A linear wireless sensor network includes nodes having monotonically varying node identifiers along each branch. The network identifiers enable the nodes to forward packets without use of routing tables. Low duty cycle wireless communication protocols enable packets to be routed to all nodes of very large networks while consuming very little electrical power. Broadcast, rather than unicast, transmissions between nodes take advantage of favorable signal propagation conditions to forward messages using largest possible hops, skipping over nodes when possible, as well as automatically adapting to time- or spatially-varying conditions. A group of packets is broadcast and forwarded by a most distant receiving node that received all packets of the group. A receiving node's clock is automatically adjusted, based on which packet(s) of a group of packets was received. A sending node synchronizes near-by receiving nodes. Nodes are provisioned over-the-air, with built-in scheduling. Health and welfare information piggybacks on other traffic.