Public land mobile network : mobile application part and interfaces: recommendations Q.1051 - Q.1063 / International Telecommunication Union
Interworking with satellite mobile systems : recommendations Q.1100 - Q.1152 / International Telecommunication Union
Specifications of signalling systems No. 6 : recommendations Q.251 - Q.300 / International Telecommunication Union
Specifications of signalling systems R1 and R2 : recommendations Q.310 - Q.490 / International Telecommunication Union