An Improved GTS Transmission Algorithm for Marine-Environment Monitoring WSN Systems

Wireless sensor network can be applied to large-scale environment surveillance such as marine environment monitoring. In such application case, besides the protocol structure and the energy consumption, the signal’s real-time transmission and successfully transmitting rate of critical nodes also play an important role in improving the whole system’s performance. In this paper, a new parameter called ‘normalized access delay’ is introduced into the media access control (MAC) layer of IEEE 802.15.4 to build a novel node time delay category table. Based on this parameter, the so-called Delay-CategoryGTS (DCGTS) transmission algorithm is proposed to reduce the transmission delay and to improve the success transmitting rate of critical nodes, enabling the dedicated guaranteed time slot (GTS) can be used for high reliability and real time signal transmission in large-scale marine-environmental monitoring network. NS-2 simulation platform is built to simulate the proposed DCGTS algorithm. The final results demonstrate that the proposed DCGTS algorithm has superior real-time transmission performance and success transmitting rate to the traditional methods.