Interest in WDM PON is resurging due to 5G network rollouts and the accompanying forecasted growth in the wireless fronthaul market. While WDM PON failed to reach volume deployments as an FTTH technology, its ability to support 25G bandwidth and meet strict latency requirements, while supporting fiber efficiency, is appealing.
China Telecom is evaluating WDM PON for 5G wireless fronthaul and recently completed several trials. The trial results are being shared as part of the Full Service Access Network group, consisting of leading PON equipment vendors, including ZTE, Huawei, and Nokia.
The resurgence of interest in WDM PON is due to the impact of 5G on wireless fronthaul expenditure. According to Ovum's recently published forecast, global wireless optical fiber-based fronthaul equipment expenditures will increase from $343m in 2018 to $1.5bn in 2023 with 5G networks accounting for $1.2bn in 2023, or 80%. Focusing on China, wireless fronthaul optical fiber-based equipment expenditures for 5G will reach $488m in 2023. Given these forecasted expenditures, operators are seeking low-cost wireless fronthaul solutions that meet the stringent requirements of fronthaul while efficiently using fiber resources.
The use of PON to support wireless fronthaul is not a new idea. However, the most widely deployed type of PON, namely TDM PON, which includes GPON and EPON, might not meet the strict latency and timing requirements for wireless fronthaul. Furthermore, next-gen symmetrical 10G GPON and 10G EPON do not meet the expected 25G bandwidth requirements of 5G networks. While extensive development efforts are underway to improve TDM PON's capabilities, operators and vendors are investigating WDM PON.
From China Telecom's perspective, reuse of its extensive optical distribution network (ODN) is a key factor for WDM PON's consideration. Consequently, WDM PON will be included in Ovum's upcoming access equipment forecast due for publication in late February.
Mobile Backhaul and Fronthaul Forecast: 2018–23, SPT002-000158 (December 2018)
2019 Trends to Watch: Broadband Access Equipment, SPT002-000143 (October 2018)
Julie Kunstler, Principal Analyst, Network Infrastructure and Software