A Distributed Adaptive Admission Control Scheme for Multimedia Wireless Mesh Networks <xref ref-type="fn" rid="fn1"/>

Wireless mesh networks (WMNs) have emerged as a key technology for next generation wireless networks and provide a low-cost and convenient solution to the last-mile problem. Security and privacy issues are of paramount importance to WMNs for their wide deployment and for supporting service-oriented applications. Moreover, to support real-time services, WMNs must also be equipped with secure, reliable, and efficient routing protocols. Therefore, a number of research studies have been devoted to privacy-preserving routing protocols in WMNs. However, these studies cannot defend against inside attacks effectively, often take it for granted that every internal node is cooperative and trustworthy, and rarely consider dividing the user privacy information into different categories according to the security requirements. To address these issues, we propose a Privacy-Aware Secure Hybrid Wireless Mesh Protocol (PA-SHWMP), which combines a new dynamic reputation mechanism based on subject logic and uncertainty with the multi-level security technology. PA-SHWMP can defend against the internal attacks caused by compromised nodes and achieve stronger security and privacy protection while maintaining reasonable balances between security and performance. We analyze the PA-SHWMP protocol in terms of security, privacy, and performance. The simulation results show that the packet delivery ratio of the proposed PA-SHWMP becomes better than that of the existing HWMP and SHWMP protocols, when the number of malicious nodes and the percentage of lossy links increase. Moreover, the convergence time of PA-SHWMP is smaller than HWMP and SHWMP with any percentage of malicious mesh routers.

Due to their installation and management simplicity, Wireless Mesh Networks (WMNs) have become a natural way to deliver wireless coverage for local, campus and metropolitan areas. In order to provide backhaul support, it is necessary to enhance the capacity of WMNs. In this paper, a scalable link quality routing protocol for multi-radio WMNs is proposed. We incorporate a local link quality metric and multi-radio support in the OLSR (Optimized Link State Routing) protocol. This simple and scalable approach helps to find shortest paths with better quality. Simulations were conducted and the results showed expressive performance improvements of the proposed protocol over the original OLSR, with a minimum overhead increase. Algorithms, Communication system routing, Computer network performance, Wireless Mesh Networks.

ETXOP: A resource allocation protocol for QoS-sensitive services provisioning in 802.11 networks

A QoS aware routing protocol for Wireless Mesh Networks is studied in this paper, the QoS metrics taken into account are bandwidth in our studies, end to end delay and stability of the routes. The routing metric reflects the maximal available bandwidth of a routing path, which is calculated based on the available bandwidth of mesh nodes with the consideration of the interference caused by the hidden terminals in WMNs. With the help of admission control decision, QRBC uses the routing metric in the route discovery process to find a QoS guarantee route for the real-time applications. The simulation results demonstrate that the QRBC protocol can find a less interfering and bandwidth guaranteed routing path for real-time flows.

Admission control is a key management function in wireless networks, particularly wireless mesh networks (WMNs), in order to support multimedia applications that require quality of service (QoS) guarantees. Even using state of the art schemes to provide QoS, if the amount of traffic in the network is allowed to increase in an uncontrolled manner, network performance will deteriorate significantly degrading the QoS for all network traffic. With admission control, a new flow is admitted only if the QoS requirements of all flows in the network still can be met after the new flow begins. This paper introduces a distributed admission control scheme, called RCAC (routing on cliques admission control) for WMNs. We propose an analytical model that enables computing the appropriate admission ratio to guarantee that the loss rate in the network does not exceed a target value; the model also allows computing end-to-end delay necessary to process flow requests with delay constraints. RCAC achieves scalability since it partitions the network into cliques; only clique heads are involved in the admission control procedure. Simulations, using ns-2, demonstrate that RCAC accepts new incoming flows only when the network target loss rate and end-to-end delay are satisfied and maintains relatively high resource utilization in a dynamic traffic load environment.

Nowadays there are inexpensive WiFi devices that have fostered the deployment of wireless communities. Well known routing protocols used in the Internet do not fit well to time varying characteristic of wireless networks. This has motivated an intensive research on routing protocols for wireless mesh networks. At this time there are a number of mature and stable implementations that are being deployed in production networks. In this paper we focus on the experimental evaluation of a production Wireless Mesh network being deployed in a testbed at Universitat Politecnica de Catalunya (UPC) and a quarter of the city of Barcelona, Spain. To our best knowledge, this is the first paper where a production community wireless network using 802.11an is analyzed.

Wireless mesh networks is a decentralized networking technology that is currently being adapted to connect peer-to-peer clients and large-scale backbone networks. Nodes are designed to act as repeaters allowing communication or very large distances. Robustness is another characteristic of wireless mesh networks, partly due to its decentralized nature which removes a central point of failure. Due to its complex nature, a number of issues are still under research. Broadband communication such as WLAN and UWB are ideal for transmission of mesh data due to their high speed. Researches in the PHY layer have come up with using multi-channel and multi-transceiver technology is being studied to improve the capacity of mesh networks. Routing protocols are also a vital research in mesh networks. Distributed routing is needed which can find the optimized path in a widely decentralized mesh network. Also, with the implementation of new PHY technology, existing routing protocols need to be revised to exploit the advantages of new the new PHY. This paper aims to improve existing protocols for wireless mesh networks and wireless adhoc networks in order to take advantage of the properties of multi-channel technology.

The increasing demand of multimedia applications requires a new conduct of routing protocols for Wireless Mesh Networks (WMN). It is necessary to support the minimum requirements for Quality of Service (QoS). In this work we propose an extension to the proactive Optimized Link State Routing (OLSR) protocol that differentiates the data traffic and multimedia traffic, in order to provide quality of service and support to applications which use TCP as their transport protocol. The proposal performance, called OLSR Dynamic Choice (OLSR-DC), is evaluated using the Network Simulator

Nowadays wireless systems changing our life experience, allowing ubiquitous communications, attracting new users, and supporting new applications, such as video streaming, VoIP, Mobile TV and other kind of multimedia applications. The combination of wireless networks and multimedia content distribution requires a new behavior of routing protocols for Wireless Mesh Networks (WMNs). Hence, new protocols must be developed to increase the user perception and optimize the usage of network resources. This paper presents a variation of the WMN routing protocol Optimized Link State Routing (OLSR), to achieve QoS and QoE requirements for multimedia applications. It is based on the dynamic choice of metrics and in a Fuzzy Link Cost (FLC) to determine the best routes for multimedia packets. Simulations were carried out to show the benefits of the proposed metric regarding user experience compared to existing versions of OLSR.KeywordsWireless Mesh NetworksQoSQoEFuzzy Logic

Admission control is one of the most crucial mechanisms for providing QoS for real time traffic in MANET. The function of admission control is to admit those flows whose QoS requirements can be satisfied. However, the change of topology due to mobility and false admission control makes the stability of the quality of service of the admitted flows a challenge. In this paper, we propose Flow-based Admission Control and QoS Maintenance protocol (FAC-QM) for real-time traffic. This is to provide QoS for the real time traffic in terms of throughput and minimize the effect of QoS violation and link failure on the throughputs of the admitted flows. The proposed protocol is implemented over AODV. The accepting or rejecting of any new flow depends on achieving the required throughput in each node on the path. The violation of the QoS is detected based on the flow stability factor in the network. The link failure is repaired locally based on QoS information resident on the node during the whole session. Through simulation by NS2 simulator, the results show that the protocol improves the performance of the admitted real time flows in terms of throughput, end to end delay and packet loss ratio.

Resource allocation and admission control algorithm based on non-cooperation game in wireless mesh networks

Wireless mesh networks (WMNs) are gaining significant momentum as a promising technology for the next-coming state-of-the-art wireless networking. Among many factors, the performance of WMNs would be largely affected by the properness of the deployed routing protocols and the efficient usage of wireless resources. Routing protocols are required to well capture WMNs' features while wireless channels should be used efficiently in order to accommodate high amount of traffics over the mesh backbone. Recently, a Tree-based Routing (TBR) protocol become a popular state-of-the-art proactive routing protocol and its tree-based broadcasting become an often used technique. Though TBR protocol is well-suited for WMNs' architecture and the skewed nature of traffic toward the root, the protocol in its current form faces issues which has to be addressed. Specifically, when some or all nodes are equipped with multiple radios, to reduce collision and co-channel interference, not only the parent-child relationship but also the sibling relationship need to be constructed by the TBR protocol in the multi-channel WMNs. In this paper, we propose a hybrid tree-based protocol for concurrent routing and channel assignment over WMNs. The protocol makes use of sibling links to mitigate the aforementioned shortcomings of TBR protocol. Moreover, in order to address high backbone traffic, the protocol integrates a receiver-based channel assignment scheme. The protocol efficiently deploys the parent-child topological relationships of nodes to enhance efficiency of broadcast transmissions over receiver-based multi-channel WMNs. Simulation results over NS-2 network simulator reveal that our proposed hybrid tree-based protocol achieves much higher performance than the utilization of the original receiver-based CA and TBR protocol.

We propose a control method for high quality and highly effective video multicasting to satisfy various QoS requirements of clients. Our method employs an MPEG-2 hierarchical coding technique for that purpose. Further, flow aggregation is introduced to achieve application level QoS (Quality of Service) guarantees. Our method can guarantee the network level QoS only if underlying networks provide some guaranteed services as in ATM, Intserv and Diffserv. We investigate the effectiveness and applicability of our method on networks with various QoS guarantees.

While more and more real-time applications are expected in wireless mesh networks (WMNs), Quality of Service (QoS) provision is of foremost importance in order to support such real-time applications. In this paper, we proposed QRBC (QoS Routing protocol with Bandwidth Consideration), a protocol using a bandwidth guaranteed routing metric towards enhancing QoS support for the real-time applications in WMNs. The routing metric accurately reflects the available bandwidth of a route with the consideration of the interference caused by the hidden terminals in WMNs. During the route discovery process of QRBC, the routing metric is updated and used with the cooperation of admission control decision to find a bandwidth guaranteed routing path. Simulation results demonstrate that QRBC can find a less interfering and bandwidth guaranteed routing path for real-time applications by avoiding “hot-spots” with severe interference, which enhances the performance of such applications significantly.

SUMMARYWith the development of wireless mesh networks (WMNs), fault diagnosis in WMNs is becoming a very challenging task. In this paper, a two‐level scheme for fault diagnosis in WMNs is presented. We partition the network into a two‐level topology architecture where level 1 is composed of mesh clients and level 2 consists of mesh routers. A new comparison approach is introduced to diagnose the two levels. On the basis of the new comparison approach, every node in WMNs can be diagnosed either as fault‐free or faulty. Our protocol assumes that the WMN's topology may change during the testing phase and utilize the shortest path spanning tree, which is constructed along with the process of fault diagnosis, to disseminate local messages and global messages in WMNs. The proposed model is only for static fault circumstances. We provide the analysis of correctness, communication complexity, and time complexity of our protocol, and the comparison between our protocol and others through both theoretical proof and practical simulation. The analysis shows that our model has significant advantages over other existing models. Copyright © 2012 John Wiley & Sons, Ltd.