Frequency Hopping Ad hoc Networks: Principles and Routing Protocols
Komalpreet Kaur, Renu Vig, Introduction To Manet · 2012
Wireless mobile ad hoc networks (MANETs) or sensor networks provide protection against interception of data which are the key requirements for military applications. These features are supported by spread spectrum (SS) techniques such as frequency hopping (FH). In an FH ad hoc network, the sequence in which the frequency hops is typically derived from the local clock reading of each node. Therefore, networkwide time synchronization is needed so that the nodes simultaneously switch to the same frequency channel, i.e., hop synchronously. Thus, a distributed decision has to be made between the nodes as to whose local time reference is chosen as the common time reference for other nodes to synchronize to. For that purpose, there has to be a predefined procedure for frequency hopping nodes to exchange synchronization information through a control channel.