NCTI Charter Communicatons Fiber - Lesson 1

In FTTx networks, what is required to power ONTs at the customer premises?

AC power must be provided at the customer premises in the case of RFoG installations to power the ONT.

Which fiber-to-the-x topology has amplifiers in the coaxial cable portion of the network?

Additional RF amplifiers may be in the coaxial cable portion of the fiber-to-the-node (FTTN) topology to maintain proper amplitude levels of the RF signal throughout the serving area.

What test equipment would the technician use to identify and locate a localized fiber attenuation problem?

An optical power meter, OTDR, or visible laser could be used to identify and locate a localized fiber attenuation problem.

What variations of the star topology are used in PONs?

Centralized split, distributed star, and home-run are variations of the star topology used in PONs.

Why can FTTx applications be more susceptible to the adverse effects of macro- and microbends bends than typical transmission applications?

FTTx standards use some wavelengths that are longer than typical transmission wavelengths, and are therefore more susceptible to the adverse effects of macro- and microbends.

What does the hybrid fiber/coax (HFC) network architecture offer broadband cable operators?

HFC network architectures have been developed to enable broadband cable operators to make a gradual, or staged, transition to an all fiber-optic cable infrastructure.

Why is it standard industry practice to use pigtail splicing as the preferred method of terminating single-mode fiber?

It is standard industry practice to use pigtail splicing as the preferred method of terminating single-mode fiber because it is faster and more reliable than installing connectors in the field.

What topology is used in passive optical network (PON) architectures?

Passive optical network (PON) architectures use fiber-to-the-premises (FTTP) topologies to make point-to-multipoint (P2MP) connections between the broadband cable headend and the customer premises.

What are some potential problems in overhead, or aerial, cable installations?

Potential problems in overhead installations include lightning, falling trees and branches, automobile accidents, fire, pole attachment problems, and gunshot and vandal damage.

What are some potential problems in underground cable installations?

Potential problems in underground installations include dig-ups, rodents, ice, improper backfilling, washouts, and landslides.

What does the radio frequency over glass (RFoG) architecture provide as envisioned by broadband cable operators?

RFoG was envisioned to provide operators with the time to make a seamless transition from the legacy hybrid fiber/coax (HFC) architecture over to gigabit PON (GPON) or Ethernet PON (EPON).

What percentage of fiber-optic trouble in the outside plant is caused by people, and what percentage by natural causes?

Statistically, about 75% of fiber-optic troubles in the outside plant are caused by people, almost all occurring during construction or maintenance activities on or near the cable right-of-way. About 25% of trouble is due to natural disasters such as storms and earthquakes.

What are the three categories of fiber-optic cable in a PON?

The fiber-optic cable in a PON is placed in one of three categories, trunk, branch, and drop, to identify the cable's location in the network.

What is the smallest allowable bend radius for G.652 standard single-mode fiber?

The smallest allowable bend radius for G.652 standard single-mode fiber is 30 mm.

What equipment should the well-equipped technician have to troubleshoot a fiber-optic system effectively and efficiently?

The well-equipped technician should have a fiber-optic cleaning kit, an optical inspection microscope, an optical power meter, a stabilized light source or an optical loss test set, a visible laser, and an optical time domain reflectometer (OTDR) to effectively and efficiently troubleshoot a fiber-optic system and identify and locate the trouble.

What are the three primary elements of a PON?

Using terminology from the telephone industry, the main elements of a PON are the optical line terminal (OLT), the optical distribution network (ODN), and the optical network unit (ONU).

What is unique about FTTx testing using the optical power meter?

Wavelength-isolating optical power meters are designed to be operated in bi-directional FTTx applications to measure both upstream and downstream ITU-, IEEE-, and SCTE-specified wavelengths.

What are optical splitters?

Optical splitters are passive branching devices that divide an optical signal across a number of output ports in the forward direction, and combine multiple signals onto a common optical fiber in the return direction.