Hop distance fairness for wireless mesh network based on queue management

Wireless mesh network （WMN） is a new multi-hop network for broadband accessing to intemet. However, there exists a server unfairness problem based on different hop distances in WMN. To solve this problem, the unfairness issue was analyzed in test-bed experiment and NS2 simulation. A dynamic queue management scheme E-QMMN was proposed, which allocates the queue buffer according to the hop distance of every flow. The experimental results show that the proposed scheme can not only increase the hop distance fairness of the legacy scheme at most 50%, but also reduce the average round trip time at least 29% in congested WMN environments.

Location Prediction for Improved Human Safety at Complex Environments

In underground operation,primary consideration is safety.In recent decades,for minimizing accident and for preventing major economic losses and casualties,wireless sensors are used by various large mineral countries through early warning.The Improved DV-Hop Localization Algorithm(IDVHLA)is used in existing works for doing this.However,accurate anchor node detection is impossible in existing works with the malicious nodes presence,where there won’t be any accurate sharing of anchor node’s location information.In case of emergency situation,faster communication is a highly complex one.A technique calledModified Distance Vector Hop based Multipath Routing Protocol(MDVHMRP)is introduced in this proposed research work for resolving this.In this work,to detect anchor node position,a Modified Distance Vector Hop technique is introduced.This research work considers time taken and session time for computing neighbour node’s presence in addition to hop count values.Malicious nodes presence can be avoided by considering session time in neighbour node presence detection.The alert message are send by people in emergency crisis to sever in initial condition.Then Dynamic Source Routing(DSR)routing protocol is used for doing immediate route path selection.In case of route path failure,for ensuring uninterrupted communication and faster communication,this work introduces amulti path routing.Themodified distance vector hop technique is used for predicting anchor node location information and predicted information will be transmitted.In NS2 simulation environment,overall evaluation of this research work is carried out.When compared with available techniques,localization accuracy is enhanced by proposed technique as proven in experimental results.

Anchor Selection for Topology Inference and Routing in Wireless Sensor Networks

Anchor-based ad-hoc networks utilize hop measurements to generate a virtual coordinate system for topology inference and routing applications.A common problem with such coordinate system is its sensitivity to anchor placement.We present a general formulation to the anchor node selection problem.Then,we relax the optimization problem by deriving an upper-bound of the objective function.We finally propose an iterative algorithm that consists in choosing additional anchor nodes based on the connectivity information provided by the current anchor set.Numerical simulations indicate that our anchor selection method is robust to missing measurements and improves network topology inference and routing performance.