New Delhi, July 5 -- The department of telecommunications (DoT) and the Telecom Regulatory Authority of India (Trai) are sparring over the allocation of a portion of the key 700 MHz spectrum to the Indian Railways. The spectrum band is crucial for Indian Railways to deploy safety and security applications as a part of its indigenous radio-based train collision avoidance system (TCAS) or Kavach.

In a letter dated 16 June, the telecom department told Trai that the assignment of an additional 5 MHz spectrum would be considered only once the 5 MHz spectrum already assigned in the 700 MHz frequency band was used.

The back reference from DoT came on Trai's recommendations to assign additional spectrum to Indian Railways for its safety and sec...