Aligned Virtual Coordinates for Greedy Routing in WSNs

Abstract

Abstract-Geographic routing provides relatively good performance at a much lower overhead than conventional routing protocols such as AODV. However, the performance of these protocols is impacted by physical voids, and localization errors. Accordingly, virtual coordinate systems (VCS) were proposed as an alternative approach that is resilient to localization errors and that naturally routes around physical voids. However, we show that VCS is vulnerable to different forms of the void problem and the performance of greedy routing on VCS is worse than that of geographic forwarding. We show that these anomalies are due to the integral nature of VCS, which causes quantization noise in the estimate of connectivity and node location. We propose an aligned virtual coordinate system (AVCS) on which the greedy routing success can be significantly improved. With our approach, and for the first time, we show that greedy routing on VCS out-performs that on physical coordinate systems even in the absence of localization errors. We compare AVCS against some of the most popular geographical routing protocols both on physical coordinate system and the virtual coordinate systems and show that AVCS significantly improves performance over the best known solutions.

Geo-logical routing in wireless sensor networks

“…Aligned Virtual Coordinate System (AVCS) [14] modifies the node's VC by replacing it with the average of its and neighboring nodes' coordinates as a solution to logical voids. Spanning Path Virtual Coordinate System (SPVCS) in [15] uses a single anchor, and coordinates are created based on depth-first search algorithm starting from a root node.…”

“…In VCR, a subset of nodes is selected as anchors [3], [4], [6], [14], and each node is characterized by VC vector with the minimum hop distances to each of the anchors. Like GR, most VC based routing schemes also use Greedy Forwarding (GF), where a packet is forwarded to the neighbor that is closest to the destination.…”

Greedy Hop Distance Routing Using Tree Recovery on Wireless Ad Hoc and Sensor Networks

“…The LER [10] protocol provides a robust landmark selection algorithm by selecting a random landmark at each round in order to counter the distortions generated in previous rounds. As the hop count based coordinate systems generally introduce large quantization errors, the Aligned-VCS [11] …”

Dimension Reduction of Virtual Coordinate Systems in Wireless Sensor Networks

“…Physical domain routing relies on the physical (geographic) position information for routing, e.g., as in Geometrical routing [1]. Virtual domain (or logical) routing is based on a set of virtual coordinates that capture the position and route information, e.g., hierarchical/clustering schemes [1], and Virtual Coordinate (VC) based routing [2], [3], [5], [6], [8][9][10][11]. The focus of this work is to reduce dimensionality of Virtual Coordinate Systems (VCSs), and thus enhance the energy efficiency without degrading the routability.…”

“…Most of the VCR schemes [2], [3], [8][9][10][11] use Greedy Forwarding (GF) combined with a back-tracking algorithm. In GF, a packet is simply forwarded to a neighbor that is closer to the destination than the node holding the packet.…”