eligible Mode S interrogator

‘eligible Mode S interrogator’ means a Mode S interrogator for which at least one of the following conditions is satisfied:

(a)the interrogator relies, at least partly, on Mode S all call interrogations and replies for Mode S targets acquisition;

(b)the interrogator locks out acquired Mode S targets in reply to Mode S all call interrogations, permanently or intermittently, in part or the totality of its coverage; or

(c)the interrogator uses multisite communications protocols for data link applications;