Fujitsu LTE website shows two LTE webstation, called the BBU and RRU, but does not describe the difference between them. I did not attend CEATEC Japan, but the page shows two photos taken at the event.
If seems like the key differentiator for Fujitsu is the 4×4 MIMO!
It will be interesting to see how Fujitsu will compete with Ericsson, the lead LTE vendor, for the Docomo deployment.
See press releases from both vendors: