Channel allocation schemes

About: Channel allocation schemes is a research topic. Over the lifetime, 10656 publications have been published within this topic receiving 182117 citations.

A Spectrum Surveying Framework for Dynamic Spectrum Access Networks

Abstract: Dynamic spectrum access networks and wireless spectrum policy reforms heavily rely on accurate spectrum utilization statistics, which are obtained via spectrum surveys. In this paper, we propose a generic spectrum-surveying framework that introduces both standardization and automation to this process, as well as enables a distributed approach to spectrum surveying. The proposed framework outlines procedures for the collection, analysis, and modeling of spectrum measurements. Furthermore, we propose two techniques for processing spectrum data without the need for a priori knowledge. In addition, these techniques overcome the challenges associated with spectrum data processing, such as a large dynamic range of signals and the variation of the signal-to-noise ratio across the spectrum. Finally, we present mathematical tools for the analysis and extraction of important spectrum occupancy parameters. The proposed processing techniques have been validated using empirical spectrum measurements collected from the FM, television (TV), cellular, and paging bands. Results show that the primary signals in the FM band can be classified with a miss-detection rate of about 2% at the cost of 50% false-alarm rate, while nearly 100% reliability in classification can be achieved with the other bands. However, the classification accuracy depends on the duration and the range of frequencies over which data are collected, as well as the RF characteristics of the spectrum measurement receiver.

Ultrascience net: network testbed for large-scale science applications

Abstract: UltraScienceNet is an experimental wide area network testbed to enable the development of networking technologies required for next-generation large-scale scientific applications. It provides on-demand dedicated high-bandwidth channels for large data transfers, and also high-resolution high-precision channels for fine control operations. In the initial deployment its data plane consists of several thousand miles of dual 10 Gb/s lambdas. The channels are provisioned on demand using layer 1 and 2 switches in the backbone and multiple service provisioning platforms at the edges in a flexible configuration using a secure control plane. A centralized scheduler is employed to compute future channel allocations, and a signaling daemon is used to generate the configuration signals to switches at appropriate times. The control plane is implemented using an out-of-band virtual private network, which encrypts the switching signals, and also provides authenticated user and application access. Transport experiments are conducted on a smaller test connection that provides us useful information about the basic properties and issues of utilizing dedicated channels in applications.

Orthogonal code division multiple access waveform format for use in satellite based cellular telecommunications

Abstract: A communications waveform format is provided for a satellite-based telecommunications system The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization The spectrum of the terminal links may be divided into multiple subbands (eg, 38), each of which may support multiple (eg, 80) ODS-CDMA channels The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FSC) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC) The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system

Cognitive Radio game for secondary spectrum access problem

Abstract: In this paper we develop a framework for resource allocation in a secondary spectrum access scenario, where a group of cognitive radios (CR) access the resources of a primary system. We assume the primary system is a cellular OFDM-based network operating in uplink. We develop an optimum resource allocation strategy, using cooperative game theory, which guarantees the primary's required QoS and allocates an achievable rate at a given bit error rate for the secondary, when possible. The proposed cognitive radio game (CRG) is a network-assisted resource management method, where users (both primary and secondary) inform the primary system's BS of their channel state information and power limitation and the base station calculates the optimum sub-channel and power allocation for all users. Using Game theoretic axiom of fairness, i.e., Nash Bargaining Solutions (NBS), we develop an alternative efficient and fair resource allocation and compare its performance with the proposed CRG method. We use Sequential Quadratic Programming (SQP) to solve the proposed non-linearly constrained CRG optimization problem.

Efficient data allocation over multiple channels at broadcast servers

Abstract: Broadcast is a scalable way of disseminating data because broadcasting an item satisfies all outstanding client requests for it. However, because the transmission medium is shared, individual requests may have high response times. In this paper, we show how to minimize the average response time given multiple broadcast channels by optimally partitioning data among them. We also offer an approximation algorithm that is less complex than the optimal and show that its performance is near-optimal for a wide range of parameters. Finally, we briefly discuss the extensibility of our work with two simple, yet seldom researched extensions, namely, handling varying sized items and generating single channel schedules.