Broadband & Access Network Technologies Flashcards
7 cards from real CTA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Broadband & Access Network Technologies flashcards as text
Which passive optical network (PON) standard is most widely deployed for fiber-to-the-home (FTTH) services?
Answer: GPON (Gigabit PON)
GPON (Gigabit Passive Optical Network), defined by ITU-T G.984, is the most widely deployed FTTH standard worldwide due to its high capacity, efficiency, and support for triple-play services.
What wavelength is used for downstream transmission in a standard GPON deployment?
Answer: 1490 nm
In GPON, the 1490 nm wavelength carries downstream (OLT to ONU) traffic, while 1310 nm is used for upstream transmission from the ONU to the OLT.
What is the maximum downstream data rate defined in the GPON standard (ITU-T G.984)?
Answer: 2.5 Gbps
The GPON standard specifies a maximum downstream rate of 2.488 Gbps (approximately 2.5 Gbps) and an upstream rate of 1.244 Gbps.
In an FTTx deployment where fiber runs to a street cabinet and existing copper carries the signal to individual homes, which architecture is this?
Answer: FTTC (Fiber to the Cabinet/Curb)
FTTC (Fiber to the Cabinet or Curb) runs fiber from the central office to a street cabinet near the customer, then uses existing copper (often VDSL2) for the short remaining distance to the home.
What is XG-PON (10G-PON), standardized as ITU-T G.987?
Answer: A passive optical network standard providing 10 Gbps downstream and 2.5 Gbps upstream
XG-PON (10-Gigabit-capable PON), defined in ITU-T G.987, delivers 10 Gbps downstream and 2.5 Gbps upstream over the same passive fiber infrastructure used by GPON.
Which access network technology uses a hybrid combination of fiber for the backbone and coaxial cable for the final distribution to subscribers?
Answer: HFC (Hybrid Fiber-Coaxial)
HFC (Hybrid Fiber-Coaxial) networks use fiber optic cable from the headend to neighborhood nodes and coaxial cable from nodes to individual subscriber premises, combining the strengths of both media.
In a GPON network, what is the maximum logical split ratio supported by the standard?
Answer: 1:128
The GPON standard (ITU-T G.984) supports a maximum logical split ratio of 1:128, meaning one OLT port can serve up to 128 ONUs, though typical deployments use 1:32 or 1:64 for bandwidth management.