0-9  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z object-relational database management system Relational database systems are being enhanced in two ways: (1) by adding an "object infrastructure" to the database system itself, in the form of support for user-defined data types, functions, and rules; and (2) by building "relational extenders" on top of this infrastructure that support specialized applications such as image retrieval, advanced text searching, and geographic applications. A system that includes both object infrastructure and a set of relational extenders that exploit it is called an "object-relational" database system. on ramp A popular term for a digital broadband connection linking a subscriber with the Internet. one-time charge Nonrecurring charge that is not associated with continuing business operations. An example would be costs associated with shutting down a division. Securities analysts often exclude these expenses from their analysis, as they are not an indicator of expected future prospects, on which most companies are being valued. opaque optical networks (OON) The current optical network in which conversions from the optical domain to the electrical and back to the optical are required periodically. Such optical-electrical-optical (OEO) conversions are required in order to re-time the signal in the digital domain; clean up signal impairments; allow fault isolation; and provide performance monitoring, particularly of signal bit error rate. open shortest path first (OSPF) A link-state routing algorithm used to calculate routes based on number of routers, transmission speed, delays and route cost. open systems interconnection (OSI) Flexible networking architecture model designed with specifications to support multiple networking protocols or physical networking systems. OSI allows multiple protocols and physical systems to operate on a base, lowest common denominator for inter operability across these varying networking elements. OSI has seven distinct layers, each of which has a set of specifications and functions. operating expenses Described as the day-to-day expenses of operating a corporation, including costs associated with sales and marketing, general and administrative personnel, and research and development. It excludes financing expenses, depreciation, and income taxes. In general, as young companies grow rapidly at the beginning of their life cycle, operating expenses as a percentage of revenue decline dramatically, in a phenomenon called, "operating leverage." Securities analysts will expect to see this trend and if it does not occur, may conclude that the company is not achieving economies of scale or being run well. operating lease A type of lease in which the contract is for substantially less than the life of the asset, thus the asset and maintenance is the responsibility of the lessor. The lessee can thus return the property, such as computers and trucks, when the equipment is no longer necessary or has become obsolete. This type of lease may be more suitable to a firm with either high volatility in its equipment needs (rapid expansion or future potential geographical move), or to a company that is unable to make the commitment needed for a capital lease or asset purchase (e.g., lack of purchasing information or immediate funds). operating system (OS) The governing function of a computer. Apple and Microsoft created their own. Linux was indepently created and is universally available for free. operations systems modifications for the integration of network elements (OSMINE) A Telcordia (formerly Bellcore) process to integrate other vendors equipment and systems into Telcordia-developed systems. Most of the incumbent service providers (RBOCs) depend on operation support systems developed by Telcordia. optical add/drop multiplexer (OADM) Also called wavelength add-drop multiplexer (WADM). An optical network element that lets specific channels of a multi-channel optical transmission system be dropped and/or added without affecting the through signals (i.e., the signals that are to be transported through the network node). optical amplifier A device that increases the optical signal strength without an optical-to-electrical conversion process. optical cable A telecommunications cable in which one or more optical fibers are used as the propagation medium. optical carrier (OC) A designation used as a prefix to denote the optical carrier level of SONET data standards. OC-1/STS-1, OC-3/STS-3, OC-12, OC?48, and OC-192 denote transmission standards for fiber-optic data transmission in SONET frames at data rates of 51.84 Mbps, 155.52 Mbps, 622.08 Mbps, 2.49 Gbps, and 9.95 Gbps, respectively. optical carrier level x (OC-x) A SONET term for an optically transmitted SONET signal at a particular speed. The base rate if 51.8 Mbps. OC-1 runs at the base rate, OC-3 runs at three times the rate, etc. Common rates are OC-1, OC-3 (155.52 Mbps), OC-12 (622.08 Mbps) and OC-48 (2.488 Gbps). optical channel monitor (OCM) A device that measures the optical signal power in several DWDM channels. optical carrier levels 3 and 12 (OC-3/OC-12) Transmit data at 51.8 million bits per second times the multiple, in this case, 155 and 622 million bits per second for OC-3 and OC-12 respectively. optical carrier level 192 (OC-192) SONET channel of 9.953 thousand million bits per second (Gbps). See SONET optical code division multiple access (O-CDMA) Code stream Technologies Corporation's implementation of CDMA on an optical network. optical cross connect (OXC) Also referred to as an OCS. An optical network element that provides for incoming optical signals to be switched to any one of a number of output ports. Some OXCs connect fibers containing multichannel optical signals to the input parts, de-multiplex the signals, switch the signals, and recombine/re-multiplex the signal to the output ports and simply switch between the two. Other OXCs connect fibers with single-channel optical signals to the input and output ports and simply switch between the two. OXCs can have optical or electrical switch matrices. The differentiator between OXCs and digital cross-connect systems is the interface rate and switch fabric granularity. optical fiber (fiber) A light guide for electromagnetic waves traveling in the infrared and visible light spectrum. An optical fiber consists of two different types of glass, core and cladding, surrounded by a protective coating. The core is the light-guiding region of the fiber, while the cladding ensures that the light pulses remain within the core. One mile of fiber, capable of transmission speeds of 2.5 Gbps, weighs about one-seventh of a pound. A copper cable with the same information-carrying capacity would weigh 33 tons. Optical Fiber Communications Conference The annual Optical Fiber Communications Conference, which is managed by the Optical Society of America (OSA). optical network The optical network will provide all basic network requirements in the optical layer (that is, capacity, scalability, reliability, survivability, and manageability). Today, the wavelength is the fundamental object of the optical network. Basic network requirements can be met through a combination of the optical transport layer (DWDM today), which provides scalability and capacity beyond 10 Gbps, and the SONET/SDH transport layer, which provides the reliability, survivability and manageability needed for public networks. The long-term vision of an "all-optical network" is of a transparent optical network where signals are never converted to the electrical domain between network ingress and egress. The more practical implementation for the near term will be of an opaque optical network (that is, one that works to minimize but still includes optical-to-electrical conversion). Optical network elements will include terminals, dynamic OADMs, and dynamic optical cross-connects. optical network management products An emerging category of optical networking software products that operate at the wavelength level and provide provisioning and management of light paths in the network at a minimum. These products will be developed (1) by equipment vendors,(as offerings integrated with transport and switching products) and (2) by third-party network management software vendors. The product class will include network and element management systems and will generally be required by service providers to stand alone as well as to integrate with existing operations-support systems. optical network market The market for optical networking products. This emerging market will grow out of the market for DWDM and SONET/SDH transport, switching, and management equipment. optical networking The natural evolution of optical transport from a DWDM-based point-to-point transport technology to a more dynamic, intelligent networking technology. Optical networking uses any of a number of optical multiplexing schemes (e.g., WDM, O-CDMA, OspanM) to multiplex multiple channels of information onto a fiber and add intelligence to the optical transport layer in order to provide the reliability, survivability, and manageability provided today by SONET/SDH. Optical networking enables the creation, configuration, and management of light paths within the optical domain. A key goal of the optical network is to bring the cost of network nodes below the cost of today's SONET/SDH-based network by reducing the number of elements required and by increasing the granularity of core network operations such as switching and routing to the wavelength level (e.g., to 2.5 Gbps, or OC-48). optical switch A relatively new category of optical-networking equipment that directs communications between disparate transmission legs of a network either in a ring or mesh architecture. Optical switches may provide, at a minimum cost, (1) performance monitoring and management; (2) restoration and re-routing enabled by interswitch signaling; (3) wavelength conversion; (4) the establishment of end-to-end light paths; and (5) delivery of customer services. This network element is also called an optical cross connect (OXC). optical time division multiplexing (OTDM) An optical multiplexing technology. optical transport products An emerging category of optical networking products that operate at the granularity of a light path and that provide the following functionality at a minimum: performance monitoring and management; restoration and re-routing; wavelength translation; and delivery of customer services. OADMs and DWDM terminals are included in this category. optics The branch of physical science concerned with light and certain phenomena of electromagnetic radiation in the wavelength range extending from ultraviolet to far-infrared. The term is often replaced by the more inclusive word photonics. optoelectronic Pertaining to any device that functions as an electrical-to-optical or optical-to-electrical transducer, or an instrument that uses such a device in its operation. optomechanical A device containing optical and mechanical elements. original equipment manufacturer (OEM)   other (Vendor Matrix) This category includes all other software or hardware products used in a network. outdoor unit (ODU) Complete modules containing a transceiver, antenna, and the associated circuitry intended for outdoor use. outside vapor deposition (OVD) A flame hydrolysis process, invented by Corning, used to manufacture optical fiber by producing a soot on a rotating mandrel, after which the mandrel is removed and the glass is heated so that it collapses around the hole, leaving a solid perform of glass. over-allotment (green shoe) Shares allocated to underwriters in an initial or a secondary offering to satisfy excess demand. The over-allotment is exercised at the sole discretion of the lead underwriter.