End-to-End Rate Adaptation to Support Heterogeneous Services for Infrastructure-Based Vehicular Networks

Vehicle to Infrastructure （V2I） communications aim to provide mobile users on the road low-cost Internet and driver safety services. However, to meet Quality of Service （QoS） requirements of various applications and officiently utilize limited wireless channel resourc- es, the transport layer protocol has to perform effective rate control in low channel quality and frequent changing topology communica- tion environment. In this paper, we propose a novel rate-control scheme in infrastructure based vehicular networks that avoids conges- tion and starvation and promotes fairness in end-to-end V2I communications. In vehicular networks, a bottleneck roadside unit （RSU） keeps track of its buffer size, aggregate incoming rate, and link throughput, and appropriately allocates bandwidth to traversing flows. With feedback information from the RSU, source nodes dynamically adjust their sending rates to avoid buffer overflow or starvation at the bottleneck RSU. Simulation results show that the proposed scheme can reduce not only packet losses owing to buffer overflow but also buffer starvation time, which improves the utilization efficiency of wireless channel resource.

Scheduling algorithms for time-constrained big-le transfers in the Internet of Vehicles

In order to transfer large les and provide high-quality services in the IoV(Internet of Vehicles),intelligent routing and scheduling are indispensable for fast transfers and effcient network utilization,particularly when multi-path routing is allowed in the wired-transfer.Thus,a network administrator must select a set of feasible paths over which the transfer can be conducted.We consider a TBTS(Time-constrained Big-le Transfer Scheduling)problem in this paper.We prove that TBTS problem is NP-hard and that the TBTS problem can be solved by addressing a corresponding maximum ow over time problem with multi-path routing technique.We then propose both a heuristic algorithm(TBTS-H)and an exact algorithm(TBTS-A)to solve the TBTS problem.Although both of the proposed approaches can solve the TBTS problem,the heuristic runs more effciently by trading accuracy for delay,while the exact algorithm can achieve high accuracy for delay,at the cost of increased running-time.The corresponding simulation results illustrate this trade-o.Additionally,we conduct some comparisons between our proposed approaches and a traditional single-path routing scheme.