Performance Comparison of Handover mechanisms in mobile wireless communication networks for Broadband Wireless Access Systems

Mobility is the mobile communication characteristics which make it diverse and attractive for all. Wireless communication is now attractive to the whole world and provides the ability of users to communicate very active. Transferring the users from one radio network to another is accomplishing the IT. The process is called the handover process. The transfer takes place by adjusting the duration of the soft transfers, the area size and either by cell crossing or by deterioration in the signal quality of the current channel — the brief overview of handover, Handover in WiMAX and LTE, types of handover, handover types solutions, approaches used in literature are typically transfer parameters and I contemporary the convergent fact for continuance in the area of mobile and wireless communication Handover

Handover in a mobile wireless communication network –A Review Phase

Mobility is the features of mobile communication that makes it desirable by all and varied. The whole world is now attractive in wireless communication as it provides users' ability to communicate on-the-go. IT is accomplished by transferring users from a radio network to another. This process is called handover. Handover occurs by adjusting the duration of soft handovers, the size of the areas and either by cell crossing or by deterioration in the signal quality of the current channel — the brief overview of handover, Handover in WiMAX and LTE, types of handover, handover types solutions, usually used handover parameters, some methods employed in the literature and I contemporary the convergent fact for continuance in the area of mobile wireless communication Handover

Multichannel Virtual Access Points for Seamless Handoffs in IEEE 802.11 Wireless Networks

Session: Handoff and Mobility Management 2International audienceWithin IEEE 802.11 Wireless Local Area Networks (WLANs), client stations can move freely, but because of the short range of their Access Points (APs), they usually need to reassociate with different APs to continue to communicate. When changing APs, a client station starts a process known as a handoff that can take up to 2 seconds, which is too long for real-time applications such as Voice over IP (VoIP). Various solutions have been proposed to change or improve the client behaviour when doing a handoff. Previously, we proposed the idea of Virtual Access Points (VAP) implemented on APs in which a client station changes APs without disrupting its current communication. Based on this new concept, we have developed a solution called Multichannel Virtual Access Points (mVAP) to take advantage of APs operating on multiple channels. We have implemented mVAP using PACMAP, a tool for packet manipulation, and evaluated its performance. Our results show that mVAP is a new efficient technique for seamless handoffs without performance degradation

A New Method of User Association in Wireless Mesh Networks

The IEEE 802.11 based wireless mesh networks (WMNs) are becoming the promising technology to provide last-mile broadband Internet access to the users. In order to access the Internet through the pre-deployed WMN, the user has to associate with one of the access points (APs) present in the network. In WMN, it is very common that the user device can have multiple APs in its vicinity. Since the user performance majorly depends on the associated AP, how to select the best AP is always remaining as a challenging research problem in WMN. The traditional method of AP selection is based on received signal strength (RSS) and it is proven inefficient in the literature as the method does not consider AP load, channel conditions, etc. This paper proposes a new method of user association in WMN such that the user selects the AP based on achievable end-to-end throughput measured in the presence of other interfering APs. The proposed association metric is independent of routing protocol and routing metric used in WMN. The simulation results show that our method outperforms the RSS based AP selection method in WMN

Controlo de mobilidade com segurança em redes estruturadas 802.11

Mestrado em Engenharia Electrónica e TelecomunicaçõesEsta dissertação aborda o problema da gestão da mobilidade com segurança em redes 802.11. Assim, começa por apresentar um estudo detalhado do protocolo 802.11, do handoff de dispositivos móveis entre pontos de acesso e de soluções apresentadas por diversos autores com o objectivo de reduzir o tempo dispendido neste processo, com e sem segurança associada. Seguidamente, são apresentadas métricas e atributos de rede que podem ser considerados no estabelecimento de políticas de mobilidade que gerem as transições de AP que cada dispositivo móvel efectua. Uma vez feito este estudo inicial, é apresentada uma solução que potencía handoffs rápidos e seguros em redes estruturadas 802.11 e que minimiza o tempo da sua preparação. Este novo protocolo representa uma evolução do trabalho desenvolvido por Rodolphe Marques no trabalho intitulado “Segurança e Mobilidade em Redes Estruturadas 802.11” referenciado em [1]; a sua novidade consiste em usar tramas 802.11 de reconhecimento da rede (Probe Request/Response) para difundir associações de segurança com os pontos de acesso ao alcance de cada dispositivo móvel. A nova abordagem implica mudanças reduzidas na arquitectura de rede considerada em [1] e permite que, no âmbito das operações de reconhecimento de pontos de acesso, que são comuns e necessárias, um equipamento móvel instale paralelamente associações de segurança nos APs que poderá vir a usar num futuro próximo, ou seja, todos os que estão ao seu alcance. ABSTRACT: This thesis handles the problem of mobility management with security in 802.11 networks. Therefore it begins by presenting a detailed study of the 802.11 protocol, the handoff process of roaming mobile nodes between access points and solutions presented by many authors with the common goal of reducing the time spent in this process, with and without associated security. After this we present metrics and attributes of the network that may be considered on the establishment of mobility policies that handle the AP transitions made by every mobile node. Once finished this initial study we present a solution that enhances fast and secure handoffs in structured 802.11 networks and minimizes the time spent in its setting. This new protocol represents an evolution on the work developed by the author Rodolphe Marques in his work named “Security and Mobility in 802.11 Structured Networks” referred in [1]; its new feature consists in using 802.11 network scanning frames (Probe Request/Response) to distribute security associations to all access points in range of each mobile node. This new approach implies some changes on the architecture proposed in [1] and allows a mobile node to install security associations simultaneously while browsing the neighborhood for access points that may be used in a near future