A Brief Review of Mobility Solutions

Thanks to rapid advances in wireless technology, the Internet is becoming increasingly mobile. Not only do smart phones become more affordable and ubiquitous; car manufacturers are also looking into leveraging Internet connectivity to cars to provide advanced applications on car maintenance, such as monitoring and diagnosis, on road assistance such as providing route navigation, weather maps, and automated toll payments, as well as on passenger entertainment including various types of Internet-enriched applications. Although most of today’s networkconnected cars still rely on telematics systems with low-bandwidth connectivity (e.g., satellite link), which do not meet the needs of emerging new applications, this situation is expected to change quickly. At the time of this writing, several car manufacturers such as General Motors are already offering Internet connectivity for a handful models of cars via the third-generation (3G) network [1]; some other manufacturers are also considering offering Internet-enabled car applications or linking smartphone applications to cars [2]. The current trend suggests that tens of millions of cars will go online in coming years, and innovative car-based Internet applications and services will emerge, which can have a major impact on both manufacturers and passenger experiences. Generally speaking, vehicle communications can be sorted into three major scenarios: vehicle to vehicle (V2V), vehicle to roadside unit (V2R), and vehicle to infrastructure (V2I). The first two types of communication scenarios are generally based on 802.11p, which is designed for shortrange data exchange between vehicles or between vehicle and roadside units. Example applications of V2V and V2R include safety alert systems, toll collection, and probe data sharing. The third scenario, V2I, can utilize a variety of wireless technologies for a car to communicate with the Internet infrastructure and to enable seamless handover from one communication medium to another. With abundant computing and communication resources from the deployed Internet infrastructure, V2I is expected to offer more advanced applications than the first two scenarios. One critical technology in enabling V2I is mobility support, which is our focus in this article. What would be the best way to provide global scale IP mobility support for Internet-enabled cars? Multiple answers exist today. In this article we first present a comprehensive survey of existing mobility solutions, and then provide an indepth analysis of the design trade-offs and remaining issues in view of vehicle networking. We discuss the requirements that are specific to automobile environment and conclude the article.