Since energy consumption is one of the main challenges in wireless sensors networks performance and efficiency, this paper discusses and proposes a mathematical model that compromises these two crucial parameters. In addition, number of clusters, cluster size, and number of cluster heads all contribute in network robustness; they have been studied and manipulated in details. This paper suggests a mathematical model that calculates and finds the optimal cluster size and number of sensors for Low Energy Adaptive Cluster Hierarchy (LEACH) protocol. Wireless Sensor Network (WSN) is a network includes devices (sensors) for collecting data by sensing the field. Clustering is one of the simplest strategies used to minimize the power lost in WSNs. Its performance is affected by network area and number of sensors. The cluster head is elected based on traditional Low Energy Adaptive Cluster Hierarchy protocol. The optimal cluster number is detected based on the condition of the LEACH delivery ratio. NS2.35 and MannaSim framework are applied for validating the proposed model. The results show that the proposed model is approved at different areas and nodes density. The optimal cluster size obtained by the proposed model is equivalent to optimal clusters number for 100 % delivery ratio of LEACH.

The opportunistic network paradigm has no stable path and synchronous end-to-end communication. In such an environment, the bundle originator or the infected node stores a redundant copy in its buffer. This copy is replicated to other encountered susceptible nodes based on routing decision. The performance of the employed routing is based on delivering the bundle through optimal paths. This paper improves the decision criteria of the PRoPHET routing. This enhancement is achieved by employing the bundle probability and the optimal path hops. We have called our proposed improved PRoPHET utilizing Optimal Path Hops (PRoPHET-OPH). The evaluating of its performance is conducted by delivery probability, mean delay and percentage of overhead. Numerical findings exhibit that the PRoPHET-OPH performance is superior compared with the traditional PRoPHET.

Mobile ad-hoc networks (MANETs) are without any infrastructure and consists only of equal peers. This paper presents an empirical tests for MANET routing protocols. The testbed based on Linux platform installed in mobile computers. Some parameters are analyzed such as movement speed and the number of hops which impact on routing performance. The testbed consists of several Raspberry Pis (RPis) without the need for any central master device. For making the RPis mobile and independent of any fixed power sockets, each of them is powered by a battery. On the other hand, for the evaluation of the testbed, two routing protocols are chosen. The first protocol is called BABEL, which considered as a distance vector routing algorithm. The other one, the Optimized Link State Routing Protocol (OLSR) which considered as proactive routing protocol. The use case was a multi-hop download of files with different size. The aim is to evaluate how multiple hops influence the bandwidth and delay. The results show that OLSR performs better regarding the throughput. But Babel has less delay and faster regarding convergence.