Optical Fiber Access Networks Using PON/FTTH

Trace the evolution of ITU-T PON standards from A pawn and B pawn through Gpon, XG PON, NG-PON2, and XGS-PON, highlighting downstream and upstream data rates and G.hsp.x development.

Trace the evolution of EPON standards from 1 gigabit per second to 50 gigabits per second, detailing IEEE 802.3 specifications and ITU-T standards shaping the PON market.

Explains how PON enables 5G cloud radio access networks, detailing radio remote unit, distributed unit, and central unit architecture and optical fiber for high-rate fronthaul, middle, and backhaul links.

The lecture explains four pon use cases for 5g networks, focusing on central and distributed unit placement and achieving high data rate, low latency links with optical fiber and splitter.

Examine a general purpose cloud network with the central unit and distributed unit hosted on a cloud server, using optical fiber and PON for high data-rate links, while reducing costs.

Connects central unit and distributed units to multiple RUs across base stations using PON technology to serve dense urban areas with small cells via an optical distribution network and splitters.

Explore the hybrid PON implementation in 5G networks, linking a central unit to remote distributed units through an optical distribution network with splitters.

Explore how total internal reflection enables optical fiber communication, as light reflects within a high-index core surrounded by a low-index cladding, with the critical angle, impurities, and dispersion shaping performance.

Explore the three types of optical fiber, multi mode step index, multimode graded index, and single mode, emphasizing core and cladding diameters and refractive index profiles.

Explain multimode step index fiber and modal dispersion, where rays with different angles take different paths, causing pulse distortion and limiting data rate due to bit errors.

Explore multimode graded index fiber, where the refractive index is highest at the center and decreases toward the cladding, producing less modal dispersion than step-index fibers.

Explore single mode optical fiber, where a tiny core supports a single propagation mode, minimizing modal dispersion and enabling high data-rate communications, while noting polarization and chromatic dispersion limits.

Polarization mode dispersion, caused by fiber imperfections, makes vertical and horizontal polarization travel at different speeds; PMD compensation or single polarization fibers mitigate this.

Explore chromatic dispersion in optical fiber, where different wavelength velocities broaden a pulse. Learn transmitter or receiver compensation to delay high-velocity wavelengths and align arrivals.

Explain how impurities and the fiber absorb light pulses, causing attenuation, with plastic fibers attenuating more than glass, and low-attenuation windows at 850 nanometer, 1300 nanometer, and 1550 nanometer.

Explains the GPON principle of wavelength division multiplexing on single-mode fiber, carrying downstream 1490 nm, upstream 1310 nm, and video at 1550 nm on one fiber without interference.

Describe how downstream data is carried in a time division multiplex frame with three time slots, split to three venues, and encrypted with the Ese algorithm using different keys.

Explain upstream data transmission from ONUs to the OLT using time slots in a TDM frame carried by same-wavelength light, with the OLT allocating slots and the splitter merging them.

Explore the MCI protocol, the ONU management and control interface used by the PON operator to manage ONUs via the OMC channel; the NMS connects to VLT to configure OT.

Explain how gem ports identify logical connections in downstream GPON, carrying voice, data, or video in GEM frames via 12-bit IDs, with downstream data broadcast and filtered to assigned ports.

Explore upstream traffic from onU to Olt, where gem ports map into transmission containers identified by allocation IDs, buffering data and enabling dynamic bandwidth allocation.

Compare GPON protocol layers with the OSI model, showing how video, data, and VoIP traffic is encapsulated through TCP/UDP, IP, Ethernet, GEM, GTC, and PON frames.

The service adaptation block converts incoming packets into gem frames and crosses them to gem port, where the pawn transmission convergence and Odin interface convert them to Pon physical frames.

Explore the ONU functional block diagram, highlighting the interface function with redundancy that converts PON physical frames into GTC frames, then Jem frames, to service ports and packets.

Describe the 125 microsecond downstream frame's physical control block downstream header with sync, ident, payload, oam downstream messages, the bit interleaved parity field, and planned field sent twice for redundancy.

Explain how gem frames comprise a gem header and gem payload, with a jam header indicating payload length indicator, jam port ID, payload type, and header error correction bits.

Understand the upstream bandwidth map field in the downstream frame header and how the olt dynamically allocates bandwidth to windows using transmission containers based on upstream needs.

Learn the GPON upstream frame structure, including the physical layer overhead, preamble, and venue ID, plus alarms, ranging, power level sequence, and dynamic bandwidth reports with jam frame headers.

Map tdm services like t1 and e1 to gem frames in gpon for transmission, while video, data, and voip traverse tcp/udp, ip, ethernet, then gtc transmission convergence and pon framing.

The undo enters the O1 initial state and stays silent, synchronizing downstream via the GTC frame's physical control block header to learn frame and bit boundaries and the frame count.

In standby, the ONU synchronizes with the OLT upstream after obtaining global network parameters from the upstream overhead message, setting the preamble, guard bits, and transmit power.

Enter oh three serial number state, create 250 microsecond upstream quiet window with empty bandwidth map, request serial numbers, receive 0–48 microsecond replies to avoid collisions, and assign Wenju ID.

Explore the ranging state, where distance measurement and equalization delay synchronize upstream transmissions to prevent collisions in pon/ftth networks.

Enter the normal operation state, enabling ONUs to transmit data upstream and to send physical layer operation and maintenance messages, while all ONUs synchronize upstream transmissions to prevent clashes.

Describes the popup state, where an ONU enters failure recovery after loss of signal or frames, starts AT02 timer, and returns to normal operation via directed or broadcast popup messages.

State seven triggers emergency stop; ONU halts upstream data and shuts its transmit laser after a disabled serial number message, then moves to standby and then operation via enable.

Dynamic bandwidth allocation assigns varying bandwidth to optical network units to maximize fiber utilization, respecting priority and quality-of-service, via status report based and known status report based modes.

Status report based dynamic bandwidth allocation (sr-dba) operation uses ONU queue reports and the OLT's DBA algorithm to allocate upstream bandwidth via a bandwidth map to three transmission containers.

The non status report based dynamic bandwidth allocation algorithm counts upstream packets from venues within intervals to gauge fiber utilization and congestion, and allocates bandwidth to transmission containers by profiles.

Understand five T-CONT DBA profile types, from fixed and short to assured plus maximum, and how each profile allocates bandwidth to transmission containers across venues.