Unreachable node recovery in wireless mesh networks

A method, performed by a network node, for restoring communication with a neighbor network node in a wireless personal area network, the method comprising:

• determining that the neighbor network node is unresponsive on a first communication channel;
• sequentially monitoring available communication channels for a communication from the neighbor network node, in response to said determining that the neighbor network node is unresponsive, in order to identify a second communication channel that enables reestablishing communication with the neighbor network node, wherein said scanning begins at a first time agreed upon with the neighbor network node prior to said determining that the neighbor network node was unresponsive;
• transmitting a response to the neighbor network node on the second communication channel when said sequentially monitoring provides an identity of the second communication channel;
• and
• monitoring the second communication channel for further communication from the neighbor network node.

A network node communicatively coupled to a neighbor network node in a wireless personal area network, the network node comprising:

• wireless connectivity circuitry configured to
• communicate with the neighbor network node on a first communication channel, and
• communicate with a coordinator node of the wireless personal area network on the first communication channel;
• and
• microcontroller circuitry, coupled to the wireless connectivity circuitry, and configured to
• determine that the neighbor network node is unresponsive on the first communication channel,
• cause the wireless connectivity circuitry to sequentially scan available communication channels, in response to determining that the neighbor network node is unresponsive, in order to identify a second communication channel that enables reestablishing communication with the neighbor network node, wherein the sequential scan begins at a first time agreed upon with the neighbor network node prior to determining that the neighbor network node was unresponsive;
• cause the wireless connectivity circuitry to transmit a message to the coordinator node identifying the second communication channel when the sequential scan provides the identity of the second communication channel and when the second communication channel is not the same as the first communication channel;
• and
• store, in a memory coupled to the microcontroller circuitry, a log entry that the neighbor network node is unresponsive if the sequential scan does not provide an identity of the second communication channel.