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
Quadrature Amplitude Modulation (QAM) - System that greatly increases the amount of information which can be carried within a given bandwidth.
Query - In data communications, process where a master station asks a slave station to identify itself and indicate its status (e.g., busy, alive, okay, waiting, etc.)
Queing - Function where incoming calls are stored on-hold until an attendant, trunk, trunk group or desired station is available to accept them. Synonym: camp or camp-on.
Rack - Aka Relay Rack. Rack-mounted equipment is usually 19" or 22" wide, and the height ranges from one to seven feet. Some racks are wall mounted, others are free standing, and designed to withstand some earthquakes (rated as Zone 4).
Rate Adaptive - Data protocol that tests the circuit for the fastest possible rate of transmission, using ping packets similar to that used in DSL.
Rate Adaptive DSL (RADSL) - Asymmetrical digital subscriber loop; version where modems test line at start up and adapt their operating speed upward to the highest speed the line can handle. Maximum upstream rate of 1 Mbps, downstream rate of 9 Mbps.
Radio Common Carrier (RCC) - Communications carrier that provides radio paging and mobile telephone services to the public.
Rain Attenuation - Rain degrades a radio signal, with the density and average amount of rainfall determining the factor of attenuation - applies for microwave/radio signals. Dry climates in the US may be as high as 6 miles, while less than a mile for wetter regions (assuming a 7 watt transmitter).
Raised Floor - Used in telecommunications and computer rooms to run connecting cables and air ducts to cool equipment.
Rate Center - Specific geographic location used by LECs to determine interchange mileage for rate determination; generally a centrally located point within the exchange area.
Rebiller - Where a telephone company buys services from a facilities based telephone company (usually at a discount), and resells it.
Redundancy - Where you would have one main, and one back up, so that if one device fails, the other can take over without loss of service. Example - SONET equipment can be configured in a redundant manner with two fiber optic routes (in a ring), and duplicates of the electronic cards controlling transmissions.
Re-homing - Network change which involves moving customer services from one switching center to another and establishing the necessary trunking facilities to do so.
Regional Bell Operating Company (RBOC) - Seven holding companies into which the 22 Bell System local telephone companies were assigned at divesture: Pacific Telesis, Qwest, Southwestern Bell Corp, Ameritech, BellSouth, Bell Atlantic, and NYNEX.
Registration Jack - Prefix for most telephone company connection and interface standards.
Rerouting - To change the medium, or physical path, of a communications signal. For example, in a SONET network, if a cable is cut, the equipment reroutes the transmission, resulting in very little or no service interruption (i.e. Self Healing Alternate Route Protection / SHARP).
Resale Carrier - Company which leases circuits or services from a major carrier and resells them to individual users.
Reseller - Aka aggregator. Usually a cellular/PCS or long distance reseller, that signs up with a long distance company as a reseller, and their customers are aggregated together to receive a bulk discount. Service is provided by the long distance or cellular company, including billing. The advantage to the customer is the value added service and consulting of the aggregator/reseller.
Reverse Direction Protection Switching (RDPS) - (1) DS3 switch that can be remotely controlled (2) in a fiber optic network, permits select traffic to be rerouted in the opposite direction when a cable cut occurs.
Riser - Telephone cable feed that runs vertically in a building from floor to floor, usually up through elevator shafts, airways, or plenums. Placed in areas called risers by architects.
Riser Cable - Twisted pair cable, consisting of several hundred pairs, distributed from the telephone company Demarc / point of entrance to a building, to each floor of a building. See Riser.
RJ11 - Most common telephone jack; 6x plug with 4 connectors.
RJ21X - Network interface / 66M150 block, designated as the demarcation point for telephone company-provided communicationslines.
RJ145 - 8 position, 8 conductor modular jack, common in LAN computer applications.
RJ48 - 8 position, 8 conductor modular jack, used to terminate T1 service.
RJ48X - 8 position, 8 conductor modular jack, terminating T1 services, with a built in shorting bar for making manual loop backs.
Roaming - Where cellular/PCS telephone has traveled outside its calling area; the phone sends a signal to any cellular site it can reach, regardless of company; if the phone can communicate with the cellular site, then the roam indicator will be displayed on the phone.
Router - (1) Interface between two networks; selects the best route even if there are several different networks in between. (2) Provides network management capabilities that allow network managers to detect and correct problems. Often used in building wide area networks (WANs). (3) Intelligent devices that forward data packets from LAN to LAN; improves network performance by selecting the most expedient route for data to travel based o n traffic load, line speeds, costs, or network failures.
Routing Table - Call handling instructions input to an automatic call distribution system, listing each incoming trunk and the steps that the calls go through. Also refers to incoming digit translation files in a PBX system's memory, instructing the system on which extension to route a call to. Also refers to a list of paths or connections through a network kept in the memory of the router, or a data filed stored in a router that keeps track of routes to network destination addresses and their circuit reference ports on the router.
Rural Serving Area (RSA) - FCC-created, includes 428 regions with two cellular carriers licensed in each which provide cellular service. Not part of metropolitan statistical areas (MSAs).