Ericsson and Essjay ericsson
I am not sure about essjay ericsson, tried searching in google too , didn't get proper answer. but so far what i can say it could be Ericsson BTS/Transmission unit (either 3rd party or some different internal unit) . Not sure about internal unit (there are main 2 units currently EIL -ericsson India limited and EGI - ericsson global india) .