MSC: Mobile Control Switch VLR: The home location register is usually along with a switch of the switch to store information for external roaming users. HLR; home location register, used to store local users, used for external switches Look for a number of switches belonging when you signal the inquiry. AUC: The authentication center of the switch is registered when registering SIM. BSC: Still Stations Control Center Manage Each Store. PCU: Packet Control Unit. The device is BSC support Equipment for business. BTS: Still. Mobile wireless network directly with mobile phone devices. SCP: Business controller, smart network equipment for business control. SMP: Business management unit, smart network equipment, for business Management. VC: Intelligent Network Recharge Center. SMSC: Short Message Center SSP: Switch and Smart Network SCP Delivery Equipment to meet the intelligent network business