Operations support systems (OSS), operational support systems in British usage, or Operation System (OpS) in NTT, are computer systems used by telecommunications service providers to manage their networks (e.g., telephone networks). They support management functions such as network inventory,

service provisioning In telecommunication, provisioning involves the process of preparing and equipping a network to allow it to provide new services to its users. In National Security/Emergency Preparedness telecommunications services, ''"provisioning"'' equates to ...

, network configuration and fault management. Together with business support systems (BSS), they are used to support various end-to-end telecommunication services. BSS and OSS have their own data and service responsibilities. The two systems together are often abbreviated OSS/BSS, BSS/OSS or simply B/OSS. The acronym OSS is also used in a singular form to refer to all the Operations Support Systems viewed as a whole

system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment (systems), environment, is described by its boundaries, ...

. Different subdivisions of OSS have been proposed by the

TM Forum TM Forum is a global industry association for service providers and their suppliers in the telecommunications industry. Members include communications and digital service providers, telephone companies, cable operators, network operators, cloud ...

, industrial research labs, or OSS vendors. In general, an OSS covers at least the following five functions: * Network management systems * Service delivery *

Service fulfillment Fulfillment of telecommunications services involves a series of supply chain activities responsible for assembling and making services available to subscribers. These activities delineate an operational infrastructure whose efficiency relies upon i ...

, including the network inventory, activation and provisioning *

Service assurance Service assurance, in telecommunications, is the application of policies and processes by a Communications Service Provider (CSP) to ensure that services offered over networks meet a pre-defined service quality level for an optimal subscriber experi ...

Customer care Customer service is the assistance and advice provided by a company to those people who buy or use its products or services. Each industry requires different levels of customer service, but in the end, the idea of a well-performed service is that ...

History

Before about 1970, many OSS activities were performed by manual administrative processes. However, it became obvious that much of this activity could be replaced by

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

s. In the next 5 years or so, the

telephone companies A telephone company, also known as a telco, telephone service provider, or telecommunications operator, is a kind of communications service provider (CSP), more precisely a telecommunications service provider (TSP), that provides telecommunicat ...

created a number of computer systems (or

software applications Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists o ...

) which automated much of this activity. This was one of the driving factors for the development of the Unix operating system and the

C programming language ''The C Programming Language'' (sometimes termed ''K&R'', after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well as ...

. The

Bell System The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over one hundr ...

purchased their own product line of

PDP-11 The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were sold, ...

computers from Digital Equipment Corporation for a variety of OSS applications. OSS systems used in the Bell System include AMATPS, CSOBS, EADAS, Remote Memory Administration System (RMAS), Switching Control Center System (SCCS), Service Evaluation System (SES), Trunks Integrated Record Keeping System (TIRKS), and many more. OSS systems from this era are described in the

Bell System Technical Journal The ''Bell Labs Technical Journal'' is the in-house scientific journal for scientists of Nokia Bell Labs, published yearly by the IEEE society. The managing editor is Charles Bahr. The journal was originally established as the ''Bell System Techn ...

, Bell Labs Record, and Telcordia Technologies (now part of Ericsson) SR-2275. Many OSS systems were initially not linked to each other and often required manual intervention. For example, consider the case where a customer wants to order a new telephone service. The ordering system would take the customer's details and details of their order, but would not be able to configure the

telephone exchange A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital syst ...

directly—this would be done by a switch management system. Details of the new service would need to be transferred from the order handling system to the switch management system—and this would normally be done by a technician re-keying the details from one screen into another—a process often referred to as "swivel chair integration". This was clearly another source of inefficiency, so the focus for the next few years was on creating automated interfaces between the OSS applications—OSS integration. Cheap and simple OSS integration remains a major goal of most telecom companies.

Architecture

A lot of the work on OSS has been centered on defining its architecture. Put simply, there are four key elements of OSS: *Processes **the sequence of events *Data **the information that is acted upon *Applications **the components that implement processes to manage data *Technology **how we implement the applications During the 1990s, new OSS architecture definitions were done by the

ITU Telecommunication Standardization Sector The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

(ITU-T) in its

Telecommunications Management Network The Telecommunications Management Network is a protocol model defined by ITU-T for managing open systems in a communications network. It is part of the ITU-T Recommendation series M.3000 and is based on the OSI management specifications in ITU-T ...

(TMN) model. This established a 4-layer model of TMN applicable within an OSS: *Business Management Level (BML) *Service Management Level (SML) *Network Management Level (NML) *Element Management Level (EML) A fifth level is mentioned at times being the elements themselves, though the standards speak of only four levels. This was a basis for later work. Network management was further defined by the ISO using the

FCAPS FCAPS is the International Organization for Standardization, ISO Telecommunications Management Network model and framework for network management. ''FCAPS'' is an acronym for fault, configuration, accounting, performance, security, the management ...

model—Fault, Configuration, Accounting, Performance and Security. This basis was adopted by the ITU-T TMN standards as the Functional model for the technology base of the TMN standards M.3000 – M.3599 series. Although the FCAPS model was originally conceived and is applicable for an IT enterprise network, it was adopted for use in the public networks run by telecommunication service providers adhering to ITU-T TMN standards. A big issue of network and service management is the ability to manage and control the network elements of the access and core networks. Historically, many efforts have been spent in standardization fora (ITU-T, 3GPP) in order to define standard protocol for network management, but with no success and practical results. On the other hand IETF SNMP protocol (Simple Network Management Protocol) has become the de facto standard for internet and telco management, at the EML-NML communication level. From 2000 and beyond, with the growth of the new broadband and VoIP services, the management of home networks is also entering the scope of OSS and network management.

DSL Forum The Broadband Forum is a non-profit industry consortium dedicated to developing broadband network specifications. Members include telecommunications networking and service provider companies, broadband device and equipment vendors, consultants an ...

TR-069 specification has defined the CPE WAN Management Protocol (CWMP), suitable for managing home networks devices and terminals at the EML-NML interface.

TM Forum

The

, formerly the TeleManagement Forum, is an international membership organization of communications service providers and suppliers to the communications industry. While OSS is generally dominated by proprietary and custom technologies, TM Forum promotes standards and frameworks in OSS and BSS. By 2005, developments in OSS architecture were the results of the TM Forum's New Generation Operations Systems and Software (NGOSS) program, which was established in 2000. This established a set of principles that OSS integration should adopt, along with a set of models that provide standardized approaches. NGOSS was renamed Frameworx.

Frameworx models

*An information model (th
Shared Information/Data model, or SID
– now more commonly referred to as the Information Framework, *A process model (th
enhanced Telecom Operation Map
or eTOM) – now more commonly known as the Business Process Framework, *An application model (th
Telecom Applications Map
– now known as the Application Framework, an architecture (the Technology Neutral Architecture) and a lifecycle model. The TM Forum describes Frameworx as an architecture that is: *"

loosely coupled In computing and systems design, a loosely coupled system is one # in which components are weakly associated (have breakable relationships) with each other, and thus changes in one component least affect existence or performance of another comp ...

" *distributed *component based The components interact through a common communications vehicle (using an information exchange infrastructure; e.g., EAI, Web Services,

EJB Jakarta Enterprise Beans (EJB; formerly Enterprise JavaBeans) is one of several Java APIs for modular construction of enterprise software. EJB is a server-side software component that encapsulates business logic of an application. An EJB web co ...

). The behavior can be controlled through the use of process management and/or policy management to orchestrate the functionality provided by the services offered by the components. The early focus of the TM Forum's NGOSS work was on building reference models to support a business stakeholder view on process, information and application interaction. Running in parallel were activities that supported an implementation stakeholder view on interface specifications to provide access to OSS capability (primarily MTNM). The MTNM work evolved into a set of Web Services providing Multi-Technology Operations System Interfaces

MTOSI In telecommunications, Multi-Technology Operations System Interface (MTOSI) is a standard for implementing interfaces between OSSs. Service providers (carriers) use multiple Operational Support Systems (OSS) to manage complex networks. Since the v ...

. Most recently, the OSS through Java initiative (OSS/J) joined the TMF to provide NGOSS-based BSS/OSS APIs.

Ongoing work - Open Digital Architecture (ODA)

Open Digital Architecture (ODA) offers an industry-agreed blueprint, language and set of key design principles to follow. It will provide pragmatic pathways for the journey from maintaining monolithic, legacy software solutions, towards managing nimble, cloud based capabilities that can be orchestrated using AI. It is a reference architecture that maps TM Forum’
Open APIs
against technical and business platform functions.

References

{{reflist

External links

Video: What is OSS/BSS?TM ForumOSS through Java initiativeOSS News ReviewOSS Observer landing page of Analysys MasonPipeline Magazine InsideTelephony OSS/BSS (2017.05.20 via Wayback Machine)Billing & OSS WorldOSS LineTelecommunications OSS and BSSTelcordia SR-2275
Network management Telecommunications systems