IEEE 802.11s Mesh Deterministic Access : Design and analysis

IEEE 802.11s is a draft IEEE 802.11 amendment for mesh networking, defining how wireless devices can interconnect to create an ad-hoc network. It includes some mesh-specific optional MAC enhancements like Mesh Deterministic Access, Common Channel Framework, Intra-mesh Congestion Control and Power Management. Mesh Deterministic Access (MDA) is an access method that allows MPs to access the channel at selected times (called MDAOPs) with lower contention than would otherwise be possible. In this work we study Mesh Deterministic Access (MDA) feature. Specifically: we implement 802.11s in ns-2 simulator and evaluate performance comparing results with those obtained with DCF. We also propose an improvement called Dynamic Relocation. Dynamic Relocation permits to overcome MDA limits by reallocating MDAOPs basing on statistics collected during transmission times. The effectiveness of MDA improved with Dynamic Relocation in a scenario with realistic traffic is then confirmed via a simulation analysis

Performance Evaluation of Multi-Channel Wireless Mesh Networks with Embedded Systems

Many commercial wireless mesh network (WMN) products are available in the marketplace with their own proprietary standards, but interoperability among the different vendors is not possible. Open source communities have their own WMN implementation in accordance with the IEEE 802.11s draft standard, Linux open80211s project and FreeBSD WMN implementation. While some studies have focused on the test bed of WMNs based on the open80211s project, none are based on the FreeBSD. In this paper, we built an embedded system using the FreeBSD WMN implementation that utilizes two channels and evaluated its performance. This implementation allows the legacy system to connect to the WMN independent of the type of platform and distributes the load between the two non-overlapping channels. One channel is used for the backhaul connection and the other one is used to connect to the stations to wireless mesh network. By using the power efficient 802.11 technology, this device can also be used as a gateway for the wireless sensor network (WSN)

802.11s QoS Routing for Telemedicine Service

The merits of 802.11s as the wireless mesh network standard provide a lowcost and high independent scalability telemedicine infrastructure. However,challenges in degradation of performance as hops increase and the absent of Quality of Service (QoS) provision need to be resolved. The reliability and timely manner are the important factor for successful telemedicine service. This research investigates the use of 802.11s for telemedicine services. A new model of 802.11s based telemedicine infrastructure has been developed for this purpose. A non deterministic polynomial path selection is proposed to provide end-to-end QoS provisioning in 802.11s. A multi-metric called QoS Price metric is proposed as measurement of link quality. The QoS Price is derived from multi layers values that reflect telemedicine traffic requirement and the resource availability of the network. The proposed solution has modified the path management of 802.11s and added resource allocation in distributed scheme.DOI:http://dx.doi.org/10.11591/ijece.v4i2.559

Emergency Prenatal Telemonitoring System in Wireless Mesh Network

Telemedicine promises a great opportunity for health care service improvement. However, it has several issues for its implementation in certain area. They include communication service quality, infrastructure and operational cost. Since Wireless Mesh Network (WMN) is designed to reduce the infrastructure cost and operational cost, an investigation of network performance for implementation of telemedicine is required.  In this paper, a simulation to investigate the wireless mesh network quality of service.  Using network simulator 2, The QoS performance analysis was performed in different routing protocol scenarios of proposed system. It showed that OLSR protocol for Mesh Network maintained the time transfer of the EPT data. The field testing of the proposed system to measure the distance with various time has already been done.  The infrastructure has been also implemented using low cost 5.8 GHz transceiver for backhauls and low cost 2.4 GHz transceiver for clients.  Test result shows that the low cost telemedicine system is able to do real time communication between patient and medical staff with medical data rate up to 2 Mbps. It shows that telemonitoring system using wireless mesh network can give a low cost application in emergency time with acceptable medical data transfer quality.

Layer 2 Path Selection Protocol for Wireless Mesh Networks with Smart Antennas

In this thesis the possibilities of smart antenna systems in wireless mesh networks are examined. With respect to the individual smart antenna tradeoffs, a routing protocol (Modified HWMP, MHWMP) for IEEE 802.11s mesh networks is presented, that exploits the full range of benefits provided by smart antennas: MHWMP actively switches between the PHY-layer transmission/reception modes (multiplexing, beamforming and diversity) according to the wireless channel conditions. Spatial multiplexing and beamforming are used for unicast data transmissions, while antenna diversity is employed for efficient broadcasts. To adapt to the directional channel environment and to take full benefit of the PHY capabilities, a respective MAC scheme is employed. The presented protocol is tested in extensive simulation and the results are examined.:1 Introduction 2 Wireless Mesh Networks 3 IEEE 802.11s 4 Smart Antenna Concepts 5 State of the Art: Wireless Mesh Networks with Smart Antennas 6 New Concepts 7 System Model 8 Results and Discussion 9 Conclusion and Future Wor

Traffic engineering multi-layer optimization for wireless mesh network transmission a campus network routing protocol transmission performance inhancement

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThe wireless mesh network is a potential network for the future due to its excellent inherent characteristic for dynamic self-healing, self-configuration and self-organization. It also has the advantage of easy interoperability networking and the ability to form multi-linked ad-hoc networks. It has a decentralized topology, is cheap and highly scalable. Furthermore, its ease in deployment and easy maintenance are other inherent networking qualities. These aforementioned qualities of the wireless mesh network bring advantages to transmission capability of heterogeneous networks. However, transmissions in wireless mesh network create comparative performance based challenges such as congestion, load-balancing, scalability over increasing networks and coverage capacity. Consequently, these challenges and problems in the routing and switching of packets in the wireless mesh network routing protocols led to a proposal on the resolution of these failures with a combination algorithm and a management based security for the network and its transmitted packets. There are equally contentious services like reliability of the network and quality of service for real-time multimedia traffic flows with other challenges such as path computation and selection in the wireless mesh network. This thesis is therefore a cumulative proposal to the resolution of the outlined challenges and open research areas posed by using wireless mesh network routing protocol. It advances the resolution of these challenges in the mesh environment using a hybrid optimization – traffic engineering, to increase the effectiveness and the reliability of the network. It also proffers a cumulative resolution of the diverse contributions on wireless mesh network routing protocol and transmission. Adaptation and optimization are carried out on the wireless mesh network designed network using traffic engineering mechanism and technique. The research examines the patterns of mesh packet transmission and evaluates the challenges and failures in the mesh network packet transmission. It develops a solution based algorithm for resolutions and proposes the traffic engineering based solution.. These resultant performances and analysis are usually tested and compared over wireless mesh IEEE802.11n or other older proposed documented solution. This thesis used a carefully designed campus mesh network to show a comparative evaluation of an optimal performance of the mesh nodes and routers over a normal IEE802.11n based wireless domain network to show differentiation by optimization using the created algorithms. Furthermore, the indexes of performance being the metric are used to measure the utility and the reliability, including capacity and throughput at the destination during traffic engineered transmission. In addition, the security of these transmitted data and packets are optimized under a traffic engineered technique. Finally, this thesis offers an understanding to the security contribution using traffic engineering resolution to create a management algorithm for processing and computation of the wireless mesh networks security needs. The results of this thesis confirmed, completed and extended the existing predictions with real measurement

Integration of multimetric path management into 802.11S for telemedicine quality of service provision

The merits of 802.11s as the wireless mesh network standard provide a low cost and high independent scalability telemedicine infrastructure. However, challenges in degradation of performance as hops increase and the absence of Quality of Service (QoS) provision need to be resolved. Reliability and timely manner are important factors for successful telemedicine service. This research investigates the use of 802.11s for telemedicine services. A new model of 802.11s based on telemedicine infrastructure has been developed for this purpose. A non deterministic polynomial path selection is proposed to provide end-to-end QoS provisioning in 802.11s. A multi-metric called QoS Price metric is proposed as measurement of link quality. The QoS Price is derived from multi layers values that reflect telemedicine traffic requirement and resource availability of the network. The proposed solution has modified the path management of 802.11s and added resource allocation in distributed scheme. This modification and resource allocation improvement of 802.11s were given the designation medQoS-802.11s. MedQoS- 802.11s could provide a link guarantee of telemedicine traffic transmission in the selected path. MedQoS-802.11s had been tested using ns3 simulation and real environment testbed. The result has shown that medQoS-802.11s could achieve the traffic guarantee for almost 95% telemedicine traffic with 58% for the resource intensive diagnostic video traffic. It has also shown that the cost of link path overhead is efficient with the transmission overhead having an increment of 6% compared to the original 802.11s. The concurrent connection results for single time transmission shows that medQoS-802.11s has a significant increase of up to 12% traffic than original 802.11s. The testbed results have verified the QoS guarantee of the intended telemedicine traffic per transmission time. In summary, the reliability and time guarantee of medQoS has highly improved 802.11s to transmit telemedicine traffic

Mesh networks for handheld mobile devices

Mesh communications emerge today as a very popular networking solution. Mesh networks have a decentralized and multihop design. These characteristics arouse interest in research for relevant novel features, such as cooperation among nodes, distribution of tasks, scalability, communication with limited infrastructure support, and the support of mobile devices as mesh nodes. In addition to the inexistence of a solution that implements mesh networks with mobile devices at the data link layer (Layer 2), there is also a need to reconsider existing metrics with new information to tackle the intrinsic characteristics of mobile devices, e.g., the limited energy resources of their battery. To tackle this problem, this thesis presents a detailed study about projects, routing protocols and metrics developed in the area of mesh networks. In addition, two data link layer solutions, Open802.11s and B.A.T.M.A.N-advanced, have been adapted and deployed in a real mesh network testbed with off the shelf routers devices installed with a customized operating system. From this testbed, Open802.11s has proved to offer better performance than B.A.T.M.A.N-advanced. Following this, a breakthrough in this work has been the integration of the 802.11s on an Android mobile device and its subsequent incorporation in the mesh network. This allowed the study of eventual limitations imposed by the mobile device on the operation of the mesh network, namely performance and energy scarcity. With this, another major novelty has followed, by designing, implementing and evaluating several energy related metrics regarding the battery status of mobile devices. This has enabled the participation of mobile devices in mesh routing paths in an efficient way. Our main objective was to implement a mesh network with mobile devices. This has been achieved and validated through the evaluation of diverse testing scenarios performed in a real mesh testbed. The obtained results also show that the operation of a mesh with mobile devices can be enhanced, including the lifetime of mobile devices, when an energy-aware metric is used.As redes mesh surgem hoje em dia como uma solução de rede em crescimento e expansão. Neste tipo de redes o comportamento entre os nós é descentralizado e numa topologia de multihop. Estas características despertam interesse na pesquisa e desenvolvimento de novas funcionalidades tais como: cooperação entre nós, distribuição de tarefas, escalabilidade da rede e comunicações mesmo em casos de uma infraestrutura limitada e o suporte de dispositivos móveis como nós de uma rede mesh. Associado à inexistência de um projecto que implemente redes mesh em dispositivos móveis na camada de ligação de dados (Layer 2), surge a necessidade de repensar as métricas já existentes com novas informações que façam face às novas características dos dispositivos móveis, neste caso, os recursos limitados de bateria. Por forma a resolver este problema, este trabalho apresenta um estudo detalhado sobre os projetos, protocolos de routing e métricas desenvolvidas na área das redes mesh. Além disso, duas soluções que utilizam a camada de ligação de dados, Open802.11s e BATMAN-advanced, estes foram adaptadao e implementados num testbed real utilizando routers com um sistema operacional costumizado instalado. Deste testbed, concluiu-se que o Open802.11s obtem um melhor desempenho que o BATMAN-advanced. Assim, um dos avanços deste trabalho foi a integração do Open802.11s num dispositivo móvel Android e sua posterior incorporação na rede mesh. Isto permitiu o estudo de eventuais limitações impostas pelo dispositivo móvel ao funcionar numa rede mesh, ou seja, desempenho e a escassez de energia. Com isso, foi concebida outra novidade, através da concepção, avaliação e implementação de várias métricas relacionadas com a energia e que têm por base o estado da bateria do dispositivo. Isto permitiu que os dispositivos móveis participem na rede mesh e a sua gestão de bateria seja feita de forma eficiente. O principal objectivo era a implementação de uma rede mesh com dispositivos móveis. Este foi alcançado e validado através de diversos cenários de teste reais. Os resultados obtidos demonstram também que o funcionamento de uma rede mesh com dispositivos móveis pode ser melhorada, incluindo o tempo de vida dos dispositivos móveis, quando uma métrica que considera a energia é utilizada

Secure and efficient routing in highly dynamic WLAN mesh networks

Recent advances in embedded systems, energy storage, and communication interfaces, accompanied by the falling prices of WLAN routers and a considerable increase in the throughput of a WLAN (IEEE 802.11), have facilitated the proliferation of WLAN Mesh Network (WMN) applications. In addition to their current deployments in less dynamic community networks, WMNs have become a key solution in various highly dynamic scenarios. For instance, WMNs are intended to interconnect self-organized, cooperative, and small Unmanned Aerial Vehicles (UAVs) in a wide range of applications, such as emergency response, environmental monitoring, and ad-hoc network provisioning. Nevertheless, WMNs still face major security challenges as they are prone to routing attacks. Consequently, the network can be sabotaged and, in the case of UAV-WMN-supported missions, the attacker might manipulate payload data or even hijack UAVs. Contemporary security standards, such as the IEEE 802.11i and the security mechanisms of the IEEE 802.11s mesh standard, are vulnerable to routing attacks, as experimentally shown in this research. Therefore, a secure routing protocol is indispensable for making feasible the deployment of WMNs in critical scenarios, such as UAV-WMN-assisted applications. As far as the author of this thesis knows, none of the existing research approaches for secure routing in WMNs have gained acceptance in practice due to their high overhead or strong assumptions. In this research, a new approach, which is called Position-Aware, Secure, and Efficient mesh Routing (PASER), is proposed. This new proposal defeats more attacks than the IEEE 802.11s/i security mechanisms and the well-known, secure routing protocol Authenticated Routing for Ad-hoc Networks (ARAN), without making restrictive assumptions. It is shown that PASER achieves —in realistic UAV-WMN scenarios— similar performance results as the well-established, nonsecure routing protocols Hybrid Wireless Mesh Protocol (HWMP) combined with the IEEE 802.11s security mechanisms. Two representative scenarios are considered: (1) on-demand ubiquitous network access and (2) efficient exploration of sizable areas in disaster relief. The performance evaluation results are produced using an experimentally validated simulation model of WMNs, realistic mobility patterns of UAVs, and an experimentally derived channel model for the air-to-air WMN link between UAVs. The findings of this evaluation are justified by the route discovery delay and the message overhead of the considered solutions