A-Interface Circuit Sharing in the MSC Pool

This feature enables the media gateway (MGW), UMG8900, to assign A-interface circuit resources configured at the local office (adopting the MSC pool networking) to terminals upon receiving A-interface circuit assignment requests from the mobile switching center (MSC) server. In the traditional networking mode, each base station controller (BSC) are connected only to its corresponding MSC server. Therefore, A-interface circuits of a BSC are managed by only one MSC server. In the MSC Pool networking mode, each BSC are connected to multiple MSC servers in the resource pool. Therefore, A-interface circuits of a BSC are able to be managed by multiple MSC servers. Each MSC server, however, can manage only the circuit resources allocated to it. As a result, circuit resources cannot be dynamically adjusted among multiple MSC servers, leading to low usage of A-interface circuit resources and complexity in maintenance work.

To tackle this issue, management of A-interface circuits is transferred from the MSC server to the MGW.

Benefits for Carriers:

• Increased usage of A-interface circuit resources and reduced investment on A-interface circuit devices
• Simplified maintenance work and capacity expansion

Node requirements:

Impact on the System

This feature has no adverse impact on the system.

Implementation Principle

The MGW manages the A-interface circuit resources, including circuit selection, preemption, dialing tests, reseting, blocking, and unblocking. To improve the TDM resource usage and facilitate TDM resource management, the MGW manages the TDM resources by trunk groups. Each BSC can have a maximum of eight trunk groups.

The mappings between BSCs and trunk groups are determined by the destination signaling points (DSPs) and network identifications (NIs). A DSP and an NI uniquely identify a BSC. In addition, if several trunk groups have the same DSP and NI as that of a BSC, the trunk groups map the BSC.