# A Novel Connectivity-Based LEACH-MEEC Routing Protocol for Mobile Wireless Sensor Network
## 1 Introduction  
The Internet of Things (IoT) is a dynamic wide-ranging network that includes varieties of mobile and static sensors, data gathering devices such as global positioning system (GPS) sensors, radio frequency identification (RFID) sensors, and laser and infrared sensing scanners that are connected through the Internet and exchange information with each other based on an agreement [1, 2]. Wireless sensor network (WSN) is a group of static sensor nodes which gather information and deliver to the base station. The data gathered by some static sensor nodes can be imprecise and it may suffer network failure, which affects connectivity and reliability of the network. Hence, it has limited applications. Due to fast development in IoT and mobile Internet technology, mobile wireless sensor network (MWSN) has become a popular field of research and replacement of static WSN. MWSN is a collection of tiny mobile sensor motes that aim to sense data from the environment and effectively deliver the base station. These mobile motes maintain the communication links among the neighboring nodes while collecting and processing the data for efficient communication, enhancing the network performance [3]. MWSN can be classified into three types [4], which are as follows. * Static base station and mobile sensor nodes  
The main difference between MWSN and WSN is sensor node mobility, which enhances the connectivity, network adaptability, and the reliability of the sensor networks. Simultaneously,MWSN stabilizes the energy utilization and improves the lifetime of the sensor network [1]. However, due to frequent changes in topology and complex environment in different applications, MWSN faces challenges related to energy efficiency, data delivery and data aggregation [5; 6]. MWSN has a wide range of applications that depend on environment and setup. Space mission sensor robots [7], border monitoring mobile sensors [8], flying bee robot-sensors (ROBOBEE) [9] and undersea submarines movement detection by mobile sensor nodes [10] are common examples of MWSNs. Routing is the core aspect of all sorts of networks, which is used to send the (sensed) data between mobile sensor nodes and base stations. This requires an efficient and reliable communication. In the literature, several routing schemes have been studied for WSN, e.g., flooding, multipath, Quality of Service (QoS), hierarchical and geographical routing, etc. Recently, much work has been done on hierarchical based routing protocols for static and mobile networks. Since it chooses a comparatively short path for routing, it is resistant to failures and efficient in the use of remaining energy. Then, it has a low overhead and enhances network lifetime [11; 12]. In a hierarchical architecture, sensor nodes are classified into optimal groups based on their homogeneous properties. Afterwards, these group members select a Cluster Leader (CL) that helps member nodes transfer sensed data to the base station. Low-Energy Adaptive Clustering Hierarchy (LEACH) is a basic energy efficient routing protocol of hierarchical routing protocol's family [13], where the sensor nodes remain static. Hence, it achieves higher energy efficiency but has limited applications. However, mobile sensors have several applications but also bring many challenges such as energy depletion and squatter network lifetime. LEACH-Mobile is the first mobility-based LEACH routing protocol [14], where CL has to wait for two successive time division multiple access (TDMA) failed cycles before declaring a mobile node as a non-member. Although such a mobile node may become a member of another CL, data for two TDMA slots is lost. Consequently, this approach increases overhead and reduces energy efficiency. Figure 1 shows an example of a single hop mobile LEACH routing protocol, where a base station is static and sensor nodes are mobile. The role of mobility models in the performance of MWSN is of enormous importance.