565 research outputs found
EVM as generic QoS trigger for heterogeneous wieless overlay network
Fourth Generation (4G) Wireless System will integrate heterogeneous wireless
overlay systems i.e. interworking of WLAN/ GSM/ CDMA/ WiMAX/ LTE/ etc with
guaranteed Quality of Service (QoS) and Experience (QoE).QoS(E) vary from
network to network and is application sensitive. User needs an optimal mobility
solution while roaming in Overlaid wireless environment i.e. user could
seamlessly transfer his session/ call to a best available network bearing
guaranteed Quality of Experience. And If this Seamless transfer of session is
executed between two networks having different access standards then it is
called Vertical Handover (VHO). Contemporary VHO decision algorithms are based
on generic QoS metrics viz. SNR, bandwidth, jitter, BER and delay. In this
paper, Error Vector Magnitude (EVM) is proposed to be a generic QoS trigger for
VHO execution. EVM is defined as the deviation of inphase/ quadrature (I/Q)
values from ideal signal states and thus provides a measure of signal quality.
In 4G Interoperable environment, OFDM is the leading Modulation scheme (more
prone to multi-path fading). EVM (modulation error) properly characterises the
wireless link/ channel for accurate VHO decision. EVM depends on the inherent
transmission impairments viz. frequency offset, phase noise,
non-linear-impairment, skewness etc. for a given wireless link. Paper provides
an insight to the analytical aspect of EVM & measures EVM (%) for key
management subframes like association/re-association/disassociation/ probe
request/response frames. EVM relation is explored for different possible
NAV-Network Allocation Vectors (frame duration). Finally EVM is compared with
SNR, BER and investigation concludes EVM as a promising QoS trigger for OFDM
based emerging wireless standards.Comment: 12 pages, 7 figures, IJWMN 2010 august issue vol. 2, no.
A host mobility support with adaptive network selection method in hybrid wireless environment
The B3G or 4G of cellular/wireless communications network is expected to be purely IP-based and consist of heterogeneous access networks from 3G cellular, WiFi, WiMAX and a converged core network. To sup-port the mobile host in the hybrid overlay wireless, a cross-layer vertical handoff control method has been proposed. Implemented architecture is composed of four part; Connection Profile Manager (CPM), Net-work Access Assistance (NAA), Neuro-Fuzzy Decision Engine (NFDE), and Peer-bind Connection Manager (PCM). The most effective connection is selected based on the attributes from the multi-layer platform that provided handoff decision component which is respon-sible for handoff decision. The proposed network selection algorithm is based on hybrid neuro-fuzzy concept with low packet loss and latency. We have analyzed our implemented model on different scena-rios. Results of the experiment indicate the advantages of the proposed scheme
Parametric Estimation of Handoff
The efficiency of wireless technology depends upon the seamless connectivity
to the user at anywhere any time.Heterogeneous wireless networks are an
integration of different networks with diversified technologies. The most
essential requirement for Seamless vertical handover is that the received
signal strength should always be healthy. Mobile device enabled with multiple
wireless technologies makes it possible to maintain seamless connectivity in
highly dynamic environment.Since the available bandwidth is limited and the
number of users is growing rapidly, it is a real challenge to maintain the
received signal strength in a healthy stage.In this work, the proposed, cost
effective parametric estimation for vertical handover shows that the received
signal strength maintains a healthy level by considering the novel concept.Comment: 5 Pages,3 figures, NCCCS-12,ISBN:978-1-4673-2837-
Wireless Heterogeneous Networks and Next Generation Internet
The recent advances in wireless access technologies as well as the increasing number of mobile applications have made Wireless Internet a reality. A wide variety of bandwidth demanding services including high speed data delivery and multimedia communication have been materialized through the convergence of the next generation Internet and heterogeneous wireless networks. However, providing even higher bandwidth and richer applications necessitates a fundamental understanding of wireless Internet architecture and the interactions between heterogeneous users. Consequently, fundamental advances in many concepts of the wireless Internet are required for the ultimate goal of communication anytime anywhere.
This special issue of the ACM Mobile Networks and Applications Journal is dedicated to the recent advances in the area of Wireless Internet. We accepted 10 papers out of 59 submissions from all over the world with a 17% acceptance rate. Papers describing management schemes, protocols, models, evaluation methods, and experimental studies of Wireless Internet are included in this special issue to provide a broad view of recent advances in this field
An Optimum Vertical Handoff Decision Algorithm for UMTS-WLAN
The integration of diverse but complementary cellular and wireless technologies in the next generation of wireless communication systems requires the design of intelligent vertical handoff decision algorithms to enable mobile users to seamlessly switch network access and experience uninterrupted service continuity anywhere and anytime. This paper provides an adaptive multiple attribute vertical handoff decision algorithm that enables wireless access network selection at a mobile terminal using fuzzy logic concepts and a genetic algorithm. A performance study using the integration of wireless wide area networks (WWANs) and wireless metropolitan area networks (WMANs) as an example shows that our proposed vertical handoff decision algorithm is able to determine when a handoff is required, and selects the best access network that is optimized to network conditions, quality of service requirements, mobile terminal conditions, user preferences, and service cost
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