Vol.:(0123456789) 1 3 Journal of Ambient Intelligence and Humanized Computing https://doi.org/10.1007/s12652-018-0901-5 ORIGINAL RESEARCH Improving reporting delay and lifetime of a WSN using controlled mobile sinks Vicky Kumar 1  · Ashok Kumar 1 Received: 22 November 2017 / Accepted: 5 June 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Wireless sensor networks (WSNs) are characterized by many to one trafc pattern, where a large number of nodes commu- nicate their sensed data to the sink node. Due to heavy data trafc near the sink node, the nodes closer to sink node tends to exhaust their energy faster compared to those nodes which are situated away from the sink. This may lead to the fragment of a network due to the early demise of sensor nodes situated closer to the sink. To pacify this problem, mobile sinks are proposed for WSNs. Mobile sinks are capable to provide uniform energy consumption, load distribution, low reporting delay and quick data delivery paths. However, the position of the mobile sink needs to be updated regularly as such position update messages may reduce the network lifetime. In this paper, we propose a novel Location Aware Routing for Controlled Mobile Sinks (LARCMS), which will help in minimizing reporting delay, enhancing network lifetime, handling sink position updates and providing uniform energy consumption. The proposed technique uses two mobile sinks in predefned trajectory for data collection and provides better results compared to existing techniques. The performance of LARCMS is evaluated by comparing with similar mobile sink routing protocols through extensive simulations in MATLAB. Keywords Mobile sink · Network lifetime · Reporting delay · Wireless sensor networks 1 Introduction The main function of a sensor node in wireless sensor net- works (WSNs) is to scrutinize the contiguous environment and disseminate the sensed data to sink for further process- ing. WSNs are widely used in various applications like bor- der security, monitoring patients in the hospitals and smart trafc control (Akkaya and Younis 2005). Sensor nodes comprise low power batteries, limited memories and compu- tational capabilities for performing their duties. These nodes are expected to work in the hostile environments and hence their batteries can neither be recharged nor be replaced in such cases. Hence, it becomes important to utilize available node power efciently. In order to enhance network lifetime, multi hop data transmission has been proposed in literature. But multi hop transmissions sufers from uneven energy depletion in the network wherein nodes closer to sink nodes have to communicate more data and tend to exhaust their energy faster. This may lead to isolation of the sink from the rest of the network (Akkaya and Younis 2005; Kumar and Kumar 2018). In literature, sink mobility has been ofered as a possi- ble solution for the sink isolation problem (Suh and Berber 2015; Wang et al. 2014). Mobile sink also helps in scattering the increased energy drainage around the sink which helps in achieving uniform energy consumption and extending the network lifetime (Ang et al. 2017). The carriers for mobile sinks may be public transportation vehicles (e.g., buses) that repetitively pursue a predefned trail with a cyclic schedule. A battlefeld surveillance scenario may be an example of mobile sink application, where sensors discover enemy troop or vehicle causes. The unmanned aerial vehicles (UAV) or the patrolling soldiers can be used as mobile sinks in such lawsuits. Trafc monitoring, smart homes, hospitals and pollution control are such applications where mobile sinks may be efectively used (Yun and Xia 2010). Sink mobility also provides security beneft which is a challenging issue in case of static sink, as tracking a mobile sink in the sensing feld is very hard as compared to static one. Even though, * Vicky Kumar vicky.kumar334@gmail.com Ashok Kumar ashoknitham@gmail.com 1 Department of Electronics and Communication, National Institute of Technology, Hamirpur 177005, India