Linear crosstalk analysis of an un-amplified ring PON architecture

Abstract

Passive optical network (PON) architectures have been proposed as a back haul for wireless networks, where the optical network units (ONUs) can now be interconnected with the antenna base stations. We focus on a ring PON approach with its inherent benefits and use simulation to analyze the effects of linear crosstalk in an un-amplified basic TDM optical ring. Our approach is based on simulation of the entire network using a combination of wavelength-domain and time-domain techniques. Typically PON networks are based on CWDM to maintain the cost of components low and in such case it is logical that any crosstalk will be negligible. However, the subpar performance of such components motivated our study into the crosstalk impact. We show that the tap ratio optimization which increases the number ONUs that can be served in the ring can also exacerbate the effects of linear interchannel crosstalk at the ONU's downstream signal receivers. The interchannel crosstalk originates from the upstream/LAN transmission and is due to nonideal WDM couplers/splitters and optical switches that are needed for wavelength multiplexing/demultiplexing and protection against node and link failures, respectively.

Improved linear crosstalk tolerance in an un-amplified ring PON

“…To our knowledge, crosstalk has not been considered in this context before, but for our previous work that was mostly focused on the linear crosstalk generation process in a system with tap split ratios optimized for a WDM coupler isolation of 30 dB [12]. In this work, we extend our analysis to include an investigation of how the overall tolerance of linear crosstalk in the system can be improved by utilizing surplus optical power in the system.…”

Crosstalk analysis of an extended reach hybrid tree-ring PON architecture

“…However, more recently, ring PON architectures have received increased interest as they offer several added features such as simple and cost-effective protection capabilities against failures in the distribution network [4][5][6][7] and also can support truly shared Local Area Network (LAN) capabilities among end [8].…”

“…This approach is different than other ring architectures that have been proposed. In these architectures the OLT and ONUs were all on the same ring [4][5][6][7]. These ring architectures either serve a limited number of ONUs [4][5]7] or they require amplification to extended reach and/or increase in the number of served ONUs [6].…”