Sandbox 4 now has SDRs which are capable of acting as LTE UE or eNBs for experimentation. Two commercial basestations are attached as well. In addition, an LTE EPC is available for interoperability tests and experimentation. Finally, a number of COTS UEs are available as client devices. More details are available at the following wiki pages:
The ORBIT Grid domain now has a USRP based massive-MIMO setup available for experiments. The first corner rack (located under node20-1) is complete and contains eight 10MHz and PPS synchronized Ettus USRP X310 software defined radios outfitted with two UBX 160 radio daughterboards each. These USRPs appear as nodes 23-1 through 23-8. More information is available in the wiki page for the Grid domain.