Performance analysis of interferometric noise due to unequally powered interferers in optical networks

Interferometric crosstalk has been identified as the cause of performance limits in future transparent all-optical networks. A large number of studies have been conducted on this phenomenon using a vast array of evaluation techniques. However, most major studies have considered that although the interfering terms may differ in number, the power contribution that they all make will be identical for all interfering terms. Although this situation is easy to analyze, it does not necessarily represent the situation that is likely to occur in a real network, which will be constructed of nodes with different degrees of connectivity, quite possibly from different vendors, and therefore with differing crosstalk characteristics. This paper describes a study on the impact of unequally powered interfering terms using a rigorous analysis technique. To validate the use of the chosen technique, the paper begins by bench-marking a number of common evaluation techniques against empirically derived, experimentally verified noise performance formulas

Integrated Wireless Backhaul Over Optical Access Networks

Recent technological advances and deployments are creating a new landscape in access networks, with an integration of wireless and fiber technologies a key supporting technology. In the past, a separation between those with fiber in the access networks and those with wireless networks, the relatively low data-rate requirements of backhaul and the relatively large cell sites, have all combined to keep fiber deployment low in wireless backhaul. As fiber has penetrated the access network and the latest wireless standards have demanded smaller, higher bandwidth cells, fiber connectivity has become key. Choices remain as to where the demarcation between key elements should be in the network and whether fiber should be used as just a high data-rate backhaul path or if a transition to radio-over-fiber techniques can afford benefits. This paper will explore the network options available in particular those demonstrated in recent European Union (EU) projects, how they can be integrated with existing access networks and how techniques such as radio-over-fiber can be deployed to offer increased functionality

A 10-Gb/s 1024-way-split 100-km long-reach optical-access network

Optical-access networks have been developed to remove the access-network bandwidth bottleneck. However, the current solutions do not adequately address the network economics to provide a truly cost-effective solution. Long-reach optical-access networks introduce a cost-effective solution by connecting the customer directly to the core network, bypassing the metro network, and, hence, removing significant cost. This paper charts the design and development of a 1024-way-split 100-km 10-Gb/s symmetrical network, which experimentally proves the feasibility of long-reach optical-access networks for both the upstream and downstream transmission

FiWiN5G-FIber-Wireless Integrated Networks for 5th Generation Delivery

This paper describes the work and structure of the FIWIN5G: FIber-Wireless Integrated Networks for 5th Generation delivery, an Innovative Training Network (ITN) funded by the European Union's Horizon 2020 research and innovation programme through the Marie Sklodowska-Curie Actions (MSCA) scheme. The programme, which started in January 2015, comprises 10 leading research institutions, a wide range of industrial partners (from multi-nationals to SMEs) and a comprehensive research training program for all 15 Early Stage Researchers (ESR) recruited

Investigation of a robust remote heterodyne envelope detector scheme for cost-efficient E-PON / 60 GHz wireless integration.

In this work, a simple remote heterodyne envelope detector scheme is proposed employing an O-SSB scheme for application in a converged E-PON/ 60 GHz scenario. The proposed PON-60GHz wireless system topology (Fig. 1) is discussed and an evaluation of this scheme is experimentally demonstrated including i) an OFDM 60 GHz wireless access system using indoor MMF, ordinary DFB lasers & ii) a 60 GHz wireless PON “bridge” using a VCSEL for the E-PON data. In both cases, the envelope detector scheme proves its robustness against phase/ wavelength variations while it preserves low cost and wavelength tolerance

Networking and Application Interface Technology for Wireless Sensor Network Surveillance and Monitoring

Distributed unattended ground sensor networks used in battlefield surveillance and monitoring missions, have proven to be valuable in providing a tactical information advantage required for command and control, intelligence, surveillance, and reconnaissance planning. Operational effectiveness for surveillance missions can be enhanced further through network centric capability, where distributed UGS networks have the ability to perform surveillance operations autonomously. NCC operation can be enhanced through UGSs having the ability to evaluate their awareness of the current joint surveillance environment, in order to provide the necessary adaptation to dynamic changes. NCC can also provide an advantage for UGS networks to self-manage their limited operational resources efficiently, according to mission objective priority. In this article, we present a cross-layer approach and highlight techniques that have potential to enable NCC operation within a mission-orientated UGS surveillance setting

Analyses of MAC Performance for Multi-Carrier based Wireless Sensor Networks

In this work we adopt an OFDMA like Multi-Carrier scheme for wireless sensor networks with the aim of improving the performance in the presence of intensive traffic load. To examine the MAC performance, a simple, yet accurate analytic model has been provided, validated by simulation results. We demonstrate that the proposed scheme can achieve better throughput under heavy offered traffic load, as a result of the higher bandwidth utilisation. In addition, energy efficiency and service delay performance can be significantly increased as well in this architecture

Bandwidth Compressed Waveform for 60 GHz Millimeter-Wave Radio over Fiber Experiment

A bandwidth compressed waveform termed spectrally efficient frequency division multiplexing (SEFDM) is experimentally demonstrated in a 60-GHz millimeter-wave (mm-wave) radio-over-fiber scenario to increase transmission data rates without changing signal bandwidth and modulation format. Experimental results show the advantages of SEFDM and confirm that the bit rate of SEFDM signals can be substantially higher than that of orthogonal frequency-division multiplexing (OFDM) signals. Experimentally, a 2.25 Gbit/s 4QAM OFDM signal is transmitted through 250 m of OM-1 multi-mode fiber and then it is optically up converted to 60 GHz band at the photodiode before delivery to a mm-wave antenna for transmission over a 3 meter wireless link. The work demonstrates that when the OFDM signal is replaced by an SEFDM signal using the same modulation format and occupying the same bandwidth, the bit rate can be increased, by a factor of up to 67%, to 3.75 Gbit/s at the expense of a 3-dB power penalty. Additionally, a bandwidth compressed 4QAM SEFDM is shown to outperform an 8QAM OFDM of the same spectral efficiency, thereby verifying that a lower order modulation format may replace a higher order one and achieve performance gain

Digital dual-rate burst-mode receiver for 10G and 1G coexistence in optical access networks

A digital dual-rate burst-mode receiver, intended to support 10 and 1 Gb/s coexistence in optical access networks, is proposed and experimentally characterized. The receiver employs a standard DC-coupled photoreceiver followed by a 20 GS/s digitizer and the detection of the packet presence and line-rate is implemented in the digital domain. A polyphase, 2 samples-per-bit digital signal processing algorithm is then used for efficient clock and data recovery of the 10/1.25 Gb/s packets. The receiver performance is characterized in terms of sensitivity and dynamic range under burst-mode operation for 10/1.25 Gb/s intensity modulated data in terms of both the packet error rate (PER) and the payload bit error rate (pBER). The impact of packet preamble lengths of 16, 32, 48, and 64 bits, at 10 Gb/s, on the receiver performance is investigated. We show that there is a trade-off between pBER and PER that is limited by electrical noise and digitizer clipping at low and high received powers, respectively, and that a 16/2-bit preamble at 10/1.25 Gb/s is sufficient to reliably detect packets at both line-rates over a burst-to-burst dynamic range of 14,5dB with a sensitivity of -18.5dBm at 10 Gb/s. (C)2011 Optical Society of Americ