717 research outputs found
Efficient radio resource management in next generation wireless networks
The current decade has witnessed a phenomenal growth in mobile wireless communication
networks and subscribers. In 2015, mobile wireless devices and connections were reported to have grown to about 7.9 billion, exceeding human
population. The explosive growth in mobile wireless communication network subscribers has created a huge demand for wireless network capacity,
ubiquitous wireless network coverage, and enhanced Quality of Service (QoS). These demands have led to several challenging problems for wireless
communication networks operators and designers. The Next Generation Wireless Networks (NGWNs) will support high mobility communications, such as
communication in high-speed rails. Mobile users in such high mobility environment demand reliable QoS, however, such users are plagued with a
poor signal-tonoise ratio, due to the high vehicular penetration loss, increased transmission outage and handover information overhead, leading
to poor QoS provisioning for the networks' mobile users. Providing a reliable QoS for high mobility users remains one of the unique challenges
for NGWNs. The increased wireless network capacity and coverage of NGWNs means that mobile communication users at the cell-edge should have
enhanced network performance. However, due to path loss (path attenuation), interference, and radio background noise, mobile communication
users at the cell-edge can experience relatively poor transmission channel qualities and subsequently forced to transmit at a low bit transmission
rate, even when the wireless communication networks can support high bit transmission rate. Furthermore, the NGWNs are envisioned to be Heterogeneous
Wireless Networks (HWNs). The NGWNs are going to be the integration platform of diverse homogeneous wireless communication networks for a convergent
wireless communication network. The HWNs support single and multiple calls (group calls), simultaneously. Decision making is an integral core of radio
resource management. One crucial decision making in HWNs is network selection. Network selection addresses the problem of how to select the best
available access network for a given network user connection. For the integrated platform of HWNs to be truly seamless and
efficient, a robust and stable wireless access network selection algorithm is needed. To meet these challenges for the
different mobile wireless communication network users, the NGWNs will have to provide a great leap in wireless network capacity, coverage,
QoS, and radio resource utilization. Moving wireless communication networks (mobile hotspots) have been proposed as a solution to providing
reliable QoS to high mobility users. In this thesis, an Adaptive Thinning Mobility Aware (ATMA) Call Admission Control (CAC) algorithm for
improving the QoS and radio resource utilization of the mobile hotspot networks, which are of critical importance for communicating nodes
in moving wireless networks is proposed. The performance of proposed ATMA CAC scheme is investigated and compare it with the traditional
CAC scheme. The ATMA scheme exploits the mobility events in the highspeed mobility communication environment and the calls (new and
handoff calls) generation pattern to enhance the QoS (new call blocking and
handoff call dropping probabilities) of the mobile users. The numbers of new and
handoff calls in wireless communication networks are dynamic random processes that can be
effectively modeled by the Continuous Furthermore, the NGWNs are envisioned to be Heterogeneous Wireless Networks (HWNs).
The NGWNs are going to be the integration platform of diverse homogeneous wireless communication networks for a convergent
wireless communication network. The HWNs support single and multiple calls (group calls), simultaneously. Decision making is an
integral core of radio resource management. One crucial decision making in HWNs is network selection. Network selection addresses
the problem of how to select the best available access network for a given network user connection. For the integrated platform of
HWNs to be truly seamless and efficient, a robust and stable wireless access network selection algorithm is needed. To meet these
challenges for the different mobile wireless communication network users, the NGWNs will have to provide a great leap in wireless
network capacity, coverage, QoS, and radio resource utilization. Moving wireless communication networks (mobile hotspots) have been
proposed as a solution to providing reliable QoS to high mobility users. In this thesis, an Adaptive Thinning Mobility Aware (ATMA)
Call Admission Control (CAC) algorithm for improving the QoS and radio resource utilization of the mobile hotspot networks, which are
of critical importance for communicating nodes in moving wireless networks is proposed
Handover Parameter Optimisation of a Cellular Network The Kenyan Case
Handover, also known as Handoff is a key procedure that ensures that the cellular users move freely through the network while still being connected and being offered quality services. It is an event taking place whenever a mobile node moves from one wireless cell to another, abandoning the connection with the first base station and getting attached to the second one. Since its success rate is a key indicator of user satisfaction, it is vital that this procedure happens as fast and as seamlessly as possible.
This paper aims to optimize the handover decision process of a cellular radio network for an in-vehicle mobile station.
This is first by determining the optimal handover parameters then developing an algorithm that determines the best time to handover using the fuzzy logic system
Regressive Prediction Approach to Vertical Handover in Fourth Generation Wireless Networks
The over increasing demand for deployment of wireless access networks has made wireless mobile devices to face so many challenges in choosing the best suitable network from a set of available access networks. Some of the weighty issues in 4G wireless networks are fastness and seamlessness in handover process. This paper therefore, proposes a handover technique based on movement prediction in wireless mobile (WiMAX and LTE-A) environment. The technique enables the system to predict signal quality between the UE and Radio Base Stations (RBS)/Access Points (APs) in two different networks. Prediction is achieved by employing the Markov Decision Process Model (MDPM) where the movement of the UE is dynamically estimated and averaged to keep track of the signal strength of mobile users. With the help of the prediction, layer-3 handover activities are able to occur prior to layer-2 handover, and therefore, total handover latency can be reduced. The performances of various handover approaches influenced by different metrics (mobility velocities) were evaluated. The results presented demonstrate good accuracy the proposed method was able to achieve in predicting the next signal level by reducing the total handover latency
The Performance Evaluation of Adaptive Guard Channel Scheme in Wireless Network
Dynamic Guard Channels (DCG) reduces the dropping and blocking rates in a network. However, most of the existing DGC allocations are not quite efficient because there were consideration for only the Handoff (HO) calls while the New calls (NC) were not considered; this leads to poor Quality of Service (QoS) for NC. Although it is better to give priority to HO calls over NC since the breaking of the connection of an established communicationis more annoying than blocking a NC. Thus, there is need to provide an alternative approach that guarantees an acceptable QoS in terms of both the HC and the NC. This paper presents the performance evaluation of an adaptive guard channel allocation; the scheme made use of two different models (1) guard channel with fuzzy logic (2) guard channel without fuzzy logic. Priority is given to handoff call due to the scarcity of radio spectrum. When all the guard channels have been allocated and the arrival rate of handoff calls keeps on increasing, new set of threshold values would be estimated by fuzzy logic model. Performance metrics are; Call Blocking Rate (CBR), Call Dropping Rate (CDR) and Throughput. Results showed that guard channel with fuzzy logic has the CBR values range from 24.02% to 69.015 and CDR values range from 12.025 to 18.90% while guard channel without fuzzy logic has CBR values range from 28.22% to 75.65% and CDR values range from 19.06% to 36.50%. The scheme proved to be more efficient in congestion control in wireless network
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Application priority framework for fixed mobile converged communication networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The current prospects in wired and wireless access networks, it is becoming increasingly important to address potential convergence in order to offer integrated broadband services. These systems will need to offer higher data transmission capacities and long battery life, which is the catalyst for an everincreasing variety of air interface technologies targeting local area to wide area connectivity. Current integrated industrial networks do not offer application aware context delivery and enhanced services for optimised networks. Application aware services provide value-added functionality to business applications by capturing, integrating, and consolidating intelligence about users and their endpoint devices from various points in the network. This thesis mainly intends to resolve the issues related to ubiquitous application aware service, fair allocation of radio access, reduced energy consumption and improved capacity. A technique that measures and evaluates the data rate demand to reduce application response time and queuing delay for multi radio interfaces is proposed. The technique overcomes the challenges of network integration, requiring no user intervention, saving battery life and selecting the radio access connection for the application requested by the end user. This study is split in two parts. The first contribution identifies some constraints of the services towards the application layer in terms of e.g. data rate and signal strength. The objectives are achieved by application controlled handover (ACH) mechanism in order to maintain acceptable data rate for real-time application services. It also looks into the impact of the radio link on the application and identifies elements and parameters like wireless link quality and handover that will influence the application type. It also identifies some enhanced traditional mechanisms such as distance controlled multihop and mesh topology required in order to support energy efficient multimedia applications. The second contribution unfolds an intelligent application priority assignment mechanism (IAPAM) for medical applications using wireless sensor networks. IAPAM proposes and evaluates a technique based on prioritising multiple virtual queues for the critical nature of medical data to improve instant transmission. Various mobility patterns (directed, controlled and random waypoint) has been investigated and compared by simulating IAPAM enabled mobile BWSN. The following topics have been studied, modelled, simulated and discussed in this thesis: 1. Application Controlled Handover (ACH) for multi radios over fibre 2. Power Controlled Scheme for mesh multi radios over fibre using ACH 3. IAPAM for Biomedical Wireless Sensor Networks (BWSN) and impact of mobility over IAPAM enabled BWSN. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in multi radios over fibre performance in terms of application response delay and power consumption by upto 75% and 15 % respectively, reduction in traffic loss by upto 53% and reduction in delay for real time application by more than 25% in some cases
Final report on the evaluation of RRM/CRRM algorithms
Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin
An integrated wireless communication architecture for maritime sector
The rapid evolution of terrestrial wireless systems has brought mobile users more and more desired communication services. Maritime customers are asking for the same, such as the concepts of “Broadband at Sea” and “Maritime Internet”. Quite a lot of research work has focused on the development of new and better maritime communication technologies, but less attention has been paid on interworking of multiple maritime wireless networks or on satisfying service provisioning. To address this, an integrated wireless Communication Architecture for Maritime Sector (CAMS) has been introduced in this article. CAMS is aimed at 1) granting maritime customers uninterrupted connectivity through the best available network and 2) providing them with the best-provisioned communication services in terms of mobility, security and Quality of Experience (QoE). To address mobility challenge, the IEEE 802.21 standard is recommended to be used in CAMS in order to achieve seamless handover. CAMS provides application-level QoE support attending to the limited communication resources (e.g. bandwidth) at sea. Certain security considerations have also been proposed to supplement this architecture
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