Kenneth C. Reichmann

A view of fiber to the home economics

Fiber to the home in the U.S. market has not been deployed as rapidly as many had hoped or predicted. We examine some of the historical, competitive, and economic reasons for this. We argue that, from a competitive service perspective, it may be difficult to construct compelling business cases for large-scale deployment without either a technical need for fiber, or significant changes in either public policy or industrial organization.

Design and optimization of fiber optic small-cell backhaul based on an existing fiber-to-the-node residential access network

As the number of wireless users and per-user bandwidth demands continue to increase, both the vendor and carrier communities agree that wireless networks must evolve toward more dense deployments. So-called heterogeneous networks are a commonly proposed evolution, whereby existing macrocellular networks are supplemented with an underlay of small cells. The placement of new small-cell sites is typically determined based on various location-dependent factors such as radio propagation calculations, user densities, and measurements of congestion and demand. The backhaul network, which can account for a significant portion of the total cost of the deployment, is then designed in reaction to the placement of small cells. In contrast, we describe a design method that first considers the locations of existing fibered and powered facilities that might be leveraged to provide inexpensive backhaul. Naturally, such a method is only feasible if the carrier has a legacy local fiber network. This article describes an efficient fiber backhaul strategy for a small-cell network, which leverages facilities associated with an existing FTTN residential access network. Once potential small-cell sites are determined from among all FTTN remote terminals, optimization techniques are used to choose the most efficient subset of sites for maximum coverage, and to design the fiber backhaul architecture.

In-service upgrade of an amplified 130-km metro CWDM transmission system using a single LOA with 140-nm bandwidth

We demonstrate a 130-km metro CWDM transmission system using a single LOA with 140-nm bandwidth. An in-service upgrade, for which one of the eight 2.5-Gb/s CWDM channels is replaced with 8/spl times/2.5-Gb/s DWDM channels, results in negligible performance degradation.

Bi-directionally amplified extended reach 40Gb/s CWDM-TDM PON with burst-mode upstream transmission

We demonstrate a 60-km CWDM-TDM PON with 40 Gb/s capacity both down and upstream. The system incorporates technologies such as volume manufacturable transmitters, burst-mode transmission, hybrid SOA-Raman amplifiers, and a cyclic CWDM multiplexer.

Optical access beyond 10 Gb/s PON

Innovation in optical access network architectures has always been tightly coupled to innovation in enabling components and subsystems. We explore some of the candidate architectures for next-generation optical access with an emphasis on enabling technologies.

240-km CWDM transmission using cascaded SOA Raman hybrid amplifiers with 70-nm bandwidth

We demonstrate the cascading of broad-band semiconductor optical amplifier-Raman hybrid amplifiers which provide nearly flat gain over 70 nm. A coarse-wavelength-division-multiplexing transmission system consisting of three spans of 80 km shows uniform performance and <1-dB power penalty.

An optical implementation of a packet-based (Ethernet) MAC in a WDM passive optical network overlay

We propose and demonstrate an optical implementation of an Ethernet (CSMA/CD) MAC on a WDM PON using spectrally slicing and novel AWG wiring connections. Fairness and throughput are demonstrated and compared to theory and simulations.

Design of cost-optimal passive optical networks for small cell backhaul using installed fibers [invited]

With the recent popularity of mobile data devices, the demand for mobile data traffic has grown rapidly as never before. Hence, service providers are trying to come up with cost-effective solutions to battle this ever increasing demand for bandwidth in their cellular networks. Deployment of a denser heterogeneous network, with a large number of small cells, has been identified as an effective strategy not only to satisfy this unabated growth in mobile data traffic but also to facilitate ubiquitous wireless access. While the cost associated with on-site small cell equipment is low in comparison with a typical macro cell, deployment of small cells opens a new set of challenges, especially in relation to expenditures and capacity requirements associated with the backhaul. In this paper we discuss an efficient small cell backhauling strategy that leverages existing fiber resourcesin a cost-optimal manner. In particular, we formulate an optimization framework for planning a cost-minimized backhaul for a small cell network, which is based on the deployment of passive optical networks on top of the existing infrastructure. We demonstrate the effectiveness of our method by using our optimization framework to design a cost-optimal backhaul for a small portion of a realistic backhaul network. Our results show that in comparison to the typical point-to-point fiber backhauling approach, our technique can halve the costs associated with small cell backhaul deployment.

A Symmetric-Rate, Extended-Reach 40 Gb/s CWDM-TDMA PON With Downstream and Upstream SOA-Raman Amplification

We demonstrate an extended reach 60 km coarse wavelength division multiplexing (CWDM)-time division multiple access (TDMA) passive optical network (PON) with 40 Gb/s capacity for both down and upstream directions. The system leverages existing 10 Gb/s TDMA PON technologies and incorporates various subsystems such as volume manufacturable optical transmitters, a prototype 10 Gb/s burst-mode receiver, hybrid semiconductor optical amplifier-Raman amplifiers, and a cyclic CWDM multiplexer. We confirm that this 32-user system has sufficient power margin to accommodate 128 users.

A

We demonstrate an 83-nm flat gain-bandwidth gain-clamped semiconductor optical amplifier-Raman hybrid amplifier for coarse wavelength-division-multiplexing (CWDM) access networks. Four channels of 2.488-Gb/s CWDM signals were amplified and the input dynamic range for 1-dB bit-error-rate power penalty exceeds 17.3 dB.