Traffic-Adapted Load Balancing in Sensor Networks Employing Geographic Routing

Abstract

Load balancing is an important issue in sensor networks especially when geographic routing is employed since in this case, a node often forwards its packet to a certain neighbor. As a result, nodes located at the intersection of multiple routes to the base station tend to be placed under great stress and drain its energy quickly. This can potentially lead to disconnection of the network. Current solutions to this problem fail to take the traffic load at nodes into account and can potentially forward packets toward the heavy trafficked region and create collisions and network congestion. In this paper, we propose a load balancing scheme, namely Traffic Adaptive Routing (TAR), which works with any geographic routing protocols. TAR relieves the aforementioned issues by having a node evaluate the level of traffic at its neighbors and decide where to forward the packet based on the distance to the base station and the traffic load. Through simulations, we have shown that when compared against the existing load balancing techniques, TAR is able to deliver 10% more packets to the base station using approximately the same amount of energy due to the reduction of the collisions and congestion.

A scalable multi-sink gradient-based routing protocol for traffic load balancing

“…As an energy consumption model, we employed the energy model used in [12]. The packet transmission and reception energy consumption were set to 50 nJ * l + 100 pJ/bit/m 2 * l * d 2 and 50 nJ * l, respectively, where each of l-bit packets is transmitted at a distance d. From the assumption of a fixed transmission range, d was set to 30 m. In addition, due to the broad-cast nature of the wireless channel, a sender's neighbor nodes overhear its transmissions even if they are not its intended receivers.…”

“…Figure 9 depicts PDR values at the time when the network lifetime is terminated. The unbalance of network traffic load causes a channel around overloaded regions to be congested, which leads to the increase in packet loss due to collisions and buffer overflow [12,17]. Hence, since SPR lacks the load-balancing functionality, it shows lower PDR performance than the other load-balancing protocols (i.e., GLOBAL, CPL).…”

“…Considering the remaining energy or the queue length of the forwarder's 1-hop neighbor nodes, the neighbor nodes with heavy traffic load or low residual energy are prevented from being selected as a next forwarder, based on their customized forwarding rules. In these protocols, however, sensor nodes cannot spread the traffic evenly since there is no way for them to get the information about heavily loaded region (i.e., hot spot regions near the sinks) several hops away from them [12].…”

Load Balancing in Wireless Sensor Networks using Kirchhoff's Voltage Law

“…The problem has appeared both in the general wireless network literature [7] and in the WSN literature [8], [9], [10].…”

“…[9] presents an algorithm that starts from the root and progressively adds nodes so as to keep the tree as balanced as possible. In [8], [10], the tree is substituted with a mesh (while still assuming a single sink).…”