GeoISA: A new road-topology-assisted geo-based content discovery scheme for vehicular named data networking

Abstract

Content discovery represents a key foundation in realizing the promising vehicular named data networking (VNDN). The highly dynamic topology of VNDN prevents content discovery from becoming a straightforward task. In the VNDN literature, vehicle-to-vehicle content discovery mainly has flooding and time-contention-based (TCB) schemes. However, these schemes have transmission overhead issues or/and do not guarantee Interest forwarding in multiple directions. Thus, the likelihood of packet loss and retransmission is high, or/and the likelihood of locating content sources opportunities is low. Therefore, we proposed a new road-topology-assisted geo-based content discovery scheme for VNDN, termed GeoISA, to address the problems mentioned. In GeoISA, we first designed a new Interest forwarding suppression control mechanism named Interest suppression area (ISA). ISA demarcates an Interest forwarding suppression geo-area to determine the nodes' forwarding direction similarity and ensure forwarding Interest over different forwarding directions. Each road's pathway direction is considered a different Interest forwarding direction. The nodes' geo-position and traveling direction and the road's number of lanes and lane identifiers are involved in ISA demarcation. Second, an ISA-assisted distance-based TCB Interest forwarding strategy (GIDiS) was proposed to mitigate broadcast concerns. Finally, we conducted a simulation-based evaluation to compare GeoISA performance with the performance of four state-of-the-art solutions in an urban area scenario. Results demonstrate that GeoISA outperforms the other considered solutions regarding the Interest satisfaction ratio and the delay and path length (hops count) of the content delivery at the expense of a moderate transmission overhead. GeoISA can help ensure widespread Interest forwarding in many directions to boost the discovery of content sources and network topology in TCB schemes and intelligent context-aware forwarding solutions.