Channel Allocation Technique Research Articles

Distributed Efficient Channel Allocation Technique for Multi-Radio Multichannel Interference-aware Multi-path Routing Protocol in Wireless Mesh Networks.

Distributed Efficient Channel Allocation Technique for Multi-Radio Multichannel Interference-aware Multi-path Routing Protocol in Wireless Mesh Networks.

Channel Allocation with Sub-Optimal Power Control in WiMAX Networks Using Fuzzy Inference System

Abstract Power allocation and energy consumption of mobile subscriber stations are very important issues for the WiMAX (IEEE 802.16) networks. This paper proposes a dynamic channel allocation technique for efficient power management in multi-channel IEEE 802.16 networks (WiMAX). In our scheme, each Subscriber Station (SS) has one transceiver and can be tuned between multiple channels, intending to eliminate the secondary interference. The Base Station (BS) identifies the data rate required by a SS for proper communication and allocates a channel with specific bandwidth with sub-optimal transmission power to suite the data rate requirement. The estimated power requirement and interference levels are fuzzified to identify the feasible solutions. Matlab Simulations demonstrate the effectiveness of the proposed method in terms of Channel Acquisition Delay, Average Transmitter Power and Packet Delivery ratio.

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.

Broadband Self-Organizing Network Channel Allocation

This paper discussed the current variety of effective multi-channel self-organizing network channel allocation techniques and proposed a combination of two access methods CSMA and TDMA. By using broadband wireless self-organizing network channel and OPNET simulation tools,the methods can build self-organizing network simulation scenarios that proposed network protocols performance analysis. This self-organizing network channel allocation can effectively transmit information and avoid the conflict of different communication node distribution of the corresponding channel.

Token based distributed dynamic channel allocation in wireless communication network

Channel allocation in wireless communication network plays a crucial role in the performance of the network. Fixed scheme for channel allocation does not account for any non-uniform traffic in the network. Dynamic scheme, on the other hand, ensures that whenever a cell requires a channel, it is allocated pertaining to the frequency reuse constraints. The fact that distributed dynamic channel allocation technique has recently gained popularity is due to its high reliability and scalability. In this paper we propose a token based mutual exclusion technique to solve the problem of distributed dynamic channel allocation. We will show through simulation, how message exchange between cells is reduced in token based relaxed mutual exclusion as opposed to other relaxed mutual exclusion techniques.

Optimal Golomb ruler sequence generation for FWM crosstalk elimination: Soft computing versus conventional approaches

Four-wave mixing (FWM) crosstalk is the dominant nonlinear effect in long haul, repeaterless, wavelength division multiplexing (WDM) lightwave fiber optical communication systems. To reduce FWM crosstalk in optical communication systems, unequally spaced channel allocation method is used. One of the unequal bandwidth channel allocation techniques is designed by using the concept of Golomb ruler. It allows the gradual computation of an optimally allocated channel set such that degradations caused by inter-channel interference (ICI) and FWM is minimal. This paper applies two soft computing based approaches, i.e., Genetic Algorithm (GA) and Biogeography Based Optimization (BBO) to generate near-optimal Golomb ruler sequences in reasonable time. The generated sequences have been compared with the two other classical approaches namely Extended Quadratic Congruence (EQC) and Search Algorithm (SA). It has been observed that BBO/GA outperforms the other two approaches.

Software Agent Structure for Performance Index Improvement of Cellular Network

Efficient reuse of limited radio spectrum is vital issue to support increasing number of mobile terminals and heterogeneous traffic scenarios. Dynamic channel allocation (DCA) technique is suitable to solve the problem. The drawback of dynamic channel allocation is it may upgrade performance of one cluster and degrade performance of other cluster in large scale cellular network. To balance performance of clusters and increase carried traffic in network, there is need of enhancement of DCA techniques. To introduce improvement in the dynamic channel approach, the paper suggested Multi Agent System (MAS) of physical agents ported at base stations working on the principle of cooperative negotiation to improve the QoS of the network. We formulated an integrated framework which includes fundamental mechanism of call admission control and resource management using hybrid channel allocation (HCA). To balance performance index of various clusters of network, agent negotiation is executed. Our simulation results show that it is possible to significantly enhance performance index of network due to MAS-HCA approach when compared with ES based and ILP based HCA schemes proposed in literature.

Dynamic resource allocation scheme under traffic condition in satellite systems

As the traffic distribution in China mainland is far from uniform, a new traffic model in China mainland is presented on the basis of per-capita Gross Domestic Product (GDP) and density of population. Based on this characteristic traffic model, a new Traffic Dependent Dynamic Channel Allocation and Reservation (TDDCAR) technique is proposed, the simulation model is built, and the strategies’ performance is evaluated through computer simulation. The simulation results show that, compared to the conventional Fixed Channel Allocation (FCA), TDDCAR estimates the traffic conditions in every spot beam and frequently adjusts the traffic according to current traffic conditions. It has achieved a significant improvement in new call blocking probability, handover blocking probability, and fair index, particularly, in heavy traffic conditions. The building of traffic model in China mainland and the analysis of the simulation results has been a key foundation for the study of resource allocation schemes in the future.

A Resource Allocation Scheme of Low-Earth Orbit Satellite System Based on the Traffic Modelling

Traffic modelling is the foundation of satellite resource management. Considering the uneven traffic distribution in China, a traffic model of low-earth orbit satellite is established in this study according to the per-capita GDP and the density of population. Base on this model, a new dynamic channel allocation and reservation (DCAR) technique is proposed. The performance of the call blocking probability, the handoff blocking probability and the channel utilisation is evaluated by simulation. Different from the fixed channel allocation, DCAR implements channel allocation by estimating the traffic conditions of all spot beams. The simulation results show that DCAR achieves a significant improvement on call blocking probability and handover blocking probability, particularly under heavy traffic load.

Forecasting-Based Dynamic Virtual Channel Management for Power Reduction in Network-on-Chips

In this paper, a forecasting-based dynamic virtual channel allocation technique for reducing the power consumption of network on chips is introduced. Based on the network traffic as well as past link and total virtual channel utilizations, the technique dynamically forecasts the number of virtual channels that should be active. It is based on an exponential smoothing forecasting method that filters out short-term traffic fluctuations. In this technique, for low (high) traffic loads, a small (large) number of VCs are allocated to the corresponding input channel. To assess the efficacy of the proposed method, the network on chip has been simulated using uniform, transpose, hotspot, NED, and realistic GSM voice codec traffic profiles. Simulation results show that up to a 35% reduction in the buffer power consumption and up to 20% savings in the overall router power consumption may be achieved. The area and power dissipation overheads of the technique are negligible.

A Hybrid Resource Allocation Strategy with Queuing in Wireless Mobile Communication Networks

The main objective of third and future wireless mobile communication networks is to provide services efficiently to the mobile users in all environments. In wireless mobile Communication the channel allocation and quality of service are the major factors and important issues to decide the system performance. Here in our work a Hybrid Channel Allocation(HCA)strategy for channel allocation and queuing technique applied to Hybrid Channel Allocation strategy for Quality of Service(QoS) provisioning are implemented. The proposed HCA strategy considers new calls in Fixed Channel Allocation (FCA) method and handoff calls in Dynamic Channel Allocation (DCA) method to reduce the call blocking and call dropping probabilities. The application of queuing technique applied to HCA strategy increases the efficiency of the cellular system performance especially in micro and pico cellular environments and effectively utilize the available allocated radio spectrum. The performance shows the decrease in call blocking and dropping and an increased number of users in the available channels.

Channel Asymmetry in Cellular OFDMA-TDD Networks

This paper studies time division duplex- (TDD-) specific interference issues in orthogonal frequency division multiple access- (OFDMA-) TDD cellular networks arising from various uplink (UL)/downlink (DL) traffic asymmetries, considering both line-of-sight (LOS) and non-LOS (NLOS) conditions among base stations (BSs). The study explores aspects both of channel allocation and user scheduling. In particular, a comparison is drawn between the fixed slot allocation (FSA) technique and a dynamic channel allocation (DCA) technique for different UL/DL loads. For the latter, random time slot opposing (RTSO) is assumed due to its simplicity and its low signaling overhead. Both channel allocation techniques do not obviate the need for user scheduling algorithms, therefore, a greedy and a fair scheduling approach are applied to both the RTSO and the FSA. The systems are evaluated based on spectral efficiency, subcarrier utilization, and user outage. The results show that RTSO networks with DL-favored traffic asymmetries outperform FSA networks for all considered metrics and are robust to LOS between BSs. In addition, it is demonstrated that the greedy scheduling algorithm only offers a marginal increase in spectral efficiency as compared to the fair scheduling algorithm, while the latter exhibits up to 20% lower outage.

Systematic Tracking of the Random Movement of a Mobile in Cellular Mobile Network

In wireless networks we evaluate the distance of a mobile from its base station and from other base stations in some neighboring cells to estimate a channel and also to measure interference caused by a co-channel. In this paper a systematic tracking of the random movement of a mobile is presented. In this work we find the position of any mobile at any point of time within its complete call duration. Using this model not only we can locate the mobile but also can find the distance of any mobile from the base station of the same cell and also when they belong to different cells. Such a model seems to be very promising in giving a platform to study the performance of HCA/FLCA and DCA like advanced channel allocation techniques.

Improvement of borrowing channel assignment for patterned traffic load by online cellular probabilistic self-organizing map

This paper describes an improvement of borrowing channel assignment (BCA) for patterned traffic load by using the short-term traffic prediction ability of cellular probabilistic self-organizing map (CPSOM). The fast growing cellular mobile systems demand more efficient and faster channel allocation techniques today. In case of patterned traffic load, the traditional BCA methods are not efficient to further enhance the performance because heavy-traffic cells cannot borrow channels from their neighboring cells with light or medium traffic that may have unused nominal channels. The performance can be increased if the short-term traffic load can be predicted. The predicted results can then be used for channel re-assignment. Therefore, the unused nominal channels of the light-or-medium-traffic cells can be transferred to the heavy-traffic cells that need more nominal channels. In this paper, CPSOM is used online for traffic prediction. In this sense, the proposed CPSOM-based BCA method is able to enhance the performance for patterned traffic load compared with the traditional BCA methods. Simulation results corroborate that the proposed method enables the system to work with better performance for patterned traffic load than the traditional BCA methods.

Using Cellular Probabilistic Self-Organizing Map in Borrowing Channel Assignment for Patterned Traffic Load

The fast growing cellular mobile systems demand more efficient and faster channel allocation techniques. Borrowing channel assignment (BCA) is a compromising technique between fixed channel allocation (FCA) and dynamic channel allocation (DCA). However, in the case of patterned traffic load, BCA is not efficient to further enhance the performance because some heavy-traffic cells are unable to borrow channels from neighboring cells that do not have unused nominal channels. The performance of the whole system can be raised if the short-term traffic load can be predicted and the nominal channels can be re-assigned for all cells. This paper describes an improved BCA scheme using traffic load prediction. The prediction is obtained by using the short-term forecasting ability of cellular probabilistic self-organizing map (CPSOM). This paper shows that the proposed CPSOM-based BCA method is able to enhance the performance of patterned traffic load compared with the traditional BCA methods. Simulation results corroborate that the proposed method delivers significantly better performance than BCA for patterned traffic load situations, and is virtually as good as BCA in the other situations analyzed.

Centralized Channel Allocation Technique to Alleviate Exposed Terminal Problem in CSMA/CA-Based Mesh Networks--Solution Employing Chromatic Graph Approach--

This paper proposes a channel allocation principle that prevents TCP throughput degradation in multihop transmissions in a mesh network based on the carrier sense multiple access with collision avoidance (CSMA/CA) MAC protocol. We first address the relationship between the network topology of wireless nodes and the TCP throughput degradation based on computer simulations. The channel allocation principle is discussed in terms of resolution into a coloring problem based on throughput degradation. The number of required channels for the proposed channel allocation principle is evaluated and it is shown that two channels are sufficient for more than 96% simulated multihop patterns. The proposed channel allocation principle is extendable to generic mesh networks. We also clarify the number of required channels for mesh networks. The simulation results show that three channels are sufficient for more than 98% patterns in the generic mesh networks when the number of nodes is less than 10.

An Efficient Channel Allocation Technique for Multiple Videos-on-Demand

There are several broadcasting protocols for video-on-demand (VOD). Most of these protocols are tailored to handle the distribution of single video for a specific range of request arrival rates. In order to distribute multiple videos, broadcasting protocols like fast broadcasting (FB), new pagoda broadcasting (NPB) and universal distribution (UD) require more channels that are proportional to the number of hot videos to be broadcast. We present here an efficient broadcasting protocol in which, channel numbers can be reduced when multiple videos are broadcast either simultaneously or asynchronously. During the low to moderate request rates, our protocol performs best as similar to other reactive protocols and saves bandwidth and requires lesser number of channels as compared to other proactive or reactive protocols.

On the development of fully adaptive channel allocation strategies for usage in high‐capacity cellular mobile radio systems

AbstractAn alternative mathematical expression for the co‐channel interference probability is used, in order to calculate the cellular mobile radio system capacity and to construct a set of compatibility constraints needed for the development of fully adaptive channel allocation (FACA) strategies. The development of such channel allocation techniques becomes a main thrust for the system engineers in order to design an efficient system to manage traffic demands over the service area of a third generation cellular system. Three proposed FACA strategies are analysed and a simulation model is developed, in order to examine the performance of these strategies. Copyright © 2001 John Wiley & Sons, Ltd.

Cellular channel assignment: a new localized and distributed strategy

As the use of mobile communications systems grows, the need arises for new and more efficient channel allocation techniques. The total number of available channels on a real-world network is in fact a scarce resource, and many assignment heuristics suffer from a clear lack of flexibility (this is the case of Fixed Channel Allocation), or from high computational and communication complexity (as with channel borrowing techniques). Performance can be improved by representing the system with an objective function whose minimum is associated with a good configuration; the various constraints appear as penalty terms in the function. The problem is thus reduced to the search for a minimum, that is often performed via heuristic algorithms like Hopfield neural networks, simulated annealing or reinforcement learning. These strategies usually require a central process to have global information and decide for all cells. We consider an objective-function formulation of the channel assignment problem that has been previously solved by search heuristics; we prove that the search time for the global minimum of the objective function is O(n log n), and therefore there is no need for search techniques. Finally we show that the algorithm that arises from this formulation can be modified so that global knowledge and synchronization are no longer required, and we give its distributed version. By simulating a cellular network with mobile hosts on a hexagonal cell pattern with uniform call distribution, we show that our technique actually performs better than the best known algorithms.

Adaptive antenna array assisted dynamic channel allocation techniques

The performance of base station adaptive antenna arrays (AAAs) is investigated in conjunction with fixed channel allocation (FCA) and dynamic channel allocation (DCA) schemes. Locally distributed DCA arrangements are studied and benchmarked against standard FCA, in the context of both line-of-sight (LOS) and multipath propagation environments. One-, two-, four-, and eight-element AAAs are employed using the sample matrix inversion (SMI) beamforming algorithm, in both the up- and the downlink. In most investigated scenarios, the locally optimized least interference algorithm (LOLIA) exhibited the best overall compromise in terms of a set of combined metrics, such as the forced termination probability, new call blocking probability, and the probability of a low quality access.