In this work, we consider the problem of reliable data
dissemination in mobile wireless sensor networks. We propose a
Localized Gradient Management Algorithm (LGMA) that operates as a
mobility sub-module for data-centric protocols. LGMA allows sensor
nodes more responsibility in keeping the gradients in their
neighborhood operational by using local information deduced from
their environment. Performance comparisons of LGMA versus a
Sink-Oriented data dissemination protocol with location updates
show that LGMA provides considerably higher event delivery ratio
under multiple scenarios and rates of sink and network mobility
while incurring much lower communication overhead and enabling
faster gradient repairs.
Data-centric protocols have been proposed as an alternative to traditional address-centric protocols for sensor networks mainly due to their inherent redundancy of data traffic. In this paper, we compare the performance of a data-centric Directed Diffusion based approach to that of a traditional address-centric routing protocol in
a target tracking sensor network. We show that the data-centric approach provides significant improvement in certain metrics directly related to performance at the application level. We also examine some mobility issues related to the data-centric approach, and describe approaches to deal with them.