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 network flow framework for online dynamic channel allocation

Abstract: We present a framework based on network flows for dynamic channel allocation. The framework allows us to gracefully extend previously proposed heuristics, while avoiding the problems associated with the optimal packing schemes. The framework is shown to yield parametrizable algorithms that tradeoff the benefit of channel reassignments with the costs. Channel reassignments are allowed to be performed not just at new call arrivals, but also at various other trigger points like call terminations and channel quality deterioration.

Resource Allocation for Video Streaming in Heterogeneous Cognitive Vehicular Networks

Abstract: In future fifth-generation (5G) communication systems, driven by the evolution of today's most demanding applications, video streaming over vehicle networks will play an increasingly significant role in our daily lives. In this paper, based on a heterogeneous architecture consisting of both cellular base stations (BSs) of wide coverage and cognitive-radio-enabled roadside infrastructures, a semi-Markov decision process (SMDP)-based resource-allocation scheme is proposed to facilitate video streaming application in terms of peak signal-to-noise ratio (PSNR) and smooth playback. In addition to improving video quality of vehicle users, quality of service (QoS) provisioning for background users that can originally exist in the cellular network is also considered in the proposed scheme. Specifically, based on the states of the background users, vehicle users, and the availability of the cognitive bands, the optimal resource allocation, aiming at maximizing the video streaming quality while guaranteeing the call-level performance of the background users, is achieved by addressing two interrelated joint call admission control (CAC) and channel allocation problems for cellular and roadside infrastructure networks, respectively. Simulation results show that the proposed scheme can well protect background users when coexisting with bandwidth-hungry vehicle video users and is effective in not only improving video streaming quality for vehicle users but boosting bandwidth utilization of the whole network as well.

Distributed wireless channel allocation in networks with mobile base stations

Abstract: A mobile computing system with no fixed nodes is presented. In traditional cellular systems with fixed base stations the channel reuse pattern is static and deterministic. When the cell layout is dynamic, due to the mobility of base stations, the cluster of cells within co-channel interference range changes with time. Consequently, the channel reuse pattern is highly dynamic, Moreover, base stations also need wireless channels to communicate amongst themselves. A communication session between a pair of nodes may have to switch channels due to the movement of other nodes into the neighborhood. Hence, there is a need for new wireless channel allocation algorithms for virtual cellular systems with mobile base stations. In this paper, principles of mutual exclusion pertaining to distributed computing systems are employed to develop such an algorithm. The inter-base station wireless links are referred to as backbone links while the base station-mobile node links are referred to as short-hop links. The proposed algorithm is distributed, dynamic and deadlock free. Disjoint sets of channels are used for backbone and short-hop links. The distributed nature of the channel allocation scheme leads to robustness as the responsibility is no longer centralized at the MTSO. Instead, it is shared among all the mobile base stations. This also makes the algorithm scalable.

Cross-Layer Resource Allocation for Video Streaming Over OFDMA Cognitive Radio Networks

Abstract: In this paper, a cross-layer resource allocation algorithm is proposed in the context of orthogonal frequency division multiple access (OFDMA)-based cognitive radio (CR) video application systems. User video quality and channel awareness are incorporated in the design, towards an optimal subcarrier and power allocation scheme, subject to minimum secondary receiver (SRx) video quality and primary receiver (PRx) interference threshold constraints. First, the relationship between PRx interference margin and power limits at the secondary transmitter (STx) is analytically derived. Then, to provide PRx with satisfactory quality of service (QoS), we propose a new probabilistic approach to mitigate the total imposed interference of the STx on PRx, considering imperfect STx to PRx channel state information (CSI). The effect of PRx interference limit violation probability, interference threshold, and error variance of imperfect CSI are evaluated through mathematical analysis and computer simulations. Results indicate that significant improvement in SRx total video quality is achieved through our proposed quality-aware (QA) algorithm over other state-of-the-art non-quality-aware (NQA) designs in the literature. The enhanced performance was obtained whilst guaranteeing SRx minimum quality and PRx prescribed QoS constraints.

Fully Distributed Optimal Channel Assignment for Open Spectrum Access

Abstract: In this paper, we address the problem of fully distributed assignment of users to sub-bands such that the sum-rate of the system is maximized. We introduce a modified auction algorithm that can be applied in a fully distributed way using an opportunistic CSMA assignment scheme and is e optimal. We analyze the expected time complexity of the algorithm and suggest a variant to the algorithm that has lower expected complexity. We then show that, in the case of i.i.d. Rayleigh channels, a simple greedy scheme is asymptotically optimal as SNR increases or as the number of users is increased to infinity. We conclude by providing simulated results of the suggested algorithms.