A Frequency Reuse-Based Design for Flexible and Scalable Passive Optical Networks (PONs)

Ibrahim M M Mohamed

doi:10.11648/j.net.20170501.13

Abstract

The accelerated growth in the bandwidth demand emphasizes the necessity to evolve from the currently deployed gigabit-class passive optical networks (PONs) to the next-generation optical access networks (NG-OANs). Different architectures were proposed in the literature in order to create a NG-OAN that is able to fulfilling the aforementioned goal. In this paper, a time-division multiplexing (TDM)/dense wavelength-division multiplexing (DWDM) scheme was proposed. The proposed scheme is sought to satisfy the current and future anticipated bandwidth demands. The architecture we proposed was able to allow different bit rate optical line terminals OLTs to use the same frequency band, and transmit their services over a 24 km shared feeder to 16 passive remote terminals (PRTs) with 16 ONU group for each. Each group can accommodate up to 16 ONU, total of 256 ONU/PRT, resulting in overall system capacity 4096 ONU. The architecture also allows the independent-upgradeability for each optical network terminal ONU.

Highlights

Gigabit-class passive optical networks PONs are being deployed in many countries nowadays because of their significant capacity as compared with the traditional copperbased access networks, which allows the delivery of broadband services, such as voice over Internet Protocol (VoIP), and video on demand (VoD)
Institute of Electrical and Electronics Engineers (IEEE) and International Telecommunications Union’s Telecommunication Standardization Sector (ITU-T) ratified their standards of high speed time division multiplexing (TDM)-PONs, (IEEE 802.3av, [10G-EPON], and ITU-T G.987, [XG-PON]) in 2009 and 2010 respectively [1, 2]. 10G-EPON specifies a symmetric 10-Gbps for both the downstream and upstream traffic, and an asymmetric 10-Gbps for downstream traffic and 1-Gbps for upstream traffic
Because it is expected for optical links to lose several dBs of their budget when bit rate increased to 10 Gbps, both the 10G-EPON and XG-PON recommend the use of forward error correction (FEC) to earn extra dB margin

Summary

Introduction

Gigabit-class passive optical networks PONs are being deployed in many countries nowadays because of their significant capacity as compared with the traditional copperbased access networks, which allows the delivery of broadband services, such as voice over Internet Protocol (VoIP), and video on demand (VoD). Similar to the 10G-EPON, XG-PON specifies a symmetric 10 Gbps for both the downstream and upstream traffic. One of the potential candidates for next-generation optical access NGOA is the Hybrid TDM/WDM-PONs. TDM/WDM-PONs were proposed to exploit both, the high speed feature offered by the TDMPONs, and the large number of wavelength counts provided by the WDM-PONs. A hybrid TDM/WDM-PON can be categorized according to the wavelength grid used as either a hybrid TDM/CWDM-PON or a hybrid TDM/DWDM-PON. The first commercial colorless gigabit TDM/WDM-PON using a remote protocol terminator was proposed and experimentally demonstrated in [3]. A scheme of four pairs of wavelengths TWDM-PON is able to multiplexing a four XG-PONs which leads to provide 40 Gbps and 10 Gbps in downstream and upstream, respectively.

AWG Architecture and Properties

The Proposed Architecture

Cost Consideration

Coexistence with Previous PON Generations

Simulation Results and Discussions

Conclusions and Future Work