Glossary - N
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
N + 1 - A formula which refers to the FCC requirements that provide for expansion of channel capacity for non-broadcast use. If the governmental, educational, public access, and leased channels are in use 80 percent of the weekdays (Monday through Friday) for 80 percent of the time during any three-hour period for six consecutive weeks, the system operator must expand the system's channel capacity within six months.
Narrowband - This medium is capable of carrying voice, fax, paging, and relatively slow-speed data (not full video applications), typically at 64Kbps or less.
Narrowcasting - Delivery of programming that addresses a specific need or highly focused audience.
National Cable Television Association (NCTA) - The trade association for the cable television industry.
National Television Systems Committee (NTSC) - Committee, which defined the analog, color television, broadcast standard used today in North America. The standard TV format for North American television transmission is named after this standards committee; the format is 525 lines in a 4MHz video bandwidth. All TV sets sold in North America are compatible.
Near Video on Demand (NVOD) - An entertainment and information service that broadcasts a common set of programs to customers on a scheduled basis. At least initially, NVOD services are expected to focus on delivery of movies and other video entertainment. NVOD typically features a schedule of popular movies and events offered on a staggered-start basis (every 15 to 30 minutes, for example). See also Video on Demand.
Net Weekly Circulation (NWC) - The estimated number of television households viewing a particular station at least once per week, Monday-Sunday, 6 a.m. to 2 a.m., EST. Used to determine whether a station is "significantly viewed" in an area and must be carried by a cable system operating in that area.
Network - Group of radio or television outlets linked by cable or microwave that transmit identical programs simultaneously, or the company that produces programs for them.
Network Address Translation (NAT) - A function, typically employed in internet connections, that performs address translation.
Network Congestion - A state of overload within a network, where there is a risk of traffic loss or service degradation.
Network Driver Interface Specification (NDIS) - Microsoft's version of the software interface between the transport protocol and the data link protocol, which allows multiple protocol stacks to run over one network adapter.
Network Interface Card (NIC) - A hardware interface card that connects a computer to the network cabling.
Network Interface Device (NID) - Generally an ADSL term, a NID is the interface between the local loop connection to a DSLAM in a Telco Central Office and the customer premise POTS and 10Base-T Ethernet (or other) local computer connection.
Network Layer - Layer 3 in the Open System Interconnection (OSI) architecture; the layer that provides services to establish a path between open systems.
Network Management - The functions related to the management of data link layer and physical layer resources and their stations across the data network supported by the hybrid fiber/coax system.
Network Operations Center (NOC) - A large group which is responsible for the day-to-day operations and maintenance of a network.
Network Termination - Part of the Access Network, (owned by the carrier or the subscriber) located on the side of the subscriber's home. The following are functions of the Network termination: coupling of home wiring to the carrier wiring, grounding, RF filtering, splitting, media conversion, remodulation, security and interdiction, provisioning, loopback testing by the carrier.
New Entrant Carrier (NEC) - This term is generally applied to new providers of competitive local exchange telephone services.
Node - An addressable unit in a network, which can be a computer, workstation or some type of communications control unit.
Noise - The word "noise" is a carryover from audio practice. Refers to random spurts of electrical energy or interference. May produce a "salt-and-pepper" pattern over the picture. Heavy noise is sometimes called "snow."
Noise Figure - A measure of the ability of an amplifier to increase the strength of a signal while adding the minimum possible self-generated noise. It is mathematically equal to ten times the log of the input S/N ratio to the output S/N ratio.
Number Portability - A capability that permits telecommunications users to maintain the same telephone access number as they change telecommunication suppliers.