3G Universal Mobile Telecommunications System Research Articles

A local search heuristic to solve the planning problem of 3G UMTS all-IP release 4 networks with realistic traffic

The purpose of this paper is to develop an efficient heuristic in order to solve the planning problem of 3rd Generation 3G Universal Mobile Telecommunication System UMTS all-IP Release 4 networks. Since the problem is NP-hard, an approximate algorithm based on the local search principle is proposed. Targeting a realistic planning tool, a realistic traffic profile was taken from real live networks. To evaluate the efficiency of the proposed heuristic, a comparative study in which the results are compared with respect to a reference model is conducted. Numerical analysis demonstrates that the local search algorithm produces solutions that are, on average, within 5.03% of the optimal solution, and in the best and worst cases at 0.87% and 9.29% of the optimal solution respectively.

Integration of the digital broadcast mobile television network and the 3G network

The paper presents the results of the research into the opportunities for the integration of mobile broadcast TV networks and cellular 3G networks. We analyzed trends in mobile television services as well as previous studies that aim at finding optimal ways to integrate different types of networks. This paper analyzes the existing mobile television technology, with a special emphasis on the DVB-H technology. We analyzed the conditions, reasons and opportunities for the integration of DVB-H and 3G UMTS (Universal Mobile Telecommunications System), and the conclusions of these analyzes are supported with the results in practice. Based on these studies, a conclusion on the feasibility of the realization of DVBH/ UMTS hybrid networks is brought.

Efficient solution of the 3G network planning problem

The 3G universal mobile telecommunications system (UMTS) planning problem is combinatorially explosive and difficult to solve optimally, though solution methods exist for its three main subproblems (cell, access network, and core network planning). We previously formulated the entire problem as a single integrated mixed-integer linear program (MIP) and showed that only small instances of this global planning problem can be solved to optimality by a commercial MIP solver within a reasonable amount of time (St-Hilaire, Chamberland, & Pierre, 2006). Heuristic methods are needed for larger instances. This paper provides the first complete formulation for the heuristic sequential method (St-Hilaire, Chamberland, & Pierre, 2005) that re-partitions the global formulation into the three conventional subproblems and solves them in sequence using a MIP solver. This greatly improves the solution time, but at the expense of solution quality. We also develop a new hybrid heuristic that uses the results of the sequential method to generate constraints that provide tighter bounds for the global planning problem with the goal of reaching the provable optimum solution much more quickly. We empirically evaluate the speed and solution accuracy of four solution methods: (i) the direct MIP solution of the global planning problem, (ii) a local search heuristic applied to the global planning problem, (iii) the sequential method and (iv) the new hybrid method. The results show that the sequential method provides very good results in a fraction of the time needed for the direct MIP solution of the global problem, and that optimum results can be provided by the hybrid heuristic in greatly reduced time.

Novel results on SCTP multihoming performance in native IPv6 UMTS-WLAN environments

Multihoming is one of the most attractive features of stream control transmission protocol (SCTP) aiming to make this prosperous transport scheme competitive in mobile environments when the mobile hosts are equipped with multiple interfaces. The complementary characteristic of the 3G universal mobile telecommunications system (UMTS) and wireless local area network (WLAN) architectures motivates operators to integrate these two successful technologies. Recently spreading wireless devices are increasingly provided with multiple networking interfaces such enabling end-users to access internet services using e.g., the WLAN's higher bandwidth wherever available, and connecting to the UMTS network in other cases. This paper investigates the performance of multihomed SCTP hosts through extensive experimental studies in such an integrated heterogeneous environment. In order to do this, we designed and implemented a real native IPv6 UMTS-WLAN testbed equipped with novel IPv6-based mobile technologies, such providing ideal conditions for SCTP multihoming performance analysis. In this testbed architecture we analysed numerous settings to measure the handover behaviour of the protocol in terms of handover effectiveness, link changeover characteristics, throughput and transmission delay. As our results show, accurate SCTP parameter setup can significantly decrease the handover delay and eliminate the data transmission interrupts.

Adaptive radio resource assignment for simultaneous services

An adaptive algorithm for selecting rate matching parameters has been developed to satisfy the operating frame error rate requirements for simultaneous services in 3G Universal Mobile Telecommunications System (UMTS) under Rayleigh fading channels. The results show that the adaptive algorithm can achieve the target error rates for multiplexed services of varying data rates and types, and only requires a few adjustments for convergence.