Description

Moving data through a wireless network involves three separate elements: the radio signals, the data format, and the network structure. Each of these elements is independent of the other two, so you must define all three when you invent a new network. In terms of the OSI reference model, the radio signal operates at the physical layer, and the data format controls several of the higher layers. The network structure includes the wireless network interface adapters and base stations that send and receive the radio signals. In a wireless network, the network interface adapters in each computer and base station convert digital data to radio signals, which they transmit to other devices on the same network, and they receive and convert incoming radio signals from other network elements back to digital data. Each of the broadband wireless data services use a different combination of radio signals, data formats, and network structure. We’ll describe each type of wireless data network in more detail later in this chapter, but first, it’s valuable to understand some general principles. We formulate the secure minimum energy routing problem with end-to-end security and good put constraints as a constrained optimization of transmission power at the physical layer and link selection at the network layer. We prove that the secure minimum energy routing problem is NP-hard, and develop exact and -approximate solutions of, respectively, pseudo- polynomial and fully-polynomial time complexity for the problem. We show how cooperative jamming can be used to establish a secure link between two nodes in the presence of multiple eavesdroppers or probabilistic information about potential eavesdropping locations by utilizing secret sharing at the network layer. We provide simulation results that demonstrate the significant energy savings of our algorithms com- pared to the combination of security-agnostic mini- mum energy routing and physical layer security.