tomdlgns 0 Posted July 21, 2013 i am looking for a NLOS (non line of sight) transmitter/receiver setup that will send analog video from a field unit to home base where the video system is recording the rest of the cameras on the property that are physically wired in. the field unit is approximately 1200 ft away from home base (that is probably the furthest it would ever be. 90% of the time the field unit will be in direct LOS, but i would like to set it up as a NLOS system, if one exists, just in case the 90 changes to 80%, 75%, etc... what is the best frequency for this? 5.8? 900? i am hoping someone has experience with wifi, on here. Thanks. Share this post Link to post Share on other sites
hardwired 0 Posted July 21, 2013 For full NLOS, you are going to need 900MHz gear. In some cases, I've been able to use 2.4GHz equipment, depending on what the obstruction is (2.4GHz can burn through a reasonable amount of trees at a short distance like what you are describing). I haven't tested any 900MHz analog transmitters, but based on my experiences with other analog wireless gear, I would tend towards using a wireless data link (Ubiquiti NanoStation LocoM9 for 900MHz, or NanoStation M2 for 2.4GHz operation), along with a encoder/decoder pair. I have several similar setups running using Ubiquiti wireless gear, and Acti encoder/decoder pairs. Keep in mind that the 900MHz band is far more prone to interference, especially in urban areas with lots of SCADA / AMR equipment (municipalities are one of the biggest offenders, they commonly take radios designed for use with 3Dbi gain antennas, and put huge, high gain Yagi antennas on them. This severely violates FCC regulations, but no one seems to care). However, at the distances you are considering, that may not present a big issue. One of the advantages with IP based radios is the option to be able to use smaller channel widths to work around interference (the 900MHz band only has four non-overlapping channels at 10 MHz channel width, but the throughput you will need for one camera can fit in a 5MHz channel, giving more options to avoid interference). Share this post Link to post Share on other sites
tomdlgns 0 Posted July 21, 2013 thank you for the reply, but i am looking for this to be all analog, no IP equipment, encoders/decoders, etc... Share this post Link to post Share on other sites
ilk 0 Posted July 22, 2013 thank you for the reply, but i am looking for this to be all analog, no IP equipment, encoders/decoders, etc... Look for COFDM transmission systems Ilkie Share this post Link to post Share on other sites
tomdlgns 0 Posted July 22, 2013 thank you for the reply, but i am looking for this to be all analog, no IP equipment, encoders/decoders, etc... Look for COFDM transmission systems Ilkie have you used any specific model that you recommend? thanks. Share this post Link to post Share on other sites
ilk 0 Posted July 22, 2013 thank you for the reply, but i am looking for this to be all analog, no IP equipment, encoders/decoders, etc... Look for COFDM transmission systems Ilkie have you used any specific model that you recommend? thanks. Ogier Electronics in the UK have a system which we have used transmitting secure CCTV images from/to Police vehicles. It can also be used as body worn or for deployable use. There are others. The technology is an off shoot from the Outside Broadcast TV industry, which means it is professional kit (i.e. very expensive!) Ilkie Share this post Link to post Share on other sites
hiwireless 0 Posted September 11, 2013 COFDM transmission systems frequency from 300MHz to 900MHz is workable. Share this post Link to post Share on other sites
