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 TitleDate AddedCompany
whitepaper A Practical Guide to WiMAX Antennas: MIMO and Beamforming Technical Overview2007-04-13 Motorola
  Wireless operators are increasingly pressured to enhance their networks and service capabilities in order to keep pace with the accelerating growth in wireless utilization and increasing demand for high performing connections. As bandwidth intensive, rich media applications are introduced, larger volumes of subscribers consume ever-growing quantities of data packets while continuing to utilize more minutes of voice. Simply acquiring more spectrum channels and deploying more sites to resolve capacity issues can be decidedly inefficient and costly. Revolutionary multiple antenna techniques at the base station and end-user device, paired with sophisticated signal processing, can dramatically improve the communications link for the most demanding application scenarios including heavily obstructed propagation environments and high speed mobility service.

Tags: Mobile - Wireless Communications, WiMAX (802.16)		   
whitepaper Inline Bandwidth Measurements: Implementation Difficulties and Their Solutions2007-04-12 Institute of Electrical and Electronics Engineers
  This paper has proposed the concept of inline network measurement, which involves the concept of "Plugging" an active bandwidth measurement into an active TCP connection. Mechanisms using this method have the advantage of requiring no extra traffic for measuring available bandwidth, whereas other active measurement tools cannot fundamentally avoid adding probing traffic onto the network. However, when the inline network measurement algorithms are implemented in general-purpose computers, some problems arise, such as the clock resolution of the kernel system, Interrupt Coalescence (IC) deployed in network interface cards, and the behavior of TCP receiver.

Tags: TCP - IP		   
whitepaper G-TCP to Govern Aggregate Throughput of the Parallel TCP Flows2007-04-05 University of Nebraska
  The growth rate of the Internet bandwidth has exponentially increased over past decades. As the Internet bandwidth grows new data-intensive applications such as climate simulation, earth observing, and high energy physics are emerging. Terabyte and petabyte data are required to transfer over the Internet. Many of these applications use the Transmission Control Protocol (TCP) for the reliable data transfer. Since the standard TCP, TCP Reno, was developed in 1988, it has been widely adopted and performed remarkably well. However, the standard TCP eventually underutilizes network bandwidth as bandwidth delay product continues to grow. The data intensive applications would demand to use tools such as GridFTP, bbcp, and pSocket which open multiple TCP flows in parallel to achieve higher throughput.

Tags: TCP - IP		   
whitepaper Application of Open Multi-Commodity Market Data Model on the Communication Bandwidth Market2007-04-01 Warsaw University
  In the paper the market model for Balancing Communication Bandwidth Trade (BCBT) is analyzed in the form of multi-commodity market data model (M3). The distinguishing feature of BCBT model is that it assumes that market players can place buy offers not only for isolated network resources - inter-node links, but also for end-to-end network paths of predefined capacity, that is, every offer concerns a point-to-point bandwidth connection between a pair of specified locations in a communication network. The model enables effective balancing of sell and buy offers for network resources in a way which maximizes global economic welfare.   
whitepaper Joint Scale-Lag Diversity in Mobile Wideband Systems2007-03-20 Ohio State University
  This paper considers the effect of mobility on a wideband Direct Sequence Spread Spectrum (DSSS) communication system, and study a scale-lag Rake receiver capable of leveraging the diversity that results from mobility. A wideband signal has a large bandwidth-to-center frequency ratio, such that the typical narrowband Doppler spread assumptions do not apply to mobile channels. Instead, the paper assumes a more general temporal scaling phenomenon, i.e., a dilation of the transmitted signal's time support. Based on uniform ring of scatterers model, the paper determines that the wideband scattering function, which quantifies the average scale spreading, has a "Bathtub-shaped" scale profile.

Tags: Mobile - Wireless Communications		   
whitepaper Inter-Protocol Fairness Between TCP New Reno and TCP Westwood+2007-03-20 French National Institute for Research in Computer Science and Control
  This paper investigates the effect of introducing TCP Westwood+ on regular TCP New Reno. By means of analytical modeling and ns-2 simulations, the paper demonstrates that the two protocols get different shares of the available bandwidth in the network. The main result is that the bandwidth sharing between the two protocols depends on one crucial parameter: the ratio between the bottleneck router buffer size and the bandwidth delay product. If the ratio is smaller than one, TCP Westwood+ takes more bandwidth. On the contrary, if the ratio is greater than one, it is TCP New Reno which gets the larger part.

Tags: TCP - IP		   
whitepaper Improving XCP to Achieve Max-Min Fair Bandwidth Allocation2007-02-27 University of California
  TCP is shown to be inefficient and instable in high speed and long latency networks. The eXplicit Control Protocol (XCP) is a new and promising protocol that outperforms TCP in terms of efficiency, stability, queue size, and convergence speed. However, Low et al. recently discovered a weakness of XCP. In a multi-bottleneck environment, XCP may achieve as low as 80% utilization at a bottleneck link and consequently some flows may only receive a small fraction of their max-min fair rates. This paper proposes iXCP, an improved version of XCP. Extensive simulations show that iXCP overcomes the weakness of XCP, and achieves efficient and fair bandwidth utilization in both single- and multi-bottleneck environments.

Tags: TCP - IP		   
whitepaper Measuring Bandwidth Signatures of Network Paths2007-02-27 North Carolina State University
  This paper proposes a practical and efficient technique, Forecaster, to estimate the end-to-end available bandwidth, and the speed of the most congested (tight) link along an Internet path. Forecaster is practical since it does not assume any a priori knowledge about the measured path, does not make any simplifying assumptions about the nature of cross-traffic, does not assume the ability to capture accurate packet dispersions or packet queueing delays, and does not try to preserve inter-packet spacing along path segments. It merely relies on a simple binary test to estimate whether each probe packet has queued in the network or not.   
whitepaper A Modeling Framework to Understand the Tussle Between ISPs and Peer-to-Peer File Sharing Users2007-02-26 Universita degli Studi di Torino
  Recent measurement studies have shown that traffic generated by Peer-to-Peer (P2P) file sharing applications has started to dominate the bandwidth consumption on Internet access links. The prevailing use of P2P applications carries with it significant implications for Internet Service Providers (ISPs): on the one hand increased levels of P2P traffic result in additional costs for an ISP, which has to provide a satisfactory service level to its subscribers. On the other hand, P2P applications are a major driving force for the adoption of broadband access, which is a significant source of revenue for the ISPs. A successful strategy to manage P2P traffic must address both the ISP perspective of costs and the subscriber perspective of quality of service.

Tags: Broadband, ISPs		   
whitepaper Resource Optimization to Provision a Virtual Private Network Using the Hose Model2007-02-14 University of Victoria
  Virtual Private Networks (VPN) provides a secure and reliable communication between customer sites over a shared network. With increase in number and size of VPNs, providers need efficient provisioning techniques that adapt to customer demands. The recently proposed hose model for VPN alleviates the scalability problem of the pipe model by reserving for its aggregate ingress and egress bandwidth instead of between every pair of VPN endpoints. Existing studies on quality of service guarantees in the hose model either deal only with bandwidth requirements or regard the delay requirement as the main objective ignoring the bandwidth cost. This paper proposes a new approach to enhance the hose model to guarantee delay requirements between endpoints while optimizing the provisioning bandwidth cost.

Tags: VPNs