Increasing Flexibility and Capacity in Real PON Deployments by Using 2/4/8-PAM Formats

Demonstration and Application of 37.5 Gb/s Duobinary-PAM3 in PONs

“…It would be expected that the OLT transmitter would require a higher bandwidth than the currently deployed 10G transmitters. As shown previously [6,7] the use of multiple modulation formats within a PON does not introduce any penalty, furthermore TDM time-slot redistribution allows nearly all users to experience an increase in network capacity.…”

“…PR30) can be met by DB-PAM3 due to the additional 3.8 dB receiver penalty relative to normal duobinary, the low and medium power budgets, PR10 and PR20, seem plausible, due to the at least 5 dB smaller channel insertion loss at these power budgets. A significant number of applications are actually in these lower power budget classes [5,6]. Thus a smaller size PON can be served closer to a net 100 Gb/s data rate in a cost-effective manner by a 25% reduction in number of transceivers.…”

“…Finally, a promising application is the use of DB-PAM3 in a flexible modulation scheme [6]. The tradeoff of DB-PAM3 in capacity and receiver sensitivity is well suited for the use inside such a scheme.…”

“…Therefore the deployed network can be utilized more efficiently, resulting in an increase in aggregated data rate of the network and reduction in congestion probability. Using the statistics of a deployed network as previously shown in [6], the aggregated downstream data rate of a 10G based PON can be increased by 192% to 29.2 Gb/s if 10 Gb/s OOK, 25 Gb/s DB-OOK, and 37.5 Gb/s DB-PAM3 are used together. Due to the use of the flexible modulation scheme, this additional aggregated data rate comes from the more efficient use of the deployed network and would not require any sensitivity upgrade of currently deployed 10G receivers in the ONUs.…”

Increasing Flexibility and Capacity in Real PON Deployments by Using 2/4/8-PAM Formats

“…Previously we have examined the potential of flexible allocation of 4-PAM in PONs [16], in this paper we extend this work by introducing downstream 8-PAM, time-interleaved with 2-and 4-PAM, which is made possible by zero-overhead data-aided equalization [17]. We demonstrate for currently deployed networks an 83% increase in aggregated data rate with 4-PAM without equalization, and a 108% increase with 8-PAM, although with the use of equalization.…”