WIRELESS MONITORING SYSTEM FOR VIDEO DETECTION IN OPTICAL NETWORK
Optical network can provide high quality streaming video, video conferencing and video telephone over one single fiber. The problem always happen in optical network is line break. Several types of breaks usually occur in underground cables. This paper focused on developing wireless monitoring system to detect video signal in optical network. The video signal can be used to monitor the optical lines to ensure the customer always receive video channel 24 hours. This system consists of optical video detector, wireless module and software interface for displaying the video signal of optical lines. The hardware and software of this system have been analyzed. The research shows that the system can monitor the video signal on all lines and send the monitoring data to central office over wireless.
Keywords: wireless monitoring, video detection, optical network.
The cable-TV operators were determined to exploit the advantages of fiber in the network . This is because fiber has unlimited bandwidth, high quality service, future-proof and superior reliability and security. Fiber optics technology has the most bandwidth capacity. It can easily provide gigabit bandwidth. And this unlimited capacity can go both downstream and upstream. This high capacity for upstream transmission is what no other broadband technology can offer. Fiber optics can provide very high bandwidth both downstream and upstream . There are unlimited possibilities for the future, for example, telecommuting or distance education.
The problem always happen in optical network is line break. Several types of breaks can also occur in underground cables. Accidental digging by construction crews is a frequent problem. Fires in manholes, or nearby, often cause cable damage, resulting in loss of service. Other cable cuts can also be the result of vandalism. In some countries, underground fiber cables even get stolen by mistake by people who want to melt the copper and sell it.
Fiber cable breaks and degradations are really one of the main causes of network service disruptions . In order to ensure continuous service delivery to customers, we develop a system that can determine the line status by monitoring the video signal in optical network .
MATERIALS AND METHODS
This system involves WDM Coupler 1310/1480/1550nm and 90/10 fused coupler. WDM functions to split optical signals according to their respective wavelength with 1310nm for data and voice signal and 1550nm for video signal. After these signals have been separated, output 1480nm will pass through WDM demultiplexer while 1550nm signal will pass through fused couple. WDM coupler has a very low loss, high quality and is small in size .
Optical coupler is used to split 1550nm signal in accordance to a specific ratio. There are coupler with ratio of 95:5, 90:10 and 50:50. It is important to select the right coupler. For coupler with splitting ratio of 50:50, only 50% of the signal will be fed back into the trunk line. This implies that the resent signal power will be weakened and causing limited distance of transmission. Based on the matched characteristics of the coupler to the system, we choose coupler with splitting ratio of 90:10.
Optical video detector
Optical video detector is used to detect video signal in optical network. This system consists of video signal receiver, RF to video converter and video to 1-bit signal converter. Video signal receiver can convert optical signal to RF signal. The signal coming from optical coupler is sent to video signal receiver. Video signal receiver has function to convert the optical signal to RF signal. RF to video converter is used to convert the RF signal to video signal. Video signal must be convert it to logic signal for data monitoring.
To transmit and receive monitoring data from optical network to the Central Office, we use XBee-PRO RF module. XBee-PRO RF Modules were engineered to meet IEEE 802.15.4 standards and support the unique needs of low-cost, low-power wireless sensor networks. The modules require minimal power and provide reliable delivery of data between devices. The modules operate within the ISM 2.4 GHz frequency band and are pin-for-pin compatible with each other .
Graphical User Interface (GUI)
Visual Basic is an ideal programming language for developing sophisticated professional applications for Microsoft Windows. It makes use of Graphical User Interface for creating robust and powerful applications. The Graphical User Interface as the name suggests, uses illustrations for text, which enable users to interact with an application. This feature makes it easier to comprehend things in a quicker and easier way .
RESULTS AND DISCUSSION
Figure 2(a) shows the output of optical video detector in which no video signal is received by video receiver. In this condition, optical video detector outputs 0 volt (logic 0). Figure 2(b) shows the output of optical detector where there is video signal in optical network. In this condition, optical video detector outputs 3.3 volt (logic 1). Figure 2(c) shows a transient response of video signal into a logic signal.
This paper successfully developed a wireless monitoring system for video detection in optical network and that allows engineer at central office to monitor the video signal via wireless. This system can give information to engineer which line is failure. Then the engineer can take action for restoration and troubleshooting to ensure the customer can enjoy video channel again.
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