ISO/IEC 15505:2003 PDF

Overview

ISO/IEC 15505:2003 defines the Message Waiting Indication (SS‑MWI) supplementary service for Private Integrated Services Networks (PISNs). The standard contains stage 1 (service view for users) and stage 2 (functional model and information flows) specifications. SS‑MWI enables a Message Centre to signal that messages are waiting for a Served User and to cancel that indication. The document describes activation, deactivation, interrogation procedures, functional entities (FE1/FE2), and dynamic behaviour (expressed in SDL).

Key topics and technical requirements

• Service scope: SS‑MWI relates to basic services (see ISO/IEC 11574) and informs users when messages are waiting; the visible indication (lamp, tone, display) is out of scope.
• Stages covered:
  • Stage 1 (clause 6): user-oriented behaviour - provision/withdrawal, normal and exceptional procedures for activation, deactivation, interrogation.
  • Stage 2 (clause 7): functional model - definitions of Functional Entities (FE1 Message Centre control entity, FE2 Served User control entity), relationships and information flows.
• Procedures:
  • Activation/Deactivation: Message Centre supplies PISN number and service; optional information may include Message Centre identity, number of messages, originator address, timestamp, and message priority.
  • Interrogation: Served User may query status for one or all services; Message Centre returns activation state and optionally the additional information above.
  • Acknowledgement: Message Centre is given acceptance indication after activation/deactivation.
• Functional behaviour:
  • Overall dynamic behaviour modeled in Specification and Description Language (SDL) illustrating idle, activate, deactivate and interrogation flows.
  • Stage 2 details information flow sequences, FE actions, behaviour and allocation to equipment.
• Interworking: Guidance for accepting MWIs from other networks or sending MWIs to Served Users in other networks.
• Conformance: A stage 3 specification (signalling protocols and equipment behaviour) is required to claim conformance to aspects of stage 1 and 2.

Applications and users

Who uses ISO/IEC 15505:2003:

• Telecom equipment manufacturers (PISN/PBX vendors) designing Message Centre or user endpoint behaviour.
• Network architects and service providers implementing voicemail, unified messaging or notification features in private networks.
• Standards developers producing stage 3 signalling protocols that must support SS‑MWI semantics.
• Test and QA teams validating activation/deactivation/interrogation flows and interworking.

Practical applications:

• Implementing reliable message waiting lamps, tones or display updates driven by backend message stores.
• Defining interfaces between voicemail/message centres and PISN exchanges.
• Ensuring consistent user experience and cross‑network interworking for message notifications.

Related standards

• ISO/IEC 11574 (basic PISN services)
• ISO/IEC 11579‑1 (PINX reference configuration)
• ETS 300 387 (method for service specification stages)
• ITU‑T Z.100 (SDL specification)