Power-efficient routing schemes for MANETs: a survey and open issues

Ubiquitous smart devices with embedded sensors are paving the way for mobile ad hoc networks (MANETs) that enable users to communicate directly, thereby playing a key role in Smart City and Internet of Things applications. In such smart environments, people with smart devices (nodes) can freely self-organize and form self-configuring MANETs to send and forward data packets to a destination over multiple hops via intermediate nodes. However, the energy consumption during routing remains a challenge in such ensemble mobile environments due to the limited battery capacity of mobile devices. This challenging issue has received substantial research attention, necessitating an exhaustive literature search over the variety of academic fields addressing this topic. The main motivation of this paper is to review various power-efficient routing schemes in MANETs that have recently been proposed to reduce the energy consumed when transmitting and receiving packets during active communication. Accordingly, these protocols are classified into six categories: (1) link state-based, (2) source-initiated-based, (3) transmission power control-based, (4) load-balancing-based, (5) location-based and (6) multicast-based routing approaches. The review covers various state-of-the-art protocols for each category and highlights their operation concepts, design challenges and key features. In addition, the various protocols are compared with emphasis on the merits and drawbacks as well as the considered metrics of each scheme. Finally, we provide a conclusion and suggest potential directions for future research in the field.