Peter Vaes

Redundancy strategies for a high splitting optically amplified passive optical network

High splitting, optically amplified, passive optical networks (SuperPONs) are investigated in terms of redundancy provision and protection mechanisms. Options for redundancy, including the important special case of dual homing, are detailed, and it is determined as to which of these options (duplication of the feeder and first distribution section, and N+1 protection of the optical amplifiers in the amplified splitter) would be required to be provided to all attached users to facilitate appropriate availability of the basic telephony service. The distributed amplified splitter dual homing solution is found to outperform the single amplified splitter solution in terms of its survivability. The protection mechanisms necessary to automatically switch to the redundant provision are discussed and it is seen that with the aid of suitable regular precautionary procedures protection switching can generally be provided rapidly (<50 ms). Finally, an availability, and cost versus availability, study confirms the aforementioned redundancy assessment for fiber-to-the-home (FTTH) implementations, but shows fiber-to-the-curb (FTTC) as needing additional redundancy.

Biodistribution and pharmacokinetic studies of SPION using particle electron paramagnetic resonance, MRI and ICP-MS

AIMnSuperparamagnetic iron oxide nanoparticles (SPIONs) may play an important role in nanomedicine by serving as drug carriers and imaging agents. In this study, we present the biodistribution and pharmacokinetic properties of SPIONs using a new detection method, particle electron paramagnetic resonance (pEPR).nnnMATERIALS & METHODSnThe pEPR technique is based on a low-field and low-frequency electron paramagnetic resonance. pEPR was compared with inductively coupled plasma mass spectrometry and MRI, in in vitro and in vivo.nnnRESULTSnThe pEPR, inductively coupled plasma mass spectrometry and MRI results showed a good correlation between the techniques.nnnCONCLUSIONnThe results indicate that pEPR can be used to detect SPIONs in both preclinical and clinical studies.

Performance of Burst-mode Receiver and Optical Repeater Units in SuperPON.

This paper describes the TDMA uplink of the ACTS PLANET project, realizing a high split long range access network using optical amplification. An overview of the network topology and the different building blocks is given. In particular, the differentiating burst mode receiver, the optical repeater units and the amplified splitter controller will be discussed. Bit error measurements were performed to define the system limits of the access network. It is shown that a feeder length of 90 km, in combination with a split factor of 2000 and a drop section length of 10 km are feasible.

Evaluation of SuperPON demonstrator

The paper presents evaluation results of the SuperPON demonstrator. It shows the feasibility of a passive optical network with increased bit rate (2.5 Gbit/s downstream and 311 Mbit/s upstream), extended range (100 km) and enlarged splitting factor (2048).

Performance of upstream optical repeaters using semiconductor optical amplifiers for high-split long-distance PONs

Summary form only given. Summary form only given. The authors show that a maximum overhead of 2 bits can be achieved, and the pulse width distortion at 155 Mbit/s is not significant with the gain control of the semiconductor optical amplifiers (SOAs). However, when undergoing the 311 M bit/s upgrade of the uplink, pulse reshaping might be necessary at the burst-mode receiver.

Embedded real time control of optically amplified repeaters in broadband access networks

This paper presents the use of distributed, intelligent control and management in optically amplified repeaters. These optical repeater units (ORUs) are used in an optical access network. A semiconductor optical amplifier (SOA) has been used in the upstream direction because of the possibility of fast switching. The real time control platform consists of both a hard- and a software part. The software control is handled with the embedded control system FORTRESS developed by IMEC.

Evaluation of a superPON demonstrator

The paper presents evaluation results of the SuperPON demonstrator. It shows the feasibility of a passive optical network with increased bit rate (2.5 Gbit/s downstream and 311 Mbit/s upstream), extended range (100 km) and enlarged splitting factor (2048).

Synchronous delay based UWB pulse generator in FPGA

This paper presents an architecture for generating UWB pulses with a high centre frequency accuracy. The architecture allows to generate frequencies twice that of the FPGA clock using synchronous delays and is implementable in all types of FPGA. With a FPGA clock of 150 MHz, we generate RF pulse of 300 MHz with a maximum fractional bandwidth of 30%. The architecture also allows pulse width increment in steps of the clock period.

A lab demonstration of a SuperPON optical access network

This paper contains experimental results obtained from the ACTS PLANET (Photonic Local Access NETwork) Lab demonstrator, which confirm the technical feasibility of the SuperPON concept. The SuperPON is an optical fibre-based ATM access network which can support a large number of subscriber Optical Network Units (ONUs) up to 2048 and cover a long distance of 100 km.