A Power Estimation Method for Energy Efficient Wireless Sensor Network

Wireless sensor networks (WSN) are composed of large number of sensor node with restricted energy. The energy is one of the most important terms in wireless sensor networks problem. Sensor node of WSN consists of processor unit, memory unit and power supply. Wireless sensor node is battery operated, therefore the biggest challenge in field of wireless sensor is the lifetimes of WSN node which can be improve by achieving communication with low power consumption. So in this proposed work, a path metric that accurately captures the expected number of link layer transmission required for reliable end to end packet delivery with minimum number of retransmission are considered; we analytically computed estimated cost with direct data transmission within the node and with shortest path between those nodes. Power is analyzed in terms of minimum cost which is the function of distance, number of packets used for transmission along with numbers of permissible hops. Comparative results are shown between time v/s delay, time v/s direct estimated cost and estimation with shortest minimum retransmission path, with variable data packets rate and number of hops. So, with the proper selection of data packet rate and number of hops for end to end transmission considerable reduction in power consumption can be obtained

Performance enhancement of IEEE 802.15.4 by employing RTS/CTS and frame concatenation

IEEE 802.15.4 has been widely accepted as the de facto standard for wireless sensor networks (WSNs). However, as in their current solutions for medium access control (MAC) sub-layer protocols, channel efficiency has a margin for improvement, in this study, the authors evaluate the IEEE 802.15.4 MAC sub-layer performance by proposing to use the request-/clear-to-send (RTS/CTS) combined with frame concatenation and block acknowledgement (BACK) mechanism to optimise the channel use. The proposed solutions are studied in a distributed scenario with single-destination and single-rate frame aggregation. The throughput and delay performance is mathematically derived under channel environments without/with transmission errors for both the chirp spread spectrum and direct sequence spread spectrum physical layers for the 2.4 GHz Industrial, Scientific and Medical band. Simulation results successfully verify the authors’ proposed analytical model. For more than seven TX (aggregated frames) all the MAC sub-layer protocols employing RTS/CTS with frame concatenation (including sensor BACK MAC) allow for optimising channel use in WSNs, corresponding to 18–74% improvement in the maximum average throughput and minimum average delay, together with 3.3–14.1% decrease in energy consumption.info:eu-repo/semantics/publishedVersio