TITLE:
Energy-Efficient Methods for Highly Correlated Spatio-Temporal Environments in Wireless Sensor Network Communications
AUTHORS:
Mohammad Abdul Azim, Zeyar Aung, Sofiane Moad, Nizar Bouabdallah, Mario E. Rivero-Angeles, Israel Leyva-Mayorga
KEYWORDS:
Wireless Sensor Networks, Aggregation, Continuous-Monitoring, Event Driven Reporting, Data Compression, Clustering
JOURNAL NAME:
Wireless Sensor Network,
Vol.6 No.5,
May
29,
2014
ABSTRACT: Continuous-monitoring (CM)
of natural phenomenon is one of the major streams of applications in wireless
sensor networks (WSNs), where aggregation and clustering techniques are
beneficial as correlation dominates in both spatial and temporal aspects of
sensed phenomenon. Conversely, in Event Driven Reporting (EDR), the efficient
transmission of sensitive data related to some predefined alarm cases is of
major importance. As such, reporting latency is a more important performance
parameter. However, in some applications, the transmission of both CM and EDR
data is encouraged or even required. For either CM or EDR applications, system
performance can be greatly improved when both the number of packets to be
transmitted as well as the packet size is reduced. This is especially true for
highly dense sensor networks where many nodes detect the same values for the
sensed phenomenon. Building on this, this paper focuses on studying and
proposing compression techniques to improve the system performance in terms of
energy consumption and reporting latency in both CM and EDR applications.
Furthermore, we extend our analysis to hybrid networks where CM and EDR are
required simultaneously. Specifically, this paper presents a simple aggregation
technique named smart aggregation (SAG) for the CM applications and an event
driven scheme named compression cluster scheme in spatial correlated region
(CC_SCR). The proposed SAG exploits both spatial and temporal correlations
where CC_SCR exploits the spatial correlation of such networks by data
compression. Rationalizing the developments is attained by simulations that
compare energy efficiency of the proposed SAG with k-hop aggregation and CM based event driven reporting (CMEDR)
schemes. Results of CC_SCR show that the technique may reduce the energy
consumption drastically. In some specific cases the reduction becomes more
than 10 times compared to a classical clustering scheme. Two different strategies
for the transmission of event reports through the CM infrastructure are
incorporated: PER and NPER protocols. Both strategies take advantage of the
cluster-based architecture which assigns a TDMA schedule for the CM data
transmission while using NP/CSMA for the transmission of the event information.
Consequently, no extra energy is consumed for separate event clusters. As such,
the number of packets to be transmitted is greatly reduced.