Integrated VLC/RF Wireless Technologies for Reliable Content Caching System in Vehicular Networks

Abstract

In a vehicular communications environment, the need for information sharing, entertainment, and multimedia will increase, leading to congestion of backhaul networks. The major challenge of this network is latency and resource limitations. Proactive caching can be obtained from local caches rather than from remote servers, which can avoid long delays resulting from limited backhaul capacity and resources. Therefore, proactive caching reduces latency and improves the quality of services. Determining which files should be cached in memory is a critical issue. The paper proposes various placement schemes for caching at the vehicle and mobile base station (MBS) layers. The optimal caching place represents better user demand and latency based on the demand and mobility model. Non-cooperative and cooperative vehicles with vehicle-to-vehicle communication (V2V) are included. In both models, the high data rate of visible light communication (VLC) in the vehicular networks tends to enhance the caching capability. We also illustrate a sub-optimal algorithm to solve optimization problems compared to the optimal brute force solver and the sub-optimal genetic algorithm. Numerical results show that proactive caching schemes have a significant gain in system performance. The analysis shows that VLC improves proactive caching performance when there are less than 25 vehicles. The joint proactive caching scheme works better as the number of vehicles increases. The V2V proactive caching is useful when vehicles per platoon are ě 10 INDEX TERMS 6G, Proactive caching, vehicular networks, visible light communication (VLC), radio frequancy (RF), vehicle-to-vehicle communication (V2V), and cooperative and non-cooperative vehicles.

Challenges in meeting QoS requirements toward 6G wireless networks: A state of the art survey

“…Caching placement is an important issue to achieve caching benefit 83 . For increasing number of vehicles, it is crucial to determine which caching scheme is effective for specified scenarios 64 …”

“…Another solution that aids in latency reduction is proactive caching. The authors conducted a study on a caching placement strategy for vehicular networks in Reference 64 where joint proactive caching of vehicular and remote light units (RLU) is considered. A hybrid VLC/RF based scheme is implemented in this vehicular network which ensures high reliability and efficiency of the network system and thus the overall proposed scheme reduces latency.…”

“…In vehicular networks, the performance of a caching scheme can be affected by velocity of the vehicles. The proposed caching strategy in Reference 64 for latency reduction needs to incorporate the effect of vehicle velocity. The reliability might be an issue since high speed of the vehicles can affect it negatively.…”

“…83 For increasing number of vehicles, it is crucial to determine which caching scheme is effective for specified scenarios. 64 Additionally, for time-sensitive wireless network, it is also essential to characterize the wireless traffic for time-dependent channels with stochastic behavior. Statistical QoS provisioning 84,85 is intended to be implemented for 6G wireless network system.…”