Design Issues of Routing Protocols for WSNs
The following are factors that must be considered to achieve efficient communications between nodes in a wireless sensor networks.
- Node deployment may be manual/deterministic or random. In the former, nodes are manually placed and data is routed via pre-determined paths. In the latter case, nodes are scattered randomly, forming an ad hoc infrastructure. If the nodes are not uniformly distributed, it may be necessary to cluster the nodes to support connectivity and enable energy-efficient operations.
- Sensor nodes are very dependent on battery lifetime because they are often left unattended for long periods of time, thus, it is imperative that communications and computations take an energy-conserving approach.
- Data reporting method is either time-driven, even-driven, query-driven or a hybrid of these methods, depending on the criticality of the data. The time-driven method allows sensor nodes to periodically turn off their transmitters to conserve power. The event- and query-driven methods require sensors to react immediately to sudden and drastic changes in the environment, and are therefore, suitable for time-critical applications. The routing protocol is very influenced by the data reporting method in terms of energy consumption and route calculations.
