| Summary: | 碩士 === 國立臺北科技大學 === 光電與通訊產業研發碩士專班 === 95 === In this thesis, the author propose and proved that the CATV PON (Passive Optical Network) based transmission network is able to deliver video information which is acquired by the IEEE 802.11b/g technology based wireless monitoring (surveillance) infrastructure. And the surveillance system is used in the community or neighborhood areas.
The IEEE 802.11g standard wireless transmission technology is utilized in the surveillance system, which is operating in the frequency band of 2.4 GHz. In the traffic intersection or in the community or neighborhood areas, the video information is catch by wireless IP cameras first, then compressed with MPEG 4 video compress technology, and using the CATV PON transmit all video information to the center for further monitoring and recording.
The 2.4 GHz band is a so-called “unlicensed band”, therefore, there are interference issues when WLAN hotspot are booming.
In this paper, a multi carrier modulation technique call COFDM (Coded Orthogonal Frequency Division Multiplexing) is used to transmit broadband video information over the air. In order to use the COFDM more efficiently, many experiments, testing and analysis are done for improve wireless coverage and handle transmission characteristics. As CATV PON infrastructure is getting more popular, the surveillance system is able to utilize the unused CATV PON bandwidth for the traffic, community and neighborhood security.
From the results of the experiments, the author proposed wireless digital surveillance system, is using the IEEE 802.11g technology, compress the video information with MPEG 4, and transmit by CATV PON. This is an typical application of converting surveillance video information into IP packets, then delivered by PON for further recording or process. In the experiment, the video information can be delivered up to 20 km by using a single mode fiber without noticeable degradation.
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