In rural areas in Africa, the topographical conditions vary, including hilly areas or flat open areas with bushes, trees and vegetation. In some cases, road and infrastructure conditions are exceedingly poor, making it challenging and costly to provide necessary maintenance and support to communication networks. When a node goes offline the remaining nodes must be able to re-establish links with each other and maintain connectivity. The routing protocol must discover an alternative shortest path route and use this path to deliver the data. The maintenance time can be slow and it might take days to attend to the faulty node in a rural area. Due to this, the network must be able to operate for long periods with the faulty node(s) and provide the best possible Quality of Service (QoS). In the past few years, Wireless Mesh Networks (WMNs) have attracted an increase in research and use due to their attractive characteristics, which include low deployment cost, a low cost option to extend network coverage and ease of maintenance due to their self healing properties. In WMNs, with an increase in scalability, the throughput of the network tends to decrease. In this paper, we carried out a performance analysis for failing node scenarios for rural telemetry networks using three protocols, namely OLSR (a proactive protocol), DSR (a reactive protocol) and HWMP (a hybrid protocol). The performance analysis of these protocols was carried out using three backhaul network topology scenarios. The simulation results were obtained using OMNET++ and the INETMANET framework. Performance metrics used for the analysis and study were packet loss and end-to-end latency as these are major factors considered for providing guaranteed Quality of Service (QoS).

There has been an escalation in deployment and research of wireless mesh networks by both the business community and academia in the last few years. Their attractive characteristics include low deployment cost, a low-cost option to extend network coverage and ease of maintenance due to their self-healing properties. Multiple routes exist between the sender and receiver nodes because of the mesh layout that ensures network connectivity even when node or link failures occur. Recent advances among others include routing metrics, optimum routing, security, scheduling, cross-layer designs and physical layer techniques. However, there are still challenges in wireless mesh networks as discussed in this paper that need to be addressed. Crosslayer design allows information from adjacent and non-adjacent layers to be used at a particular layer for performance improvement. This paper presents a survey of cross-layer protocol design approaches applied to the IEEE 802.11 standards for wireless multi-hop mesh networks that have been proposed over the last few years for improved performance. We summarize the current research efforts in cross-layer protocol design using the IEEE 802.11 standard in identifying unsolved issues that are a promising avenue to further research.Section 3 presents some WMN protocol and design challenges that arise because of the architecture of WMNs. Section 4 gives a brief overview of CLD principles and presents the different cross-layer signalling architectures found in research to utilize information from different layers. The signalling architectures show that information can be used directly by non-adjacent or adjacent layers; by the use of a central database or server and any layer can use information from it; by interlayer signalling where the information passes through all layers and any layer can use it; and finally, by the use of information from a layer at a different node.Section 5 presents the survey on the application of CLD to WMNs to address some of the challenges in WMNs. The proposed cross-layer solutions are classified according to the cross-layer signalling architectures presented in Section 4. Many solutions are classified as using the networkwide cross-layer signalling architecture that includes among others routing metrics and soft computing techniques used in multi-path routing. Table III presents an individual summary of these articles. The table also presents the essence of the individual techniques. Table IV presents a comparison between the different approaches in terms of the modifications made to the layer architecture by these different cross-layer applications.The majority of the applications of CLD have been in the area of routing. In Section 6, we further assess the suitability of the proposed cross-layer protocols for use in three proposed use case scenarios. The comparisons, classifications and suitability by analysing the cross-layer protocol designing approaches are solely the views of the authors in this survey paper.Section 7 presents some future research directi...

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