BACKBONE Engineerig, Procurement and Construction for: Fiber Optic for Block Interconnection, Fiber Optic Installation between Stations LAN/WAN Installation Using UTP and STP Cable Traindispatching Some Experiences: Radio Traindispatching Installation in Jabodetabek (Sec.1&2), Radio Traindispatching Installation in Lampung (Sec.1), Radio Traindispatching Installation in North Sumatera (Sec.1), Installation of Taindispatching Cross Bogor-Padalarang, Radio Traindispatching to Support Airport Train Radio Link Some Experiences: Radio Link Installation between Martapura – Prabumulih Installation of Radio Link, Data Transmission and Power Rectifier Replacement of Radio and Traindispatching Replacement of Radio Link from 1,4 GHz to 8 GHz