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A new genre of P2P systems, P2P Video-on-Demand (P2P-VoD), has not only received substantial recent research attention, but also been implemented and deployed with success in large-scale real-world streaming systems, such as PPLive. The essential characterization of P2P-VoD systems is to take full advantage of peer upload bandwidth contribution with a cache on each peer. Meanwhile, the asynchronous...
The planar UWB antenna with single band-notched characteristic is proposed. It is designed for Ultra-wideband wireless communications with a notch frequency response in the WLAN bands. The antenna consists of a rectangular slot etched out from the ground plane of a FR4 substrate (dielectric constant = 2.2) and a CPW-fed. The antenna is successfully designed, implemented and measured. The measured...
This simple and scalable Differentiated Services (DiffServ) QoS control model is acceptable for the core of the network. However, more explicit and stringent admission and reservation based QoS mechanisms are required in the wireless access segment of the network, where available resources are severely limited and the degree of traffic aggregation is not significant, thus rendering the DiffServ principles...
Traditional congestion control algorithms exhibit low convergence speed to equilibrium in high BDP (Bandwidth Delay Product) networks. The Fast Max-Min Kelly Control (FMKC) is a new and promising protocol that performs well especially in fairness convergence speed. FMKC utilizes packet loss to switch temporarily into a fairing mode and thereby improve the fairness convergence speed. In this paper,...
It has been widely recognized that the multipath routing can be fundamentally more efficient than the traditional approach of routing along single path. A self-adaptive traffic splitting algorithm, called Dynamic Weighted Round-Robin (DWRR), has been developed to distribute traffic fairly in term of the weight so as to obtain good performance of network load balance. In addition, DWRR can get lower...
As researchers continue to architect massive-scale systems, it is becoming clear that these systems will utilize a significant amount of shared hardware between processing units. Systems such as the IBM Blue Gene (BG) and Cray XT have started utilizing flat (i.e., scalable) networks, which differ from switched fabrics in that they use a 3D torus or similar topology. This allows the network to grow...
Linear source-filter models have been widely used by researchers as a front-end for speaker identification systems. It uses the cepstral features derived from the power spectrum of the speech signal. But it is also well known that a significant part of the acoustic information cannot be modeled by the linear source-filter model, and thus, the need for nonlinear features becomes apparent. In this paper,...
We present a State Estimation based Internet traffic flow control system where the objective is to maximize the aggregate bandwidth utility of network sources over their transmission rates. The network links and sources are viewed as processors of distributed computation and the control mechanism is based on estimation and optimization framework to solve the dual problem. The novelty of our approach...
When you design networks that transport voice over packet, frame, or cell infrastructures, it is important to understand and account for the delay components in the network. If you account correctly for all potential delays, it ensures that overall network performance is acceptable. Delay guarantees are critical to real-time applications. To ensure the end-to-end delay guarantee of a flow, the previous...
A 2-6 GHz WiMAX low noise amplifier (LNA) is designed and implemented in 0.18-??m CMOS process. This low noise amplifier utilizes a current-reused technique, and a high-pass input matching network. The LNA presents a maximum power gain of 18.4 dB at 2 GHz. The minimum noise figure (NF) is 2.1dB. S11 is less than -16 dB. The total power consumption is 17.4 mW under a 1.8 V power supply. The chip size...
In overlay IP over WDM networks, there are only limited information exchanges between the two layers through the user network interface (UNI) [1] for service requests and responses. To enhance the overlay network performance while maintaining its simplicity, we propose for the first time to learn from the historical data of lightpath setting up costs maintained by the logical layer network operator(s),...
This paper presents results of experiments on characterization of wireless channels inside a tall building in Hung Hom, Hong Kong with the transmitter located atop the DE Block of the Hong Kong Polytechnic University and the channel measurements are made inside a nearby tall residential building. The channel probing signal centered at 1.8 GHz had a bandwidth of 60 MHz. The results were analyzed for...
In this paper, we proposed bandwidth based power-aware routing protocol with signal strength detection instead of using GPS. In our proposed routing protocol, we used the variation of received signal strength to predict transmission bandwidth and lifetime of a link. Accordingly, the possible data transmission amount and remaining power after data transmission can be predicted. With the prediction...
The coexistence of multimedia services in e-communication systems, with varying bandwidth utilization characteristics, impedes the efficiency of rate control and thereby impacts on the Quality of Service (QoS), in terms of low throughput. As such, the rate control for multimedia flows remains an open problem. This paper proposes a memetic optimization approach to rate allocation of multiclass services...
Orthogonal Frequency Division Multiplexing (OFDM) has emerged as a potential application for the delivery of broad band wireless access. Both DS and FH systems reduce the average power spectral density of a signal and affects by broadband noise. Narrowband interference impacts severely on an FH signal than a DS signal on the same channel. The combination of OFDM with Direct Sequence Spread Spectrum...
As one of the most popular high speed networks, InfiniBand demonstrates several enhanced features, such as RDMA and zero-copy mechanisms, which offer high bandwidth and low latency. Communication stacks IPoIB and SDP (Sockets Direct Protocol) have been proposed on InfiniBand for sockets based applications to take advantage of these features. However, these protocols are inefficient to utilize the...
The file download process over Internet is usually slow. This paper presents design and simulation of a distributed and co-ordinated file transfer protocol for the Internet applications. Presented approach, known as hybrid parallelized file transport protocol (HPFTP), consist of a centralized server that distributes the download process across multiple file servers based on QoS parameters as available...
Mobile ad-hoc network (MANET) is a multihop wireless network formed by a collection of mobile nodes wherein the nodes move arbitrarily thus making the topology dynamic. MANETs have low bandwidth wireless links hence the routing protocols with less consumption of bandwidth are of great importance. This paper presents a new location aware hybrid routing algorithm with reduced diffusion of routing related...
Ring is a promising on-chip interconnection for CMP. It is more scalable than bus and much simpler than packet-switched networks. The ordering property of ring can be used to optimize cache coherence protocol design. Existing ring protocols, such as the snooping ring protocol and the ring-order protocol need a retry and acknowledgement scheme or use the ordering property of the ring respectively to...
We consider the problem of allocating a large number of independent, equal-sized tasks to a heterogeneous large scale computing platform. We model the platform using a set of servers (masters) that initially hold (or generate) the tasks to be processed by a set of clients (slaves). All resources have different speeds of communication and computation and we model contentions using the bounded multi-port...
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