Simulative analysis of optimal resource allocation and routing inIBCN's

The problem of resource allocation for future integrated broadband communication networks (IBCNs) is addressed. It mainly involves resource allocation at the connection level. The resource allocation problem is decomposed into the following interdependent tasks: given that a network can accommodate the bandwidth demand of a call request, determine a route for the corresponding asynchronous transfer mode (ATM) virtual connection; and allocate bandwidth, i.e. links inside the trunks of the chosen route, to this connection according to predefined limits on bandwidth use by various service calls. Various link allocation schemes combined with routing algorithms are examined. Their performance in terms of service call blocking is evaluated using a software package developed, for that purpose. It is shown that the traditional complete sharing (CS) and complete partitioning (CP) policies are not adequate for IBCNs. Movable boundary (MB) policies are more flexible and present near-optimal performance when access of broadband service to narrowband service resources is allowed and suitable routing algorithms are dynamically applied     

An object-oriented analysis of a BISDN control system with a focus on the UNI protocol object

The control system of a BISDN network will undoubtedly be very complex to design, implement and maintain. Its complexity has led researchers to look for ways of breaking down the problem into smaller and manageable parts. This has motivated the use of an object-oriented approach to analyse and comprehend the BISDN control system. This paper thus presents an object-oriented analysis (OOA) of a BISDN control system. This analysis is based on a method introduced by Coad and Yourdon and comprises five steps. All five steps, namely identifying subjects, identifying objects, identifying structures, defining attributes, and defining operations, will be worked out in detail with an emphasis on the user network interface (UNI) signalling protocol object. Four subjects, nine objects, and three structures are identified in the problem space at hand. This structuring offers a framework to analyse in detail the three aspects, data, structure and dynamic behaviour, of the UNI signalling protocol. A parallel between this approach and the well known approach used by the International Telecommunication Union (ITU) for specifying signalling protocols and contained in Recommendation I.130 is drawn. The Coad and Yourdon OOA approach applied to a BISDN control system can be used for the analysis of different aspects of such systems. This paper focuses on the UNI signalling protocol object which leads to a complete specification. Any protocol resulting from such analysis can be claimed to be object-oriented protocol. This approach offers modularity and thus offers a way of structuring the problem space into identifiable objects and data. Full benefits of object orientation can be gained only in the consistent use of object orientation throughout all steps in the development process. The proposed approach allows one to create libraries of generic procedures which can be reused in specific implementations.     

Distributed call processing for personal communications services

The authors present a control architecture, procedures, and a signaling system to support advanced personal communication services (PCS). They describe the current cellular system architecture, and its algorithms and data management schemes for providing services. They present review how current cellular systems operate with a focus on mobility management and call and connection control. The benefits of this architecture include lower signaling traffic over wireless links, lower network load for signaling traffic, low call/connection delivery times, ubiquitous service offering, and more efficient routing of connections     

The extended connection‐dependent threshold model for call‐level performance analysis of multi‐rate loss systems under the bandwidth reservation policy

Firstly, we reviewed two extensions of the Erlang multi‐rate loss model, whereby we can assess the call‐level QoS of telecom networks supporting elastic traffic: (i) the extended Erlang multi‐rate loss model, where random arriving calls of certain bandwidth requirements at call setup can tolerate bandwidth compression while in service; and (ii) the connection‐dependent threshold model, where arriving calls may have several contingency bandwidth requirements, whereas in‐service calls cannot tolerate bandwidth compression. Secondly, we proposed a new model, the extended connection‐dependent threshold model. Calls may have alternative bandwidth requirements at call setup and can tolerate bandwidth compression while in service. We proposed a recurrent formula for the efficient calculation of link occupancy distribution and consequently call blocking probabilities, link utilization, and throughput per service class. Furthermore, in the proposed model, we incorporated the bandwidth reservation policy, whereby we can (i) equalize the call blocking probabilities of different service classes, (ii) guarantee specific QoS per service class, and (iii) implement different maximum bandwidth compression/expansion rate per service class so that the network supports both elastic and stream traffic. The accuracy of the new model is verified by simulation. Moreover, the proposed model performs better than the existing models. Finally, we generalize the proposed model by incorporating service classes with either random or quasi‐random arrivals. Copyright © 2011 John Wiley & Sons, Ltd.     

A Two-Level Call Model for IN and B-ISDN Integration

1IntroductionIntelligentNetwork(IN)canofferrapidandflexibleservicedeployment,andhasbeenevolvedtoProvideintelligenttelephoneservicesinpublicnetwork.Ontheotherhand,broadbandconUnwhcahonhasbecomeahotissuetomeetvallousservicesrequirementSinmoderninformationsociety.BroadbandoffersaveryPOwerfuldigitalbearerandfleholembopulationofvallouscounechontypes.AnimportantunderlyingcharacterishcofBroadbandISDN(B-ISDN)signalingistheconceptofseparationofcallandbearerconnechoncontrol.msseparationfeatUreal…     

A Novel Probability-Based Handoff Strategy for Multimedia LEO Satellite Communications

A novel bandwidth allocation strategy and a connection admission control technique arc proposed to improve the utilization of network resource and provide the network with better quality of service （QoS） guarantees in multimedia low earth orbit （LEO） satellite networks. Our connection admission control scheme, we call the probability based dynamic channel reservation strategy （PDR）, dynamically reserves bandwidth for real-time services based on their handoff probability. And the reserved bandwidth for real-time handoff connection can also be used by new connections under a certain probability determined by the mobility characteristics and bandwidth usage of the system. Simulation results show that our scheme not only lowers the call dropping probability （CDP） for Class I real-time service but also maintains the call blocking probability （CBP） to certain degree. Consequently, the scheme can offer very low CDP for rcal-time connections while keeping resource utilization high.     

The effect of call admission policies on the system benefit of CDMA communication networks

Previous studies of call admission control (CAC) in mobile communication networks focused on call blocking and call dropping mechanisms. However, achieving global optimization of the system benefit is a complicated process. In this paper, we propose a benefit optimization model that accommodates as many users as possible, while simultaneously maintaining system-wide quality of service (QoS) in terms of admission control. To clarify the CAC concept, we construct a framework of CAC policies, derive associated interference models based on the framework, and then investigate the effects of the policies on the system benefit. In addition, to solve the complicated integer programming problem, we adopt the Lagrangean relaxation approach, and employ Lagrangean multipliers to perform sensitivity analysis of several parameters. The contribution of this study is twofold: the novel problem formulation and the improvement in the system benefit. The computational results demonstrate that the system accrues more benefit as new traffic is loaded and the number of users increases. Meanwhile, the sensitivity analysis shows that proper assignment of the strength of power-controlled signals is a key factor in the global optimization of the system benefit.     

基于数据挖掘的CDMA2000移动网络防盗用技术

针对CDMA2000 EVDO移动网络中的盗用问题,结合CDMA网络无线宽带原始计费话单的生成机制,对AAA的原始计费话单内容进行了分析和解构;基于数据挖掘理论和技术提出了原始计费话单分析模型,从中发现话单与盗用行为的关联性,并通过编写分析脚本,实现了可疑话单的筛选.最后,利用广东电信现网数据进行分析,对系统模型进行了...     

3G动态预留呼叫接纳控制算法研究

第三代移动通信技术支持不同服务质量(QoS)的多媒体业务,而呼叫接纳控制(CAC)技术是移动通信中的关键技术之一.本文提出一种动态预留呼叫接纳控制算法,该算法根据小区中各业务的话务量预测各业务所需信道教,从而为切换业务和新业务预留一定的信道.通过比较动态预留算法与新呼叫受限算法和中断优先级算法的性能,得出动态预留算法在降低语音和数据业务的呼叫阻塞率、中断率方面有明显的改善,是一种比较理想的呼叫接纳控制算法.     

基于TD网络实现组呼的策略研究

针对政府、企事业、军队等集团单位对组呼通信业务的需求,提出基于时分同步的码分多址技术的通信网络实现组呼通信的思路;首先介绍了基于时分同步的码分多址技术的通信网络实现组呼时的网络结构,然后对组呼通信中的建立/释放流程作了详细说明,最后分析了在实际应用中可能存在的问题及其相关的解决策略;通过分析表明基于时分同步的码分多址技术的集群通信系统解决好时延和越区切换,必有广阔的发展前景。     

The broadband call control demonstrator — a platform for ITU-T, DAVIC and TINA-C implementations

The paper firstly provides an introduction to the broadband call control demonstrator platform developed at BT Laboratories. It describes the basic connection level functionality used to give point-to-point and point-to-multipoint call demonstrations. It then describes the introduction of a Digital Audio-Visual Council (DAVIC)-conformant session control capability and how this is used as the basis of a more comprehensive demonstration. The paper also examines how future networking concepts such as object orientation and distributed processing environments are being introduced, in particular the interworking between DAVIC and Telecommunications Information Network Architecture Consortium (TINA-C) approaches. Finally, some of the evolutionary aspects of the broadband call control demonstrator platform are introduced.     

A Study of Feature Interactions in Intelligent Networks

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Methods, Tools, and Observations on Flow Control in Packet-Switched Data Networks

Flow control covers several concepts. In an end-to-end connection, it intends to adapt sender's output to receiver's capabilities. In a shared resources communication network, it attempts to prevent congestion by restricting traffic flows. Flow control mechanisms are built with a small number of basic throttling tools. However, they are always tied into a resource management problem, which depends on a large variety of environmental parameters. Techniques used in end-to-end connections are summarized. Congestion control in store-and-forward packetswitching networks is covered extensively, and techniques used or proposed are discussed. Memoryless networks, such as broadcast local networks are shown to be simpler systems in the area of flow control. In conclusion, arguments are made for a service oriented approach, which would optimize resource usage through differentiated service characteristics.     

IP电话发展新动向

介绍了NTT公司为参与到IP电话领域而进行的可行性论证、公司内部IP电话实验以及面向商业用户而推出的三种VoIP服务。对新的IP电话网从呼叫控制、通话建立、QoS和编译码、计费方面进行了介绍，并对IP国际电话、呼叫中心及新推出的服务进行了说明。     

Intelligent network requirements for personal communicationsservices

It is shown that a moderate set of capabilities within the service switching point (SSP), service control point (SCP), and intelligent peripheral (IP), which are the intelligent network (IN) components directly responsible for the real-time execution and control of end-user services, can engender a wide range of end-user personal communication service (PCS) features. These capabilities could be used as the starting point for an economic analysis of IN implementation costs versus service worth. From a very large target set of call model trigger check points (TCPs), the dozen or so identified in the CCITT Capability Set 1 are shown to be sufficient. The SCP and IP functional entity actions identified are also sufficient to support PCS core network functions     

基于SIP的紧急呼叫系统设计

随着反恐、医疗紧急救助、火警和自然灾害救援等紧急呼叫业务重要性的不断提高,在现有网络上利用已有的软交换和网络服务质量技术提供该类服务,可以实现巨大经济和社会效益.为解决现有IP网络上提供紧急呼叫存在的问题,提出了基于SIP的紧急呼叫系统设计方案,详细解析了系统的运行过程,考虑和分析了系统设计方案的实现和实际应用.     

Pricing based adaptive scheduling method for bandwidth allocation

In this paper we present a packet scheduling method which guarantees bandwidth of the connection and optimizes revenue of the network service provider. A closed form formula for updating the adaptive weights of a packet scheduler is derived from a revenue-based optimization problem. The weight updating procedure is fast and independent on the assumption of the connections’ statistical behavior. The features of the algorithm are simulated and analyzed with and without a call admission control (CAC) mechanism. We also show in context with the CAC procedure a mechanism for guaranteeing a specified mean bandwidth for different service classes.     

A distributed control strategy for wireless ATM networks

Cellular networks are expected to be upgraded to offer Personal Communication Services (PCS). The mobility management and wireless call control approach used in cellular networks are currently being proposed for use in PCS networks. Recent work indicates that both the signaling load and database update rates caused by these mobility management and call control procedures will increase significantly in next generation PCS networks. In this paper, we propose and analyze a new cluster-based architecture and define algorithms to effectively handle mobility management and call control functions for PCS. We assume an ATM network infrastructure. Some of the key aspects of our proposal include simplifying the mobile location and tracking function, performing connection setup in segments, eliminating the need for user service profile downloads between networks, and more efficient routing of connections by removing the need for an anchor switch. Advantages of this approach include a reduction in signaling traffic load, improved call/connection setup delays, and more efficient routing of connections. We carry out an analysis of our solution for high-tier PCS applications.     

Adaptive channel reservation for call admission control to support prioritized soft handoff calls in a cellular CDMA system

This paper proposes a prioritized call admission control (CAC) model to support soft handoff calls with quality of service (QoS) assurances for both the uplink and downlink connections in a CDMA system. CAC is formulated as a combinatorial optimization problem in which the problem objective is to minimize the handoff forced termination rate. The model, which is based on the adaptive channel reservation (ACR) scheme for prioritized calls, adapts to changes in handoff traffic where the associated parameters (reserved channels, and new and handoff call arrival rates) can be varied. To solve the optimization model, iteration-based Lagrangean relaxation is applied by allocating a time budget. We express our achievements in terms of the problem formulation and performance improvement. Computational experiments demonstrate that the proposed ACR scheme outperforms other approaches when there are fewer rather than more channels, and it reduces the handoff call blocking rate more efficiently when the handoff traffic is heavily loaded. Moreover, the model can be adapted to any kind of reservation service.     

Wireless and cellular architecture and services

Cellular architecture partitioning can improve the performance of telecommunications systems. The model proposed by the author allows for changing the cell size for different services and the number of users. The cell size that will ensure the best possible performance and quality of service can be derived by the model. The main task of a telecommunication system is call processing. This includes identifying incoming calls, establishing a communication path for the duration of the connection, and disconnecting the call after the conversation has ended. Call processing uses different components of the software architecture and involves processes and messages performing different functions and accessing various resources. In addition, the system requires administration and maintenance that also involves processes using different resources