  It is starting to become a big trend in the era of social networking that
people produce and upload user-generated contents to Internet via wireless
networks, bringing a significant burden on wireless uplink networks. In this
paper, we contribute to designing and theoretical understanding of wireless
cache-enabled upload transmission in a delay-tolerant small cell network to
relieve the burden, and then propose the corresponding scheduling policies for
the small base station (SBS) under the infinite and finite cache sizes.
Specifically, the cache ability introduced by SBS enables SBS to eliminate the
redundancy among the upload contents from users. This strategy not only
alleviates the wireless backhual traffic congestion from SBS to a macro base
station (MBS), but also improves the transmission efficiency of SBS. We then
investigate the scheduling schemes of SBS to offload more data traffic under
caching size constraint. Moreover, two operational regions for the wireless
cache-enabled upload network, namely, the delay-limited region and the
cache-limited region, are established to reveal the fundamental tradeoff
between the delay tolerance and the cache ability. Finally, numerical results
are provided to demonstrate the significant performance gains of the proposed
wireless cache-enabled upload network.
