3rd mediator host implementation best practice in two room three node sun cluster 3.3 in guest domai

we have a two node campus cluster and the setup is explained below, now we are going to implement a third node. we need your advise on where and in which room ( recommended ) to hold a mediator host. sun cluster 3.3 implemented in SPARC guest domains , solaris 10 lasest update. Room-1 ---contains node1(T5-4) and storage-1(VMAX) Room-2 ---contains node2(T5-4) and storage-2(VMAX) Room-3 ----contains a quorum server dual-string mediators exists ( diskset is mirrored in SVM across two storage ) Requirement: now we are going to implement a third node in room-1 in the existing sun cluster. please suggest, in which room we need have a mediator host?