A Cost Function for QoS-Aware Routing in Multi-tier Wireless Multimedia Sensor Networks

International audienceWireless Multimedia Sensor Networks (WMSNs) are composed of small devices that are able to capture video or audio information and to transmit it over wireless channels. The development of wireless technologies, such as: WiFi, Bluetooth, Zigbee, and UWB, encourages the emergence of heterogeneous networks. However, only a few existing solutions take into account the constraints of multi-tier and multi-MAC wireless sensor networks. In this paper, we propose a cost function coupled to a new generic (i.e. independent from any MAC protocol) cross-layer routing protocol adapted to multimedia traffic over hierarchical and heterogeneous networks. The goal of our proposed protocol is to dynamically assess the routing process cost and the requirement of the multimedia application in order to ensure a sufficient quality of service (Soft QoS). Furthermore, the cross-layer approach is needed to use the physical and MAC parameters on the routing operation. Simulation results show that our solution is efficient and gives better results than classical protocols

A Heterogeneous Communications Network for Smart Grid by Using the Cost Functions

Smart Grids (SG) is an intelligent power grid in which the different SG node types with different communication requirements communicates different types of information with Control Stations (CS). Radio Access Technologies (RATs) due to its advantages are considered as the main access method to be used in order to have bidirectional data transferring between different node types and CS. Besides, spectrum is a rare source and its demand is increasing significantly. Elaborating a heterogeneous in order to fulfill different SG node types communication requirements effectively, is a challenging issue. To find a method to define desirability value of different RAT to support certain node types based on fitness degree between RAT communication characteristics and node type communication requirements is an appropriate solution. This method is implemented by using a comprehensive Cost Function (CF) including a communication CF (CCF) in combination with Energy CF (ECF). The Key Point Indicators which are used in the CCF are SG node type communication requirements. The existing trade of between Eb/N0 and spectral efficiency is considered as ECF. Based on the achieved CCF and ECF and their tradeoffs, SG node types are assigned to different RATs. The proposed assigning method is sensitive to the SG node types densities. The numerical results are achieved by using MATLAB simulation. The other different outcomes of the research output such as cognitive radio in SG and collectors effect number on data aggregation are discussed as well