IP-based A Interface

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

On the traditional network, the A interface adopts the time division multiplexing (TDM) bearer. To meet the requirements of service development, the UMG8900 provides the A interface that adopts the IP bearer. Both the base station subsystem (BSS) and the network subsystem (NSS) adopt the IP packet transmission technology, which makes an all-IP network possible. In addition, the BSS and NSS can share the IP bearer network, which simplifies the network structure.

The IP-based A interface has the following advantages:

• The A interface can transmit both the G.711 codec and the compressed global system for mobile communications (GSM) codecs such as the full rate (FR), enhanced full rate (EFR), half rate (HR), adaptive multi-rate (AMR), and adaptive wideband-multi-rate (WB-AMR) codecs.
• The IP-based A interface enables the voice channels to implement the transcoder free operation (TrFO), saves transcoder (TC) channels, and improves voice quality.
• The A interface supports Real-time Transport Protocol (RTP) multiplexing, which saves transmission bandwidth.

Benefits for Carriers implementing IP A-Interface:

This feature expands new services, reduces the networking cost, and saves the transmission bandwidth.

Adoption Scenario:

The IP bearer is adopted between multimedia media gateway (MGW) 1 and base station controller (BSC) 1 and between MGW 2 and BSC 2 to carry voice and data services. The TDM bearer is adopted between MGW 2 and BSC 3. The networking shows in figure below (figure 1) .

Figure 1 Basic networking for the IP-based A interface

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For more details on IP based A-Interface please refer to UMG8900 product documentation.