2,327 research outputs found
Handover Necessity Estimation for 4G Heterogeneous Networks
One of the most challenges of 4G network is to have a unified network of
heterogeneous wireless networks. To achieve seamless mobility in such a diverse
environment, vertical hand off is still a challenging problem. In many
situations handover failures and unnecessary handoffs are triggered causing
degradation of services, reduction in throughput and increase the blocking
probability and packet loss. In this paper a new vertical handoff decision
algorithm handover necessity estimation (HNE), is proposed to minimize the
number of handover failure and unnecessary handover in heterogeneous wireless
networks. we have proposed a multi criteria vertical handoff decision algorithm
based on two parts: traveling time estimation and time threshold calculation.
Our proposed methods are compared against two other methods: (a) the fixed RSS
threshold based method, in which handovers between the cellular network and the
WLAN are initiated when the RSS from the WLAN reaches a fixed threshold, and
(b) the hysteresis based method, in which a hysteresis is introduced to prevent
the ping-pong effect. Simulation results show that, this method reduced the
number of handover failures and unnecessary handovers up to 80% and 70%,
respectively
Fuzzy-logic framework for future dynamic cellular systems
There is a growing need to develop more robust and energy-efficient network architectures to cope with ever increasing traffic and energy demands. The aim is also to achieve energy-efficient adaptive cellular system architecture capable of delivering a high quality of service (QoS) whilst optimising energy consumption. To gain significant energy savings, new dynamic architectures will allow future systems to achieve energy saving whilst maintaining QoS at different levels of traffic demand. We consider a heterogeneous cellular system where the elements of it can adapt and change their architecture depending on the network demand. We demonstrate substantial savings of energy, especially in low-traffic periods where most mobile systems are over engineered. Energy savings are also achieved in high-traffic periods by capitalising on traffic variations in the spatial domain. We adopt a fuzzy-logic algorithm for the multi-objective decisions we face in the system, where it provides stability and the ability to handle imprecise data
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂşblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
An Overview of Multi-Attribute Decision Making (MADM) Vertical Handover Using Systematic Mapping
The evolution of infotainment industries yet the advancement of cellular gadgets such as smartphones, tablets, and laptop had increased the request on cellular traffic demands. As a result, a Heterogeneous Wireless Network (HWN) has been introduced to fulfil users requests in having seamless mobility and better Quality of Services (QoS) for the users. A lot of research works have been done in order to provide a seamless connection to the users. Even though a lot of methods have been proposed, a Multi-Attribute Decision Making (MADM) has been seemed like a promising way due to its ability to evaluate many attributes simultaneously. Previously, many reviews based on MADM methods in a Heterogeneous Wireless Network provides a details review which required researchers time in order to determine the possible potential areas to be explored. Therefore, in this study, we present an overview of the MADM method in performing vertical handover via a systematic mapping method. This will enable future researchers to identify the trends and research opportunities within this area. This mapping study analysed 30 papers. Results from the study show eight main potential research issues can be explored by researchers, including normalisation, criteria weighting, ranking abnormality, network selection, and performance comparison between MADM algorithms, network selection for a group of calls, mobility patterns and handover triggering
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