Wireless sensor networks are deployed to render services unattended, making them tightly time-barred. Such networks require energy-cognizant optimizations in every protocol and algorithm that they deploy. While a sensor network is principally designed to sense and transmit, the individual sensor nodes utilize most of their energy to route own and other？s data. Therefore routing stands atop the phenomena that are investigated to conserve energy. In this paper, we focus our efforts to the routing problem in a special kind of sensor network, the IEEE 802.15.4 network. These networks pose unique challenges to the designers of the routing protocols？Challenges that arise from their constrained nature such as in energy, memory size, computational power, and packet size result into ineptness of hop count (HC)-based routing protocols to provide robust routability while wireless links fail occasionally. IEEE 802.15.4 networks also offer certain technological features, which are explored here to enhance the routability of IEEE 802.15.4 networks. More specifically, we use Link Quality Indication (LQI) mechanism in IEEE 802.15.4 networks to with in conjunction with HC to form a composite lexical routing metric. Our experiments on standard reactive routing protocols validate the robustness of the lexical routing metric in untapped for.
