No abstract

Low-coherence interferometric measurement has been used to investigate optical waveguide devices with high accuracy. By utilizing an incoherent light source, one can generate separate interferogram features for each optical path. The distance between adjacent features of a ring resonator is related to ring length. With small ring radius, the interferogram spectrum exhibits severe cross-interference between adjacent features that hinders one to analyze the optical path individually. We propose a novel technique to overcome the light-source bandwidth limitation by signal-processing technique, which allows one to characterize small radius micro-ring resonator. This technique has been applied to both numerical simulations and experimental data with significant improvement of the extracted ring parameters. The improvements allow one to better understand the wavelength dependency properties of small radius micro-ring resonators.

No abstract

In this paper, we focus on IEEE 802.11e enhanced distributed channel access (EDCA) protocol, which can provide QoS guarantee for multimedia applications in mobile ad hoc networks. First, we briefly explain the concept of EDCA protocol. Then we implement EDCA protocol in GloMoSim via configuring special contention parameters for multimedia applications and introducing a virtual collision disposal mechanism in the MAC layer. In the end, we provide performance analysis for EDCA protocol through plentiful simulations. The simulation results show an excellent performance of the EDCA protocol we proposed.