Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). At low transmission rates data can also be transferred via an electrical interface. The method was developed to replace the plesiochronous digital hierarchy (PDH) system for transporting large amounts of telephone calls and data traffic over the same fiber without the problems of synchronization.
Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern. This method transmits two or more digital signals or analog signals over a common channel. It can be used when the bit rate of the transmission medium exceeds that of the signal to be transmitted. This form of signal multiplexing was developed in telecommunications for telegraphy systems in the late 19th century, but found its most common application in digital telephony in the second half of the 20th century.
In telecommunications rating is the activity of determining the cost of a particular call. The rating process involves converting call-related data into a monetary-equivalent value.
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 Recommendation series X.700.
Many services running on modern digital telecommunications networks require accurate synchronization for correct operation. For example, if telephone exchanges are not synchronized, then bit slips will occur and degrade performance. Telecommunication networks rely on the use of highly accurate primary reference clocks which are distributed network-wide using synchronization links and synchronization supply units.
Oscilloquartz, a company of ADVA Optical Networking, is a manufacturer of frequency sources, such as GPS& GLONASS receivers or caesium clocks for telecommunications applications and has been producing similar products for about 60 years. It also providers synchronization solutions for turnkey synchronization projects in e.g. PDH, SDH, SONET and all kind of mobile telecom networks e.g. GSM, X-CDMA, TETRA, 2.xG, 3G, 4G, UMTS, WiMAX.
Ethernet over PDH or EoPDH is one of many techniques that provided Ethernet connectivity over non-Ethernet networks. Specifically, EoPDH is a standardized methodology for transporting native Ethernet frames over the existing telecommunications copper infrastructure by leveraging the established PDH transport technology. EoPDH is one of several Ethernet transport technologies that enables Telecommunication Service Providers to offer "Carrier Ethernet" services. Also commonly used as a means of connecting businesses to a Metro Ethernet network.
Telecom Electric Limited began life as a small project within the National Grid plc to determine the feasibility of running suspended optical fibre cables across the pylons of the high voltage power distribution network owned by the company. Three principal techniques were considered:
- Optical Ground Wire (OPGW), which replaced the earth wire that runs across the top of the pylons with a new cable that contained a tubular core in which up to 24 optical fibres could be placed. However this option was expensive to implement as it would mean writing off the capital value of the old earth cable many years before it was due to be replaced as part of the normal operation and maintenance cycle. Installation was also very expensive and methods to reduce costs in this area needed to be developed.
- Wrapped Fibre (WF), which involved a new technique of taking a variant of underground cable and wrapping it in a spiral fashion around the earth wire. A specially adapted machine was designed for the job to that made installation cost-effective. The challenge for the company however was how to protect the fibres in the cable from damage caused by starlings pecking at the cable sheath, which split open the cable exposing the fibres to water which would affect the optical transmission properties.
- All Dielectric Self Supporting (ADSS) Cable, which consisted of non-metallic suspension components and was already used on low voltage power distribution networks in various parts of the world. However, it was found that at 275 kV and 400 kV, the voltages used on the National Grid infrastructure, the electromagnetic fields from the power cables were sufficient to induce microsparks inside the cable that degraded the dielectric materials causing the cable to fail and collapse.
Frameworx is an enterprise architecture framework geared towards communications service providers.
Circuit emulation service (CES) is a telecommunication technology used to send information over asynchronous data networks like ATM, ethernet or MPLS, so that it is received error-free with constant delay, similar to a leased line.
An element management system (EMS) consists of systems and applications for managing network elements (NE) on the network element-management layer (NEL) of the Telecommunications Management Network (TMN) model.
Objective Systems Integrators (OSI) is a multinational computer technology corporation that develops, manufactures, licenses, and supports software products which automate the monitoring, control, delivery, and management of services for multinational corporation service providers including:
NetExpert monitors and controls networks and service impacting resources using object-oriented and expert systems technologies.
Netcracker Technology Corp., a wholly owned subsidiary of NEC Corporation, is a provider of business support system (BSS), operations support systems (OSS) and software-defined networking (SDN) and network functions virtualization (NFV) solutions. The company also offers professional services, as well as managed services.
Avaya Unified Communications Management in computer networking is the name of a collection of GUI software programs from Avaya utilizing a service-oriented architecture (SOA) that serves as a foundation for unifying configuration and monitoring of Avaya Unified Communications Servers and data systems.
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. They support management functions such as network inventory, service provisioning, network configuration and fault management.
Telecommunications billing is the group of processes of communications service providers that are responsible to collect consumption data, calculate charging and billing information, produce bills to customers, process their payments and manage debt collection.
Digital Data Systems, or DDS, was a consultancy firm specializing in operations support systems (OSS) and business support systems (BSS) in the public switched telephone network (PSTN) and carrier marketplace within the telecommunications industry. DDS was an independent provider of OSS and BSS during a time when such systems were provided by the large telecommunications switch vendors. It completed in OSS / BSS head-to-head against AT&T, Northern Telecom, and others in providing services that sold and deployed amongst the Regional Bell Operating Companies, including: Bell Atlantic, Southwestern Bell, and Pacific Telesis. It had a hardware joint venture with MIPS Computer Systems who provided the hardware platform upon which it ran. The business was acquired by Computer Sciences Corporation (CSC) in 1992.
VOSS Solutions is a British-founded multinational unified communications and collaboration corporation, headquartered in Richardson, Texas, that provides service delivery and management software. It developed a real-time automated unified communications and collaboration service delivery platform called VOSS-4-UC.
ALBEDO Telecom is a company that designs and manufactures products for the telecom industry including testers, synchronization nodes and networking devices. Typical users are R&D laboratories, Mobile and Telecom operators to verify and install the infrastructures that support any kind of applications based on voice, video and data. It is headquartered in Barcelona, Spain in the European Union.
