A Low rate WPAN supports three different types of topologies.
. Star Topology
. Peer-to-Peer Topology
. Cluster Tree/Mesh Topology
Star Topology
The star topology (Fig: 2.1) is one of the most common forms of network formation. This type of topology can be used in monitoring applications where several devices monitor their applications and report to the coordinator. And the coordinator, a highly capable FFD, reacts to the situation at hand. In this type of network formation the communication between any two devices is forbidden. All devices can only communicate with the coordinator irrespective of their device type. Thus, a device can communicate with the coordinator and vice versa. No routing of information is possible. Given this reduced functionality of the system, routing functionalities like Address Resolution, and Routing finding to certain extent can be disabled.
Peer-to-Peer Topology
The Peer-to-Peer topology (Fig: 2.2) is a mode of communication where routing of data among devices is possible, as long as they are with in the operating space of each other. Complicated applications where devices need sharing of information are intended targets for the implementation of a peer-to-peer topology. Thus possible communication scenarios are between node-to-node, node-to-coordinator, and coordinator-to-node. As is evident if two devices need to transfer data, both have to be full function devices. Applications such as industrial control and monitoring, wireless sensor networks, asset and inventory tracking, intelligent agriculture, and security would benefit from such a network topology. A peer-to-peer network can be ad hoc, self-organizing and self-healing.
Cluster-Tree Topology
The cluster tree topology can in a way be considered as a derivative of the peer-to-peer topology. Several small clusters, each being able to communicate peer-to-peer, can be controlled with a PAN coordinator. And each cluster can have its own coordinator. And the coordinators are answerable to the PAN Coordinator. Among several existing clusters, the coordinators can compete with each other to choose a PAN coordinator.
