Infomobility Provision through MBMS/UMTS in Realistic Scenarios A. Bazzi, B.M. Masini, A. Conti and O. Andrisano Abstract—New wireless communication technologies enable new services for infomobility. In this work we explore the feasibility of infomobility applications through multimedia broadcast multicast service (MBMS), a new feature added to the universal mobile telecommunication system (UMTS). We assume to transmit, through MBMS channels, real time traffic information to all vehicles under coverage; such information will be exploited by on board smart navigation systems to update the best route to the destination. Activating this service, part of the base station (BS) power is wasted by MBMS, thus reducing resources available for typical UMTS traffic. In this paper, performance is investigated through simula- tions, adopting a complete simulation platform that we carefully developed taking into account, by means of an integrated approach, all network protocol layers and realistic road traffic with mobility models. Numerical results are provided by con- sidering as reference scenario the medium-size Italian city of Bologna. I. INTRODUCTION Most of worldwide cities are congested by traffic caused by the increased motorization, urbanization and population growth. Congestion reduces efficiency of transportation in- frastructure and increases travel time, number of accidents, air pollution and fuel consumption [1], [2]. The average number of vehicles in the year 2001 was 582 per 1000 inhabitants in Europe, 768 in Italy and 955 in Rome [3]. According to a 2007 Texas Transportation Institute report [4], in 2006, in the United States, there were 6 million traffic crashes, the urban congestion problem resulted in 4.2 billion hours of travel delay, 2.9 billion gallons of wasted fuel, and a net urban congestion cost of nearly 80 billion dollars. Recent researches on the intelligent transportation systems (ITS) is showing that new communication technologies pro- viding traffic and roadway information have a significant impact on congestions and accidents; for these reasons, ITS are gaining an increasing interest in today’s society for transportation safety and mobility. In order to let information technologies really impact traffic management it is needed that real time information is communicated to vehicles on a real time basis, providing up-to-date personalized and scaled information related to traffic conditions and suggesting alter- native routes in case of congestions. Nowadays, transportation management centers are de- ployed over the territory and, in some metropolitan areas, they are also equipped with closed-circuit television cameras Alessandro Bazzi, Barbara Masini and Oreste Andrisano are with WiLAB c/o University of Bologna, Italy. (e-mail: name.surname@unibo.it) Andrea Conti is with the Engineering Department (ENDIF), Univer- sity of Ferrara, and WiLAB c/o University of Bologna, Italy. (e-mail: a.conti@ieee.org) and traffic and weather sensors to monitor traffic flows on streets; to inform drivers of any incidents or congestions they mainly adopt variable message panels [5] or broadcast radio. However, these messages, in spite of being dynamic, cannot always be real time updated and rarely suggest alternative routes. Moreover, they only refer to highways and few other main streets. In this work we envision to transmit a relatively high amount of information to all users in order to dynamically help in defining the best route on a real time and a person- alized basis. At this scope we consider the universal mobile telecommunication system (UMTS) in the frequency division duplex (FDD) version as the enabling technology, exploiting the potentialities given by the multimedia broadcast/multicast system (MBMS) technology, which is a feature introduced from the release 6 of 3GPP specifications (see, e.g., [6], [7], [8]). The advantage of considering an existing technology such as UMTS consists in the spreading of its radio cov- erage in most countries allowing to take advantage of the existent infrastructure, thus avoiding new set-up or expen- sive installations. Moreover, several international projects, consortia (e.g., [9], [10]) and researches [11] are working on the development of new standards and ad-hoc technologies (such as IEEE 802.11p) for infomobility. However, ad-hoc networks are not well suited for the proposed service (that will be deeply discussed in the following sections), since the spreading of information is not always guaranteed by inter-vehicles communication (e.g., when few vehicles are running in a certain area). It is also worth noting that an infrastructure based system makes security and privacy protocols implementation easier than ad-hoc networks [2]. The objective of this paper is to evaluate the feasibility of the proposed service and the impact that it would have on the performance of other communication sessions. MBMS for infomobility services was also studied in [12], where a sim- plified scenario was investigated by means of an analytical approach. Here we will consider a realistic scenario by means of a simulative approach, taking into account all aspects related to users mobility and wireless communications, not neglecting any aspect of the entire protocol pillar that may affect the quality of service perceived by the final user. The remainder of this paper is organized as follows: in Sections II and III we describe the envisioned service, the considered scenario and the enabling technologies focusing on MBMS; in Section IV the simulation platform and the main simulation settings are characterized. In Section V numerical results are presented and our conclusion are given in Section VI.