Abstract:We propose a new WDM-PON architecture using Fabry-Pérot laser diodes (FP-LDs) that are injection-locked by continuous wave (CW) seed light. The modulation characteristics of the CW light injection-locked FP-LD are first investigated. Both uplink and downlink transmissions at 10 Gb/s are experimentally demonstrated using the proposed CW injectionlocked FP-LDs. It is shown that up to 16 laser cavity modes can be selectively injection-locked with side mode suppression ratio larger than 30dB. The effects of the location of FP-LD cavity modes, transmission distance, and injection wavelength detuning on the overall transmission performance are investigated. The possibility of eliminating polarization dependence of the proposed CW injection scheme is also experimentally demonstrated by properly configuring a depolarizer. The deployment cost for the proposed WDM PON is potentially low from the fact that the CW laser sources located at the central office can be shared by many WDMPONs and low-cost FP-LDs are used as light sources for data rates as high as 10 Gb/s.

Large scale path loss measurements in sea port are presented. This investigation is useful before deploying Worldwide Interoperability for Microwave Access (WiMAX) equipments to provide last mile Broadband Wireless Access (BWA) for ships and boats in the sea port. Measurements were carried out at 5.8 GHz. Two-ray model fits measured large scale path loss reasonably well. When the distance is very large, the received signal was found to attenuate at the rate of more than double of that of the free space. The attenuation rate was found to depend on the antenna's height.

We developed a framework for simulating wireless communications in the ocean environment, The framework incorporates three unique maritime features: the wave montion and its effect on wireless transmissions, the ocean surface path loss characteristics, and the mobility pattern of the ships conducting wireless transmissions. We implemented our design in the Qual-Net network simulator. Using the enhanced simulator, we were able to produce simulation results comparible to experimental measurments carried out under similar settings. In addition, we observed the expected communication quality changes as the sea condition worsens in the network simulator. 0-933957-35-1 ©2007 MTS

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We propose a new technique for multiple-wavelength upstream transmission in time division multiplexed-passive optical networks using Fabry-Perot laser diodes (FP-LD) at optical network units (ONU). The FP-LD transmits at one of strategically separated seeding wavelengths from the optical line terminal enabling the ONUs to join one of few TDM upstream channels. The scheme increases upstream capacity without the use of costly, higher speed burst mode transceivers. We present experimental results showing that up to 9 upstream channels at 2.5 Gb/s data rate can be achieved with this scheme. The paper presents locking characteristics of the FP-LD relevant for this application such as suppression of other seeding wavelengths, minimum wavelength separation and burst mode operation.