Using Transmit-Only Sensors to Reduce Deployment Cost of Wireless Sensor Networks

We consider a hybrid wireless sensor network with regular and transmit-only sensors. The transmit-only sensors do not have the receiver circuit (or have a very low data-rate one), hence are cheaper and less energy consuming, but their transmissions cannot be coordinated. Regular sensors, also called cluster-heads, are responsible for receiving information from the transmit-only sensors and forwarding it to sinks. The main goal of such a hybrid network is to reduce the cost of deployment while achieving some performance goals (minimum coverage, sensing rate, etc). In this paper we are interested in the communication between the transmit-only sensors and the cluster-heads. Since the sensors have no feedback, their transmission schedule is random. The cluster-heads, on the contrary, adapt their reception policy to achieve the performance goals. Using a mathematical model of random access networks developed in [1] we define and evaluate packet admission policies for different performance criteria. We show that the proposed hybrid network architecture, using the optimal policies, can achieve substantial dollar cost and power consumption savings as compared to conventional architectures while providing the same performance guarantees.