Performance Analysis of an ATM Multiplexer with Multiple QoS VBR Traffic

In this paper, we propose a new queuing model, MMDP/MMDP/1/K, for an asynchronous transfer mode (ATM) multiplexer with multiple quality of service (QoS) variable bit rate (VBR) traffic in broad band-integrated services digital network (B-ISDN). We use the Markov Modulated Deterministic Process (MMDP) to approximate the actual arrival process and another MMDP for service process. Using queuing analysis, we derive a formula for the cell loss probability of the ATM multiplexer in terms of the limiting probabilities of a Markov chain. The cell loss probability can be used for connection admission control in ATM multiplexer and the calculation of equivalent bandwidth for arrival traffic. The major advantages of this approach are simplicity in analysis, accuracy of analysis by comparison of simulation, and numerical stability.     

A middleware service for employing and evaluating resource management algorithms in distributed networks

The first part of this paper introduces the design of a middleware‐based service which is valuable for distributed networks for mainly managing their resources. The second part evaluates the performance of a distributed intelligent network (D‐IN), which comprises the proposed service together with a resource management algorithm. We test the network's performance by building and emulating its basic functionality, based on distributed object technology (DOT), in a real environment. The resource management algorithm mainly aims at avoiding congestion and balancing load. Its implementation uses the ICALB algorithm (Comput. Commun. 2002; 25 (17):1548–1556) model. Its incorporation is succeeded through the use and implementation of the distributed middleware‐based service. It is a CORBA‐based service that is used for successfully managing resource management algorithms, such as ICALB, facilitate their operation, and solving classes of problems related to communications over the distributed network, sharing of resources spread over the network, scheduling, synchronization, and management of various tasks. By this means we argue that the method that we use can be employed for operating in various distributed networks. We also evaluate the network's performance by measuring various D‐IN node parameters with critical meaning and by showing the improvements that appeared to the D‐IN from the operation of both the ICALB algorithm and the proposed service. Copyright © 2005 John Wiley & Sons, Ltd.     

Optimizing the server utilization in intelligent broadband networks

Intelligent network (IN) architectures are investigated globally as potential candidates for the rapid introduction of advanced multimedia services. The IN concept is based on the introduction of intelligent servers in the network, able to handle complex service requests by cooperating with the signalling system of the network. The design and implementation of the physical entities participating in an IN session is a critical issue as it defines the system performance. In this paper we propose a methodology for modelling the physical and functional entities which is used to capture the performance of IN‐based configurations. We put our emphasis on the processing speed required for the execution of the IN processes in the servers and we present results with reference to the system performance and the mapping of functions to physical entities. Copyright © 2000 John Wiley & Sons, Ltd.     

Impact of the intelligent network on the capacity of networkelements

The effect that integration of the intelligent network (IN) concept into the existing network architecture has on the capacity of the various network elements is addressed. The effect of excessive load on that and other existing services is also examined. The discussion covers: methods of characterizing capacity and performance; major causes of increased load with the IN; perception of increased delay by the user; effect of delay on service introduction; and methods of improving IN performance. The example of the call-forwarding service is used to show the effect that IN can have on the performance of services, as perceived from the delays experienced by the user     

On throughput capacity of large-scale ad hoc networks with realistic buffer constraint

The problem of determining the throughput capacity of an ad hoc network is addressed. Previous studies mainly focused on the infinite buffer scenario, however, in this paper we consider a large-scale ad hoc network with a scalable traffic model, where each node has a buffer of size B packets, and explore its corresponding per node throughput performance. We first model each node as a G/G/1/B queuing system which incorporates the important wireless interference and medium access contention. With the help of this queuing model, we then explore the properties of the throughput upper bound for all scheduling schemes. Based on these properties, we further develop an analytical approach to derive the expressions of per node throughput capacity for the concerned buffer-limited ad hoc network. The results show that the cumulative effect of packet loss due to the per hop buffer overflowing will degrade the throughput performance, and the degradation is inversely proportional to the buffer size. Finally, we provide the specific scheduling schemes which enable the per node throughput to approach its upper bound, under both symmetrical and unsymmetrical network topologies.     

Performance modeling and analysis of hypoexponential network servers

Hypoexponential servers are commonly seen in today’s computer and communication networks whereby incoming packets are processed by the network server in multiple stages with each stage having a different processing time. This paper presents an analytical model to capture the behavior and subsequently analyze the performance of these network servers or similarly behaving systems. From our model, we derive key performance measures and features which include CPU utilization, system idleness, mean throughput, packet loss, mean system and queuing packet delays, and mean system and queue sizes. In addition, we present two popular finite queueing models (namely, M / D / 1 / K and M / M / 1 / K) to approximate our hypoexponential model. Results show that the both of these approximate models give close results when the system queue size is large.     

Advanced intelligent networks: now a reality

This paper looks first at the background to the development of intelligent networking concepts and then tracks this development to the advanced intelligent networks (AINs) of today. The network architecture and basic nodal functions are explained, and a brief review given of the essential intelligent network building blocks, namely the IN (intelligent network) call model and the enhanced CCITT No.7 signalling system. Typical intelligent network services are examined and the tutorial finishes with a review of the latest IN standards     

智能网与先验位置信息在呼叫连接中的应用

在个人通信以及联网寻呼中，怎样能够以最小的网络负载和最少的费用最快地期望的用户，最值得研究的问题。本文基于智能网提出了先验位置信息的概念，并给出了这种信息在位置登记器中的应用算法。计算机性能模拟显示它使原有的位置登记器中的智能网性能得到了改善。     

Perspectives on the AIN architecture

The advanced intelligent network (AIN) is examined in terms of its history, present day architecture, and future evolution. The history of the AIN is traced from predivestiture 800 and calling card service capabilities, through IN/1, IN/2, and IN/1+, leading to the various AIN releases. The present-day view of the AIN architecture includes the switching system and other network systems, as well as operations. The AIN functionality supported by this architecture is described from a customer point of view, by means of an illustrative service that could be provided from an AIN platform. The next steps in the AIN evolution are discussed. An appendix that provides detailed information about the AIN Release 1 call model is included     

On the design of node architectures and MAC protocols for optical burst-switched ring networks

Efficient multiple-token-based MAC protocols have been proposed for optical burst-switched (OBS) unidirectional ring networks using a TT-TR-based node architecture in our previous research. However, the unidirectional OBS ring network is difficult to scale to larger networks. As wavelengths accessibilities are dominated by tokens, network performance is restricted by the frequency of capturing a token. If the network is too large, it takes a long time for tokens to rotate. Thus, a destination queue may wait for a long time to be served, which results in large queuing delays and inefficiency of network resource utilization. In order to improve network efficiency and scalability for OBS ring networks using multiple tokens, this work is extended to a bidirectional ring system that uses the tunable transmitter and tunable receiver (TT-TR)-based node architecture with two pairs of transceivers, so that each queue can be served by tokens from both directions. Furthermore, two kinds of node architectures differing in sharing the two pairs of transceivers, either shared or not, are proposed. Then, two MAC protocols considering different queue scheduling algorithms are proposed for the ring network using the proposed node architectures, in order to use the network resources more efficiently. They are improved from general round-robin (GRR) and termed as half-ring round-robin (HfRR) and co-work round-robin (CoRR), respectively. The network performance of the two proposed node architectures and the two proposed MAC protocols for the networks using them as well as the network scalability are evaluated with the OPNET simulator.     

Performance Analysis of Interconnected Communication Networks

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A novel relay-aided centralized cooperative spectrum sensing scheme using radio frequency energy harvesting

In a cooperative spectrum sensing (CSS) network, the primary signal can be used as a radio frequency (RF) source in order to power the energy-constrained sensor nodes of the secondary network. This work presents a novel hybrid model combining an optimal relay selection scheme to incorporate RF energy harvesting in a centralized CSS network. The secondary users, which are equipped with RF energy harvesting capabilities, act as relays in order to forward the sensing information to a fusion center. Here, we have derived an enhanced multi-relay selection strategy to maximize the end-to-end signal-to-noise ratio of the links. Furthermore, a new voting rule is proposed based on the generalized K-out-of-M rule, such that it minimizes our objective error function. The performance analysis of our proposed model is presented with respect to the flexible relay positions. We have used complementary receiver operating characteristic curves for analyzing the detection performance of the CSS model with our derived voting rule. Simulation results using MATLAB show that the proposed model gives a better detection probability and a smaller error rate than some related existing works.     

An efficient clustering and load balancing of distributed cloud data centers using graph theory

The prime focus of the Cloud Service Providers is enhancing the service delivery performance of the distributed cloud data centers. The clustering and load balancing of distributed cloud data centers have significant impact on its service delivery performance. Hence, this paper models distributed cloud data center environment as a network graph and proposes a two‐phase cluster‐based load balancing (CLB) algorithm based on a graph model. The first phase proposes a Cloud Data Center Clustering algorithm to cluster the distributed cloud data centers based on their proximity. The second phase proposes a Client‐Cluster Assignment algorithm to perform uniform distribution of the client requests across the clusters to enable load balancing. To assess the performance, the proposed algorithms are compared with other K‐constrained graph‐based clustering algorithms namely, graph‐based K‐means and K‐spanning tree algorithms on a simulated distributed cloud data center environment. The experimental results reveal that the proposed CLB algorithm outperforms the compared algorithms in terms of the average clustering time, load distribution, and fairness index and hence improves the service delivery performance of the distributed cloud data centers.     

Multiscale Fitting Procedure Using Markov Modulated Poisson Processes

This paper proposes a parameter fitting procedure using Markov Modulated Poisson Processes (MMPPs) that leads to accurate estimates of queuing behavior for network traffic exhibiting long-range dependence behavior. The procedure matches both the autocovariance and marginal distribution of the counting process. A major feature is that the number of states is not fixed a priori, and can be adapted to the particular trace being modeled. The MMPP is constructed as a superposition of L 2-MMPPs and one M-MMPP. The 2-MMPPs are designed to match the autocovariance and the M-MMPP to match the marginal distribution. Each 2-MMPP models a specific time-scale of the data. The procedure starts by approximating the autocovariance by a weighted sum of exponential functions that model the autocovariance of the 2-MMPPs. The autocovariance tail can be adjusted to capture the long-range dependence characteristics of the traffic, up to the time-scales of interest to the system under study. The procedure then fits the M-MMPP parameters in order to match the marginal distribution, within the constraints imposed by the autocovariance matching. The number of states is also determined as part of this step. The final MMPP with M2 ^L states is obtained by superposing the L 2-MMPPs and the M-MMPP. We apply the inference procedure to traffic traces exhibiting long-range dependence and evaluate its queuing behavior through simulation. Very good results are obtained, both in terms of queuing behavior and number of states, for the traces used, which include the well-known Bellcore traces.     

Methods of addressing the interactions of intelligent networkservices with embedded switch services

A key factor in the transition of the existing network to an intelligent network (IN) environment is the need to partition the network intelligence and to ensure the coexistence of the embedded switch services with the externally controlled services. If the network intelligence can be defined by entities (e.g. access control and routing, connection control, basic call control, feature control, etc.), then the issue is how to manage their distribution over the evolving network elements (NEs). The authors focus on the early phases of the IN, during a 1991-2 time frame, when these features must interwork with the existing features (e.g. those within the Centrex service). They provide an overview of the features interactions and arbitration policies prevailing in today's network. They then describe the framework for both single- and multinode networked features models. The issues of call control distributed over the NEs of the IN are treated as extensions to the concepts and interfaces needed to provide networked services like areawide Centrex and private virtual networks. A model for offering IN/1+ services is described     

Multihop Virtual Topology Design in WDM Optical Networks for Self-Similar Traffic

In this paper, we consider the problem of designing virtual topologies for multihop optical WDM networks when the traffic is self-similar in nature. Studies over the last few years suggest that the network traffic is bursty and can be much better modeled using self similar process instead of Poisson process. We examine buffer sizes of a network and observe that, even with reasonably low buffer overflow probability, the maximum buffer size requirement for self-similar traffic can be very large. Therefore, a self-similar traffic model has an impact on the queuing delay which is usually much higher than that obtained with the Poisson model. We investigate the problem of constructing the virtual topology with these two types of traffic and solve it with two algorithmic approaches: Greedy (Heuristic) algorithm and Evolutionary algorithm. While the greedy algorithm performs a least-cost search on the total delay along paths for routing traffic in a multihop fashion, the evolutionary algorithm uses genetic methods to optimize the average delay in a network. We analyze and compare our proposed algorithms with an existing algorithm via different performance parameters. Interestingly, with both the proposed algorithms the difference in the queuing delays, caused by self-similar and Poisson traffic, results in different multihop virtual topologies.     

The intelligent network in France

The introduction of an intelligent network (IN) architecture in France by France Telecom is described. Two main technical issues of present IN architecture are discussed: the programming interface to be used for service creation and the control-resource interface such as the SSP/SCP interface. The long-term evolution of IN, including the application to networks other than public switched telephone networks (PSTN) and the development of operating systems to handle IN-supported services, is outlined. Major technical problems in implementing a global IN architecture are also discussed     

Consideration on common channel signaling evolution for globalintelligent networking

With the evolution of digital networks and intelligent network (IN) capabilities, the role of common channel signaling has become more and more important. In respect to IN, common channel signaling would play a significant role not only inside one network but also over multiple networks. International credit card validation and internetworking for digital mobile services represented by GSM (Global System for Mobile Communications) are examples which utilize internetwork signaling capabilities in the framework of the initial-phase IN. Enhanced service providers (ESPs) may access the public network through the common channel signaling interface to make use of the IN capabilities, as is being discussed in terms of ONA (open network architecture) or ONP (open network provision). This paper first identifies various scenarios where internetwork signaling interactions would take place in the framework of IN in the forthcoming era. It then identifies various requirements to cope with these scenarios. It finally discusses the directions for evolution of common channel signaling toward global intelligent networking     

Mobile agents - enabling technology for active intelligent networkimplementation

The emerging notion of active networks describes the general vision of communication network evolution, where the network nodes become active because they take part in the computation of applications and provision of customized services. In this context mobile agent technology and programmable switches are considered as enabling technologies. This article looks at the impact of mobile agent technology on telecommunication service environments, influenced by the intelligent network (IN) architecture. The authors illustrate how the integration of mobile agent platforms into IN elements, notably into the IN switches, will realize an active IN environment. This enables telecom services implemented through mobile service agents on a per user basis to be instantly deployed at programmable switching nodes, which results in better performance and fault tolerance compared to traditional IN service implementations     

GI/Geom/1 queue based on communication model for mesh networks

In mesh networks architecture, it should be permitted to visit the mobile client points. Whereas in mesh networks environment, the main throughput flows usually communicate with the conventional wired network. The so‐called gateway nodes can link directly to traditional Ethernet, depending on these mesh nodes, and can obtain access to data sources that are related to the Ethernet. In wireless mesh networks (WMNs), the quantities of gateways are limited. The packet‐processing ability of settled wireless nodes is limited. Consequently, throughput loads of mesh nodes highly affect the network performance. In this paper, we propose a queuing system that relied on traffic model for WMNs. On the basis of the intelligent adaptivenes, the model considers the influences of interference. Using this intelligent model, service stations with boundless capacity are defined as between gateway and common nodes based on the largest hop count from the gateways, whereas the other nodes are modeled as service stations with certain capacity. Afterwards, we analyze the network throughput, mean packet loss ratio, and packet delay on each hop node with the adaptive model proposed. Simulations show that the intelligent and adaptive model presented is precise in modeling the features of traffic loads in WMNs. Copyright © 2013 John Wiley & Sons, Ltd.