An Optimized RPL Protocol for Wireless Sensor Networks
In Wireless Sensor Networks (WSNs), controlling transmission power is a commonly used technique to extend battery life. This paper describes a novel mechanism using measured RSS (Received Signal Strength) to calculate optimal transmission power. This technique works in multipath environments and with nodes with differing transmission capability. Our technique achieves automatic configuration employing modifications to RPL (Routing Protocol for Low-power and lossy networks) router discovery without requiring extra steps or messages. Consequently, each node can send packets with ideal transmission power, which will usually be lower than maximum power and will help to prolong its lifetime. We evaluate the effectiveness of the proposed scheme, using performance metrics such as energy consumption and packet loss, on an WSN testbed. Several factors that impact the RSS, such as antenna, multipath environment, output power and the node’s capabilities are also investigated. Moreover, two RSS estimation techniques are evaluated and compared to the average measured RSS. The experimental results show that energy consumption is reduced by using the proposed technique.