Single-ended in-service hybrid monitoring of fiber-extended copper lines

We report on the simultaneous monitoring of both fiber and copper links in the context of analog radio signal transmission over fiber-extended copper mobile fronthaul networks. The same monitoring signal is used to determine both the fiber's and copper's characteristics, which translates into a low-complexity monitoring structure readily embeddable in the transmitter. A copper-tofiber converter unit is devised so that both monitoring and data signals can coexist even when the control is centralized at the central office. In-service fiber monitoring is achieved with a spatial resolution of 10 m and >7 dB dynamic range, while in-service copper monitoring is achieved with a maximum reach of 100 m and an error in fault location smaller than 1 m. Low-cost centralized monitoring of hybrid networks represents a step toward the deployment of fiber-extended copper lines, which is a promising candidate for next-generation communication architectures.