ISO/IEC 21989:2002 PDF

Overview

ISO/IEC 21989:2002 specifies the Short Message Service (SMS) for Private Integrated Services Networks (PISNs). It defines both the user-visible service (stage 1) and the functional model with information flows (stage 2). The standard bases Service Centre functionality on GSM 03.40, so interoperability with a GSM network requires implementing a QSIG interface. Interworking with other air interfaces is outside the scope.

Key topics

• Service definition (Stage 1): SMS behaviour as seen by PISN users - sending/receiving Short Messages (SMs), Validity Period, Status Reports and Commands.
• Functional model (Stage 2): Identification of functional entities (Service Centre / SC, Message Centre, terminals), allocation to physical equipment and detailed information flows between entities.
• Service Centre (SMSC) functionality: store-and-forward delivery, retry logic, responsibility until delivery or expiration, generation of Status Reports, handling of Commands.
• Short Message Waiting Data (SMWD) and ScAlert: mechanisms to notify SCs when a previously unreachable receiving user becomes reachable or has memory again.
• Operational cases: Terminal Case vs Message Centre Case (who handles SMS procedures) and interactions with other supplementary services.
• Conformance guidance: Stage 3 (not included) must define signalling protocols and equipment behaviour adequate to support stage 1 and 2 aspects relevant to the interface or equipment.

Practical applications

• Implementing SMS functionality in enterprise PBXs and PISNs for internal and inter-network messaging.
• Designing or deploying Service Centre (SMSC) solutions that mirror GSM 03.40 behaviour for private networks.
• Enabling interworking between PISN SMS and public mobile networks using a QSIG interface for interoperability with GSM SMSCs.
• Implementing message waiting indicators and store-and-forward message handling for users and mobile/desktop terminals.
• Using the stage 2 information flows and functional model as the basis for developing stage 3 protocol specifications, testing plans, and conformance testing.

Who should use this standard

• Telecom equipment vendors and PBX manufacturers implementing SMS in PISNs
• Network architects and system integrators planning SMS interworking with mobile networks
• Test labs and standards bodies developing stage 3 protocol specifications
• Service providers deploying enterprise messaging and message-centre features

Related standards

• GSM 03.40 / ETSI TS 100 901 (GSM SMS technical realization)
• GSM 03.38 (alphabets and encoding)
• ISO/IEC 11574, ISO/IEC 11579‑1 (PISN addressing and PINX)
• ETSI ETS 300 387 (method for supplementary services)

Keywords: ISO/IEC 21989:2002, Short Message Service, SMS, PISN, Service Centre, QSIG, GSM 03.40, SMSC, Short Message Waiting Data.