Next-Generation Optical Access Networks

TLDR

The access segment is the main bandwidth bottleneck, and broadband fiber access such as passive optical networks (PONs) using time‑division multiplexing (TDM) are the current industry standard, while next‑generation C+1 and C+2 PONs are expected to provide near‑term upgrades and long‑term dramatic improvements via wavelength‑division multiplexing, respectively. This paper reviews current TDM‑PONs (generation C) and next‑generation C+1 and C+2 PONs, categorizing them and examining key enabling components while highlighting future research directions. The authors conduct a literature review of current TDM‑PONs and next‑generation C+1 and C+2 PONs, categorizing them and evaluating key enabling components and technologies.

Abstract

The main bandwidth bottleneck in today's networks is in the access segment. To address that bottleneck, broadband fiber access technologies such as passive optical networks (PONs) are an indispensable solution. The industry has selected time-division multiplexing (TDM) for current PON deployments. To satisfy future bandwidth demands, however, next-generation PON systems are being investigated to provide even higher performance. In this paper, we first review current TDM-PONs; we designate them as generation C. Next, we review next-generation PON systems, which we categorize into C+1 and C+2 generations. We expect C+1 systems to provide economic near-term bandwidth upgrade by overlaying new services on current TDM-PONs. For the long term, C+2 systems will provide more dramatic system improvement using wavelength division multiplexing technologies. Some C+2 architectures require new infrastructures and/or equipment, whereas others employ a more evolutionary approach. We also review key enabling components and technologies for C+1 and C+2 generations and point out important topics for future research.