Network Infrastructure

Network infrastructure is described in two series of ITU-T Recommendations. The Q.1741 series covers  “IMT-2000 references to Release [x] of GSM evolved UMTS core network” and the Q.1742 series covers “IMT 2000 references (approved as of [date]) to ANSI-41 evolved core network with cdma2000 access network.” These are the two IMT Family members that comprise the majority of global mobile systems.

There are some national and regional systems still in limited use but these are being supplanted by the systems described in these two series of ITU-T Recommendations. Both series may be accessed at www.itu.int/rec/T-REC-Q/e.

While these Recommendations include introductory text, basic architecture diagrams and brief descriptions of the entities in the architecture, they are still complex documents. For example, clause 4 of 3GPP specification 23.002 (which includes all the versions of this specification - scroll to the bottom of the page for the most current version) is entitled “The basic entities of the mobile system” yet requires careful reading in order to be understood. This specification is one of the fundamental core network specifications transposed by the 3GPP Organizational Partners and then referenced in the ITU-T Recommendation Q.1741 series. A similar situation exists for the other major IMT Family Member where the current version of S.R0005 provides the “Network Reference Model for cdma2000 Spread Spectrum Systems.”