Figure 1.
Example Connectivity and Members.
Figure 2.
Node 1 is the master. Piconets are identified by their hopping sequence.
Figure 1. Example Connectivity and Members. |
Figure 2. Node 1 is the master. Piconets are identified by their hopping sequence. |
The Bluetooth system supports both point-to-point and point-to-multi-point connections. Units that are within the range can set up an ad-hoc connection. Two or more Bluetooth units that share the same channel form a piconet. To regulate traffic on the channel, one of the participating units becomes a master of the piconet. Any unit may be a master and the remaining members become slaves. Nodes may request to exchange roles if desired. The master is responsible for synchronization as well as controlling all traffic on the channel. The master employs a polling scheme to avoid collisions and all traffic is routed through the master first.
Several Piconets can be established and linked together ad hoc, where each piconet is identified by a different frequency hopping sequence. A collection of piconets constitute a scatternet. All users participating on the same piconet are synchronized to this hopping sequence. The topology can best be described as a multiple piconet structure. Up to eight mobile hosts can actively participate in a piconet but it contain several "sleeping" members. Units may belong to several piconets, but not simultaneously. If a unit is a master and it leaves its piconet to participate in another, then all traffic is suspended until it returns.
For more information