Vehicular edge computing (VEC) is a promising technology to support real-time
applications through caching the contents in the roadside units (RSUs), thus
vehicles can fetch the contents requested by vehicular users (VUs) from the RSU
within short time. The capacity of the RSU is limited and the contents
requested by VUs change frequently due to the high-mobility characteristics of
vehicles, thus it is essential to predict the most popular contents and cache
them in the RSU in advance. The RSU can train model based on the VUs' data to
effectively predict the popular contents. However, VUs are often reluctant to
share their data with others due to the personal privacy. Federated learning
(FL) allows each vehicle to train the local model based on VUs' data, and
upload the local model to the RSU instead of data to update the global model,
and thus VUs' privacy information can be protected. The traditional synchronous
FL must wait all vehicles to complete training and upload their local models
for global model updating, which would cause a long time to train global model.
The asynchronous FL updates the global model in time once a vehicle's local
model is received. However, the vehicles with different staying time have
different impacts to achieve the accurate global model. In this paper, we
consider the vehicle mobility and propose an Asynchronous FL based
Mobility-aware Edge Caching (AFMC) scheme to obtain an accurate global model,
and then propose an algorithm to predict the popular contents based on the
global model. Experimental results show that AFMC outperforms other baseline
caching schemes.Comment: This paper has been submitted to The 14th International Conference on
Wireless Communications and Signal Processing (WCSP 2022