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An autonomous self-healing technique utilizing a self-injection-locked Fabry-Perot laser is proposed for optical and wireless seamless communication systems. The proposed technique is more promising than the other techniques because of its high reliability and simple configuration. It has been experimentally confirmed that the selfhealing technique can be adopted in optical and wireless communication systems with plural wireless back-up links.

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SUMMARYBluetooth is a short-range wireless system using the 2.4-GHz band, but has the problem of degradation of communication quality caused by the noise radiated by microwave ovens which share the same frequency band. In this paper, we theoretically and experimentally study the impact of microwave oven noise on Bluetooth. Time variations in the bit error rate with a fixed channel frequency are theoretically evaluated applying the time domain oven noise model represented by frequency and amplitude modulated wave to the theoretical equation of the bit error probability for frequency shift keying (FSK). The average bit error rate and the average packet error rate with the frequency hopping spread spectrum (FH-SS) scheme are also evaluated. The results of theoretical study show that (1) microwave oven noise using an inverter power supply (inverter-type) degrades average packet error rate more seriously than does a microwave oven not using an inverter power supply (transformer-type), and that (2) FH-SS is less effective in mitigating interference from inverter-type oven noise compared with transformer-type oven noise. Experiments are conducted using Bluetooth terminals. Error rates are measured using actual ovens and oven noise simulator based on the noise model. The effectiveness of the noise model applied in this paper in the evaluation of the Bluetooth transmission characteristics during microwave oven noise interference is demonstrated.