A Data Transmission Protocol for Wireless Sensor Networks: A Priority Approach

Abstract

Recent development in the field of a wireless sensor network has shown the significant improvement and has emerged as a new energy efficient wireless technology for low data rate applications. Handling different types of event data altogether is a crucial task in the sensor networks. This paper presents the solution to the problem of heterogeneous data transmission of long distance prioritised nodes in low data rate wireless sensor networks (LR-WSNs). The solution comprises three main algorithms, namely data reporting, traffic scheduling, and centralised reporting rate mechanism. The data reporting algorithm reports the demanded data in each specified decision window size with variable reporting rate. The traffic aware packet scheduling algorithm performs the packet reprioritisation and scheduling. The priority assignment is designed based on the data priority and hop count. It serves transient traffic against newly sensed packets, or less hop distance travelled packets. As a result, it minimises the chances of dying earlier than its deadline. The third algorithm presents the flexible data gathering approach based on the level of the buffer either sensed by its own or recently received information from hop node. It uses a decision interval window for managing the frequency of data delivery. This centralised decision approach makes the sink node more adaptive for data gathering and controlling the active source nodes. This multi-tier framework functions over CSMA/CA due to its unique feature of energy saving, especially for LR-WSNs. The reported work is simulated and examined over various scenarios in the multi-hop wireless sensor networks. Moreover, the performance of the scheduler proves better data transmission rate for prioritybased traffic over regular traffic flows; approximately 7% over First-Come-First-Served (FCFS) and 5% against Precedence Control Scheme (PCS) mechanism using theoretical analysis and computer simulations.