Entry Date:
April 14, 2000

LEACH (Low Energy Adaptive Clustering Hierarchy): Routing Protocols for Sensor Networks

Principal Investigator Hari Balakrishnan

Co-investigator Anantha Chandrakasan


LEACH (Low Energy Adaptive Clustering Hierarchy) is designed for sensor networks where an end-user wants to remotely monitor the environment. In such a situation, the data from the individual nodes must be sent to a central base station, often located far from the sensor network, through which the end-user can access the data. There are several desirable properties for protocols on these networks: Use 100's - 1000's of nodes, Maximize system lifetime, Maximize network coverage, and Use uniform, battery-operated nodes.

Conventional network protocols, such as direct transmission, minimum transmission energy, multi-hop routing, and clustering all have drawbacks that don't allow them to achieve all the desirable properties. LEACH includes distributed cluster formation, local processing to reduce global communication, and randomized rotation of the cluster-heads. Together, these features allow LEACH to achieve the desired properties. Initial simulations show that LEACH is an energy-efficient protocol that extends system lifetime.

SPIN is a family of protocols used to efficiently disseminate information in a wireless sensor network. Conventional data dissemination approaches like flooding and gossiping waste valuable communication and energy resources sending redundant information throughout the network. In addition, these protocols are not resource-aware or resource-adaptive. SPIN solves these shortcomings of conventional approaches using data negotiation and resource-adaptive algorithms. Nodes running SPIN assign a high-level name to their data, called meta-data, and perform meta-data negotiations before any data is transmitted. This assures that these is no redundant data sent throughout the network. In addition, SPIN has access to the current energy level of the node and adapts the protocol it is running based on how much energy is remaining. Simulation results show that SPIN is more energy-efficient than flooding or gossiping while distributing data at the same rate or faster than either of these protocols.

Internet host mobility -- As part of the Migrate project, we are exploring a pure end-to-end architecture for Internet host mobility, believing that infrastructure-based approaches to handling host mobility on the Internet does not address an important set of mobility problems.

INS message routing -- Using the intentional naming system, WIND applications achieve mobile resource discovery using a late binding option, since INS integrates name resolution and message routing. This allows applications to bind names to network locations "late" in the resolution process, enabling them to track rapid change. A common thread in all our routing work is application-controlled routing (in some cases, application-level routing), in which applications have a much greater say in influencing routing/forwarding decisions than in current architectures.