Cluster-based routing protocol in wireless sensor networks for tracking livestock movements in Mongolian nomadic herding

Mongolian nomadic herding is characterized by a large number of livestock and vast pastureland. In this paper, firstly, we present an architecture of wireless sensor network for tracking livestock movements considering scalability, mobility and energy efficiency. To solve the problems of scalability and energy efficiency, we adopt cluster-based wireless sensor network architecture. And a mobile sink is introduced to solve the problems of mobility and the absence of communications infrastructure. Secondly, we design a cluster-based routing protocol for the architecture by combining and tailoring two existing cluster-based routing protocols, LEACH-Mobile Enhanced (LEACH-ME) and Mobile Sink based Routing Protocol (MSRP), to allow for achieving energy efficiency, scalability and mobility. The routing protocol designed for the architecture is based on a mobility metric “remoteness” for cluster head election and the declaration of membership of a cluster for mobile sensor nodes, which ensures high success rate in data transfer between a cluster head and its sensor nodes even though nodes are moving. And the mobile sink moves in the clustered wireless sensor network to collect sensed data from cluster heads within its vicinity, which prolongs network lifetime.