Virtual grid-based rendezvous point and sojourn location selection for energy and delay efficient data acquisition in wireless sensor networks with mobile sink

Rendezvous points (RPs) based data acquisition methods are widely accepted as the solution for data acquisition delay/latency problem. In these methods, RPs are a subset of sensor nodes, that store the data of other sensor nodes and forward them to the mobile sink (MS). The locations where MS must arrive to acquire data from RPs are called as sojourn locations. RPs are prone to exhaust energy due to the additional activity of forwarding the data and create the energy-hole problem. Although re-selection of RPs mitigates the energy-hole problem, however, it increases the control overhead due to topology reconstruction. Among the various type of RPs selection methods, the grid-based RP selection is a straight-forward and one-time topology construction method. In the existing grid-based RP selection, grid cell coordinators serve as RPs, which are also considered as sojourn locations of MS, and it increases data acquisition latency. This paper proposes a new virtual grid-based rendezvous point and sojourn location selection (VGRSS) method for energy and delay efficient data acquisition that exploits the virtual-grid and constructs an energy efficient search region inside each grid cell. Afterward, it adopts fuzzy interference system to select/re-select RPs from this region. Additionally, the distributed re-selection of RPs for each grid cell reduces between 10 and 30.84% reconstruction overhead of the entire topology. Along with this, the selection of intersection points of four grid cells as sojourn locations of MS decreases between 14 and 31.25% the data acquisition latency in VGRSS. Through simulation results, this paper demonstrates that the VGRSS is efficient over state-of-the-art in terms of energy consumption, control overhead, network lifetime and data acquisition latency.