Technology

Mesh Formation

A key attribute of wireless sensor networks based on TSMP is the ability to rapidly self-organize the mesh. Every mote has the intelligence to discover neighbors, measure RF signal strength, acquire synchronization and channel hopping information, and then establish paths and links with neighbors.

Each mote has the ability to route traffic from neighbors as dictated by RF connectivity and/or network performance requirements. During the life of an installation, it may be the case that a mote joins as an end node, becomes a routing node due to changing RF conditions, and then reverts to an end node. This type of behavior is not uncommon in mesh networks and happens automatically.

Each network has a unique ID, which is included in all communications, and allows for multiple networks to operate in the same radio space without the risk of sharing data or misrouting information. If a mote attempts to join a network and detects other motes with a network ID not matching its own, it continues unsynchronized listening until it hears a device with the right ID. Network integrity is also protected by a "join key" that encrypts a request to join the network. If a mote has the wrong join key, its join request is ignored and the mote reverts to unsynchronized listening. The ability for motes to join quickly (and for the network to reconfigure quickly as well) is critical to the ease of use and cost of operation of these networks. Not all meshes are created equal in this respect: Dust Networks ensures that the intelligence required for quick network formation and healing is built into every product.