11
overarChIng toPICs
• Two possible options: Prolong PSTN usage with platform
upgrades required or implementation of soft switch solu-
tion (replacing PSTN network with a separate new one,
no customer contract required)
2. One platform (IMS)/full PSTN migration toward NGN
IP-based architecture:
• One joint core platform (IMS)
• Full retirement of PSTN with only one network remaining
• Migration of all PSTN customers
• Two possible options for voice-only customers: Migration
to MSAN POTS card (emulation of PSTN with no
customer impact and contact required) or migration to
broadband port (full IP solution, but customer contact and
action required)
Combined approaches of interim solutions and full migration at
different areas are also possible ...