HEED: Hybrid Energy Efficient Distributed Clustering

1. HEED: Hybrid Energy Efficient Distributed Clustering Shannon Seefeld

2. What is HEED • HEED was designed to select different cluster heads in a field according to the amount of energy that is distributed in relation to a neighboring node.

3. Goals of HEED • Four primary goals: • prolonging network life-time by distributing energy consumption • terminating the clustering process within a constant number of iterations/steps • minimizing control overhead • producing well-distributed cluster heads and compact clusters.

4. What is Clustering? • We find that clustering plays a dominant role in delaying the first node death, while aggregation plays a dominant role in delaying the last node death • In each cluster one node acts as a cluster head which is in charge of coordinating with other cluster heads

5. Alternatives • To increase energy efficiency and prolong network lifetime we can consider intra cluster communication cost as a secondary clustering parameter. • Intra clustering communication involves communicating with other cluster heads • Cost is a function of cluster properties and whether power levels are permissible for transmission within a cluster

6. Advantages • HEED distribution of energy extends the lifetime of the nodes within the network thus stabilizing the neighboring node. • Does not require special node capabilities, such as location-awareness • Does not make assumptions about node distribution • Operates correctly even when nodes are not synchronized.

7. Advantages Cont. • Creates well distributed clusters • Terminates in constant time • Requires only local communication • Reduces energy load • Extends network lifetime

8. Advantages Cont. • The advantages of HEED are that nodes only require local (neighborhood) information to form the clusters • the algorithm terminates in O(1) iterations • the algorithm guarantees that every sensors is part of just one cluster, and the cluster heads are well-distributed.

9. Disadvantages • the random selection of the cluster heads,may cause higher communication overhead for: • the ordinary member nodes in communicating with their corresponding cluster head • cluster heads in establishing the communication among them, or • between a cluster head and a base station. • the periodic cluster head rotation or election needs extra energy to rebuild clusters.

10. WSN limitations • Communication • Bandwidth is limited and must be shared among all the nodes in the sensor network • Spatial reuse essential • Efficient local use of bandwidth needed

11. WSN Limitations Cont. • Sensor energy • Each sensor node has limited energy supply • Nodes may not be rechargeable • Eventually nodes may be self-powered • Energy consumption in sensing, data processing, and communication • Communication often the most energy-intensive • For some sensors, sensing may also be energy-intensive • Must use energy-conserving protocols

12. Bibliography • http://www.sigmobile.org/mobicom/2003/posters/14-Younis.pdf • http://www.cs.purdue.edu/homes/fahmy/papers/heed.pdf • http://www.ece.rochester.edu/courses/ECE245/lectures/Lecture22-23.pdf