English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Caching at mobile devices, accompanied by device-to-device (D2D)communications, is one promising technique to accommodate the exponentiallyincreasing mobile data traffic. While most previous works ignored usermobility, there are some recent works taking it into account. However, theduration of user contact times has been ignored, making it difficult toexplicitly characterize the effect of mobility. In this paper, we adopt thealternating renewal process to model the duration of both the contact andinter-contact times, and investigate how the caching performance is affected bymobility. The data offloading ratio, i.e., the proportion of requested datathat can be delivered via D2D links, is taken as the performance metric. Wefirst approximate the distribution of the communication time for a given userby beta distribution through moment matching. With this approximation, anaccurate expression of the data offloading ratio is derived. For thehomogeneous case where the average contact and inter-contact times of differentuser pairs are identical, we prove that the data offloading ratio increaseswith the user moving speed, assuming that the transmission rate remains thesame. Simulation results are provided to show the accuracy of the approximateresult, and also validate the effect of user mobility.

Mobility Increases the Data Offloading Ratio in D2D Caching Networks