Coverage Characteristics of Symmetric Topologies for Pervasive Sensor Networks

The success of pervasive computing environments comprising ubiquitous loco-dynamic sensing devices is very dependent upon the coverage characteristics (CCs) of the network topology. These characteristics include blanket coverage, network density, affects on surrounding environments and intra-sensor coverage overlaps. This paper presents a systematic mathematical model to quantitatively investigate the effects of CCs and provides a comparison with other well used topologies e.g. hexagonal, triangular and square grid. The paper uses connectivity, density saturation, conflict regions and effectiveness of the topology as quality parameters in simulation studies for a disaster recovery network in various irregular terrains. Numerical as well as simulation results confirm the improved performance of hexagonal topology (HT) in terms of the above mentioned quality parameters which can be used to tune the network design to ensure the required QoS throughout the life of the network

Reducing Power Consumption in Hexagonal Wireless Sensor Networks Using Efficient Routing Protocols

Power consumption and network lifetime are vital issues in wireless sensor network (WSN) design. This motivated us to find innovative mechanisms that help in reducing energy consumption and prolonging the lifetime of such networks. In this paper, we propose a hexagonal model for WSNs to reduce power consumption when sending data from sensor nodes to cluster heads or the sink. Four models are proposed for cluster head positioning and the results were compared with well-known models such as Power Efficient Gathering In Sensor Information Systems (PEGASIS) and Low-Energy Adaptive Clustering Hierarchy (LEACH). The results showed that the proposed models reduced WSN power consumption and network lifetime

Self organising cloud cells: a resource efficient network densification strategy

Network densification is envisioned as the key enabler for 2020 vision that requires cellular systems to grow in capacity by hundreds of times to cope with unprecedented traffic growth trends being witnessed since advent of broadband on the move. However, increased energy consumption and complex mobility management associated with network densifications remain as the two main challenges to be addressed before further network densification can be exploited on a wide scale. In the wake of these challenges, this paper proposes and evaluates a novel dense network deployment strategy for increasing the capacity of future cellular systems without sacrificing energy efficiency and compromising mobility performance. Our deployment architecture consists of smart small cells, called cloud nodes, which provide data coverage to individual users on a demand bases while taking into account the spatial and temporal dynamics of user mobility and traffic. The decision to activate the cloud nodes, such that certain performance objectives at system level are targeted, is carried out by the overlaying macrocell based on a fuzzy-logic framework. We also compare the proposed architecture with conventional macrocell only deployment and pure microcell-based dense deployment in terms of blocking probability, handover probability and energy efficiency and discuss and quantify the trade-offs therein