Bandwidth Recycling using Variable Bit Rate

IEEE 802.16 standard was designed to support the bandwidth demanding applications with quality of service (QoS). Bandwidth is reserved for each application to ensure the QoS. For variable bit rate (VBR) applications, however, it is difficult for the subscriber station (SS) to predict the amount of incoming data. To ensure the QoS guaranteed services, the SS may reserve more bandwidth than its demand. As a result, the reserved bandwidth may not be fully utilized all the time. In this paper, we propose a scheme, named Bandwidth Recycling, to recycle the unused bandwidth without changing the existing bandwidth reservation. The idea of the proposed scheme is to allow other SSs to utilize the unused bandwidth when it is available. Thus, the system throughput can be improved while maintaining the same QoS guaranteed services. Mathematical analysis and simulation are used to evaluate the proposed scheme. Simulation and analysis results confirm that the proposed scheme can recycle 35% of unused bandwidth on average. By analyzing factors affecting the recycling performance, three scheduling algorithms are proposed to improve the overall throughput. The simulation results show that our proposed algorithm improves the overall throughput by 40% in a steady network. Keywords: WiMAX, IEEE 802.16, Bandwidth Recyclin

WiMAX: Performance Analysis and Enhancement of Real-time Bandwidth Request

This paper carried out a study on the bandwidth request for real-time polling services. In our study, we discovered that although the base station granted the subscriber station an allocation to send the bandwidth request, the subscriber station may not be able to allocate the bandwidth request to the allocation. It is due to processing delay and multicast polling in the subscriber station, which results the bandwidth request being padded unintentionally. The loss of bandwidth requests will cause the degradation of the real-time polling service performance. Therefore, we propose a scheme to overcome this problem. The results of the experiment show that the proposed scheme improves the performance of real-time polling services

USING THE CONCEPT OF A MAC SCHEDULING ALGORITHM FOR WIMAX NETWORKING ARCHITECTURE

Wimax is wireless digital communication system which is intended for wireless Metropolitan area networks. Wimax standsfor worldwide interoperability for microwave access. Wimax Technology enables ubiquitous delivery of wireless broadbandservice for fixed and or mobile users. An IEEE 802.16 wireless system can provide broadband wireless access to subscriberstations and operate in mesh mode. The communication between a subscriber station and a base station can pass through oneor more intermediate subscriber stations. The IEEE 802.16 standard provides a centralized scheduling mechanism thatsupports contention-free and resource-guarantee transmission services in mesh mode. This paper show how MAC schedulingarchitecture is emphasized for IEEE 802.16 standards.Keywords: MAC, QoS class scheduling, IEEE 802.16, WiMax, Network

An enhanced approach for augmentation of synchronized bandwidth request in WiMAX

This paper carried out a study on the bandwidth request for real-time polling services. In our study, we discovered that although the base station granted the subscriber station to send the bandwidth request, the subscriber station may not be able to allocate the bandwidth request. It is due to processing delay and multicast polling in the subscriber station, which results the bandwidth request being padded unintentionally. The loss of bandwidth requests will cause the degradation of the real-time polling service performance. Therefore, we propose a scheme to overcome this problem. The results of the experiment show that the proposed scheme improves the performance of real-time polling services

Survey on WI-MAX System Based on Wavelet Packet Modulation Technique

A study within the field of Worldwide ability for Microwave Access system or communication system is way required as communication services. rippling Packet Modulation is AN helpful technique of multicarrier modulation that has high information measure, potency and adaptability. This paper inquires, simulation of IEEE802.16 in MATLAB software package victimization rippling packet modulation in WIMAX. The results show that BER performance of words per minute system is best than OFDM that uses cyclic prefix and consequently has higher SNR. The study is simulated over AN AWGN channel and frequency selective Rayleigh channel. BER performance of various rippling families is planned for this channel conditions OFDM is being wide utilized in wireless communication systems for its ability to cut back the information measure and enhance the information rate. The scheme provides lustiness against interference and may adapt simply to weakening eventualities. This paper offers a comparison of channel performance victimization numerous modulation techniques over completely different weakening environments. Modulation schemes include BPSK, QPSK, 64- QAM that are utilized beneath the influence of AWGN, Rayleigh, flat weakening, frequency selective and Rican attenuation channels. BER (Bit Error Rate) and SNR (Signal to Noise ratio) functions are wont to analyze the performance of information transmitted over these channels Mat research lab is employed to develop the OFDM model and analysis the performance of WiMAX system

High frequency of low noise amplifier architecture for WiMAX application: A review

The low noise amplifier (LNA) circuit is exceptionally imperative as it promotes and initializes general execution performance and quality of the mobile communication system. LNA's design in radio frequency (R.F.) circuit requires the trade-off numerous imperative features' including gain, noise figure (N.F.), bandwidth, stability, sensitivity, power consumption, and complexity. Improvements to the LNA's overall performance should be made to fulfil the worldwide interoperability for microwave access (WiMAX) specifications' prerequisites. The development of front-end receiver, particularly the LNA, is genuinely pivotal for long-distance communications up to 50 km for a particular system with particular requirements. The LNA architecture has recently been designed to concentrate on a single transistor, cascode, or cascade constrained in gain, bandwidth, and noise figure

Uncertain Bandwidth Calculation in Networks with Non-Linear Services

ABSTRACT : The data transfer rate in maximum level of network. It is used to observe how much amount of data can send through connection. Most of the networks are fail to guess the bandwidth availability accurately in the wireless setting. So that advance bandwidth reservation can become a critical task to improve the network resources utilization. This type of system will provide increased inconsistency of wireless channel conditions difficult for bandwidth calculation. To overcome these problems we are introducing a scheme as "Bandwidth Recycling", (i.e.) to recycle the unused bandwidth without changing the existing bandwidth reservation. We are calculating the each node in the networks bandwidth calculation considering through the queries for long time periods. For small scale networks we are using optimal algorithm with exponential time complexity, for large scale networks we are developing the heuristics with polynomial time complexity and we are using token bucket algorithm to avoid packet loss while it travelling in the network. By using this bandwidth calculation we can achieve both good accuracy and accurate levels in the networks for each node

Public safety and cognitive radio

This book gives comprehensive and balanced coverage of the principles of cognitive radio communications, cognitive networks, and details of their implementation, including the latest developments in the standards and spectrum policy. Case studies, end-of-chapter questions, and descriptions of various platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented in practice. Extensive treatment is given to several standards, including IEEE 802.22 for TV White Spaces and IEEE SCC41