IMPACT OF INTERFERENCE ON WIRELESS TRANSMISSION
Radio systems for most of us are quite puzzling concept . Under this strange sounding name simply hide devices that use some of the laws of physics to transmit video, audio or data - here just right radio wave propagation . Every law has limitations , which significantly affect the correct operation of the device. When it comes to radio systems produced by CAMSAT we cannot fail to mention the main rule which conditions the proper operation of these systems - the preservation of a clear first Fresnel zone . Fresnel zone is nothing but the area of radio wave propagation , located along the line connecting the transmitter and receiver . Colloquially, we call it the line of sight.
On the market there are available CCTV wireless video transmission kits of all kinds: - analogue , digital , IP and HD video transmission and , what we can proudly emphasize, each kind can be found in CAMSAT`s offer. Each of these types of devices operates on license free radio frequency 5GHz - allocated to us by the European Union - which supplanted earlier available , but currently very heavily used 2.4GHz band .
There are many factors that affect the correct operation of wireless audio/video transmission equipment. In the following text, we will try to present the most common types of interference and simple ways to eliminate them.
Exchange to good quality, system requirements matching, stabilized or transformer PSU, will restore proper operation of wireless devices .
At the beginning of the article we already mentioned the main law conditioning proper operation of radio systems – line of sight. Every obstacle - be it a tree , a building , resulting from urbanization mains – has a significant impact on wireless systems malfunction, interfering with the free radio waves propagation. The previously noted analogue devices (an example could be the device from CAM5816 or TCO5807 series ) require absolutely clear first Fresnel zone , but a very simple way to solve such problem is to repeat the signal using an additional kit in point which " sees " optically first and last site.
Digital devices from CDS5021 or CDS - 5IP series thanks to OFDM modulation and multi-antenna transmission are able to cope with the obstacle. Take into account the fact, that every obstacle absorbs a significant part of radio signal , what has a significant impact on declared by manufacturer operation range of the system. Another advantage of digital devices , which allows for correct image transmission and potential anomalies elimination is high resistance to industrial interference or interference from other wireless networks or mains and this trait should have influence on your choice of this series when it comes to industrial areas and dense urban development.
Digital video transmission exceeds in a certain degree analogue devices , especially when it comes to IP series , there is a possibility to scan the radio spectrum and to obtain information on unoccupied by another user frequency. This feature eliminates interference before it occurs , we can avoid interference from any other wireless network in our area of interest prior to installation of equipment.
The continuous development of the security sector entails an increase not only the number of monitored objects , but also the number of cameras , largely SAMSUNG , installed on many of them. Increasingly, customers are looking for wireless solutions, attempt to alleviate not only the costs but also the workload related to traditional cable . Number of cameras and the desire to solve image transmission over radio involves the use of a large amount of wireless transmission systems. Often this amount requires the use of analogue ( CAM5816 series ) and digital systems (CDS series).
Analog microwave systems due to their structure are sensitive to other radio devices , particularly ones that are located near its transmitter , and the specificity of digital kits is to have the transmitting antenna on transmitter and receiver side, for feedback between devices . Exactly this feature till recent past, was affecting the appearance of interference at installs with a large number of cameras and numerous fortifications associated with distance of radio masts from each other. This was the main cause of installers problems.
Now, after introduction of the improved version of CDS series - with an additional driver - the problem of mutual interference can be easily eliminated by choosing radio systems tailored to the installation conditions - CDS5021 (STR ).
Analysis of several of the above examples leads us to the conclusion that most of the disturbances affecting the correct operation of wireless radio transmission systems can be easily eliminated , as long as you follow the rules in this wireless world. If anyone of you, our clients , encounters similar problem , we are here to help. Please contact us.
Małgorzata Ruszewska, CAMSAT