An intelligent network (IN) is a network containing distributed processors that facilitate the creation and provisioning of advanced network features. These processors incorporate the logic required to execute advanced features and access databases that contain customer information on their specific network design and its features.
An IN is an excellent example of the growing merger between computers and communications. Computers provide advanced services to specific customers, and a communications network (e.g., Signaling System 7) provides access and transport capabilities between the users and the network-based processors.
The intelligent network separates basic call processing services from enhanced services. Rather than requiring feature software in every switch, the intelligence is in the SS7 network and is passed to switches as required. This also means that switches must be able to recognize that handling a particular call requires additional information from the service control point (SCP). These “triggering events” must be handled in each switch.
Intelligent Network Standards
The IN has been standardized by multiple organizations. In the United States, two organizations are responsible for the IN standards.
The first is the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T); their Q.1200 series of recommendations define the full capabilities of an intelligent network. The Q.1200 series are further broken down into what are considered capability sets (CS). The recommendations define three capability sets, CS1 through CS3. Currently, only CS1 is fully defined.
The second standards body for intelligent networks is Bellcore. In the early 1990s, Bellcore defined the advanced intelligent network (AIN). These definition have been refined and are published in a series of generic requirements (GR) documents. GR-1298-CORE defines the AIN switching system generic requirements, GR-1299-CORE and GR-1280-CORE the SCP requirements, GR-1129-CORE the peripheral interface requirements, and GR-1286-CORE the operational requirements. Further definitions of the AIN are found in various Technical Requirements, Technical Advisories, and Special Reports. Bellcore has identified numerous releases of the AIN, from Release 0.1 and 0.2 to AIN Release 1. It is envisioned that Release 1 objectives will be met some time in the future.
Other IN standards are available from European Telecommunications Standards Institute (ETSI) and Japan’s Telecommunications Technology Committee (TTC).
The visual depicts the elements of a generic intelligent network (IN) architecture. The network elements are either physical or functional, and include those listed below.
- Service switching points (SSP): As defined for SS7.
- Service control points (SCP): As defined for SS7.
- Signaling transfer points (STP): As defined for SS7.
- Service management system (SMS): Provides the functions necessary to provision, maintain, and administer AIN services.
- Network access points (NAP): Provide IN functions to a switching office or other equipment (e.g., PBX) that does not have SSP functions. A NAP uses existing signaling facilities to access an SSP for AIN services via the SS7 network.
- Adjunct: Performs similar functions as an SCP, but connected directly to an SSP. Provides local service control functions.
- Intelligent peripheral (IP): Provides access to peripheral equipment (call recorders, announcement units, etc.) for IN functions.
The combination of these elements allows the creation and management of advanced call services, independent of the serving central offices.