FOA CFOS/DC flashcards
FOA CFOS/DC · Build recall with a focused review session.
30 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Link loss budget
- Maximum allowable optical loss between transmitter and receiver, calculated as transmitter output minus receiver sensitivity, less a safety margin for aging, repairs, and temperature effects.
- Receiver sensitivity
- Minimum optical power at which a receiver meets its bit-error-rate specification; used as the low end of the loss budget calculation.
- Safety margin
- Extra decibels reserved in a loss budget for future splices, connector reterminations, component aging, and temperature variation; commonly around 3 dB.
- Connector loss allowance
- Typical planning value of 0.3 to 0.75 dB per mated connector pair, depending on connector polish and quality; counted for every mated pair in the channel.
- Splice loss allowance
- Planning value of roughly 0.1 to 0.3 dB per fusion splice, applied to every splice in the link when summing channel loss.
- OS2 attenuation values
- Single-mode fiber planning loss of about 0.35 dB/km at 1310 nm and 0.20 to 0.25 dB/km at 1550 nm; used for long-reach backbone calculations.
- OM4 modal bandwidth
- Approximately 4700 MHz·km at 850 nm, giving longer 10G and 40G/100G multimode reach than OM3, which is about 2000 MHz·km.
- Bandwidth-limited distance
- Maximum reach set by modal dispersion and signaling rate rather than by optical power; the shorter of loss-limited and bandwidth-limited distance governs design.
- MPO polarity method B
- Trunk assembly with a flipped fiber arrangement, key-up to key-up at both ends; paired with the correct patch cords so each transmitter reaches the matching receiver.
- Duplex patch cord A-to-B
- Straight-through duplex cord wired A-to-B, used in pairs so that transmit at one end lands on receive at the other end of a duplex LC channel.
- Centralized cabling
- Design where horizontal cables run from work areas to one main cross-connect, reducing active electronics and simplifying administration at the cost of longer cable runs.
- Zone cabling
- Design using an intermediate connection point serving a floor area, reducing cable quantities and easing moves-adds-changes in high-density or open-plan spaces.
- 100GBASE-SR4 media
- 100G Ethernet using four 25G lanes over eight multimode fibers with MPO connectors at 850 nm; reach depends on OM3/OM4 bandwidth and loss.
- 100GBASE-LR4 media
- 100G Ethernet using four LAN-WDM wavelengths near 1310 nm over duplex single-mode fiber, supporting 10 km reach with OS2 cabling.
- Horizontal channel length
- Permanent link of up to 90 m plus up to 10 m of patch cords, giving a 100 m channel limit for twisted-pair; fiber backbone limits follow application budgets.
- Route diversity
- Physically separate cable paths for protected or redundant links, so a single conduit cut or building incident cannot disable both working and protection paths.
- Work breakdown structure
- Deliverable-oriented hierarchy of project scope; each element is assigned an owner, duration estimate, and acceptance criterion before scheduling begins.
- Critical path
- Longest-duration sequence of dependent activities through the schedule network; it determines the earliest project completion date and has zero total float.
- Total float
- Amount of time an activity can slip without delaying project completion, computed as late start minus early start or late finish minus early finish.
- Cost variance formula
- CV equals earned value minus actual cost; a negative result means the project has spent more than the value of work completed.
- Schedule variance formula
- SV equals earned value minus planned value; a negative result indicates work is behind the planned schedule baseline.
- Cost performance index
- CPI equals earned value divided by actual cost; a value below 1.0 signals cost overrun relative to the value delivered.
- Schedule performance index
- SPI equals earned value divided by planned value; a value below 1.0 indicates the project is progressing slower than the baseline plan.
- Risk register entry
- Record containing risk description, probability, impact, score, owner, response strategy such as avoid, mitigate, transfer, or accept, and the trigger condition.
- Change control board
- Group that reviews change requests, assesses cost and schedule impact, and approves, rejects, or defers changes to the approved project baseline.
- Approved baseline
- Formally accepted version of scope, schedule, and cost used to measure performance; changes require documented approval and rebaselining.
- Long-lead procurement
- Ordering cable reels, MPO trunks, cabinets, and transceivers early because delivery times exceed normal installation sequencing; dates tie to milestones.
- Acceptance test gate
- Planned checkpoint with pre-defined pass/fail criteria, such as insertion loss and OTDR results, that must be met before handover to the next phase.
- Stakeholder register
- List of project roles and interested parties with their influence, interest, communication needs, and escalation path for issue resolution.
- Decision log
- Running record of project decisions, rationale, date, and owner; used to prevent scope creep and to preserve traceability during audits and handover.