Transmission solutions and architectures for heterogeneous networks built as C-RANs

A novel end-to-end transport network solution is proposed to meet the operational and technical challenges of heterogeneous networks built as C-RANs with centralized base band processing and CPRI links. The flexibility of the proposed architecture to support distributed architectures and Ethernet links is also described and the results of a C-RAN proof of concept demonstration are discussed. Substantiated by the evolution of key optical technologies, including a novel WDM-PON based solution, we conclude that backhaul and metro network strategies need to flexibly support both centralized and distributed radio baseband solutions, as well as being multiservice capable. Additionally, as a complement to fiber, we propose use of the 70/80 GHz frequency band (E-band) to provide high performance microwave links for both centralized and distributed architectures.