USING THE CONCEPT OF A MAC SCHEDULING ALGORITHM FOR WIMAX NETWORKING ARCHITECTURE

Wimax is wireless digital communication system which is intended for wireless Metropolitan area networks. Wimax standsfor worldwide interoperability for microwave access. Wimax Technology enables ubiquitous delivery of wireless broadbandservice for fixed and or mobile users. An IEEE 802.16 wireless system can provide broadband wireless access to subscriberstations and operate in mesh mode. The communication between a subscriber station and a base station can pass through oneor more intermediate subscriber stations. The IEEE 802.16 standard provides a centralized scheduling mechanism thatsupports contention-free and resource-guarantee transmission services in mesh mode. This paper show how MAC schedulingarchitecture is emphasized for IEEE 802.16 standards.Keywords: MAC, QoS class scheduling, IEEE 802.16, WiMax, Network

Servicios en comunicaciones de emergencia

Las telecomunicaciones han sufrido transformaciones a lo largo de los últimos años y han modificado a las sociedades y los modelos culturales del mundo. En la actualidad es necesario afrontar realidades adicionales como lo son el cambio climático y las situaciones de origen antrópico y no antrópico, apoyados en la tecnología. Es por ello que se deben modelar y simular sistemas de telecomunicaciones en emergencia garantizando la prestación de servicios de telecomunicaciones en situaciones de emergencia en sus diferentes etapas de prevención, atención y recuperación. El diseño de redes con modelos robustos es útil para el manejo de diferentes tipos de paquetes y el manejo de prioridades de tráfico de información

End-to-End Bandwidth Reservation in IEEE 802.16 Mesh Networks

Abstrac

Network Simulation and Performance Evaluation of WiMAX Extensions for Isolated Research Data Networks

IEEE 802.16 is yet a very recent technology and released hardware does frequently only support standards partially. The same applies to public available simulation tools, in particular for NS-2. As the latter is the de-facto standard in science and as we use it for our research in the context of the WEIRD project, we evaluate the IEEE 802.16 support for NS-2. We present several general but also specific issues, which areimportant in order to carry out reliable research based on thesetools. In particular, we show in much detail where modulesdeviate significantly and even fail totally

Diseño de la Red De Nueva Generación Tipo Mesh, para la Atención Y Prevención De Emergencias En Bogotá, En La Banda De 4,9 Ghz, Bajo La Resolución 1661 de 18 De Julio De 2006 para la Coordinación De Acciones De Socorro Y Salvamento.

Las redes inalámbricas son vitales en situaciones de emergencia, estas deben ser adaptativas, robustas y contar con la menor intervención posible del hombre en su operación, con arquitectura cambiante según las situaciones o fenómenos presentados, deben tener redundancia, escalabilidad, auto conformación y auto regeneración, bondades que ofrecen las redes Mesh. Este tipo de redes son una evolución de WIFI y una extensión de las redes Ad Hoc permitiendo la descentralización del envío de la información entre los nodos, estas redes están constituidas por enrutadores Mesh y clientes Mesh, como elementos vitales para su formación, en esta investigación se propone una red heterogénea (nodos móviles y fijos). Las redes malladas responden como alternativas fuertes en un evento de gran magnitud como lo es un Terremoto, de esta forma se mantienen comunicación entre diferentes entidades conformando una red heterogénea con nodos fijos y nodos móviles, de esta forma se crean redes redundantes y adaptativas transportando información vital en emergencia indiferente de operadores o de sistemas ya establecidos, todo esto se ha realizado bajo un ambiente simulado en la herramienta de redes NS-2; integrándolo al marco legal vigente como lo es la resolución 1661 de 2006 en la cual se dispone de anchos de banda de 1 a 20 MHz en la banda de 4,9 GHz para comunicaciones de emergencia. Permitiendo realizar sistemas de comunicaciones robustos y capaz de ofrecer diversos servicios, todos sobre una red de banda ancha inalámbrica heterogénea como la propuesta en esta tesis.Abstract. Wireless networks are vital in emergency situations, they must be adaptive, robust and have the least possible human intervention in its operation, with changing architecture according to situations or phenomena presented, must have redundancy, scalability, self-forming and self-healing, offering bounties mesh networks. Such networks are an evolution of WIFI and an extension of the Ad Hoc networks allowing decentralization of sending information between nodes, these networks consist of mesh routers and mesh clients, as vital to its formation, this research proposes a heterogeneous network (fixed and mobile nodes). Respond mesh networks as a powerful alternative major event such as an earthquake, thereby maintaining communication between different network entities forming a heterogeneous fixed nodes and mobile nodes, thus redundant networks are created carrying information and adaptive indifferent vital emergency operators or established systems, all this has been done under a simulated environment in the networking tool NS-2, integrating the existing legal framework such as the resolution 1661 of 2006 in which, wide band of 1-20 Megas in the band of 4.9 GHz for emergency communications. Allowing perform robust communications systems capable of providing various services, all on a network of heterogeneous wireless broadband as proposed in this thesis.Maestrí

Dynamic Adaptation of the Distributed Election Procedure in IEEE 802.16 WMNs

The goal is to propose an algorithm wich gives to every node of the mesh network the possibility to adapt the holdoff time dynamically and than evaluate the performance

Bandwidth Balancing in Multi-Channel IEEE 802.16 Wireless Mesh networks

In wireless mesh networks, the end-to-end throughput of traffic flows depends on the path length, i.e. the higher the number of hops, the lower becomes the throughput. In this paper, a Fair End-to-end Bandwidth Allocation (FEBA) algorithm is introduced to solve this problem. FEBA is implemented at the Medium Access Control (MAC) layer of single-radio, multiple channels IEEE 802.16 mesh nodes, operated in a distributed coordinated scheduling mode. FEBA negotiates bandwidth among neighbors to assign a fair share to each end-to-end traffic flow. This is carried out in two steps. First, bandwidth is requested and granted in a round-robin fashion where heavily loaded links are provided with a proportionally higher amount of service than the lightly loaded links at each round. Second, at each output link, packets from different traffic flows are buffered in separate queues which are served by the Deficit Round Robin (DRR) scheduling algorithm. If multiple channels are available, all of them are shared evenly in order to increase the network capacity due to frequency reuse. The performance of FEBA is evaluated by extensive simulations and is shown to provide fairness by balancing the bandwidth among traffic flows