The E1 lightning protection board of the BTS is used to connect the BTS to the BSC. The name of the E1 lightning protection board varies according to the BTS model.
For the BTS3012, BTS3012AE, BTS3006C, and BTS3002E, the E1 lightning protection board is the DELU.
For the BTS3036, BTS3036A, DBS3036, BTS3900 GSM, BTS3900 GSM, and DBS3900 GSM, the E1 lightning protection board is the UELP.