A network-assisted mobile VPN for securing users data in UMTS

Reliability and survivability are the two important attributes of cellular networks. In the existing literature, these measures were studied through the simulation. In this paper, we construct an analytical model to determine reliability and survivability attributes of third generation and beyond Universal Mobile Telecommunication Systems (UMTS) networks. Hierarchical architecture of UMTS networks is modeled using stochastic models such as Markov chains, semi-Markov process, reliability block diagrams and Markov reward models to obtain these attributes. The model can be tailored to evaluate the reliability and survivability attributes of other beyond third generation cellular networks such as All-IP UMTS networks and CDMA2000. Numerical results illustrate the applicability of the proposed analytical model. It is observed that incorporating fault tolerance increases the network reliability and survivability. The results are useful for reliable topological design of UMTS networks. In addition, it can help the guarantee of network connectivity after any failure, without over dimensioning the networks. Moreover, it might have some impact from the point of view of the design and evaluation of UMTS infrastructures.

This paper presents a methodology for evaluating the quality of service provided by a cellular network for background services, such as e-mail and text messaging. Data collected from drive testing were used as the means to evaluate different drive routes on a Universal Mobile Telecommunications System (UMTS) network. Although one type of cellular network was tested, this methodology may be readily adapted to fit other types of cellular networks.

One of the key objectives of Universal Mobile Telecommunications System (UMTS) is the realization of enhanced end-user experience through the provision of rich multimedia services, ensuring in parallel an economical delivery cost for service providers. Multimedia Broadcast/Multicast Services (MBMS) framework of UMTS epitomizes the increasing popularity of such applications by efficiently delivering multimedia traffic to a large number of users and optimizing the radio interface of UMTS networks. For exploiting resource efficiency, MBMS specifications consider the Counting Mechanism which decides whether it is more economic to deliver MBMS multicast traffic over point-to-point (PTP) or point-tomultipoint (PTM) bearers. However, the necessity to further improve MBMS resource efficiency and integrate new technologies such as High Speed Downlink Packet Access (HSDPA) stresses the need for an advanced Counting Mechanism. To this direction, in this paper we propose a novel Power Counting Mechanism which performs optimal power resource utilization and incorporates the HSDPA broadband extension of UMTS for enhanced performance.

A distinguishing feature of the Universal Mobile Telecommunications System (UMTS) is the support of different levels of quality of service (QoS) as required by subscribers and their applications. To provide QoS, the UMTS backbone network needs an efficient QoS mechanism to provide the demanded level of services on UMTS network. We implement a model to investigate end-to-end quality of service (QoS) provisioning approaches for UMTS networks in a DiffServ IP network environment. The effort was put on QoS classes mapping from DiffServ to UMTS, Access Control, buffering and scheduling optimization. The DiffServ Code Point was utilized in the E2E UMTS QoS provisioning to differentiate different types of traffic. We hybridized our work by applying Resource reservation protocol (RSVP) in routers and hosts. The main advantages and drawbacks are discussed. We found that our proposed model (hybridized model (DiffServ/RSVP)) improves the end-to-end delay and end-to-end variation compared with DiffServ model only, and it is superior to DiffServ regarding to throughput, utilization and packet loss ratio. The overall work guarantees the E2E QoS parameters of each service class, especially for real-time applications and improved the bandwidth utilization. Simulation results show that DiffServ can be an effective candidate for UMTS backbone bearer service.

Abstract. An expanded effort is under the way to support the evolution of UMTS (Universal Mobile Telecommunication System). Apart from delivering high data rates, future UMTS releases will also require to provide high network performance in terms of system capacity, low radiated power, and high coverage. Well promising performance-enhancing technologies are smart antennas as well as multiuser detection. Although these new radio technologies have recently been subject to intense research, main UMTS network integration aspects with their specific constraints have been neglected in many cases. Especially the interaction with UMTS radio resource control being required to meet Quality of Service (QoS) constraints has to be included to assess the applicability of these technologies for UMTS. In this paper, we study the interaction of beamforming concepts as well as multiuser detection with load and power control. We also work out UMTS specific constraints like signal-to-interference-plus-noise ratio (SINR) operating points, pilot power pollution or channel estimation, all strongly limiting network performance. Results are shown for capacity gains and power reduction for all beamforming concepts of interest as well as linear multiuser detection schemes. The results show that fix as well as user-specific beamforming significantly improves network performance gains in downlink. In uplink multiuser detection indicates fairly modest system capacity gains, while it reduces tremendously mobile station power.

Interconnection of different access network technologies is an important research topic in mobile telecommunications systems. In this paper, we propose an ns-3 architecture for simulating the interconnection of wireless local area network (WLAN) and Universal Mobile Telecommunications System (UMTS). This architecture is based on the architecture proposed by the Third Generation Partnership Project, being the use of virtual interfaces as its main innovation. In order to demonstrate the value of the proposed simulation framework, we implemented the UMTS and WLAN interconnection considering three joint radio resource management strategies for distributing arriving calls. From the simulations results, we can conclude that the proposed simulation architecture is suitable to test and evaluate performance aspects related to the interconnection and joint management of UMTS and WLAN technologies. Copyright © 2012 John Wiley & Sons, Ltd.

Universal Mobile Telecommunication System (UMTS) is a third generation mobile communication technology based on wideband CDMA (WCDMA) and can facilitate the users in much better way as compared to the second generation of mobile communication. UMTS is superior to second generation in terms of bandwidth efficiency, quality of service, speech quality, speed and capacity. At present, more than 60 countries using WCDMA technology are operating commercially in 25 countries. In this paper, we focus on soft and hard handover issues in UMTS networks. In order to simulate a typical UMTS scenario we use OPNET modeler where a number of users are generating traffic and are free to move in various cells.

Mobile networks face an exponential traffic increase and growing importance to users. It is therefore increasingly important that mobile networks support various applications without disruption. This paper proposes a new recovery algorithm in the WDM based Universal Mobile Telecommunications System (UMTS) networks that guarantee dynamic utilization of backup paths, considering traffic characteristics such as priority and Shared Risk Link Group (SRLG). This paper also has developed an analytical model and performed performance analysis for the proposed algorithms in terms of two performance factors: restoration time and blocking probability.

In this letter, we propose a global model to solve the expansion problem of universal mobile telecommunications system (UMTS) networks. Since the network expansion problem is a generalization of the network design problem, the proposed model can be used for the design of UMTS networks. The proposed model deals simultaneously with the cell, the access network and the core network planning subproblems. This global approach has the advantage of providing better results since, in general, optimal solutions to all subproblems do not provide an optimal solution to the global problem. Moreover, this model fits real life situations in which mobile users have the choice to subscribe or to leave a service providers. Numerical results are presented and analyzed

Voice telephony is the predominant service on today's cellular mobile networks, in terms of number of customers, revenues and network usage. However, it is difficult to predict how long this will be the case given the rising demand for new Internet multimedia services. It is therefore essential that 3rd generation (3G) mobile networks support a voice telephony service, but also that these networks are also capable of providing Internet multimedia services using the same technology. This paper provides an overview of how voice telephony is provided in the initial phase of the universal mobile telecommunications system (UMTS). It then describes how this is expected to evolve in later phases — so that voice telephony becomes one of a large number of multimedia services provided from a common Internet protocol-based mobile network.

Introduction and penetration of high-speed and innovative mobile data services including social media and video services have been increasing significantly across the globe. This growth is driven by deployment and availability of capable and affordable mobile networks and smartphones. These trends have also been observed in Ethiopia as the country’s sole incumbent operator ethio telecom has expanded coverage and capacity of its mobile data network, especially for universal mobile telecommunications system (UMTS) network. The successful provision of these innovative services requires mobile operators to have continuous monitoring of the quality of their networks and customer satisfaction. To that end, this monitoring allows the operator to make timely network optimization, marketing and other relevant decisions that enhance service quality. Traditionally measurement and analysis of network quality of service (QoS) is performed using data from network management system (NMS) and drive/walk test (DT/WT). In recent times, the usage QoS data from crowdsourcing (CS) is also emerging as useful monitoring tool. However, all these methods do not fully capture users’ quality of experience (QoE), which is a function of not only network QoS but also other factors including subjective users’ technical literacy and opinion. As a result, operators have recently provided attention not only for QoS but also QoE. Yet, most quality related analyses are performed using data from only subjective survey, NMS, DT/WT, or CS. It is not straightforward to find quality investigation based on data from all the methods. More importantly, such quality investigation has not been made in the context of Ethiopia’s mobile market. In this paper, we perform QoS and QoE evaluation for UMTS mobile data service based on quality data from all NMS, WT, CS and subjective survey for a business area in Addis Ababa. The evaluation is made using downlink user throughput and mean opinion score (MOS) metrics. The obtained 50th percentile throughput results from NMS, WT and CS are good enough for web browsing and offline video streaming but not for high definition (HD) video calls and live HD video streaming. Furthermore, CS provides optimistic results compared to NMS and WT and its 90th percentile throughput is very good even for live HD video streaming. Moreover, the obtained MOS results from subjective survey almost fit to the QoS results, thus indicating that the network QoS is a significant contributor to users’ perceived QoE.

It is common knowledge that the transition of mobile networks from one generation to another is basically for the improvement in the network’s Quality of Service (QoS). Bearing this in mind, we will assumme that the Universal Mobile Telecommunication System (UMTS) will outperform the Global System for Mobile Communication (GSM), hence, the motivation to conduct this study in Calabar, Nigeria, for four mobile networks; MTN, Airtel, Globacom and 9mobile. With the aid of a TEMS investigation software installed in a laptop, a measurement campaign was carried out and log files collected, with focus on Call Setup Success Rate (CSSR), Dropped Call Rate (DCR), Handover Success Rate (HOSR), Call Setup Time (CST), network coverage and network quality. The collected data was analyzed with the aid of a TEMS discovery software. The analyzed data for each Key Performance Indicator (KPI) was compared with the minimum benchmark of the telecommunications regulatory body, the Nigerian Communication Commission (NCC). Result reveal that there was no outright improvement in the QoS and there was fluctuation in the QoS provided by the network operators. We therefore conclude that the network operators, either did not make accurate planning before installing their base stations or do not optimize their networks frequently and this led to poor QoS in most cases.

Internet Key Exchange version 2 (IKEv2) is taking the responsibility for distribution and management of reliable authentication key. IKEv2 can secure fast hand off, confidentiality of data, safe transmission, and multihoming to transmission node. In this paper, we designed and constructed the network based on real mobile node and experimented the modeling of IKEv2 protocol through the simulation. We analyzed the resetting of authentication key and re-exchange problem. And we experimented the effect that key exchange is affected by a limited bandwidth based on data analysis. To overcome delay time, we proposed multi-interface of node and analyzed performance and latency for authentication setting and exchange process. The simulation results show that re-authentication of key is impossible to reset because of limited bandwidth of network. Also, the use of proposed multi-interface can minimize key exchange latency that happened by hand off for IPSec transmission.

In this paper, we propose a new cooperative algorithm based on tabu search (TS) and genetic algorithm (GA) in order to solve the global planning problem of Universal Mobile Telecommunications System (UMTS) networks. This problem has been shown to be NP-hard as it is composed of three different subproblems (each one being NP-hard): the cell planning problem, the access network planning problem and the core network planning problem. As a result, approximate algorithms are necessary in order to solve larger instances of the problem. Numerical results show that the cooperative algorithm can find solutions with an average gap of 0.24% with respect to the optimal solution in a reasonable amount of computation time. By combining TS and GA, we show that better results can be obtained than using each algorithm separately.

Admission Control in UMTS Networks based on Approximate Dynamic Programming