-computed SRTT value.
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5. A computer-readable medium on which is stored a data structure for use by a first wireless network node in selecting a channel for transmitting data to a second wireless network node in accordance with a protocol, the data structure comprising:
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a data field for identifying the second node; a data field for indicating whether the second node is known to use the protocol; a data field for storing a physical address associated with each known network interface of the second node; a data field for storing a channel quality estimate associated with each known network interface of the second node; a data field for identifying a current preferred channel for transmitting data to the second node; a data field for recording a most recent time at which a channel was selected; a data field for recording a most recent time at which a message was either sent to or received from the second node; and a data field for storing times associated with unacknowledged messages. - View Dependent Claims (6, 7)
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Specification