Dcv Ns: A New Energy Efficient Transmission Scheme For Wireless Sensor Networks

In this paper, an energy-efficient communication scheme for low-power wireless networks is proposed which is based on encoding the messages by a novel source coding technique, called Dual-message Compression with Variable Null Symbol (DCVNS), followed by using the concept of Silent Communication. The source coding technique used in this scheme interleaves bits from two messages and encodes every two consecutive bits of this interleaved dual-message by one of four symbol values so that the overall message length is reduced by a factor of two. The transmitter is kept silent during the periods of the most dominant symbol which is dynamically changed. A hybrid modulation / demodulation technique using non-coherent FSK and ASK is used to have 43.46% energy savings on an average at the transmitter using a channel with Additive White Gaussian Noise (AWGN), and 50% energy savings at the receiver over the conventional Binary Frequency Shift Keying (BFSK), with equal likelihood of all possible strings of binary messages. Simulation results with real-life sensor data show that we can get still higher energy savings at the transmitter, ranging from about 54.1% to 58.9%. Also, the transmission time is reduced by a factor of two due to the reduced length of the encoded message. The scheme is suitable for multihop communication in low cost wireless sensor network applications.