Telecom Minister Manoj Sinha has said the instances of call drops have declined over a period of time and various steps have been taken to address the issue. <br/><br/>Replying to a supplementary during Question Hour in the Lok Sabha, Mr. Sinha said the telecom service providers have also been asked to improve the coverage of signal by installing more Base Transceiver Stations . <br/><br/>On signal blind-spots in wireless network, Mr. Sinha said it is a natural phenomenon which may happen due to various reasons including poor radio coverage and loading of available spectrum.