Short message service center

A Short Message Service Centre ( SMSC) is a part of a GSM, UMTS or LTE mobile radio network. It is responsible for the storage, transmission, conversion and delivery of messages of the Short Message Service.

The full name in the specification documents of the 3GPP is Short Message Service - Service Centre (SMS -SC).

Function

The functions to be implemented and capabilities of a SMS -SC are defined by the 3GPP only very briefly, specifies the protocols to be used only in the form of a non-binding proposal.

Often, however, the term is used SMSC for the entire transmission chain for short messages in the mobile network.

The actual SMS -SC takes on the following tasks:

  • Delivery of short messages to mobile subscribers
  • Receive short messages from mobile subscribers
  • Processing of the delivery confirmation of messages from the MSC
  • Processing of the delivery confirmation of messages from a landline
  • Compliance with the existing validity in the news
  • Generating a unique time stamp in short messages
  • Delivery of delivery notifications to mobile subscribers
  • Delivery of delivery notifications to the fixed network
  • Overwriting of short messages in mobile devices

Shipping

A short message that sends a terminal in the mobile network is referred to as SM MO (Short Message Mobile Originated ). The case triggered processes are:

  • The message is transmitted from the terminal to the MSC
  • The MSC fetches information from the VLR using the sending participant. These may consist of instructions on disabling the subscriber or booked additional services
  • If the information received does not stand in the way ( SMS Interworking MSC) MSC forwards the message to an SMS IWMSC further
  • The SMS IWMSC requested from the HLR of the target subscriber information on the message path to be used
  • The SMS IWMSC forwards the message to an appropriate SMS -SC further

Reception

A short message which receives a terminal in the mobile network is referred to as SM MT (Short Message Mobile Terminated). The case triggered processes are:

  • The message to be delivered is present in the SMS -SC
  • The SMS -SC forwards the message to an SMS - GMSC ( SMS gateway MSC) further
  • The SMS - GMSC requested from the HLR of the target subscriber information on the message path to be used
  • The SMS - GMSC delivers the message to the responsible MSC from
  • The MSC uses the information obtained in the receiving subscriber VLR. These may consist of instructions on disabling the subscriber or booked additional services
  • If the information received is not contrary to the MSC delivers the message to the end user from
  • The terminal generates a receipt on request
  • The MSC forwards the acknowledgment of receipt to the SMS - GMSC
  • The SMS - GMSC forwards the acknowledgment of receipt to the SMS -SC further
  • The SMS -SC generates a delivery for the ansendenden participants. These will be delivered in the same way as a normal short message

Short messages can also be forwarded from one network element in the IP network to an SMS -SC with the protocols UCP or SMPP. This possibility is used by mobile operators to send short messages automatically generated for information or as part of value-added services to mobile subscribers.

Transmission protocols for text messages

For the transmission of short messages, the European Telecommunications Standards Institute has (English European Telecommunications Standards Institute, ETSI ) standardized the following network protocols.

  • Short Message Peer to Peer ( SMPP ) of the SMS Forum
  • Computer Interface to Message Distribution ( CIMD ) by Nokia
  • External Machine Interface / Universal Computer Protocol ( EMI / UCP) of Logica
  • Open Interface Specification ( OIS ) of the Specialty Equipment Manufacturers Association ( SEMA )
  • Telecator Alphanumeric Protocol (TAP ) Motorola
Universal Mobile Telecommunications System Network switching subsystem#Mobile switching center .28MSC.29 EMI (protocol)
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