Carlos Bock

Optical network unit based on a bidirectional reflective semiconductor optical amplifier for fiber-to-the-home networks

An optical access network transceiver based on a reflective semiconductor optical amplifier operating as modulator and photodetector is demonstrated. Device characterization and modulation/detection tests show the system proper operation at 1.25 Gb/s to 30-km reach. This optical network unit design is a simple and capable solution for future fiber-to-the-home networks.

Hybrid WDM/TDM PON using the AWG FSR and featuring centralized light generation and dynamic bandwidth allocation

A novel time/space/wavelength division multiplexing (TDM/WDM) architecture using the free spectral range (FSR) periodicity of the arrayed waveguide grating (AWG) is presented. A shared tunable laser and a photoreceiver stack featuring dynamic bandwidth allocation (DBA) and remote modulation are used for transmission and reception. Transmission tests show correct operation at 2.5 Gb/s to a 30-km reach, and network performance calculations using queue modeling demonstrate that a high-bandwidth-demanding application could be deployed on this network.

Full-duplex single fiber transmission using FSK downstream and IM remote upstream Modulations for fiber-to-the-home

Full-duplex single fiber bidirectional transmission, using frequency-shift-keying modulation for downstream, by direct modulation of a tunable laser, and intensity modulation for upstream, in a wavelength-division-multiplexing passive optical access network is demonstrated. The optical network unit, located at the end user premises, reflects and orthogonally remodulates the received light. Rayleigh scattering effects are reported and analyzed. The system shows proper operation up to 1 Gb/s at 30-km reach.

Remotely amplified combined ring-tree dense access network architecture using reflective RSOA-based ONU

Feature Issue on Passive Optical Network Architectures and TechnologiesA highly scalable access architecture achieving high density and featuring resiliency, centralized light-generation control, remote amplification, and colorless optical network unit with reflective semiconductor optical amplifier (RSOA) for upstream modulation is presented and experimentally demonstrated. It is based on a user-single-fiber completely passive outside plant and provides broadband connections to >1000 users distributed along large distances. It is believed to represent an intermediate step toward metro-access convergence and offers flexible configurations covering high- and low-density population areas.

RSOA-based optical network units for WDM-PON

Designs of low cost ONU for WDM-PON are presented and evaluated. Reflective-SOAs are proposed to be used as core of the ONU in a bidirectional single-fiber single-wavelength topology. FEC is employed to mitigate crosstalk effects

WDM/TDM PON Experiments using the AWG Free Spectral Range Periodicity to transmit Unicast and Multicast Data

A hybrid WDM/TDM PON architecture implemented by means of two cascaded Arrayed Waveguide Gratings (AWG) is presented. Using the Free Spectral Range (FSR) periodicity of AWGs we transmit unicast and multicast traffic on different wavelengths to each Optical Network Unit (ONU). The OLT is equipped with two laser stacks, a tunable one for unicast transmission and a fixed one for multicast transmission. We propose the ONU to be reflective in order to avoid any light source at the Costumer Premises Equipment (CPE). Optical transmission tests demonstrate correct transmission at 2.5 Gbps up to 30 km.

Extension of TDM-PON Standards to a Single-Fiber Ring Access Network Featuring Resilience and Service Overlay

A novel single-fiber ring-tree topology overlying multiple time-division-multiplexed (TDM) passive optical networks is presented and demonstrated. Each TDM service is overlaid on a different wavelength-division-multiplexing channel. A concatenation of advanced coupler-based remote nodes (RNs) distributes the channels in an optimal geographical distribution to secondary trees, which connect to the end users. With the proposed configuration, the network features flexible deployment and provides resilience capabilities in case of a fiber cut. To compensate power losses and fulfill ITU-T G.984/IEEE 802.3ah recommendations in terms of power budget (PB) and sensitivity, remote amplification is implemented at the RNs. This technique amplifies the dropped wavelengths at each RN while keeping a totally passive outside plant. A PB study, together with optical transmission experiments and network dimensioning simulations, demonstrates the feasibility of the network design.

Bidirectional single fiber transmission based on a RSOA ONU for FTTH using FSK-IM modulation formats

Full-duplex bidirectional transmission using FSK modulation for downstream and remote IM using a reflective SOA for upstream in a single-fiber WDM-PON access network is demonstrated. The system shows proper operation at 1 Gbit/s to 30 km reach.

Software-defined open architecture for front- and backhaul in 5G mobile networks

New software-defined open network concepts are proposed in this paper to enable an efficient implementation of front- and backhaul solutions for future 5G mobile networks. Main requirements for 5G front- and backhaul are derived and then related to the open network architecture enabling multiple operators to share the same physical infrastructure. The value of software-defined networking (SDN) is particularly outlined therefore. For the use of SDN in the fronthaul, CPRI over Ethernet (CoE) is proposed as a new transport protocol. In the backhaul, distributed security can be implemented using SDN where direct links are confined inside the access domain, as opposed to the current centralized security solution including also the transport domain. In this way, low latency can be realized e.g. for machine-type communications. As the benefits for fixed-mobile convergence are evident, SDN should be enabled increasingly in the access domain.

Scalable WDMA∕TDMA protocol for passive optical networks that avoids upstreamsynchronization and features dynamic bandwidth allocation

A hybrid wavelength-division multiple-access (WDMA)∕time-division multiple-access (TDMA) protocol specifically designed for access is presented. With shared tunable laser sources located at the central office (CO), reflexive optical network units (ONUs), and a dynamic time-assignation protocol, there is no need to synchronize upstream transmission because access to the shared media is given by the CO. This hybrid access protocol is scalable in terms of number of lasers, offers flexible bandwidth allocation, and is suitable for all wavelength-selective network topologies. The proposed protocol was evaluated by mathematical analysis and simulations.