IP-based Iu Interface

Brief Introduction:

The IP network is the trend of the telecom network evolution. The development of new IP services requires carriers to provide an IP network with sufficient bandwidth, high efficiency, and low costs.

The radio network controller (RNC) are connected to the mobile switching center (MSC) server and the UMG8900 over the Iu interface. On a traditional network, the Iu interface is in asynchronous transfer mode (ATM). After IP is enabled on the Iu interface, signaling and data are transmitted on the signaling plane and bearer plane between the UMG8900 and the RNC, enabling a wideband code division multiple access (WCDMA) network to evolve to an all-IP network.

Benefits to carriers: This feature helps with Reduced network cost and saved network bandwidth

Impact to system: This feature has no adverse impact on the system.

Application Limitations:

• The RNC interconnected with the UMG8900 must support the IP-based Iu interface.
• The RFC2833 function must be disabled in local exchanges supporting the IP-based Iu interface.
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Application Scenario

After IP is enabled on the Iu interface, the UMG8900 can connect to radio access network (RAN) devices in different bearer modes. The Nb interface also supports multiple bearer modes. Figure 1 shows the networking of the IP-based Iu interface.

Figure 1 Networking of the IP-based Iu interface

http://localhost:7890/pages/31185046/01/31185046/01/resources/figure/fig_cn_10_02_0025501.png

In this network, the IP-based Iu interface may interwork with the BSC or RNC based on the TDM or ATM bearer mode. Alternatively, the IP-based Iu interface may interwork with the Nb interface based on the TDM or IP bearer. The Nb interface may correspond to the public switched telephone network (PSTN), TDM-based CN, or IP-based CN.

When the Iu interface is in IP mode, the MGC server transfers the IP addresses of the MGW and RNC and sets up the link on the signaling plane to the RNC. If the RNC is not directly connected to the MGC, the MGW transfers the packets. When the Iu interface is in TDM or ATM mode, the MGW must serve as the SG to adapt to the Base Station Subsystem Application Part (BSSAP) or Radio Access Network Application Part (RANAP) signaling from the BSC or RNC.