The emergence of low power consumption, high data rate and small size sensor network applications, has increased the demand for high-performance network services. To meet this challenge, we propose an Improved Distributed Scheduling Algorithm (IDSA), a novel heuristic scheduling technique that can provide effective collision free broadcasting, lower energy consumption, minimum message overhead and enhanced channel utilization. In contrast to earlier traditional scheduling algorithms of medium access control (MAC), which are generally designed for sequential slot assignments, this paper presents an improved algorithm for distributed scheduling. The IDSA has several unique features. First, it optimizes energy through collision free transmission by scheduling conflict-free slots. Second, it can adapt the changes in topology explicitly without reconstructing the global transmission schedule with minimum message overhead. Furthermore, the IDSA also provides improved performance in terms of message overhead, slot assignment per round and energy consumption. Simulation results show that the IDSA significantly outperforms a representative distributed random slot assignment algorithm (DRAND).