Nonuniform Traffic Research Articles

Dynamic Beam Hopping and Resource Allocation for Non-Uniform Traffic Demand in NGSO Satellite Communication Systems

Dynamic Beam Hopping and Resource Allocation for Non-Uniform Traffic Demand in NGSO Satellite Communication Systems

Performance Analysis of RL-Based Binary Power Control for Small Cell Networks with Nonuniform Traffic Distribution

Performance Analysis of RL-Based Binary Power Control for Small Cell Networks with Nonuniform Traffic Distribution

Separated traffic grooming for Low Earth Orbit (LEO) optical satellite networks with wavelength dimensioning

SummaryIntersatellite laser links have the advantages of high bandwidth, low delay, and low power consumption, which makes wavelength division multiplexing (WDM) with wavelength routing a promising alternative to accommodate the tremendous increasing traffics from terrestrial users. To make better use of the finite wavelengths in optical satellite networks (OSNs), traffic grooming is necessary for the sake of its inherent superiority in partitioning wavelength channel into multiple low‐rate channels to satisfy the traffic requests. However, in most occasions, wavelength dimensioning is taken as a part of traffic grooming, which increases the complexity of application. Therefore, this paper investigates a novel separated traffic grooming method to minimize the number of wavelengths while satisfying the traffic requests, of which the process can be divided into two parts. Firstly, the basic connection requests are bundled to construct aggregation units (AUs). And then, the AUs are groomed onto wavelengths. In the process, an AUs construction method with multihop lightpath bypass grooming (MHLBG) is designed for uniform traffics, and a bandwidth reorganization algorithm (BRA) with MHLBG is customized for nonuniform traffics. Finally, we evaluate performance in simulation, and the results show that the proposed method has realized a good compromise between numbers of wavelengths to be used with the average end‐to‐end delay. Also, the separated traffic grooming method yields better performance than the integrated one.

Secrecy Throughput in Inhomogeneous Wireless Networks with Nonuniform Traffic

We investigate the secrecy throughput of inhomogeneous wireless network, especially in cases of independent and uniform eavesdropper with single antenna and multiple antennas. Towards the inhomogeneous distribution of legitimate nodes, we novelly construct a circular percolation model under the idea of transforming “inhomogeneous” to “homogeneous.” Correspondingly, the information is transmitted by two ways: intracluster transmission and intercluster transmission. For intracluster transmission, a per-node secrecy throughput of [Formula: see text] is derived by circular percolation model, where n and [Formula: see text] represent the number of nodes and clusters in the network, respectively. As for intercluster case, a connection called “information pipelines” is built. Then the per-node secrecy throughput of [Formula: see text] can be obtained, where [Formula: see text] denotes the minimum node density in the network. Moreover, when the eavesdropper is equipped with [Formula: see text] antennas, the per-node secrecy throughput of [Formula: see text] and [Formula: see text] is achieved for intracluster and intercluster transmission, respectively.

Performance evaluation of MIC@R NoC for real-time applications

The smart electronic homes evolution is strongly related to the System-on-Chip (SoC) development. This, in turn, requires an efficient intercommunication between its Intellectuals Proprieties (IPs). Network-on-Chip (NoC) represents the suitable solution. This paper presents a design and implementation of MIC@R NoC architecture performed with non-uniform traffics. This architecture offers lowest routing latency (1 cycle) and allows supporting several adaptive routing algorithms. The proposed NoC architecture is implemented in ASIC technology and performed in 2D mesh networks. In this paper we present a study of NoC evaluation. This NoC uses the four routing algorithms: Deterministic X-Y, Fully Adaptive (FA), Proximity Congestion Awareness (PCA) and Proximity Hot-Spot Awareness (PHSA). The PHSA scheme is a novel routing technique proposition that is more efficient than the other ones. NoC performance evolution is measured with non-uniform traffics that are hot-spot and transpose patterns. Obtained results show that MIC@R router combined with proposed routing techniques is efficient in terms of low latency and generic aspect.

Dynamic Communication Performance of the TESH Network under Nonuniform Traffic Patterns

Interconnection networks play a crucial role in the performance of massively parallel computer systems. Hierarchical interconnection networks provide high performance at low cost by exploring the locality that exists in the communication patterns of massively parallel computer systems. The Tori-connected mESH (TESH) Network is a 2D-torus network of multiple basic modules, in which the basic modules are 2D-mesh networks that are hierarchically interconnected for higher level networks. In this paper, we evaluate the dynamic communication performance of the TESH network using dimension order routing algorithm under various nonuniform traffic patterns. We present a proof that the routing algorithm for the TESH network is deadlock free using 2 virtual channels – 2 being the minimum number for dimension-order routing. We evaluate the dynamic communication performance of TESH, mesh, and torus networks by computer simulation. It is shown that the dynamic communication performance of the TESH network is better than that of the mesh and torus networks.

An Analytical Model for the Reverse Link of WCDMA Systems With Repeaters in Nonuniform Traffic Distributions

The current extensive third generation network deployment has to cope with the existence of nonhomogeneous spatial traffic distributions, which are usually in the form of areas with high density of traffic. The concentration of users in some areas, particularly those far away from the base stations, can result in quality-of-service degradation due to high propagation losses. In this context, repeaters have turned out to be cost-effective nodes that are capable of mitigating these negative effects. This paper describes and models a multicellular/multiservice wideband code division multiple access system with repeaters in an environment with spatial nonuniformities. An analytical model is presented, and the expressions for the required transmission power, outage probability, and block error rate are derived for the reverse link. The implications of the noise amplification caused by the deployment of the repeaters as well as the variation of the propagation loss have been taken into account. Results focus on determining the maximum load factor for a given outage probability. In particular, special attention is paid to the effect of key parameters such as the gain between the base station and the repeaters, denoted as coupling gain, and the location of the different repeaters.

Channel Assignment for a Metro Hub Under Nonuniform Traffic

We consider a metro wavelength-division-multiplexing (WDM) network in which a metro hub connects multiple local networks to a backbone network. In many practical scenarios, the metro WDM network has nonuniform traffic. A metro hub recently studied in the literature can effectively transport nonuniform traffic via nonuniform channel assignment. To realize this feature, it is necessary to assign wavelength channels within the hub to fulfill the given channel requirements while avoiding wavelength conflict. In this letter, we formulate this wavelength assignment problem and propose an efficient method to solve it.

Nonuniform Traffic Distribution Model in Reverse Link of Multirate/Multiservice WCDMA-Based Systems

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper focuses on the modeling of the reverse link of a wideband code division multiple access system in a nonhomogeneous environment with a single cell. Multiple traffic spatial and service nonuniformities are considered in the analytical model, and then, expressions for required transmitted power and the associated outage probability and block error rate are derived. Special attention is also paid to the effect caused by different transmission bit rates and the spatial location of the traffic nonuniformities. From the presented expressions, it is possible to set appropriate load thresholds to control the desired error rate. Although the model considers a single cell, results in terms of maximum allowable load can also be applicable in multicell scenarios. </para>

Performance Analysis of Banyan-Type Multistage Interconnection Networks Under Nonuniform Traffic Pattern

Multistage Interconnection Networks(MINs) have a number of applications in the areas of computer and communications. The most widely researched structure among MIN's is the (1)banyan type network. It has several variations such as buffered banyan, batcher-banyan, tandem banyan, recirculating banyan and banyan with contention resolution phase. Analytical performance evaluation is crucial for justifying the merit of the design in different operational conditions. While several analytical models have been proposed for the performance evaluation of MINs, they are mainly for uniform traffics. Even the models for nonuniform traffics have several shortcomings such as they only consider output buffered structure or do not consider blocking conditions. In this paper, the more accurate models than any other ones so far have been proposed for the performance evaluation of multibuffered banyan-type MIN's under nonuniform traffic condition is obtained. The accuracy of proposed models are conformed by comparing with the results from simulation. Firstly, single buffer model is developed. Markov chain is used for the analysis. Multibuffer model is obtained from single buffer model. Simulation is performed using Discrete Evenet Simulaton(DES) method. As a results, proposed model proves to be very accurate.

A Round-Robin Scheduling Algorithm by Iterating Between Slots for Input-Queued Switches

Input-Queueing is becoming increasingly used for high-bandwidth switches and routers for its scalability, but it needs an elaborate scheduling algorithm to achieve good performance. Round-Robin algorithms have been extensively investigated due to its simplicity and parallelism. However, the present Round-Robin algorithms suffer from poor performance under nonuniform and burst traffic. This paper proposes a Round-Robin algorithm named iSLOT, which can approximate the maximum matching algorithms by iterating the scheduling decision between slots and using the randomness of the queue length. Simulation results show that iSLOT not only is stable under uniform i.i.d traffics, but also outperforms the existing round-robin algorithms under burst and nonuniform traffics in throughput and delay performance.

Adaptive Routing and Wavelength Assignment Algorithm for WDM Networks With Uniform and Non-Uniform Traffic Model

This letter studies routing and wavelength assignment (RWA) problem in wavelength-routed wavelength-division multiplexing networks with both uniform and nonuniform traffic model. Our research shows that the potential traffic load information is a crucial factor for routing algorithm design. Based on our analysis, an adaptive RWA algorithm is proposed. The simulation shows that the proposed algorithm performs much better than other adaptive RWA algorithms.

Use of Adaptive Sectorisation for Capacity Enhancement in CDMA Cellular Systems with Non-Uniform Traffic

This paper discusses the application of adaptive sectorisation in the capacity enhancement of a CDMA cellular system dealing with non-uniform traffic. It considers the particular case where the traffic distribution consists of isolated areas of congested traffic called Hot Spots (HS). It is envisaged that the traffic density inside a HS is many more times that outside the HS. A more even traffic distribution among sectors is attempted by re-adjustment of sector boundaries using finite antenna beam switching. System capacity is estimated on the basis of tolerable interference in a sector taking into account of both intrasector and intersector interference in a multicell environment. Interference is evaluated under the assumption of perfect power control in the uplink. Normal propagation environment is assumed in the cell that allows path losses and shadowing losses in the mobile radio signal. Variation in the antenna gain is also accommodated by taking appropriate radiation pattern into account. It is shown that successive sector adjustment with increasing HS traffic intensity can deter call blocking in the HS sector. It is also shown that a significant improvement in system capacity could be obtained with adaptive sectorisation particularly when the HS user density is several orders of magnitude higher than that outside the HS.

Performance of Reservation in Call Admission Control Schemes for Code-Division Multiple Access Systems with Nonuniform Traffic Distribution Among Cells

In this paper, we propose the reservation type call admission control (CAC) scheme to resolve the intercell unbalanced traffic problem. Differently from a conventional CAC scheme where the system resource is fully allocated to the local users in the home cell, the proposed CAC scheme reserves a small portion of the system resource for new calls occurring in the neighboring cells instead of fully allowing the local users in the home cell to occupy the system resource. As a result, the proposed CAC scheme improves the overall call blocking probability when the traffic is nonuniformly distributed among cells. More specifically, the proposed CAC scheme improves the overall call blocking probability by 15% when one cell has 67% more traffic than its surrounding cells.

Performance of Buffered Multistage Interconnection Networks in a Nonuniform Traffic Environment

Multistage interconnection networks (MIN) are used to connect processors to memories in shared-memory multiprocessor systems. They have also been proposed as switching fabrics in ATM switches in Broadband ISDN networks. A multistage network consists of several stages of switching elements (SE) connected by a permutation function. Since routing conflicts among packets at the SEs cause blocking and reduce the performance of the network, analytical models have been developed and simulation studies carried out for performance evaluation of MINs in the presence of uniform traffic in the network, Buffers are used at SEs to increase the performance of the network, The suitability of two existing models for possible use in the presence of a hot spot is investigated in this paper, Results show that errors from the models are large. In this paper, we propose a new and efficient Markov chain model for performance evaluation of a single-buffered Omega network in the presence of a hot spot. Results obtained from the existing models and the proposed model for the uniform and the hot spot traffic patterns are presented. It is shown that the proposed model is better than existing models in the presence of hot spot traffic, While the existing models produce small errors in the case of low blocking in the network, the errors become prominent with increased blocking. The proposed model produces accurate results in the more general case of a hot spot traffic, whereas the existing models produce accurate results only in the special case of uniform traffic.

Optimal Channel Allocation For Cellular Mobile Systems With Nonuniform Traffic Distribution

AbstractThe problem of optimally allocating available communication channels in a cellular mobile system with nonuniform traffic distribution is considered. This problem is to minimize the weighted average blocking probability subject to cochannel interference constraints. We use the concept of pattern to deal with the problem more conveniently. Using Lagrangean relaxation and subgradient optimization techniques, we obtain high-quality solutions with information about their deviations from true optimal solutions. Computational experiments show that our method works very well.

Queuing delays for uniform and nonuniform traffic patterns in a MIN

In this paper we show that queuing delays or waiting times for messages impose a significant degradation in the performance of a buffered packet switching Multistage Interconnection Network subjected to heavy uniform traffic, and nonuniform traffic patterns. Hotspots and Nonuniform Traffic Spots were introduced to cause nonuniform traffic. The "average standard deviation queue time" is found to be a good measure of network congestion at each stage of a MIN, in a message passing environment. We also show that "tree saturation" effect is present even for MINs with infinite buffer queues.