Erik Weis

An OFDMA-based optical access network architecture exhibiting ultra-high capacity and wireline-wireless convergence

This article presents ACCORDANCE, a novel optical access network architecture based on OFDMA technology and applied on a PON topology. In compliance with next generation optical access requirements, this architecture aims to outperform existing PON solutions in terms of total capacity, bandwidth allocation flexibility, number of users, and network reach. Moreover, it provides the opportunity for convergence with wireless technologies and a smooth migration path from legacy access solutions like TDMA-PONs and DSL.

37.5 km urban field trial of OFDMA-PON using colorless ONUs with dynamic bandwidth allocation and TCM [invited]

The orthogonal frequency division multiple access (OFDMA)-based passive optical network (PON) is a potential candidate to meet the flexibility requirements for next-generation optical access networks. We propose an OFDMA-based PON with a transmission employing intensity modulation/direct detection in the downstream and a remodulation of a remotely seeded carrier provided by the optical line terminal with coherent detection in the upstream, which enables cost-effective colorless optical network units (ONUs). Furthermore, an OFDMA-PON field trial using the proposed scheme over 37.5 km feeder fiber is demonstrated. A power budget supporting 32 ONUs with dynamic bandwidth allocation and trellis coded modulation (TCM) is reported.

Next-generation optical access seamless evolution: concluding results of the European FP7 Project OASE

Increasing bandwidth demand drives the need for next-generation optical access (NGOA) networks that can meet future end-user service requirements. This paper gives an overview of NGOA solutions, the enabling optical access network technologies, architecture principles, and related economics and business models. NGOA requirements (including peak and sustainable data rate, reach, cost, node consolidation, and open access) are proposed, and the different solutions are compared against such requirements in different scenarios (in terms of population density and system migration). Unsurprisingly, it is found that different solutions are best suited for different scenarios. The conclusions drawn from such findings allow us to formulate recommendations in terms of technology, strategy, and policy. The paper is based on the main results of the European FP7 OASE Integrated Project that ran between January 1, 2010 and February 28, 2013.

Architectural options and challenges for next generation optical access

Potential challenges towards next generation optical access technologies and architectures are reviewed based on operator requirements. Additionally the impact of new business models on network architecture is discussed.

Trials of a Coherent UDWDM PON Over Field-Deployed Fiber: Real-Time LTE Backhauling, Legacy and 100G Coexistence

Transmission capabilities of a coherent real-time UDWDM PON over deployed fibers in two testbeds (Berlin and Darmstadt, Germany) are demonstrated. Extensive coexistence tests including LTE backhauling and GPON, RF-Video, 100G and OTDR were performed. A silicon photonics-integrated CMOS laser was used for parts of the trial.

Demonstration of an SOA-assisted open metro-access infrastructure for heterogeneous services

An open converged metro-access network approach allows for sharing optical layer resources like fibers and optical spectrum among different services and operators. We demonstrated experimentally the feasibility of such a concept by the simultaneous operation of multiple services showing different modulation formats and multiplexing techniques. Flexible access nodes are implemented including semiconductor optical amplifiers to create a transparent and reconfigurable optical ring network. The impact of cascaded optical amplifiers on the signal quality is studied along the ring. In addition, the influence of high power rival signals in the same waveband and in the same fiber is analyzed.

Assessment of future backhaul and fronthaul networks for HetNet architectures

Mobile traffic is heavily increasing in the last years and a massive continuous growth is forecasted for the next decade. To cope with this significant traffic increase in mobile networks and the further evolving competitive market situation, operators are looking for solutions to increase the capacity of their mobile networks, while keeping the cost low. Besides enhancements of mobile radio technology and adding new spectrum to the existing sites, densification of radio sites, by so called small cells, is considered as a very promising option to increase capacity. Adding small cells to the already existing macro cell layer lead to heterogeneous networks (HetNet). Because of the scarce radio spectrum it is most likely that the radio sites in HetNets will use the same frequencies and therefore create interferences. To mitigate this impact different coordination methods have been proposed creating new challenging requirements on the transport network compared to todays backhaul. Cost effective and scalable transport solutions are an important fundament for wide and successful deployment of HetNets. This paper investigates and assesses techno-economically different architectures for backhaul and fronthaul transport of existing and newly deployed radio sites in HetNet architectures taking requirements from interference co-ordination into account.

Field trials of a coherent UDWDM PON: Real-time LTE backhauling, legacy and 100G coexistence

Transmission capabilities of a coherent UDWDM PON over deployed fiber are demonstrated, including LTE backhauling and GPON, RF-Video, 100G and OTDR coexistence. A Silicon Photonics integrated CMOS laser was used for parts of the trial.

Field trial of a novel FTTH/PON monitoring technique based on unique wavelength-selective mirror combinations

Our novel PON monitoring concept succeeded in a field trial. Subscribers located at equal distances were individually identified across a PON with at least 30.7 dB one-way loss and utilization of low cost components.

European and American research toward next-generation optical access networks

Next-generation optical access networks will deliver substantial benefits to consumers including a dedicated high-QoS access to bit rates of hundreds of Megabits per second. They must also deliver significant benefits to network owners/operators to justify the needed infrastructure investment expected to reach billions of Euros. Benefits to network owners/operators are expected to include reduced total cost of ownership, due to higher reliability, lower energy consumption, better flexibility and efficiency, and a smaller number of sites needed to support network operations. This paper will describe recent progress toward that goal including R&D efforts in Europe under the FP7 projects ALPHA and OASE and in the US at Stanford University under the SUCCESS and DAN projects.