Sign in Subscribe

SGs Interface (Signalling Gateway)

Last updated on 

The SGs Interface

The SGs (Signalling Gateway) interface is an optional interface between a 2G (GERAN) / 3G (UTRAN) Mobile Switching Center (MSC) and an LTE/EPC (Evolved Packet Core) Mobility Management Entity (MME). It is used for Mobility management (MM) and paging procedures between the EPS (Evolved Packet Services) and CS (Circuit Switched) domain.

Purpose of the SGs Interface

The SGs interface is used to facilitate mobility management and paging procedures between the EPS and CS domain. This enables users to seamlessly transition between 2G/3G and LTE/EPC networks while maintaining their call sessions.

Benefits of the SGs Interface

The SGs interface offers several benefits, including:

  • Improved mobility management: The SGs interface provides a more efficient way to manage user mobility between the EPS and CS domain. This can improve call quality and reduce dropped calls.
  • Reduced network congestion: The SGs interface can help to reduce network congestion by optimizing the use of network resources.
  • Support for CS fallback: The SGs interface supports CS fallback, which allows users to make and receive voice calls over the CS domain if the EPS domain is unavailable.

Technical Details of the SGs Interface

The SGs interface is based on the Signalling Connection Control Part (SCCP) protocol. It uses the SGs Application Protocol (SGsAP) to exchange messages between the MSC and the MME.

Deployment of the SGs Interface

The SGs interface is not widely deployed, but it is used by some operators. It is typically used in areas where there is a significant overlap between 2G/3G and LTE/EPC coverage.

Conclusion

The SGs interface is an optional interface that can be used to improve mobility management and paging procedures between the EPS and CS domain. It is not widely deployed, but it is used by some operators.