Tactical apps - resist spoofing, jamming, detection, and direction finding. Multipath effects cause signal fades, often many per packet, necessitating error correction and redundancy. Spectral width of signal should not exceed coherence bandwidth, or else notches in symbol spectrum will occur. FDMA is simpler to implement, but achieves lower channel efficiency since any given band may remain idle for a while. TDMA requires synchronization of transmissions.
Stations know about all radios in the network, and compute network topology.
PRs may have to serve as repeaters in ad hoc networks. Packets contain a preamble for gain control and synchronization timing acquisition by receiver PRs. When a station is first connected, it begins the labelling process. A station has a maximum number of nodes that it can label, and labels time out and must be refreshed. Two stations that have labelled a common repeater are called neighbors.