An Efficient and Adaptive Superframe Structure for IEEE 802.15.7-Based Real-time Sensor Networks

Abstract

The Internet is expanding with new bandwidth-intensive applications and the network's sensor count, resulting in spectrum constraints. The IEEE 802.15.7 standard specifies optical wireless communication (OWC) as a solution as it utilizes terahertz of unlicensed spectrum, is resistant to radio frequencies, and is more secure to harness. Nevertheless, the standard does not address the adaptive data demands of sensors, nor does it consider priority data transmission, which is a crucial quality of service demand. Wireless sensors are increasingly being used in personalized medical health care, and our proposed research focuses on their delay, adaptive traffic management, and overall network throughput. We have suggested a novel superframe structure that enables adaptive sleep mode for priority data handling. The proposed superframe structure is simulated for the contention access period (CAP) as well as the contention-free period (CFP). The suggested approach works in hybrid mode, i.e., with the CSMA/CA and GTS allocation techniques. We illustrate the importance of our proposed work by comparing it to IEEE 802.15.7 in terms of delay and throughput. Across both factors, the simulation results demonstrate a significant improvement. Additionally, we have computed the collision probability in our suggested adaptive superframe structure.