In intelligent networks (IN) and cellular networks, service layer is a conceptual layer within a network service provider architecture. It aims at providing middleware that serves third-party value-added services and applications at a higher application layer. The service layer provides capability servers owned by a telecommunication network service provider, accessed through open and secure Application Programming Interfaces (APIs) by application layer servers owned by third-party content providers. The service layer also provides an interface to core networks at a lower resource layer. The lower layers may also be named control layer and transport layer (the transport layer is also referred to as the access layer in some architectures).
The concept of service layer is used in contexts such as Intelligent networks (IN), WAP, 3G and IP Multimedia Subsystem (IMS). It is defined in the 3GPP Open Services Architecture (OSA) model, which reused the idea of the Parlay API for third-party servers.
In software design, for example Service-oriented architecture, the concept of service layer has a different meaning.
Service layer in IMS
The service layer of an IMS architecture provides multimedia services to the overall IMS network. This layer contains network elements which connect to the Serving-CSCF (Call Session Control Function) using the IP multimedia Subsystem Service Control Interface (ISC). The ISC interface uses the SIP signalling protocol.
Elements of the IMS service layer
The network elements contained with in the service layer are generically referred to as 'service platforms' however the 3GPP specification (3GPP TS 23.228 V8.7.0) defines several types of service platforms:
- SIP Application Server
- OSA Service Capability Server
SIP Application Server
The SIP Application Server (AS) performs the same function as a Telephony Application Server in a pre-IMS network, however it is specifically tailored to support the SIP signalling protocol for use in an IMS network.
OSA Service Capability Server
Service layer in SOA
In Service oriented architecture (SOA), the service layer is the third layer in a five abstraction layer model. The model consists of Object layer, Component layer, Service layer, process layer and Enterprise layer.. The service layer can be considered as a bridge between the higher and lower layers, and is characterized by a number of services that are carrying out individual business functions.
- ^ Kristofer Kimbler, Service Interaction in Next Generation Networks: Challenges and Opportunities. Feature Interactions in Telecommunications and Software Systems. Papers from the sixths International Workshop on Feature Interactions in Telecommunications and Software Systems May 2000. Edition: illustrated. Published by: IOS Press, 2000. ISBN 1586030655, 9781586030650.
- ^ http://www.3gpp.org/ftp/Specs/html-info/23228.htm
- ^ Service-oriented Architecture Compass: Business Value, Planning, and Enterprise Roadmap. Author: Norbert Bieberstein, Sanjay Bose, Marc Fiammante, Keith Jones, Rawn Shah. Edition: illustrated. Published by: FT Press, 2005. ISBN 0131870025, 9780131870024
Wikimedia Foundation. 2010.
Look at other dictionaries:
Enterprise Service Layer — ESL is the highest level of abstraction in a SOA architecture. An API defined at ESL can cross domain boundaries; it calls directly the Domain Service Layer, which in turn interacts with the Application Service Layer or the RDBMS Service Layer.… … Wikipedia
Service Oriented Programming — (SOP) is a programming paradigm that uses services as the unit of computer work, to design and implement integrated business applications and mission critical software programs. Services can represent steps of business processes and thus one of… … Wikipedia
Service Data Unit — (SDU) is a set of data that is sent by a user of the services of a given layer, and is transmitted to a peer service user semantically unchanged.Basically the SDU is the data that a certain layer will pass to the layer below. It differs from the… … Wikipedia
Service-oriented architecture — (SOA) is a method for systems development and integration where functionality is grouped around business processes and packaged as interoperable services . SOA also describes IT infrastructure which allows different applications to exchange data… … Wikipedia
Service discovery — protocols are network protocols which allow automatic detection of devices and services offered by these devices on a computer network. Service discovery is an essential ingredient of the Semantic Web, since the future Web must allow software… … Wikipedia
Layer 3 — Als OSI Modell (auch ISO OSI Schichtmodell, OSI Referenzmodell; engl. Open Systems Interconnection Reference Model) wird ein Schichtenmodell der Internationalen Standardisierungsorganisation (ISO) bezeichnet. Es wurde als Designgrundlage von… … Deutsch Wikipedia
Service Access Point — A Service Access Point or SAP is an identifying label for network endpoints used in OSI networking. When using the OSI networking layer (CONS or CLNS), the base for constructing an address for a network element is an NSAP address, similar in… … Wikipedia
Layer Two Tunneling Protocol — L2TP im TCP/IP‑Protokollstapel: Anwendung L2TP Transport UDP Internet IP (IPv4, IPv6) Netzzugang Ethernet Token … Deutsch Wikipedia
Layer 2 MPLS VPN — A Layer 2 MPLS VPN is a term in computer networking. It is a method that Internet service providers use to segregate their network for their customers, to allow them to transmit data over an IP network. This is often sold as a service to… … Wikipedia
Layer 2 Tunneling Protocol — L2TP im TCP/IP‑Protokollstapel: Anwendung L2TP Transport UDP Internet IP (IPv4, IPv6) Netzzugang Ethernet Token … Deutsch Wikipedia