This paper aims to present the design and the achieved results on a CMOS electronic and photonic integrated device for low cost, low power, transparent, mass-manufacturable optical switching. An unprecedented number of integrated photonic components (more than 1000), each individually electronically controlled, allows for the realization of a transponder aggregator device which interconnects up to eight transponders to a four direction colorless-directionless-contentionless ROADM. Each direction supports 12 200-GHz spaced wavelengths, which can be independently added or dropped from the network. An electronic ASIC, 3-D integrated on top of the photonic chip, controls the switch fabrics to allow a complete and microsecond fast reconfigurability

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. Keywords-Centralized baseband, WDM-PON, 70/80GHz Eband microwave, CPRI, C-RAN, Heterogenous networkI.

The telecommunication community has reached a broad consensus that current RAN and underlying transport will not be able to scale up to the traffic volume and quality expected in 5G. Thus, it is mandatory to remove all the technological bottlenecks and operational rigidities to ensure a painless migration from the existing radio scenario to the 5G one. This article presents a transport architecture able to serve as backhaul and fronthaul, to convey radio traffic on the same optical infrastructure. Cornerstones of the solution are: a novel photonic technology used to provide optical connectivity complemented with a dedicated agnostic framing; a deterministic switching module; a flexible control paradigm based on a layered scheme and on the slicing concept to facilitate optimal interaction of transport and radio resources while preserving a welldemarcated mutual independence. Simulations and experiments are presented to demonstrate the aforementioned features.

In addition to CPRI, new functional splits have been defined in 5G creating diverse fronthaul transport bandwidth and latency requirements. These fronthaul requirements shall be fulfilled simultaneously together with the backhaul requirements by an integrated fronthaul and backhaul transport solution. In this paper, we analyze the technical challenges to achieve an integrated transport solution in 5G and propose specific solutions to address these challenges. These solutions have been implemented and verified with pre-commercial equipment. Our results confirm that an integrated fronthaul and backhaul transport dubbed Crosshaul can meet all the requirements of 5G fronthaul and backhaul in a cost-efficient manner.

This paper reports the performances of a silicon photonics optical switch matrix fabricated by using large-scale threedimensional (3-D) integration. The wavelength selective optical switch consists of a photonic integrated circuit (PIC), with 1398 circuit elements, interconnected in a 3-D stack with its control electronic integrated circuit (EIC). Each PIC element can be trimmed Manuscript