Summary

Recommendation ITU-T K.97 deals with lightning protection of a distributed base station (DBS) on the tower site. A DBS is a new type of radio base station which consists of a remote radio unit (RRU) located on the tower, and a base band unit (BBU) inside the shelter at the bottom of the tower. Lightning protection of DBS is not fully covered by Recommendation ITU-T K.56.

The main objective of this Recommendation is the lightning protection of RRU and rectifier interfaces with direct current (DC) power cable, and bonding of the DBS.

Protection of these interfaces is achieved by installing a protection module. Possible protection schemes for such installations are also described.

This Recommendation indicates when these protection modules should be used, and provides indication of their withstand current. The surge protective device (SPD) needed on the feeder cable is also indicated.

Bonding configurations of the protection module and of the optical fibre cable are also illustrated.

Appendix I shows an example of an isolated protection solution.