Optical Transport Network

About: Optical Transport Network is a research topic. Over the lifetime, 6055 publications have been published within this topic receiving 85783 citations.

An optical infrastructure for future telecommunications networks

Abstract: For the transport of the increasing traffic volume caused by existing and new narrowband services and evolving broadband services, the enhancement of the existing public telecommunication transport network is necessary. For this purpose an optical network layer with cross-connect and add/drop functionalities will be added to the existing transport network. A comparative analysis of space, time, and optical frequency division multiplexing has shown that for the time being optical frequency multiplexing is best suited for the realization of that new network layer. This multiplexing scheme offers the greatest advantages such as very high bandwidth utilization in the fiber and simple and efficient cross-connecting of high bitrate streams. In the near future, technology will be mature enough for the realization of a demonstrator network based on optical frequency division multiplexing. The functionalities of the optical network are evaluated and the results clearly show that optical frequency conversion and regeneration should be provided by the optical network. The article also deals with the realization aspects (cross-connecting, supervision, and operation and maintenance) of an optical node. >

Optical cascade star network - A new configuration for a passive distribution system with optical collision detection capability

Abstract: A new fiber-optic passive network configuration with novel star couplers is reported. The new optical network configuration, an Optical Cascade Star Network, optimizes contradictory requirements for network system size and cable cost, and matches the actual layout in offices or factories. The star coupler is novel in that the optical signal does not return to the source terminals. This feature enables cascade connection of star networks, the use of simple repeaters for system extension, and the easy support of carrier sense multiple access with collision detection (CSMA/CD) bus access procedure. Experimental results obtained from novel star couplers, optical transceivers with (CSMA/CD) bus compatibility, and a total network system are also discussed.

Architecture on demand design for high-capacity optical SDM/TDM/FDM switching

Abstract: Reconfigurable optical add/drop multiplexers (ROADMs) are key elements in operators' backbone networks. The breakthrough node concept of architecture on demand (AoD) permits us to design optical nodes with higher flexibility with respect to ROADMs. In this work, we present a five-step algorithm for designing AoD instances according to some given traffic requests, which are able to support subwavelength time switching up to wavelength/superchannel/fiber switching. We evaluate AoD performancein terms of power consumption and number of backplane optical cross-connections. Furthermore, we discuss trade-offs involved in the migration from a fixed to a flexible grid with regard to the optical node size, capacity, and power consumption. We compare several ROADM architectures proposed in the literature with AoD in terms of power consumption and cost. We also study different technologies for enhancing the scalability of AoD. Results show that AoD can bring significant power savings compared to other architectures while offering a throughput of hundreds of terabits per second.

On the power and offset allocation for rate adaptation of spatial multiplexing in optical wireless MIMO channels

Abstract: Visible light communication (VLC) using optical sources which can be simultaneously utilized for illumination and communication is currently an attractive option for wireless personal area network. Improving the data rate in optical wireless communication system is challenging due to the limited bandwidth of the optical sources. In this paper, we design the singular value decomposition (SVD)- based multiplexing multiple-input multiple-output (MIMO) system to support two data streams in optical wireless channels. Noting that the conventional allocation method in radio frequency (RF) MIMO channels cannot be applied directly to the optical intensity channels, we propose a novel method to allocate the optical power, the offset value and the modulation size for maximum sum rate under the constraints of the nonnegativity of the modulated signals, the aggregate optical power and the bit error rate (BER) requirement. The simulation results show that the proposed allocation method gives the better performance than the method to allocate the optical power equally for each data stream.

Optical feeder links for high throughput satellites

Abstract: Optical feeders for geostationary High Throughput Satellites (HTS) systems based on 1.55μm wavelength technology are expected to enable to transmit up to several terabits over one active link. A desirable option of transmission architecture is an optical feeder link transparent with respect to the user air interface. This can be implemented using either a digital or an analog modulation of the optical carrier. The digital option increases the optical bandwidth to be transmitted, however it benefits from error correcting codes, interleaving and framing which are efficient against atmospheric turbulence impairments. The analog option is more efficient concerning the optical bandwidth; however the atmospheric turbulence impairments can only be mitigated by a more complex optical ground terminal. Both analog and digital options could be feasible in the 2025-2030 time-frames but the digital option is more mature with respect to the atmosphere impairments mitigation techniques.