Optimal Data Replication in RSU Aided Vehicles Networks
Brief Introduction
Roadside Units (RSUs), which enable the vehicles-to-infrastructure communication, are deployed along the roadside to handle the growing communication demands as the number of vehicles increases. How to optimally deploy the RSUs and efficiently use them to enhance the vehicular network performance are important problems in the RSU-aided opportunistic networks. In order to solving these problems, we need to understand fundamental laws and properties of the opportunistic contacts. In this project, we carry out an extensive experiment involving tens of thousands of operational taxis in Beijing city. In terms of contact time between the RSUs and vehicles, we find it obeys exponential distribution, while in terms of contact rate, we find it follows Poisson distribution. Our observations reveal fundamental patterns for large scale vehicular mobility, and further provide useful guidelines for the design of new routing protocols and their performance evaluation for RSU-aided vehicular opportunistic networks.
Roadside Units (RSUs), which enable the vehicles-to-infrastructure communication, are deployed along the roadside to handle the growing communication demands as the number of vehicles increases. How to optimally deploy the RSUs and efficiently use them to enhance the vehicular network performance are important problems in the RSU-aided opportunistic networks. In order to solving these problems, we need to understand fundamental laws and properties of the opportunistic contacts. In this project, we carry out an extensive experiment involving tens of thousands of operational taxis in Beijing city. In terms of contact time between the RSUs and vehicles, we find it obeys exponential distribution, while in terms of contact rate, we find it follows Poisson distribution. Our observations reveal fundamental patterns for large scale vehicular mobility, and further provide useful guidelines for the design of new routing protocols and their performance evaluation for RSU-aided vehicular opportunistic networks.
Our Contribution
- By analysing large volume of realistic urban vehicular mobility traces, in terms of contact rates, we find that the inter-contact time distribution is exponential, which reveals that the rates of the communication contact between the vehicles and RSU exhibits strong Poisson property.
- In terms of the contact time, we find that it obeys exponential distribution with very high accuracy. This is contrast to the existing finding of a power law exhibited in human mobility.
- We consider the RSU-aided vehicular mobile content dissemination problem with the realistic heterogeneous settings that 1) the network contains heterogeneous vehicles in terms of data preference, 2) the mobile data items are multi-types of different delay sensitivity and size, and 3) the RSU’ storages for content sharing are limited in size. These realistic conditions were not taken into account in the previous works for simplicity reasons.
