Static Channel Allocation Research Articles

JARVA: Joint Application-Aware Oblivious Routing and Static Virtual Channel Allocation

This article proposes a joint application-aware oblivious routing and static virtual channel allocation framework to enable better deadlock-free performance in on-chip interconnection networks.

Joint Application-Aware Oblivious Routing and Static Virtual Channel Allocation

Application-aware oblivious routing that supports flow-specific routing and static virtual channel (VC) assignments can achieve better performance than conventional oblivious routing by accounting for traffic demands of various flows in a given application. However, because these prior approaches consider the application-aware routing and static VC assignment steps separately, they unnecessarily impose routing restrictions to avoid deadlocks. In this letter, we propose a joint application-aware oblivious routing and static VC allocation framework that optimally solves both problems together to enable better deadlock-free performance. The experimental results show that our approach can achieve up to 30% better performance than the state-of-the-art application-aware oblivious routing algorithms and substantially better still in comparison with conventional oblivious routing approaches.

An improved fast transform algorithm based on adaptive hybrid channel allocation in TSCH networks

Time Slotted Channel Hopping (TSCH) is one of the five access behavior technologies defined in the IEEE 802.15.4e standard. Research shows that the wireless sensor network with single dynamic and static channel allocation in TSCH mode has higher performance. The clogging rate results in unnecessary energy waste. Therefore, this paper proposes an adaptive hybrid channel allocation strategy (AHCA) to measure the link quality change of wireless sensor networks in TSCH mode. The strategy estimates the part of the channel quality and determines whether the node wants to transmit on this channel and the optimal channel for node information transmission. According to the change of the amount of information transmitted, the hybrid channel allocation scheme of the dynamic and static channel ratio is adaptively adjusted to reduce the energy consumption of the information transmission process. This article performs experimental simulation on Contiki-NG. The experimental results show that the proposed scheme has shorter transmission time and lower congestion rate than the single dynamic static channel allocation wireless sensor network. The more reasonable and effective measurement, analysis and use of channel resources can fundamentally increase the amount of information transfer in wireless sensor networks per unit time, and thus extend the lifetime of wireless sensor networks.

Noise-suppressing channel allocation in dynamic DWDM-QKD networks using LightGBM.

Integrating quantum key distribution (QKD) with existing optical networks is highly desired to reduce the deployment costs and achieve efficient resource utilization, and some point-to-point transmitting experiments have verified its feasibility. Nevertheless, there are still many problems in the realistic scenario where QKD coexists with dynamic data traffics. On the one hand, the conventional static channel allocation schemes cannot guarantee the quality of quantum channels in the presence of the time-varying noises. On the other hand, considering the complex noise generation caused by dynamic classical data traffics with variable characters, it is challenging to achieve online high-performance quantum channel assignments. To address these problems, we propose a machine learning based noise-suppressing channel allocation (ML-NSCA) scheme. In this scheme, the LightGBM based ML framework is trained to predict the optimal channel allocations with lowest noise impacts, according to which, the quantum channels are periodically reallocated to guarantee high secure key rate. To improve the accuracy and scalability of the ML framework, we also optimize the method of feature extraction during the training process. The performance evaluation results indicate that the proposed scheme can effectively resist the dynamic noise impacts in the realistic optical networks and obtain higher secure key rate with less operation complexity than the previous schemes.

Approximating Common Control Channel Problem in Cognitive Radio Networks

Cognitive radio networks (CRNs) involve an extensive exchange of control messages to coordinate spectrum sensing, medium access, routing, etc. Static control channel allocation uses preassigned common control channel (CCC) contrary to the opportunistic access paradigm. We propose a k-hop clustering scheme for the optimal CCC assignment problem (k-CCCP) for CRNs. We prove that the k-CCCP problem is NP-hard (nondeterministic polynomial-time hard) by reduction using minimum dominating set problem. We also found that the k-CCCP problem is approximable hard. We propose a ln Δ approximation algorithm for the k-CCCP problem, where Δ is the largest cardinality among all khop neighborhood in a CRN. To account for primary user dynamics, we propose a distributed ranking algorithm for the k-CCCP problem with message complexity O(nδk), where n, δ, and k are number of nodes, the largest node degree, and hop parameter, respectively. To address the negative effect of multihop clustering, we also propose a mechanism to find the optimal k value in multihop clustering. For performance comparison, extensive simulations are performed and the results show that our proposed scheme outperforms with the competitive schemes.

A Channel Allocation Mechanism for Cellular Networks

In cellular networks, call blocking causes lower customer satisfaction and economic loss. Therefore, the channel allocation for call block avoidance is an important issue. This study proposes a mechanism that considers the real-time traffic information (e.g., traffic flow and vehicle speed) and the user behavior (e.g., call inter-arrival time and call holding time) to analyze the adaptable number of communication calls in the specific cell for channel allocation. In experiments about call block probabilities (CBP), this study simulated two cases that are the situations of the whole day and traffic accident. The simulation results show that all CBPs in the scenario of whole day are less than 21.5% by using the proposed mechanism, which is better than using the static channel allocation (SCA) mechanism. Moreover, all CBPs in the scenario of traffic accidents are less than 16.5% by using the proposed mechanism, which is better than using the SCA mechanism. Therefore, the proposed mechanism can decrease the number of CBPs effectively.

Fault-Aware Load-Balancing Routing for 2D-Mesh and Torus On-Chip Network Topologies

Routing algorithm design for on-chip networks (OCNs) has become increasingly challenging due to high levels of integration and complexity of modern systems-on-chip (SoCs). The inherent unreliability of components, embedded oversized IP blocks, and fine-grained voltage-frequency islands (VFIs) management among others, raise several challenges in OCNs: (a) network topologies become irregular or asymmetric making circular route dependencies that lead to deadlock hard to detect; and (b) routing algorithms that lack strong load-balancing properties often saturate prematurely. In order to address the aforementioned deadlock and load-balancing problems, we propose the traffic balancing oblivious routing (TBOR) algorithm. It is a two-phase routing algorithm consisting of: (1) construction of the weighted acyclic channel dependency graph (CDG) for the OCN to efficiently maximize available resource utilization; and (2) channel ordering across turn models to keep the underlying CDG cycle-free to guarantee deadlock-freedom using one or more turn-models. Channel bandwidth utilization and traffic balancing are achieved through static virtual channel allocation according to residual bandwidth of healthy links. In addition, we introduce in this work two schemes of different granularity of fault detection and analysis while guaranteeing in-order packet delivery by assigning a unique path to each flow. Extensive experiments demonstrate the proposed routing methodology outperforms previous algorithms.

Dynamic Channel Allocation in Mobile Multimedia Networks Using Error Back Propagation and Hopfield Neural Network (EBP-HOP)

In mobile multimedia communication systems, the limited bandwidth is an issue of serious concern. However for the better utilization of available resources in a network, channel allocation scheme plays a very important role to manage the available resources in each cell. Hence this issue should be managed to reduce the call blocking or dropping probabilities. This paper gives the new dynamic channel allocation scheme which is based on handoff calls and traffic mobility using hopfield neural network. It will improve the capacity of existing system. Hopfield method develops the new energy function that allocates channel not only for new call but also for handoff calls on the basis of traffic mobility information. Moreover, we have also examined the performance of traffic mobility with the help of error back propagation neural network model to enhance the overall Quality of Services (QoS) in terms of continuous service availability and intercell handoff calls. Our scheme decreases the call handoff dropping and blocking probability up to a better extent as compared to the other existing systems of static and dynamic channel allocation schemes.

Dynamic Channel Allocation Technique for Distributed Multi-radio Multichannel Multi-path Routing Protocol in Wireless Mesh Networks

Wireless Mesh Networks (WMNs) have gained main attraction in providing flexible network services and support to the end users. There are many efforts seen to design robust routing protocol for WMNs and solutions are proposed to standardized channel allocation techniques. There are various approaches dedicated to maximize the network though put and minimize network interface. Existing multi radio multi channel routing protocols utilize only single channel situation and static channel allocation degrades the performance of the WMNs. The challenge is to allocate channel without link interference and to improve end-to-end throughput efficiency in multipath routing for WMNs. In this paper, we propose a dynamic channel allocation technique is proposed for multi path routing protocol for WMNs. Dynamic channel allocation is used to avoid the inter-flow and intra-flow channel competition and interference. The protocol establishes and maintains multiple channel dimensional disjoint points changing frequently and each data flow is separated into multiple paths. NS2 simulations are carried out for the evaluation of the performance of the proposed channel allocation technique and compared with popular routing protocols of Mesh Networks Ad hoc On Demand Distance Vector Routing Protocol (AODV) and Hybrid Wireless Mesh Protocol (HWMP). The simulation results show that proposed dynamic channel allocation technique achieve better adaptability with less overhead and interference. The multipath routing show increase end-to-end throughput significantly.

An Efficient Adaptive Channel Allocation Scheme For Cellular Networks

Cellular networking is providing global information access to users on the move. Handoff algorithms allow the users to move among heterogeneous wireless networks. In this paper, the authors have proposed an efficient Adaptive Channel Allocation Scheme (ACAS) where the number of guard channels is adjusted automatically based on the average handoff blocking rate measured in the past certain period of time. The handoff blocking rate and the new call blocking rates are minimized. It is seen that the proposed scheme is far efficient than the Static Channel Allocation Scheme. The resource utilization of the proposed scheme is more.

Optimal and Heuristic Application-Aware Oblivious Routing

Conventional oblivious routing algorithms do not take into account resource requirements (e.g., bandwidth, latency) of various flows in a given application. As they are not aware of flow demands that are specific to the application, network resources can be poorly utilized and cause serious local congestion. Also, flows, or packets, may share virtual channels in an undetermined way; the effects of head-of-line blocking may result in throughput degradation. In this paper, we present a framework for application-aware routing that assures deadlock freedom under one or more virtual channels by forcing routes to conform to an acyclic channel dependence graph. In addition, we present methods to statically and efficiently allocate virtual channels to flows or packets, under oblivious routing, when there are two or more virtual channels per link. Using the application-aware routing framework, we develop and evaluate a bandwidth-sensitive oblivious routing scheme that statically determines routes considering an application's communication characteristics. Given bandwidth estimates for flows, we present a mixed integer-linear programming (MILP) approach and a heuristic approach for producing deadlock-free routes that minimize maximum channel load. Our framework can be used to produce application-aware routes that target the minimization of latency, number of flows through a link, bandwidth, or any combination thereof. Our results show that it is possible to achieve better performance than traditional deterministic and oblivious routing schemes on popular synthetic benchmarks using our bandwidth-sensitive approach. We also show that, when oblivious routing is used and there are more flows than virtual channels per link, the static assignment of virtual channels to flows can help mitigate the effects of head-of-line blocking, which may impede packets that are dynamically competing for virtual channels. We experimentally explore the performance tradeoffs of static and dynamic virtual channel allocation on bandwidth-sensitive and traditional oblivious routing methods.

Survey of Channel Allocation Algorithms Research for Cellular Systems

<b> </b><b> </b>In recent years, we have witnessed a huge interest in the study of channel allocation and handoff strategies for cellular systems to ensure continuous services that guarantee QoS to mobile users. In this paper, we have a detailed discussion of different categories of wireless channel allocation schemes. The basic purpose of the study is to provide a comprehensive review of different categories of channel allocation algorithms in cellular systems and to recommend future directions of research in the area. The paper gives a survey of published papers for discussing channel allocation schemes for cellular system. The QoS is always a major concern for the services offered through cellular systems and it is observed that there are always trade-offs among various parameters of the QoS of these services. There are many published papers which have taken care of different QoS parameters such as call blocking probability, call dropping probability along with other performance parameters. This paper provides details of the different categories of channel allocation schemes including static channel allocation, dynamic channel allocation and hybrid channel allocation studied in literature. Also in this paper, we explore the different channel allocation strategies, including the scenarios in which channel allocation strategies based on centralized channel control, distributed channel control, mutual exclusion algorithms and genetic algorithms, are used. Also, we have summarizes trade-offs between different channel allocation schemes in terms of their complexity and performance. In this paper, channel allocation in different context of complex situations such as the ones arising in offering multimedia based services and other arising in the channel allocation for mobile base station systems and use of power management in channel allocation are explained. This paper also examines different handoff handling provision and prioritization schemes proposed in the literature for cellular systems.

Cluster-Based Control Channel Allocation in Opportunistic Cognitive Radio Networks

Cognitive radio networks (CRNs) involve extensive exchange of control messages, which are used to coordinate critical network functions such as distributed spectrum sensing, medium access, and routing, to name a few. Typically, control messages are broadcasted on a preassigned common control channel, which can be realized as a separate frequency band in multichannel systems, a given time slot in TDMA systems, or a frequency hopping sequence (or CDMA code) in spread spectrum systems. However, a static control channel allocation is contrary to the opportunistic access paradigm. In this paper, we address the problem of dynamically assigning the control channel in CRNs based on time- and space-varying spectrum opportunities. We propose a cluster-based architecture that allocates different channels for control at various clusters in the network. The clustering problem is formulated as a bipartite graph problem, for which we develop a class of algorithms that provide different tradeoffs between two conflicting factors: number of common channels in a cluster and the cluster size. Clusters are guaranteed to have a desirable number of common channels for control, which facilitates for graceful channel migration when primary radio (PR) activity is detected, without the need for frequent reclustering. We perform extensive simulations that verify the agility of our algorithms in adapting to spatial-temporal variations in spectrum availability.

A Novel Adaptive Channel Allocation Scheme To Handle Handoffs

Wireless networking is becoming an increasingly important and popular way of providing global information access to users on the move. One of the main challenges for seamless mobility is the availability of simple and robust handoff algorithms, which allow a mobile node to roam among heterogeneous wireless networks. In this paper, the authors devise a scheme, A Novel Adaptive Channel Allocation Scheme (ACAS) where the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain period of time. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the ACAS is done through simulation of nodes. The result shows that the ACAS scheme outperforms the Static Channel Allocation Scheme by controlling a hard constraint on the handoff rejection probability. The proposed scheme achieves the optimal performance by maximizing the resource utilization and adapts itself to changing traffic conditions automatically.

Application-aware deadlock-free oblivious routing

Conventional oblivious routing algorithms are either not application-aware or assume that each flow has its own private channel to ensure deadlock avoidance. We present a framework for application-aware routing that assures deadlock-freedom under one or more channels by forcing routes to conform to an acyclic channel dependence graph. Arbitrary minimal routes can be made deadlock-free through appropriate static channel allocation when two or more channels are available. Given bandwidth estimates for flows, we present a mixed integer-linear programming (MILP) approach and a heuristic approach for producing deadlock-free routes that minimize maximum channel load. The heuristic algorithm is calibrated using the MILP algorithm and evaluated on a number of benchmarks through detailed network simulation. Our framework can be used to produce application-aware routes that target the minimization of latency, number of flows through a link, bandwidth, or any combination thereof.

Optimal scheduling for dynamic channel allocation in wireless LANs

Channel allocation schemes that have been used in cellular wireless networks have limited applicability to wireless LANs (WLANs) because of the small number of available channels and irregular cell geometries in WLAN environments. In this paper, we propose a dynamic, frame-based channel allocation architecture for WLANs. In this architecture, time is divided into a sequence of consecutive frames (in the order of milliseconds), and in each frame, only a non-interfering subset of access points (APs) is activated. Under broad traffic assumptions, we prove that the attainable system throughput can be optimized by scheduling APs and allocating channels in each frame such that a weighted sum of queue sizes at the activated APs is maximized. This optimality criterion for AP scheduling and channel allocation leads to a novel graph problem which is a variant of the well-known maximum independent set problem. We develop an approximation algorithm that has quadratic time complexity (in the number of APs) and, under certain conditions, yields a constant (6) factor approximation bound. Using the ns2 simulator we conducted experiments to compare our frame-based approach to static channel allocation. Results of our simulation indicate that our approach is able to deliver system throughput improvements of more than 50%.

Dynamic Wavelength and Bandwidth Allocation in Hybrid TDM/WDM EPON Networks

We discuss a wavelength-division-multiplexed-based passive-optical-network (PON) architecture that allows for incremental upgrade from single-channel time-division multiple-access PONs in order to provide higher bandwidth in the access network. Various dynamic-wavelength and bandwidth-allocation algorithms (DWBAs) for wave-division multiplexed PON are presented; they exploit both interchannel and intrachannel statistical multiplexing in order to achieve better performance, especially when the load on various channels is not symmetric. Three variants of the DWBA are presented, and their performance is compared. While the first variant incurs larger idle times (and, hence, poor performance), the other two algorithms achieve better but different performance with critical dissimilarities. Our analysis also focuses on the fair assignment of excessive bandwidth in the upstream direction to highly loaded optical network units. We compare the performance of DWBA to another algorithm that relies on static-channel allocation. Furthermore, a study is presented wherein the number of wavelengths increases, and a comparison with interleaved polling with adaptive cycle time is shown. We use extensive simulations throughout this paper

A simulation environment for GPRS traffic in an advanced travellers information system (ATIS)

General Packet Radio Service (GPRS)—a bearer service to GSM—has been deployed worldwide, and is widely considered a technology precursor to the evolving third generation (3G) wireless networks. The general conception has been that while users will be exposed to faster wide-area wireless data access, experience gained from GPRS could well prove useful for 3G, and also for systems beyond 3G deployment. In this paper, we present a comprehensive simulation study for different traffic scheduling algorithms for Quality of Service (QoS) in GPRS at the IP level. We first study the correlation between GSM and GPRS users, and show how a dynamic channel allocation scheme between GSM–GPRS can give substantially better performance than the static ones. We then extend our study by taking into account users requirements for different QoS profiles, based on seven different scheduling algorithms in GPRS. By simulating traffic related to an ATIS (Advanced Travellers Information System) at the IP level, we show how traffic scheduling algorithms perform by taking into account different performance parameters such as the average traffic, average waiting time in the scheduler, packet loss probabilities in the scheduler based on static and dynamic channel allocation schemes, packet priorities as well as average throughput per-GPRS user. The study gives a comparative analysis for various scheduling