Cognitive Networks: Towards Self-Aware Networks

3.3. Network Functions

Given a network and the need to transmit data from a node(s) to another node(s) within the network, the network typically implements the following functions: (1) constructing hop-by-hop connectivity to establish connections between nodes within the network; (2) routing data from a source node to a destination node; (3) scheduling data transmission to avoid collisions or scheduling node duty cycles to conserve energy; and (4) controlling data transmission rate to avoid congestion or buffer overflow. Changes in the dynamic factors described in Section 3.2 may affect the performance or interrupt the service continuity of those network functions. A network needs to adapt its network functions to mitigate the effects of those changes. This section describes those network functions in details.

3.3.1. Constructing Hop-by-Hop Connectivity

Hop-by-hop connectivity refers to either a physical link or a logical connection between two nodes used to exchange data. A network constructs and maintains hop-by-hop connectivity to establish a connected topology that allows data transmission between any pair of nodes in the network. Figure 3.2(a) shows the initial network with the dotted lines representing potential connections between nodes. Figure 3.2(b) illustrates the same network after it has constructed hop-by-hop connectivity to form a connected topology. Figure 3.2(b) also shows that only a subset of potential links is used to construct the connected topology. A network ...