Alternative Methods to Prolong Wireless Sensor Networks Lifetime
MS Thesis Proposal
by
Murat Işık
03.10.2003
Thesis Advisor: Professor Cem Ersoy
A Wireless Sensor Network (WSN) is an ad-hoc network composed of densely-populated tiny electronic sensing
devices, distributed over an area or volume. The basic function of the network is to observe some phenomenon
by using the sensors in the tiny devices and communicate it to a central point called the sink. Some typical
physical quantities that can be observed by sensor nodes are: temperature, motion, pressure, humidity, chemical
composition. [1]
The wireless sensor networks are usually randomly deployed to cover an area such as a pollution site or a battle
field. Since the deployment and thus the topology is random, the network must include the intelligence to selforganize. The capability for self organization must be provided in several protocol layers. [2], [3].
The miniature network nodes typically obtain their power from an internal battery. Since the battery has a certain
lifetime, the overall lifetime of the wireless sensor network is highly dependent on the conservation of battery
power at the nodes. This is a stringent task, and has to be handled at all layers of networking throughout the node
population.
The lifetime of a wireless sensor network is dependent on several factors. [4] gives a brief account of these
factors and tries to mathematically determine an upper bound to network lifetime depending on this data:
Region of observation
Source behaviour within the region (including protocols)
Sink location
Number of nodes
Radio path loss characteristics
Efficiency of node electronics
Energy available on a node
The below figure from [1] clearly indicates that at all layers of the protocol stack in the sensor nodes, poweraware intelligence is needed:
One could think of several measures to prolong the lifetime of a sensor network. Some of these are:
Power-aware routing
Intelligent self-organization techniques
Re-deployment of sensor nodes in key areas
The research proposal is to survey and compare the alternative techniques to increase network lifetime. After the
survey and comparison using simulation, alternative methods for deployement of sensors and sinks and/or
routing to prolong lifetime of WSNs will be proposed.
References
[1]
I.F. Akyıldız, W. Su, Y. Sankarasubramaniam, E. Cayirci: “Wireless Sensor Networks: a survey”,
Elsevier Computer Networks 38, 2002
[2]
Katayoun Sohrabi, Jay Gao, Wishal Ailawadhi, Gregory J. Pottie: “Protocols for self-organization of a
wireless sensor network”, IEEE Personal Communications, October 2000
[3]
Alberto Cerpa, Deborah Estrin: “ASCENT: Adaptive Self-configuring Sensor Network Topologies”,
Computer Networks, 2002
[4]
Manish Bhardwaj, Timothy Garnett, Anantha P. Chandrakasan: “Upper Bounds on the Lifetime of
Sensor Networks”, IEEE International Conference on Communications ICC’01, Helsinki, June 2001