SMS Evolution from 2G to 5G
May 13, 2023

SMS, Short Message Service, is a secure system that helps protect your customers’ and employees’ data and allows you to contact all users who have a mobile phone.

📕 In 2G and 3G, MAP protocols have been defined to support the SMS. MAP interface is built on top of SS7 (TDM or SIGTRAN) using the following layers (TCAP, SCCP, and MTP).

📕 With the 4G introduction, an intermediate environment (without IMS) was specified. This is called SMS over SGs (evolved Gs interface). A hybrid approach that allows the transmission of native SMS from CS infrastructure over the LTE radio network.

📕 Diameter protocol was introduced with 4G, in order to transport SMS between MME and SMSC.

📕 With the IMS introduction, the VoLTE network could also support the SMS sent over SIP. IPSM-GW, placed between the IMS core and the legacy domain, provides the possibility for the users to register and deregister, in order to enable or disable the possibility to send/receive SMSs over IP.  IP-SM-GW is connected to the HLR/HSS and is able to communicate with it both with MAP and Diameter.

📕 MAP and Diameter are supported in 5G between SMSF and SMSC. And HTTP2 on top of TCP, Transmission Control Protocol (no longer SCTP) will be used as the network protocol for SBA.

SMS Evolution from 2G to 5G

📃 SMS evolution towards 5G will see the potential support for legacy MAP/Diameter signaling for SMS.

📃 The current IMS core network architecture to transport SMS over IP can be in combination with the legacy CS network OR standalone EPC network.

🔋 MAP: Mobile Application Part.
🔋 SMS-C: Short Message Service Center.
🔋 SMSF: SMS Function (5G).

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