RBSE SS Voc Telecom key terms

The fixed relationship in a circuit stating that voltage equals current multiplied by resistance (V = I × R). It lets a technician calculate the third value when two of the three are known.

The opposition a material offers to the flow of electric current, measured in ohms. In telecom work it causes signal loss in copper cable and heat in components.

The rate at which electrical energy is transferred in a circuit, measured in watts. It is calculated as voltage times current and determines equipment supply and heat load.

Direct current flows steadily in one direction, as from a battery or rectifier. Alternating current reverses direction periodically, as from the mains supply, and is described by its frequency and amplitude.

A check made with a multimeter to confirm that a conductor path is unbroken and has low resistance. It is used to verify cable pairs, earth bonds and fuse integrity before powering equipment.

A handheld instrument that measures voltage, current and resistance, and often continuity. Technicians use it for fault finding on power feeds, exchange batteries and customer wiring.

A device that converts alternating current into direct current. In telecom exchanges and base stations it feeds DC power to equipment while charging the backup battery bank.

A system that supplies power to critical load without interruption when the mains fails, usually through a battery and inverter. It protects exchanges, servers and transmission nodes from outages and voltage dips.

Connecting exposed metalwork and equipment reference points to the ground through a low-resistance path. Proper earthing protects people from electric shock and reduces noise and lightning damage.

Devices and practices that divert or limit sudden high-voltage spikes, such as those caused by lightning or switching. They protect lines, equipment and staff in exchanges and customer premises.

A set of measures, including air terminals, down conductors and surge arrestors, that gives lightning current a safe path to earth. It is essential for towers, antennas and overhead telecom lines.

A signal that varies continuously and can take any value within a range, such as the electrical wave from a microphone. It is sensitive to noise and distortion during transmission.

A signal represented by discrete levels, usually binary ones and zeros. It can be regenerated, stored and processed, and it resists noise better than analog transmission over long distances.

The process of varying a carrier wave's amplitude, frequency or phase to carry information. It allows signals such as voice or data to travel efficiently over radio, cable and optical links.

The range of frequencies a channel can carry, measured in hertz, or the data rate a link supports, measured in bits per second. Wider bandwidth allows more information to be sent.

The loss of signal strength as it travels along a cable, fiber or radio path. It is measured in decibels and limits the distance a link can span without repeaters or amplifiers.

A logarithmic unit used to express ratios of power or signal level. Telecom workers use it for loss, gain and signal strength, so a 3 dB loss means about half the power remains.

The ratio of usable signal power to unwanted noise power at a point in a system, usually expressed in decibels. A higher ratio means clearer reception and fewer transmission errors.

The physical path that carries a signal between two points, such as twisted copper pair, coaxial cable, optical fiber or free space. Each medium has different loss, bandwidth and installation characteristics.

Two insulated copper conductors twisted together to reduce interference and crosstalk. It is the main medium for subscriber lines and structured cabling in local networks.

Unwanted signal coupling from one cable pair or channel into another. Twisting, shielding and careful jointing reduce it, and it is a common cause of noise on subscriber lines.

A method of converting an analog signal into digital form by sampling, quantizing and encoding it into binary code. It is the basis of digital telephony and many transmission systems.

A switching centre that connects subscriber lines and trunk circuits and routes calls between them. Modern exchanges are digital and controlled by stored programs.

The process of setting up, maintaining and releasing a temporary path between two parties in a network. It lets many subscribers share transmission facilities economically.

The selection of a path for a call or data packet through a network. Good routing minimises delay and cost while providing alternative paths when a link fails.

The exchange of control information between network elements to set up, supervise and clear calls. It carries addressing, alerting and release messages separately from the voice path.

The structured scheme that assigns unique telephone numbers to subscribers, exchanges and services. It defines dialling rules, prefixes and country codes so calls can be routed correctly.

A high-capacity internet access service that supports always-on, high-speed data transfer. It is delivered over copper, fiber, cable or wireless and enables services such as video and cloud applications.

The addressing and packet-routing rules that let devices send data across interconnected networks. Each device uses an IP address so packets can be forwarded to the correct destination.

A network device that forwards data packets between networks using IP addresses. It connects a customer site to the internet and selects the best path for traffic.

A device that converts digital data into a form suitable for a transmission line and back again. It links customer equipment to a broadband or dial-up access network.

A mobile system that divides an area into cells, each served by a base station, so frequencies can be reused. Handover and roaming let users move while staying connected.

The fixed radio equipment and antennas that connect mobile handsets to the network in a cell. It manages radio channels, power control and the link to the core network.

A measure of how strongly an antenna concentrates radiated power in a particular direction compared with a reference antenna, expressed in dBi or dBd. Higher gain narrows the coverage pattern.

The process of transferring an active mobile call or data session from one cell to another without dropping it. It relies on signal measurements and coordination between base stations.

A thin glass strand that guides light by total internal reflection, carrying very high data rates with low loss. It is immune to electrical interference and is used in backbone and access networks.

The permanent joining of two optical fibers, usually by an electric arc fusion splicer, to create a low-loss continuous path. Splice loss is measured after jointing to confirm quality.

A test instrument that sends light pulses into a fiber and analyses the reflections to locate breaks, splices and losses along the length. It is central to fiber fault diagnosis and acceptance testing.

The resistance measured between a conductor and its insulation or earth, indicating whether the cable is sound. A low reading suggests moisture or damage and a risk of leakage or failure.

Telecom equipment located at the customer's site, such as a telephone set, modem, router or set-top box. It connects the customer's wiring to the operator's network and is often maintained by the user.

The systematic process of locating the cause of a service problem by testing, observation and elimination. It starts at the customer end and works toward the network to isolate the faulty section.

The precautions taken when working on poles, towers or ladders, including fall arrest, tool tethering and exclusion zones. It prevents falls and dropped-object injuries during telecom installation and maintenance.

The clothing and gear worn to reduce injury risk, such as helmets, gloves, safety footwear, eye protection and high-visibility vests. It is the last line of defence and must suit the task.

Correct selection, positioning and securing of ladders, including the one-in-four angle rule, three-point contact and inspection before use. It prevents slips and falls during installation and repair work.

The process of identifying an opportunity, organising resources and taking calculated risk to create a telecom-related venture or service. It combines initiative, planning and customer focus.

A written document describing a venture's market, services, operations, costs and financial projections. It guides the owner and is used to obtain finance and monitor performance.

The way a telecom provider or technician interacts with subscribers, including response time, clarity, courtesy and follow-up. Good service builds trust and reduces repeat fault calls.