Search results for "IEEE 802"

PHY and MAC layer performance optimization of the IEEE 802.16 system

2012

WINSE: WiMAX NS-2 extension

2009

IEEE 802.16 standard defines the wireless broadband technology called WiMAX. When compared to other wireless technologies, it introduces many interesting advantages at PHY, MAC, and QoS layers. Heavy simulations are needed to study IEEE 802.16 performance and propose further enhancements to this standard. Link level simulations are not always sufficient, while system level simulators are not always accurate to capture MAC and transport protocol details. We implemented a 802.16 extension for the NS-2 network simulator. It includes upper PHY modeling, almost all the features of the 802.16 MAC layer, as well as the QoS framework. This article describes the implemented features, simulation meth…

Measurement and Modeling of the Origins of Starvation of Congestion-Controlled Flows in Wireless Mesh Networks

2009

Significant progress has been made in understanding the behavior of TCP and congestion-controlled traffic over CSMA-based multihop wireless networks. Despite these advances, however, no prior work identified severe throughput imbalances in the basic scenario of mesh networks, in which a one-hop flow contends with a two-hop flow for gateway access. In this paper, we demonstrate via real network measurements, testbed experiments, and an analytical model that starvation exists in such a scenario; i.e., the one-hop flow receives most of the bandwidth, while the two-hop flow starves. Our analytical model yields a solution consisting of a simple contention window policy that can be implemented vi…

Supporting a Pseudo-TDMA Access Scheme in Mesh Wireless Networks

2013

Wireless mesh networks appear a promising solution for pro- viding ubiquitous low-cost wireless access, but cannot rely on simple CSMA access protocols because of the critical inefficiencies that arise in topologies with hidden nodes. To overcome these limitations, some important protocol extensions based on synchronization and reservation mechanisms have been ratified. In this paper we show that an alternative approach to the standardiza- tion of new features and signaling messages for mesh networks can be the utilization of programmable nodes able to execute different MAC protocols programmed on the fly. Signaling messages are used only for disseminating the new protocol among the nodes. …

Testbed implementation of the meta-MAC protocol

2016

The meta-MAC protocol is a systematic and automatic method to dynamically combine any set of existing MAC protocols into a single higher layer MAC protocol. We present a proof-of-concept implementation of the meta-MAC protocol by utilizing a programmable wireless MAC processor (WMP) on top of a commodity wireless card in combination with a host-level software module. The implementation allows us to combine, with certain constraints, a number of protocols each represented as an extended finite state machine. To illustrate the combination principle, we combine protocols of the same type but with varying parameters in a wireless mesh network. Specifically, we combine TDMA protocols with all po…

An automatic cooperative retransmission MAC protocol in Wireless Local Area Networks

2009

Existing solutions for cooperation in wireless networks either require simultaneous transmission of source and relay nodes or impose major modifications to original MAC protocols. In this paper, a new efficient retransmission MAC protocol is proposed for IEEE 802.11 based cooperation communications, with minimum modifications to the DCF scheme. Throughput and access delay performance of the proposed protocols is analyzed in error-prone and highly temporally correlated channels. Numerical results show that significant benefits can be achieved with our cooperative protocol, compared with the legacy schemes.

Hybrid QoS Based Routing for IEEE 802.16j Mesh Infrastructure

2014

Acceptance rate: 29%; International audience; With the growth of wireless networks, Wireless Mesh Network (WMN) has appeared as an emerging key solution for broadband Internet access with a low-cost deployment. Moreover, providing QoS guarantees for real-time and streaming applications such as VoIP (Voice over IP) and VoD (Video on Demand) is a challenging issue in such environment. In this paper, we propose a hybrid wireless mesh architecture to provide mesh clients with Internet access while guaranteeing QoS. It is formed by an IEEE 802.16j based infrastructure and several IEEE 802.11s based client domains. A lustering algorithm is developed to enhance scalability issues within the mesh i…

Smart Network Selection and Packet Loss Improvement during Handover in Heterogeneous Environment

2013

BEST PAPER AWARD; International audience; Seamless Handover between networks in heterogeneous environment is essential to guarantee end-to-end QoS for mobile users. A key requirement is the ability to select the next best network. Currently, the implementation of the IEEE 802.21 standard by National Institute of Standards and Technology (NIST) considers only the signal strength as a parameter to determine the best network. In this paper, we propose including additional parameters such as available bandwidth, mobile node speed and type of network during selecting a new network to improve the QoS for mobile user's application. The results of the experiments that we performed using Network Sim…

Integrated Fuzzy Solution for Network Selection using MIH in Heterogeneous Environment

2013

ISSN: 1942-2644; International audience; Seamless handover between networks in heterogeneous environment is essential to guarantee end-to- end QoS for mobile users. A key requirement is the ability to select seamlessly the next best network. Currently, the implementation of the selection algorithm of the IEEE 802.21 standard by National Institute of Standards and Technology considers only the signal strength as a parameter to select the best destination network. In this paper, we improve the implementation of the existing selection algorithm by proposing an integrated solution to select the best destination network. Our proposed solution consists of proposing a Multi Criteria Selection Algo…

IP-Based Mobility Management and Handover Latency Measurement in heterogeneous environments

2017

International audience; One serious concern in the ubiquitous networks is the seamless vertical handover management between different wireless technologies. To meet this challenge, many standardization organizations proposed different protocols at different layers of the protocol stack. The Internet Engineering Task Force (IETF) has different groups working on mobility at IP level in order to enhance mobile IPv4 and mobile IPv6 with different variants: HMIPv6 (Hierarchical Mobile IPv6), FMIPv6 (Fast Mobile IPv6) and PMIPv6 (Proxy Mobile IPv6) for seamless handover. Moreover, the IEEE 802.21 standard provides another framework for seamless handover. The 3GPP standard provides the Access Netw…