A multi-radio sensor node is provided that includes two or more
communication devices. The communication devices include radio frequency
(RF) devices like radios. Each communication device supports simultaneous
communications among multi-radio sensor nodes of respective independent
network clusters. A network structure is provided that includes two or
more local network clusters. Each local network cluster includes numerous
multi-radio sensor nodes. Each communication device of a multi-radio
sensor node supports communication among the multi-radio sensor nodes of
a different one of the local network clusters so that simultaneous
communications are supported among the multi-radio sensor nodes of the
local network clusters. The multi-radio sensor nodes of the local network
clusters determine their locations relative to the other multi-radio
sensor nodes of the independent network clusters with which they
communicate. The location determination includes performing timing
synchronization via synchronization signals communicated among the local
network clusters, and acoustic signaling.