Schedule Algorithms for File Transmission in Vehicular Ad Hoc Networks

The development of vehicular ad-hoc networks has lead to several new services, such as instant messages, multi-media videos and large data transmissions. These applications have altered the pattern of data transmissions on VANETs to include larger volumes of data with different file sizes. Unstable links in vehicular networks are common due to channel fading and because of the vehicle moving, file transmissions are vulnerable to link interruption. How to utilize the limited link duration to transfer more files of different sizes successfully is a significant problem. Currently, the common practice to schedule file transmissions is a First In First Out (FIFO) mechanism defined in the DSRC (Dedicated Short Range Communication) standard. The algorithms presented in this paper show significant performance improvements. We proposed two algorithms, one based on transmission times and one based on due times. Both algorithms solve this problem by dynamically scheduling the file transmitting sequence according to selected criteria. Simulation results show that our algorithms significantly improve performance compared with FIFO mechanism for the transmission success rate and the network throughput.