CRZ ?An ideal choice for low BER in XG-PON Hybrid (DWDM-PON/ FSO) Network at 80 (8X10) Gb/s over 60 km fiber length in upstream transmission

In this paper, we have dealt with possibilities of exploring the right candidate from amongst the various types of modulation formats (RZ, NRZ & CSRZ), in XG-PON Hybrid (DWDM-PON/ FSO) Network. The purpose was to achieve low BER at high bit rates of 80(8X10) Gb/s over link distance of 60 km fiber length in upstream transmission from amongst the individual modulation formats. These modulation formats were evaluated with perspective to permissible limits of parameters Q-factor and BER in RSOA based Hybrid optical access networks

On the Performance Analysis of Wireless Receiver in Cascaded Fading Channel

In this paper, we provide a unified analysis for wireless system over cascaded fading channels modeled either by cascaded Nakagami-m or Weibull fading models. These cascade fading models are developed by the product of independent Nakagami-m or Weibull random variables, which are not necessary identically distributed. The performance measures such as amount of fading, average bit error rate, and signal outage are computed in this analysis. We first use the Padé approximation (PA) technique to find simple to evaluate rational expressions for the moment generating function (MGF) of output signal-to-noise ratio (SNR), unlike previously derived intricate expressions in terms of MeijerG function for cascaded Nakagami-m fading channel. Rational expressions for the MGF of the cascaded Weibull random variable are also computed to provide new set of performance results. Using these rational expressions, we analyze the performance of wireless receivers under a range of representative channel fading conditions using both cascaded fading models. To verify the correctness of the proposed rational expression formulation numerical and computer simulations has been done, which shows perfect match

Investigation of bandwidth optimization hybrid scheduling algorithm for hybrid WDM/TDM passive optical system

Hybrid WDM/TDM optical access network has evolved as a cost-effective solution to the higher requirements of bandwidth in the access network. Bandwidth allocation and scheduling mechanism have become critical issues in the optical access networks. In this paper, a novel upstream bandwidth optimization hybrid scheduling algorithm has been proposed in which optical network units can employ tunable wavelength for upstream transmission with a single optical source. Resources allocations have been done utilizing multi point control protocol and for wavelength scheduling the shortest length of channels have been computed. Investigation of the proposed algorithm for providing improved channel utilization has been performed and a comparative analysis has been done for validation

Robust entanglement

It is common belief among physicists that entangled states of quantum systems loose their coherence rather quickly. The reason is that any interaction with the environment which distinguishes between the entangled sub-systems collapses the quantum state. Here we investigate entangled states of two trapped Ca$^+$ ions and observe robust entanglement lasting for more than 20 seconds

Ectopic expression of alkaline phosphatase in proximal tubular brush border membrane of human renal cell carcinoma

AbstractThe present study was conducted to find out any alteration in the expression and activity of alkaline phosphatase in the brush border membrane (BBM) from renal cell carcinoma (RCC) in comparison to normal renal BBM. The specific activity of alkaline phosphatase was drastically reduced in homogenate as well as BBM from RCC kidney when compared to ALP activity in BBM of normal kidney. Kinetic studies revealed that diminished activity of alkaline phosphatase in BBM isolated from RCC was fraternized with decrease in maximal velocity (Vmax) and increase in affinity constant (Km) of the enzyme. SDS-PAGE studies showed that the BBM proteins having molecular weights ranging from 95 to 170 kDa were poorly expressed in RCC BBM in relative to normal kidney BBM. Incubation of SDS-PAGE gel with BCIP/NBT dye clearly showed that the expression of ALP in tumor renal BBM was markedly reduced as compared to normal kidney. Further, Western blot analysis using anti-alkaline phosphatase antibody also confirmed the reduced expression of ALP in tumor renal BBM. Lipid composition in reference to phospholipids, glycolipids and cholesterol in tumor renal BBM was altered to that of normal renal BBM, indicating alteration in membrane fluidity of tumor renal BBM

Implementation and performance analysis of three dimensional (3D) space/wavelength/time single pulse per plane codes with direct detection

a b s t r a c t In this paper, we present space/wavelength/time single pulse per plane (SPP) codes with direct detection (SPPDD) and implemented it as two dimensional codes by using W 2 T scheme. We analyze these codes by varying the number of space channels (S) and keeping other two dimensions, wavelength (W) and time (T) constant and report that it gives better results when (W > S). It is found that the space channels S = 2 and S = 3 provide better BER rate than other space channels and also analyze these 3D codes by using different data modulation formats. It is found that OCDMA system with NRZ data modulation format performs better than RZ

Experiments towards quantum information with trapped Calcium ions

Ground state cooling and coherent manipulation of ions in an rf-(Paul) trap is the prerequisite for quantum information experiments with trapped ions. With resolved sideband cooling on the optical S1/2 - D5/2 quadrupole transition we have cooled one and two 40Ca+ ions to the ground state of vibration with up to 99.9% probability. With a novel cooling scheme utilizing electromagnetically induced transparency on the S1/2 - P1/2 manifold we have achieved simultaneous ground state cooling of two motional sidebands 1.7 MHz apart. Starting from the motional ground state we have demonstrated coherent quantum state manipulation on the S1/2 - D5/2 quadrupole transition at 729 nm. Up to 30 Rabi oscillations within 1.4 ms have been observed in the motional ground state and in the n=1 Fock state. In the linear quadrupole rf-trap with 700 kHz trap frequency along the symmetry axis (2 MHz in radial direction) the minimum ion spacing is more than 5 micron for up to 4 ions. We are able to cool two ions to the ground state in the trap and individually address the ions with laser pulses through a special optical addressing channel.Comment: Proceedings of the ICAP 2000, Firenz