Short Message Service Center (SMSC)

What is an SMSC?

SMSC stands for “short message service center.” This is the part of a mobile network that handles all SMS operations. Take storing, forwarding, routing, converting, and delivering of Short Message Service (SMS) messages. When an SMS is sent from any mobile phone, it must get to an SMSC before it is forwarded to the end-point or destination.

YateUCN redundant MSC

To summarize the major points, an SMSC Solution:

To better understand the concept of Short Message Service Center, you need to have a clear image of its functions and how it relates to other network functions.

The sections below describe the main functions of an SMSC, as well as our solution equipment.

We provide two types of SMSC solution:

  • YateSMSC – full production SMSC LTE, GSM and UMTS. It uses the SMSC SS7 and SMSC SMPP protocols. 
  • MiniCore – a small factor PC computer that has preinstalled the SMSC software.

Main functions of the SMSC

  • Reception of text messages (SMS)
    » The SMSC receives the short message from the MSC. If your subscriber is roaming in a different country the visited MSC is sending the SMS to the home SMSC.
    » At this point, the SMSC receives the Mobile-Originated SMS. After that, it turns the message into a Mobile-Terminated SMS. This way the SMSC can extract the destination number.
  • Sending SMS request to HLR
    » Once the SMSC receives the message from the phone, it sends a request to the Home Location Register (HLR). The HLR requests routing to that destination number.
  • Reception of Request and Response
    » The HLR receives the message from the SMSC and responds with a routing decision or with an error. This error is then interpreted by the SMSC.
  • Forward or Storage of message
    » For an inactive customer, the SMSC stores the message (as long as the end period is not exceeded).
    » For an active user, the SMSC forwards the message to the correct mobile device.
  • Verification
    » When delivering an SMS the SMSC waits for the result of the delivery from the mobile station. If it fails, it will retry at different times in the future depending on the configured retrial policy.

How the SMS center relates to other elements of the network

    » The HSS, which stands for a Home Subscriber Server is a major part of LTE and IMS core networks. This is a user database stored in a single logical node. Its corresponding function in GSM is the HLR (Home Location Register).
    » Its main function is to communicate with the Core Network. The HSS/HLR also provides authentication of subscribers and their profile information. It is a database that carries different information of mobile users on a mobile network. It stores mobile numbers, services, and the current location the subscriber registered from.
    » The SMSC stores the messages and requests the HLR information about the target address. It will receive the MSC/SGSN address where the subscriber is registered in and try to do a delivery to that destination
    »If the recipient is a user of another network, the home SMSC sends the message to the address returned by the destination’s HSS/HLR. That being its network SMSC of the MSC/SGSN where the destination user is registered.
    » Any operator needs to send and receive SMSs of its subscribers. That is why it is mandatory to interconnect the SMSC.
  • SMPP interconnect
    » The Short Message Peer-to-Peer Protocol enables the sending and receiving of SMSs. The SMSC SMPP connects third-party services and interconnects operator’s SMSCs.
  • Charging Server
    »The Charging Server handles processing accounting and billing information for subscribers. It allows service providers to charge customers in real-time based on the service rendered.

Types of Businesses that need an SMSC

Every SMSC has the function of receiving, forwarding, storing, and delivering SMSs in GSM, UMTS, LTE, or custom networks. This is mostly used by MNOs, MVNOs, private networks, and labs.

  • MNOs
    Unlimited data plans are growing. OTT communication apps have caused revenue from SMS services to decline. Yet, it remains a major service that every MNO needs to offer. A cost-effective and scalable solution is a must for MNOs since they have the largest number of subscribers.
  • MVNOs
    » Small or medium virtual mobile operators who wish to have their own SMSC . Not depending on MNOs for SMS services is desirable for independent MVNOs. They are another type of business that needs such function.
    » A cost-effective SMSC solution that can work on a small subscriber base is a great option for them. The revenue is not worth a huge investment.
  • Private Networks
    » Enterprises and businesses that need a high-speed network choose private LTE. This means the user is trying to set up a small scale network in a particular location to achieve its goals.
    » Having an SMSC depends on the needs and goals of the network. The network could profit from acquiring its own SMSC function or not. This has priority in deciding the needed network elements.
  • Laboratories
    » Labs operate SMSC simulators (aka SMPP server simulators) for research and development.
    » Testing SMS text messaging capabilities within custom applications.
    » They simulate SMSCs interactions and performance such as Session Management, Message Submission, Message Delivery.

Yate-based SMSC solutions

We provide two types of SMSC solutions for all types of businesses. Our solution is highly scalable and suitable for any operator size and structure. We implemented YateSMSC according to the standard SMSC protocol.

Full production SMSC software

YateSMSC is a conventional Short Message Service Center with the functions of receiving, forwarding, storing, and delivering SMS in GSM, UMTS, LTE, or custom networks. In addition to forwarding and delivering “Subscriber to Subscriber” messages. You can also implement various “application to Subscriber” and “Subscriber to Application” scenarios using YateSMSC.

It is an easy to operate SMSC solution for MNOs, MVNOs, private networks, and labs using a JSON API through YateMMI (Mobile Management Interface) web-interface.



Testing SMSC solution - MiniCore

The MiniCore is a small factor PC computer that has pre-installed the SMSC software component. Our test equipment is the just-a-dimmed-down version (in terms of range and number of users) of a standard mobile network.

MiniCore combines our YateHSS/HLR, YateUCN and YateSMSC in a small package.
It can be used as a second core network for testing. Software-based testing solutions will allow customers to test the SMSC quickly and easily.

As a LTE, 3G or GSM SMSC, the MiniCore has the following functionality:

  • SMS store-and-forward, routing, home routed SMS
    » Format: SMS PDU (MO and MT)
    » MAP/SS7 transport (T-PDU format)
    » SIP MESSAGE transport (SMS over IP, R-PDU format)
    » The SMPP standard version 3.3
    » Supports bidirectional communication


  • Setup/edit mobile network and component preferences via MMI management interface
  • Minimal monitoring of each network component, additional YateBTS monitoring possible
  • Wireshark capture of communication between components including decrypted IMS traffic
  • JSON API integration with any SIM management and CRM systems
  • JSON and REST API for sending SMS
  • Can use both SIGTRAN/SS7 and Diameter for signaling
  • Supports both IPv4 and IPv6
  • Works both stand alone and with external components
MiniCore diagram