In this thesis a routing protocol is adopted for wireless sensor networks to provide efficient routing, scalability, high reliability and efficient use of energy and resources. These goals are achieved by basing the design on expedient schemes. Firstly, the devised link quality estimator scheme is responsible for determining the quality of communication link among the neighbor nodes. Secondly, an adaptive routing packets sending scheme is used to reduce the number of routing packets travelling in the stable network by using trickle algorithm. Thirdly, the energy-efficient parent selection scheme is adopted. Fourthly, the snooped mechanism and link layer acknowledgement are based on link layer. The snooped mechanism is used to capture the data packets that are destined to another node in order to update the routing table, while the link layer acknowledgement provides the declaration to the network layer data packets. The ARP (adopted routing protocol) is built using the simulation tool Castalia. Several new C++ modules are written and added to Castalia and also some other Castalia modules are modified to meet the requirements. The ARP is evaluated on 18 different simulation scenarios. Each simulation scenario of ARP is evaluated through a set of significant metrics for a WSN application including data delivery ratio, control overhead, duplicate data packets, latency, consumed energy, transmitted and received data packets. These tests revealed the high performance of the devised ARP. The data delivery ratio is very high ranging from 98.6% to 99.4% in highly dynamic environments. The duplicated data packets are very low ranging from 0.06% to 0.14% and the transmitted control overhead is moderate.