The Visitor Location Register (VLR) Emulator adds the ability to support combined GPRS/IMSI attaches and location updates to UMTS network testing as well as Message Service Center (MSC) functionality for Short Message Service (SMS) testing in both UMTS and LTE networks.
Network Interface Support
The VLR Emulator can be used in several configurations to support SMS testing in a UMTS network and in an LTE network in circuit-switched fallback mode. 3G and 4G interfaces can be used simultaneously to support evolution deployment testing and roaming or fallback scenarios.
When a VLR Emulator supports multiple interfaces, it also supports the interaction between those interfaces.
- Multiple SGs interfaces enable support for MME-MME mobility;
- SGs and Gs interfaces enable support for MME-SGSN mobility;
- Multiple Gs interfaces enable support for SGSN-SGSN mobility.
Execute timed chains of test events with a run-time command or during an automated test to trigger VLR-initiated procedures.
- VLR Failure.
One VLR Emulator can support any mixture of the interfaces shown in the diagram above, up to a maximum of 1000 client connections. Multiple VLR Emulators can be instantiated on a single server. In this mode each emulator can support multiple interfaces, up to an aggregate of 1000 client connections across all emulators. The VLR nodes are fully independent and their subscriber configurations may be independent, overlap, or be duplicated.