Abstract
Most of the cellular network operators are nowadays striving to solve the problem caused by the increasing demand of mobile data users. In the near future, vehicles will be equipped not only with cellular connectivity, but also with dedicated short-range wireless devices, used to connect via single or multiple hops to fixed road side units attached to the infrastructure network to gain Internet access. Taking this hybrid-connectivity scenario, we propose S eamless I nternet 3G and Opportunistic WL AN V ehicular I nternet Co nnectivity (SILVIO), a solution for providing Internet connectivity in multi-hop vehicular ad hoc networks. Vehicles use the cellular network to assure always-on connectivity, while they opportunistically select to offload some non-critical flows to the multi-hop wireless local area network (WLAN). The advantages of this approach are twofold: the users can benefit from a higher bandwidth, while the operators can alleviate their overloaded cellular networks. SILVIO makes use of existing standard mobility mechanisms integrated, enhanced and extended to provide a seamless connectivity experience without introducing much complexity nor signalling overhead. One of the main contributions of this article is the proposal and analysis of different handover strategies between 3G and multi-hop WLAN networks for the vehicular scenario. A trace-driven simulator was developed to evaluate the performance improvements provided by SILVIO. Real traffic traces from the city of Madrid were used to feed the simulator which considers large vehicles as obstacles, as well. The obtained results show that using SILVIO the cellular network can be offloaded by a factor up to 80%.
Highlights
Internet connectivity is today a need for many users
Note that we focus on suburban and inter-urban scenarios, where it is feasible to deploy fixed wireless local area network (WLAN) point of attachments on the road–whose effective coverage can be extended by selfforming Vehicular ad hoc networks (VANETs)–and where there is good and ubiquitous 3G coverage
We argue that vehicles need to be equipped with two different wireless communications technologies: (i) 3G, to provide close-to always available connectivity, and (ii) WLAN, to provide opportunistic access through a multi-hop VANET whenever possible
Summary
Internet connectivity is today a need for many users. The Internet has evolved in just a few years from an experimental infrastructure that allowed a small number of academic institutions to exchange data into what was going to become the most essential tool for private companies and public institutions to develop their activity, as well as for users to access to news, play games, talk to friends across the world, share information, etc. The mobile router deployed in the vehicle needs to be notified of such a WLAN availability event in order to be able to perform a flow handover, offloading part of the in-vehicle traffic from the 3G network to the VANET.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
