As the number of communication components can be integrated into a single chip increases, the possibility of high volume but low cost sensor nodes is realizable in the near future. These small sensor nodes could be deployed in industries such as transportation, health care, disaster recovery, warfare, security, and even space exploration.  By connecting these small sensor nodes by radio links, the sensor nodes could perform tasks which traditional single sensor nodes are hard to match, e.g. detecting danger spots in a disaster area.

The ability to connect an untethered collection of sensor nodes to the fixed network to provide a reliable, guaranteed service, collaborative environment is important in many applications.  For example, the use of sensor nodes is crucial in a wide range of events, such as accidental release of hazardous material or a deliberate terrorist-based release of highly toxic chemical or biological agents.  The unique characteristics of the sensor networks are:
 

• Sensor networks' topology changes very frequently.
• Sensor nodes use broadcast communication paradigm whereas most networks are based on point-to-point communications.
• Sensor nodes are very limited in power, computational capacities, and memory.
• Sensor nodes are very prone to failures.
• Sensor nodes may not have global identification (ID) because of the large amount of overhead.
• Sensor nodes are densely deployed in large numbers.