Multihop Wireless Networks: Opportunistic Routing

7.2 Mobile Content Distribution in VANETs

Vehicular communication has been a topic of great interest in recent years. Typically, a vehicular network consists of roadside units (RSUs), which are access points along the road, and on-board units (OBUs) mounted on vehicles, which can either communicate with the RSUs or with other OBUs in an ad hoc manner. Since the advent of dedicated short-range communications (DSRC) (Jiang et al. 2006); see also www.standards.its.dot.gov/Documents/advisories/dsrcadvisory.htm., IEEE 802.11p and IEEE 1609 standards (WAVE 2006), people have envisioned and designed numerous tempting applications of vehicular networks, ranging from safety warnings (Li et al. 2009) and intelligent navigation, to mobile infotainment (Lee et al. 2006). Among them, content distribution, especially “popular” multimedia content distribution to vehicles inside a geographical area of interest, is particularly attractive. Examples of such mobile content distribution (MCD) include live video broadcast of road traffic and conditions to vehicles driving towards it for intelligent navigation, which is especially useful during inclement weather; periodical broadcasts of multimedia advertisements for local businesses in a city to vehicles driving through a segment of suburban highway (like a digital billboard) and the dissemination of an accurate update of the GPS map about a city or a scenic area.

The challenges of providing a MCD service in VANETs are threefold. On the one hand, content ...