I am trying to plot RF coverage for our 900mhz clusters and I’m running into a problem. I hope some of the other RM users can offer some advice.
I have my pretty SRTM and GTOPO30 map showing our location, but I’m having trouble getting an RF coverage map to display. I defined my network (starting simple with one cluster), set the unit properties, and then attempted to show a single polar RF coverage map.
Unless I define a 2nd unit I won’t get the [Draw] button to become active. There must be a setting I’m missing some where that will allow me to plot the RF coverage from an AP cluster without having to define a slave unit.
Here is a screen shot of my “Units” setup:
Here are the “network properties” screens:
Thanks for any pointers you can offer, it would be much appreciated!
I managed to get some coverage maps using visual coverage instead of Radio coverage. What method are you using to create your maps?
If you are using visual coverage and assuming your AP are set with zero downtilt, would you set the min elevation to -30 deg and the max to 30?
Your first tact was correct. Visual coverage does exactly what it sounds like it does, uses the landform data to calculate “laser line of sight.”
Unless I define a 2nd unit I won’t get the [Draw] button to become active.
That is exactly right. You need to define a subscriber Unit that is a memeber of the same Network as the AP. When you run a singal polar coverage sweep, RM is basically calculating the the RF performance of the AP unit connected to the SM unit at every point in the radial arc you define.
Long story short, you need a SM unit to calculate against.
ahull wrote: Your first tact was correct. Visual coverage does exactly what it sounds like it does, uses the landform data to calculate "laser line of sight."
Unless I define a 2nd unit I won't get the [Draw] button to become active.
That is exactly right. You need to define a subscriber Unit that is a memeber of the same Network as the AP. When you run a singal polar coverage sweep, RM is basically calculating the the RF performance of the AP unit connected to the SM unit at every point in the radial arc you define.
Long story short, you need a SM unit to calculate against.
Thanks for the confirmation Andrew, much appreciated.
I have GPS coorids on most all of my SM's so I should be able to plot single polar coverage as well. It may be more work than it is worth to do the entire network but probably would be helpful for some "questionable" links.
you might want to double check your power levels on your radio systems, they look at little off; I haven’t seen a canopy radio yet that has a power of 1 watt.
ac_babitzke wrote: you might want to double check your power levels on your radio systems, they look at little off; I haven't seen a canopy radio yet that has a power of 1 watt.
I was using what I read in another post where Jerry Richardson was using the following:
Transmit power on the 900AP is 1W and the integrated antenna is 12dB integrated. (EIRP is 4W). Receiver Threshold is -90dB
That post is here:
http://www.cambiumnetworks.com/forum/viewtopic.php?f=1&t=2727&hilit=12dB&sid=cc331bf2b55453f788e6f9da7bdb17de
ac_babitzke wrote: you might want to double check your power levels on your radio systems, they look at little off; I haven't seen a canopy radio yet that has a power of 1 watt.
He's right, but missed the underlying theory.
Assuming you're in the USA, then the FCC limits your EIRP to 4 watts or 36dB. So you should set the power output in the Canopy equipment to 36 db minus the gain of the antenna you are using.
From your screenshot, you are using a 12 dB antenna. Therefore you should limit your power output to 36 - 12 = 24 db. If the power is set higher then 24, you are breaking the law.
Since modeling software is only as accurate as the data you give it, you should match the antenna gain and (pre antenna) power output (and every thing in Radio Mobile, really) as closely as possible.
Hope that's not too confusing,
Andrew
ahull wrote: [quote="ac_babitzke":2gcbb2b9]you might want to double check your power levels on your radio systems, they look at little off; I haven't seen a canopy radio yet that has a power of 1 watt.
He's right, but missed the underlying theory.
Assuming you're in the USA, then the FCC limits your EIRP to 4 watts or 36dB. So you should set the power output in the Canopy equipment to 36 db minus the gain of the antenna you are using.
From your screenshot, you are using a 12 dB antenna. Therefore you should limit your power output to 36 - 12 = 24 db. If the power is set higher then 24, you are breaking the law.
Since modeling software is only as accurate as the data you give it, you should match the antenna gain and (pre antenna) power output (and every thing in Radio Mobile, really) as closely as possible.
Hope that's not too confusing,
Andrew[/quote:2gcbb2b9]
Makes sense. I also took the radiosys.dat file that the other fellow in the preceding radio-mobile post and used that as well.
I'll adjust the power levels to get the proper output, I was so focused on trying to get the single polar map to work I put the rest aside, now that I know the visual coverage is what I'm stuck with (for what I want to do) I can fine tune the settings.
Thanks!
if you need the output ( transmit power on this version ) power levels they are in the canopy systems user guide. They list all of the radio power levels, and yes you do have to be careful what you use for radios and antennas / reflectors as you can easily get over the limits that IC and FCC have passed down.