(S (S (BASENP (PRP It)) (VP (VBZ has) (VP (ADVP (RB also)) (VP (VBN proposed) (S (BASENP (DT a) (JJ single) (NN window) (NN clearance) (NN system)) (VP (TO to) (VP (VP (VB authorise) (BASENP (JJ such) (NNS networks))) (COMMA ,) (PP (IN with) (NP (BASENP (DT the) (NN assurance)) (SBAR (IN that) (S (BASENP (DT the) (JJ requisite) (NNS clearances)) (VP (MD will) (VP (VB be) (VP (VBN provided) (PP (IN within) (BASENP (NN three) (NNS months))))))))))))))))) (PERIOD .))