An optical packet switch employing shared parametric wavelength converters

The analysis of a shared-per-node OPS switch employing parametric wavelength converters (SPN-PWC) is reported. The results demonstrate a 38 - 63% reduction in the number of converters when SPN-PWC is compared with SPN employing single-channel wavelength converters

Optical generation of IR-UWB pulse based on weighted sum of modified doublets

We propose a relatively simple optical generation concept for impulse radio ultra wideband (IR-UWB) pulse over fiber transmission using a weighted sum of a modified doublet with its inverted and delayed version. The generated pulses not only fi4ly comply with the FCC spectral mask but also are highly power efficient in the available spectrum. We verified our approach using both simulation and experimental demonstration. The concept has a potential to be integrated with other optical functions on a compact optical chip, making it very suitable for wide UWB deployment for highspeed wireless access at low costfor in-building network applications

320-to-10 Gbit/s all-optical demultiplexing using sum-frequency generation in PPLN waveguide

A 320-to-10 Gbit/s all-optical demultiplexer based on sum-frequency generation in a periodically-poled lithium niobate (PPLN) waveguide is demonstrated. A bit-error-rate of 10-9 is achieved with a power penalty of 1.5 dB

Recent Results From the EU POF-PLUS Project: Multi-Gigabit Transmission Over 1 mm Core Diameter Plastic Optical Fibers

Recent activity to achieve multi-gigabit transmission over 1 mm core diameter graded-index and step-index plastic optical fibers for distances up to 50 meters is reported in this paper. By employing a simple intensity-modulated direct-detection system with pulse amplitude or digital multi-tone modulation techniques, low-cost transceivers and easy to install large-core POFs, it is demonstrated that multi-gigabit transmission up to 10 Gbit/s over 1-mm core diameter POF infrastructure is feasible. The results presented in this paper were obtained in the EU FP7 POF-PLUS project, which focused on applications in different scenarios, such as in next-generation in-building residential networks and in datacom applications

Techniques for flexible radio-over-fibre networks

Radio-over-fibre systems can efficiently deliver broadband wireless services in access and in-building networks. RoF signal transport and routing techniques are presented which are robust against fibre dispersion and provide capacity-on-demand for high-capacity multi-tone radio signals

Novel generation and transmission of 2 Gbps impulse radio ultra wideband over MMF for in-building networks application

We propose novel generation technique of IR-UWB pulse by linearly combining two monocycles using different pulse shapes. We experimentally demonstrate DSP based BER measurement of 2 Gbps IR-UWB over multimode fiber for in-building networks application.</p

Demonstration of an application-aware resilience mechanism for dynamic heterogeneous networks

Business uptake of IP-centric services has been strong and necessitates reliable, highly-available, high-quality Internet access. Real time services such as mission-critical broadcast video, video conferencing and voice over IP (VoIP) have low tolerance for short-term network outages. However, applications like bulk data transfer maybe much more resistant to such events. Many different network resilience mechanisms can be offered to customers by service providers allowing for slower (or faster) recovery of network access. Yet in current networks, offering different resilience mechanisms for different services is complicated, involving multiple interfaces. In this work, we propose that services be offered differentiated resilience levels within a single physical interface. In order to do so, an application aware resilience mechanism is proposed based on using the supplementary IP header type of service (ToS) field to define arbitrary values in addition to the 6-bit differentiated services code points (DSCP). This mechanism allows different levels of resilience to be assigned to applications such as VoIP for emergency and mission critical services

Impact of type and level of stabilizers and fermentation period on the nutritional, microbiological, and sensory properties of short-set Yoghurt

Open Access JournalThis study aimed to produce short set yoghurt with different stabilizers at different concentrations and determine the effects of the stabilizers and length of fermentation on the nutritional, microbiological, and sensory properties of short set yoghurt. Stabilized yoghurt samples were produced using 0%, 0.5%, and 1.0% concentrations of carboxyl methylcellulose (CMC), corn starch, and gum acacia with different fermentation periods (1–5 hr), respectively. Samples were analyzed for the proximate, physicochemical, microbial, and sensory properties using standard laboratory methods. Results showed that an increase in stabilizer concentration and fermentation time decreased the moisture content but increased the total solids, protein, fat, ash, sugars, pH level, and total titratable acidity. The viscosity of the yoghurt samples significantly (p < .05) increased with the addition of stabilizers (1.48 ± 0.03 cP to 275.57 ± 4.08 cP), with CMC having the highest increase (p < .05) and gum acacia the least. However, the lactic acid production reduced as the concentration of stabilizers increased but showed an increase with fermentation time. The total viable count (TVC) reduced significantly (p < .05) with an increase in the concentration of stabilizer and fermentation time. Hence, short set yoghurt samples containing CMC yielded highest protein (0.5%), fat (1.0%), and ash contents (1.0%). Yoghurt samples produced with a 1.0% concentration of gum acacia gave an optimum pH (0.5%), TTA, mouthfeel, appearance, flavor, and taste. In contrast, yoghurt produced with corn starch produced the most desirable overall acceptability, viscosity, total solids at 1.0%, and TVC (at 0.5%) concentration