Project Title: Load Balancing Routing for Large-Scale Wireless Networks
Sponsor: UNC-Charlotte Faculty Research Grant (FRG)
Duration: January 2008 - May 2009
Investigators: Dr. Yu Wang (PI)
Students: Fan Li, Siyuan Chen
With the development of wireless technology and availability of cheap wireless devices, large-scale wireless networks are becoming a reality. Routing is one of the key topics in wireless networks which determine the route or path taken by packets as they flow from a source to a destination. Various routing protocols have been proposed and studied in literature. Most of the existing routing protocols are based on the shortest path algorithm where the packets are traveled via the shortest distance path between the source and the destination. Taking the shortest path can achieve smallest delay and shortest traveled distance, however it may lead to uneven distribution of traffic load in a network. As observed in previous work, under uniform communication scenario, the center of a network becomes crowded, since shortest paths go through the center rather than through the periphery of a network. This is also the observation from metropolitan transportation system where downtown area is always the hot spot for traffic and congestion. This crowded center effect causes extraordinary problems especially within large-scale wireless networks. To address the uneven load distribution problem of current routing protocols and eliminate the crowded center effect, in this project, we focus on the design of new load balancing routing protocols for large-scale wireless networks.
Develop efficient routing protocols and algorithms to balance traffic load in large-scale wireless networks, which can optimize load distribution of the network while guaranteeing the performance of communications in a highly dynamic environment.
We are studing the following load balancing routing problems in large-scale wireless networks, which aims to address the uneven load distribution problem of current routing protocols and eliminate the crowded center effect :
Design new load balancing routing protocols for two-dimensional wireless networks based on stereographic projection techniques.
Provide the theoretical analysis of the performances of the proposed methods using graph theory and projective geometry analysis.
Design new load balancing routing protocols for three-dimensional wireless networks.
Stereographic Projection Method: Imagine that nodes are deployed on the surface of a three dimensional sphere instead of a planar shape. If nodes communicate only on the sphere surface and the communication is uniform, the crowded center effect vanishes due to symmetry (there is no such thing as a "center" on the sphere surface). Thus, a natural idea is to find a way to map the two-dimensional network on a 3D sphere and route greedily on those virtual coordinates. In projective geometry, the stereographic projection is a certain mapping (or function) that projects a sphere onto a plane.
Research Findings and Outcomes: