Cooperation in wireless multihop networks remains a significant research problem to be addressed as a node's selfishness can cause communication failure. Incentive mechanisms in the form of reputation or credit rewards have been proposed to stimulate nodes to cooperate. Complementing each other, a hybrid of the two types of schemes has been proposed to improve efficiency in mitigating selfishness, at the cost of high communication overhead. This paper proposes an alternative to reputation level incentive named Recharge-As-Reward (RAR) mechanism, as an explicit reward to strengthen motivation for nodes to cooperate. RAR is also combined with a Credit-As-Reward (CAR) mechanism that is based on centralized credit-based architecture, which makes our scheme a hybrid incentive mechanism. Through a comparison with another hybrid scheme, we show that RAR/CAR is able to increase nodes' forwarding rates while reducing message/communication overhead by being less reliant on a central agent.

Observations of natural phenomena are considered to be the best information source of spontaneous synchronization. Natural phenomena tend to match wireless sensor network (WSN) responses closely. Such synchronization is vital for the proper coordination of power cycles for energy conservation. A large number of fireflies employ the principle of pulse-coupled oscillators for light flash emission to attract mating partners. With respect to WSNs, the nodes are generally unable to afford packet transmission and reception simultaneously, thus preventing complete network synchronization. This paper presents a literature overview concerning the impact of the deafness problem on clock synchronization in a WSN. Data transmission based on synchronization can also be ensured through the optimization of energy usage periodic data capturing in a WSN. This study serves as a useful information source of clock synchronization to assist WSN researchers and novices in obtaining a better understanding of the impact of the deafness problem on clock synchronization and to enable them to promote effective designs and systems that address this problem.

Dynamic windows implicit geographic forwarding (DWSIGF) routing protocol promises a minimal selection on attacker as a hop node. However, it was tested only on blackhole attack with a single optimal attacker. Thus, a thorough investigation was performed to examine whether the protocol is secure against other routing attacks. This study presents a comprehensive analysis of an impact of blackhole and Sybil attacks on the DWSIGF. The analyses on blackhole attack were carried out on a single and multiple attackers using priority selection, random selection, an optimal relay, non‐optimal relay, with and without clear to send (CTS) rushing attack. While on the other hand, the Sybil attack's analyses were investigated on the impact of single attacker using optimal and non‐optimal relay over increasing traffic loads and growing number of Sybil attackers. The study showed that the DWSIGF promised a superior protection against blackhole/selective forwarding and Sybil attacks with minimum attacker selection and high performance in packet delivery ratio even without inserting any security mechanism in the routing protocol.