Point to point (PtP), wavelength division multiplexing (WDM) and time division multiplexing (TDM) optical interfaces are discussed as solutions for backhaul, midhaul, and fronthaul networks. The evolution of radio access networks (RANs) for 5G and beyond is introduced and PtP is identified as the most deployed solution, with many transceiver technologies available to cover the different needs for each RAN configuration. WDM and TDM interfaces remain of interest when a lack of fiber occurs. WDM technologies are being adapted to answer to this RAN market with the appearance of medium-WDM (MWDM) and autotunable dense-WDM (DWDM) transceivers. TDM technologies are trying to evolve towards higher bit rates and lower latency to cope with RAN backhaul specifications. A gap in the transceiver technologies is identified for each of those interface types and also for bit rates above 25 Gbit/s that will impose more complex optics, electronics, and integration.

中文翻译：

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5G及以后的光接入网络接口[邀请]

点对点 (PtP)、波分复用 (WDM) 和时分复用 (TDM) 光接口被讨论为回程、中程和前程网络的解决方案。引入了面向 5G 及更高版本的无线电接入网络 (RAN) 的演进，并且 PtP 被确定为部署最多的解决方案，有许多收发器技术可用于满足每个 RAN 配置的不同需求。当缺少光纤时，WDM 和 TDM 接口仍然很受关注。随着中波分复用 (MWDM) 和可自动调谐密集波分复用 (DWDM) 收发器的出现，WDM 技术正在适应这个 RAN 市场。TDM 技术正试图向更高比特率和更低延迟发展，以应对 RAN 回程规范。