Delay Constrained Routing Algorithm for WSN with Mobile Sink

Wireless Sensor Network (WSN) is a collection of large number of sensors with low-power transceivers effectively used for collecting data in various applications like environmental monitoring, healthcare, civil and military applications. Efficient data transmission protocols are required to reduce transmission delay and energy of sensors to increase lifetime of sensor nodes. Recent researches in WSNs primarily focus on energy efficient routing with static sinks. Static sinks cause energy hole reducing the network lifetime substantially. Mobile sinks improve network lifetime by eliminating energy holes but causes delay in data collection. In this paper, we propose a routing algorithm with sink mobility in hierarchical WSNs. In our proposal, we consider upper and lower bound on delay while optimizing sojourn locations and sojourn time. An MILP formulation is also presented. Simulations in NS2 prove the feasibility and effectiveness of our proposal.