UMG8900 UG01SHPU0 Central Processing Unit Signaling High Level 03037088

When the UMG8900 functions as an access gateway (AG) on the fixed network, a user access module (UAM) is required.
When the UMG8900 functions as a trunk gateway (TG) or a media gateway on the mobile network, no UAM is required. The server switching module (SSM) and the UAM are connected over TDM. Physically, the connection is E1 or SDH based. The two modules communicate with each other using a private protocol. The SSM performs maintenance and management of the UMG8900.

The UMG8900 is of flexible configuration, and thus can serve as the following service gateways at the access layer in the NGN:
* Trunk gateway (TG)
* Embedded signaling gateway (SG)
* NGN-enabled switch
* Integrated application of the TG, and SG
* Extended integration of fixed and mobile network services

The UMG 8900 has two size chassis SSM-256 and SSM-32 with different Main Control Card.
SSM256 has one standard Slot, but SSM32 has two standard Slots on Main Control Board.

The SSM, core unit of the UMG8900, implements convergence, switching, processing, and forwarding of service streams, provides interfaces with the softswitch, and exchanges gateway control messages.
The UMG8900 hardware platform is designed to support both time division multiplexing (TDM) circuit switching services and IP packet switching services.
The integrated packet and TDM switching platform addresses the requirements for the TDM network and the packet network as well.
Therefore, the existing networks can evolve to all-IP networks smoothly by software upgrade rather than hardware replacement to reduce investment.
The UMG8900 supports the following types of frames: SSM-256, SSM-160, and SSM-32. SSM-256 and SSM-32 frames can self-cascade with frames of the same type or cascade with frames of the other type. The SSM-160 frame supports only self-cascading. Different cascading modes enable the optimum configuration of 32 to 7168 E1 channels in the synchronous digital hierarchy (SDH)/synchronous optical network (SONET), E1/T1 and E3/T3 transmission modes to protect investment effectively.

* The UMG8900, which is developed based on the softswitch architecture, can serve in the evolution from time division
multiplexing (TDM) based global system for mobile communications (GSM) networks to Internet Protocol (IP) based universal mobile telecommunications system (UMTS) networks.
* The UMG8900 can support MSC Pool networking. Without upgrade of devices in the access network, the UMG8900 can interconnect with each MSC Server in the MSC Pool. Resources can be shared among MSC Servers in the MSC Pool for load sharing. If an MSC Server fails, The others MSC Server in the MSC Pool can take over subscribers of the faulty MSC Server, that is, network disaster tolerance.
* VMGW
A virtual media gateway (VMGW) is a logical MGW. Multiple VMGWs can be integrated physically. The UMG8900 supports the VMGW function. An physicalUMG8900 can be configured to multiple VMGWs with independent logical functions. The VMGWs are identified by the VMGW ID and can be managed by different softswitches. The bearer resources of the physical MGW can be allocated to different VMGWs in exclusive or resource-sharing mode so that the flexibility of the UMG8900 is enhanced.
* Dual-homing function, enabling the UMG8900 to automatically switch to the slave MGC without interrupting services if the master MGC fails.
* Stream Control Transmission Protocol (SCTP) multi-homing feature: Multi-homing in SCTP refers to supporting multiple IP addresses. That is, in an association the two sides can have multiple addresses in an association, to provide more reliable end-to-end multi-path transmission mechanism for the upper layer subscribers.
* IuPS feature to establish the connection between the radio network controller (RNC) and the serving GPRS support node (SGSN)
The Iu PS interface is between the RNC in the access network and the SGSN in the core network. In actual networking
applications, no physical connection may exist between the SGSN and the RNC, and the UMG8900 is required to transfer services of the Iu PS interface.
* IP-based Iu interface
The IP packet transmission technology is adopted in the radio access network (RAN) and the core network, to build an all-IP network where the RAN and the core network may share the IP bearer network.
* IP-based A interface
Carriers' investment is protected and the IP-based core network serves to a full extent. Compressed codes such as GSM FR, GSM EFR, and GSM HR are transmitted, bandwidth is saved, transcode free operation (TrFO) for the full voice channel is possible, Transcoder Channel (TC) resource utilization is improved, and the voice quality is enhanced.
* Acting as an IP multimedia media gateway (IM-MGW) to implement the service interworking between the IP multimedia subsystem (IMS) domain and the circuit switched (CS) domain and the transparent transmission of H.264 and moving pictures experts group (MPEG)4 video codes.
* The UMG8900 can work with the MGC to act as a visited mobile switching center (VMSC), tandem mobile switching center (TMSC), or gateway mobile switching center (GMSC) in the GSM or R99 network. The UMG8900 can independently act as a media gateway (MGW) in the R4 network or an IP multimedia-MGW (IM-MGW) in the IP multimedia subsystem (IMS).