Improve channel availability in vehicular IPTV systems by a hybrid transmission scheme

One important factor restricting the capacity of IPTV service over vehicular-to-infrastructure (V2I) networks is the limited radio resource reserved on the road-side-units (RSUs). This paper elaborates a hybrid video transmission scheme to improve the channel availability in vehicular IPTV systems. The advanced scalable video coding (SVC) technique is applied to encode TV channels. SVC layers are transmitted in different modulation and coding schemes (MCSs), so as to provide differentiated robustness and resource utility efficiency. The hybrid transmission scheme intelligently delivers SVC layers to vehicles via either pure V2I or inter-vehicle relay connections. Comprehensive simulation experiments are conducted and show that, compared to the legacy V2I transmission scheme, the proposed hybrid scheme can effectively enhance user quality of experience (QoE) by significantly increasing channel availability, with only slightly deteriorating the transmission delay for the enhancement layers.