This paper presents an energy-efficient communication protocol which distributes a uniform energy load to the sensors in a wireless microsensor network. This protocol, called Distance-Based Segmentation (DBS), is a cluster-based protocol that divides the entire network into equal- area segments and applies different clustering policies to each segment to reduce total energy dissipation and hence prolong the lifetime of the network. To evaluate the DBS protocol, a simulator was implemented using the MATLAB software. Simulation results show that the DBS can achieve as much as 16% reduction in total dissipated energy as compared with conventional protocols. In addition this protocol is able to distribute energy load more evenly among the sensors in the network, and hence yields up to 24% increase in the useful network lifetime. The DBS guarantees reliable and low-latency communications between sensor nodes by adding a mechanism to media access control (MAC) protocols.