Multi-radio unification protocol

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 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.

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 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)*SRTTold
• wherein 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.

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:

• 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.