What is the application of the Huawei UMG8900?

When applied in a mobile network, the Huawei UMG8900 provides the following, 

• Transport and forwarding of voice and circuit-switched data
• Conversion of circuit-switched service stream formats of mobile access networks to public circuit-switched networks (like PSTN and ISDN), to other networks (such as GSM and CDMA), or to packet networks
• Packet switching which is key to the evolvement to an all-IP network

The Huawei UMG8900 is made to serve as, 

• MGW in the UTMS R4 core network
• UMTS R99 VMSC/TMSC/GMSC along with the MSOFTX3000
• GSM VMSC/GMSC along with the MSOFTX3000
• IM-MGW in the UMTS R5 core network