Section 19(7)(iii) in The Delhi Metro Airport Express Line, General Rules, 2010
(iii)if Automatic Train Protection information is not available from the track side equipment, the train can be driven with traffic controller's permission in "Restricted Manual" Mode in which the on board Automatic Train Protection equipment restricts the speed of the train to twenty five kilometers per hour and when the Automatic Train Protection information is again available from the track, the mode automatically upgrades to Coded Manual;