The customer needs to access the following information points: AP, PC, POTS, and CATV. Which of the following statements about data transmission of these information points by ONUs is correct?

Question

Options

• AAll types of data are encapsulated into Ethernet frames before PON-related encapsulation and
• BWhen an OLT is connected downstream to an ONU, one fiber and two wavelengths are used to
• CPOTS voice services are TDM services and directly encapsulated in GEM frames.
• DWhen an OLT is connected downstream to an ONU, one fiber and two wavelengths are used to

• A
  4% (1)
• B
  75% (21)
• C
  14% (4)
• D
  7% (2)

Explanation

Service Types and Transmission: AP/PC (Data Services): These services are typically Ethernet-based and encapsulated into Ethernet frames before being transmitted over the PON network. POTS (Voice Services): Voice services can be either TDM-based or packetized. In modern GPON/XGS- PON systems, POTS is often packetized into Ethernet frames. CATV (Video Services): CATV uses a separate wavelength (1550 nm) for analog or digital video Wavelength Division Multiplexing (WDM): GPON/XGS-PON systems use WDM to transmit multiple services over a single fiber: One wavelength (1490 nm or 1577 nm) is used for data services (Ethernet). Another wavelength (1550 nm) is used for CATV. Analysis of Options: Option A: Incorrect because CATV is not encapsulated into Ethernet frames; it uses a separate Option B: Correct because CATV uses a separate wavelength, and other services are encapsulated into Ethernet frames before PON transmission. Option C: Incorrect because POTS services are typically packetized into Ethernet frames in modern systems, not directly encapsulated in GEM frames. Option D: Incorrect because POTS is not transparently transmitted in modern GPON/XGS-PON Thus, the correct answer is B.

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