isn t it a part of confidence building measure, to notify other country in case of ballistic missile test...
only Pakistan 24 hours before the test, so that they dont mis understand the test, their is also no fly zone at the area where test takes place, we do inform other like US, UK, Russia etc, but their is no treaty or international obligation to inform them.
Plus such test in our case allow us to monitor what progress Pakistan has made in missile, specially with AWAC now with IAF.
The confidence at which DRDO has stated Prahaar and the spin off from AAD programme, will be good news waiting to brake.