Evaluation of location area planning scenarios in future mobile telecommunication systems

In third generation mobile telecommunication systems, signalling requirements due to location updating and paging are expected to be remarkable, mainly because of the huge number of mobile subscribers. Location area planning is characterised by the trade-off between the number of location updates and the amount of paging signalling that the network has to deal with. Location area planning should be based on criteria which guarantee that signalling load will be kept under tolerable levels. Various approaches for location area planning in a city environment—the worst case environment—are discussed in this paper. The simplest approach is the use of heuristic algorithms for approximating the optimum location area configuration. Then more complex scenarios which are based on geographical criteria (population distribution, highway topology, etc.) are investigated. Finally, user mobility characteristics are taken into account in the most complex scenarios. All scenarios are applied over a simulation model representing a city area, providing us with a very clear view of their performance characteristics.This paper has been partially funded by the CEC through the RACE 2066 MObile NETwork (MONET) project. The paper does not present the views of the project as a whole, but those of the authors.     

Performance bounds of a multiple-step paging strategy in future universal mobile telecommunication systems

In future mobile telecommunications, due to the huge number of users and the specific functions that support mobility, a significant amount of signaling load will have to be carried by the finite capacity of the radio link. Hence, methods aiming at radio link signaling load reduction are welcome. In this paper we propose and analyze a method that saves paging signaling load by exploiting information related to the terminal location during the most recent interaction between the terminal and the network. The penalty paid is extra processing power and extra paging delays. An analytical model is developed so as to describe the performance versus traffic intensity and mobility conditions. The performance of the proposed paging scheme is investigated, and it is shown that the method operates well even in the worst case, which is the high user mobility conditions. Possible extensions of the method, which exploit information related to the mobility degree of each individual user or information characterizing the mobility conditions in a certain location area, are also proposed.This paper has been partially funded by CEC through the RACE 2066 Mobile Network (MONET) project. The paper does not present the views of the project as a whole, but those of the authors.     

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     

Cellular Network Performance Analysis: Handoff Algorithms Based on Mobile Location and Area Information

Mobile world's rapid growth has spurred development of new protocols and new algorithms to meet changing operation requirements such as mobile networking, and quality-of-service support. A key requirement in the bearer capabilities is the handover. The freedom to be able to make and receive calls anywhere, at any time, creating a totally new dimension in human communications has frequently been advertised as the main advantage of new wireless systems. Handovers are a key concept in providing this mobility. It makes it possible for a user to travel from one cell to another while having a seamless connection. Network operators give emphasis to optimize handover, since it is strongly related to dropped calls, network overload and subsequently users' criticism. The ability of a cellular network to perform efficient handovers is crucial to offer attractive services as real-time applications or streaming media as planned in third generation networks. Since signal propagation and pathloss are complex in nature, we can expect unnecessary and wrong handoff executions. Both UMTS and those of the second generation (GSM) systems will require redefined handoff algorithms of active connections as the smooth mobility support and continuous connection are essential issues for obtaining high performance and increasing user satisfaction. In this paper we present a set of intelligent algorithms using the mobile terminal (MT) location information and area awareness to assist safe handoff decisions. The implemented algorithms are validated by means of cellular network simulators that clearly show the impact of these techniques to major system performance metrics.     

Method for efficient location area planning in mobile telecommunications

Location area dimensioning is based on the tradeoff between the amount of signalling generated due to paging and location updating. The authors present a new approach which compares the frequency of location updates per mobile terminal with the frequency of mobile terminating calls. This leads to the concept of useless location updating, when location updating occurs but this information is not subsequently used.<>     

Steady-state and transient delay analysis of ARQ protocols

A technique for the performance evaluation of ARQ protocols is presented. General distributions for the packet interarrival times at the transmitter are assumed. Two specific ARQ protocols, the stop-and-wait ARQ and the continuous ARQ are examined in particular. Both the transient and steady-state behaviour are obtained. A simple iterative scheme is proposed for the computation of the delay experienced by the packets and for the packet interdeparture time distribution. The latter result can be applied to the analysis of networks using an ARQ protocol in their datalink control layer. This method is demonstrated for the special case of a network consisting of N nodes connected in tandem. Analytical results are compared with simulation runs and excellent agreement is observed.     

Overview of ATM networks: functions and procedures

The purpose of this paper is to present an overview of the ATM technique. The basic principles of the ATM transfer technique, the B-ISDN layered protocol reference model, as well as the architecture and the main functions of the ATM network, are described in this tutorial. In particular, we present the main characteristics of the ATM technique, the structure of the ATM cell, the functions which deal with the protection from errored cells (HEC procedure) and the identification of the boundaries of the ATM cells (cell delineation and scrambling). The VP/VC concept is explained in detail, and the main principles and functions of the three lowest layers (Physical, ATM and Adaptation) of the B-ISDN layered protocol reference model are surveyed. The issue of Quality of Service parameters in ATM networks is reviewed, and the problem of the allocation of the network resources in response to user demands, as well as the problems of congestion control, Usage Parameter Control (UPC) and traffic modelling in ATM networks, are assessed. Finally, we present ‘possible’ sets of traffic characterization parameters, and show how possible B-ISDN sources can be modelled according to the basic on-off ATM traffic source model.     

Combined URN and TDMA scheme for multiple-access protocols

Local area networks provide communications facilities for high-speed data transfer between computers and erminals within a limited geographical district. The investigation of methods of improving the throughput-delay behaviour of such systems, even under heavy traffic conditions, is an open and challenging research area. A new family of hybrid multiple-access protocols is proposed for contention resolution in local networks. These protocols are a combination of random and deterministic multiple-access protocols. A dynamic frame construction is used. The frame consists of a status slot, followed by an RTDMA period and a URN period. This scheme provides stability under any circumstances and allows for control mechanisms so that good throughput-delay characteristics can be achieved. Analysis shows that the proposed protocols behave better than the isolated URN or RTDMA schemes, exhibiting low access time under normal traffic, while under heavy traffic, channel utilization remains high and the delay at acceptable levels.     

Building a signaling protocol architecture for future mobile networks

Third-generation mobile systems are emerging. These systems will support a unified user access to a variety of services, including the existing mobile and fixed network (PSTN, N-ISDN) services, the enhanced multimedia and multiparty services envisaged for broadband networks, and personal communication services as well. The role of signaling is predominant in building a flexible, efficient, and evolving system. The aim of this paper is to provide a framework for developing a signaling protocol architecture for future mobile networks. The study especially focuses on the universal mobile telecommunication system (UMTS). Within this framework various design and operational requirements imposed on UMTS can be satisfied. A method to deal with the functional complexity of UMTS is provided. Mobile networks are viewed as integral parts of the broadband infrastructure and are built upon the IN principles.