Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks

Abstract

Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax, the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar, the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar.The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work.It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy efficiency than the choice of the mobility radius of the sink. Moreover, for small values of the duty cycle, a static sink turns out to be optimal in terms of both Emax and Ebar. For larger values of the duty cycle, a mobile sink has advantages over a static sink, especially in terms of Emax. These insights into the basic interrelationship between duty cycle value and mobility radius of a mobile sink are relevant for energy efficient operation of homogeneous WSNs beyond our model scenario.

Using Mobile Data Collectors to Enhance Energy Efficiency a nd Reliability in Delay Tolerant Wireless Sensor Networks

“…In some aspects, this is similar to using several static sinks. However, using several static sinks requires additional global communication for collecting all of the data at a single final point [16,17].…”

“…All of which have consequences with respect to energy efficiency and data collection strategies. In the following discussion, we summarize some proposed solutions for each type of mobility [17,18]. This paper basically classifies and evaluates the mobility metrics into two categories-direct mobility metrics and derived mobility metrics.…”

Ant Colony Optimization Approaches in Wireless Sensor Network: Performance Evaluation

“…Sensor nodes in WSN have very limited abilities in terms of energy, memory, computational power and communication capacity (Sendra et al, 2011;Khan et al, 2013). In order to preserve the energy, the data aggregation technique is introduced.…”

Time Efficient Data Collection With Mobile Sink and vMIMO Technique in Wireless Sensor Networks

“…Recently, mobile sinks are proposed and explored as an alternative solution to achieve load balancing and uniform distribution of energy consumption in sensor networks [4][5][6][7]. As the sink moves, hotspot nodes change and thus the high energy consumption zones around sinks shift.…”