The correct answer is:
(c) protocol
In the context of cognitive radio and network management, a protocol structure is used to handle changes in the air interface. Cognitive radios are designed to adapt to varying network conditions, including changes in the air interface, which refers to the communication link between the device and the network. Protocols in cognitive radio networks define the rules and procedures for communication, including how to manage dynamic spectrum allocation, interference, and network reconfiguration.
Here’s a brief breakdown of the options:
(a) model: While models are used in the design and simulation of cognitive radio networks, they are not typically applied directly to handle changes in the air interface during real-time operation.
(b) logical: Logical structures refer to abstract models for managing and organizing information but are not typically the first choice for addressing dynamic changes in the air interface.
(c) protocol: Protocols are sets of rules that govern the communication process between devices in a network. They are essential in cognitive radios for adapting to changing air interface conditions, ensuring efficient and reliable communication.
(d) flow: Flow typically refers to the movement of data packets through the network or the control flow of processes. It is not the direct answer to managing the air interface changes in cognitive radio networks.
Thus, protocol is the most appropriate term here for managing network changes, particularly in the context of cognitive radios adapting to changing air interface conditions.
So, the correct answer is (c) protocol.