Protocol or rules to measure resources of spectrum

[proy1_10]

Anyone have a protocol to measure frequency bands dedicated to digital radiolinks?

As you know spectrum is saturated (@6-7GHz) and i would like to know before to propose a channel if this channel is occupied. Also to know procedures as measure C/N, C/No, C/I,...

Anyone can help me? Thanks in advance

[byja]

First of all, do you have a regulatory body (government agency) that deals with spectrum allocation, permits for radio links, etc.? If you do have it, then the task of determing which channels are available for a proposed radio link is theirs, and not yours.
Second, what exactly do you want to measure, and what will you accomplish by it? If you simply want to see if channel is available, do a site survey, bring a wideband horn antenna, or a 0.3 dish for planned band and a spectrum analyzer and see if you're picking up anything in the desired angle ±20° for both vertical and horizontal. If you're ok with it for both frequencies and both locations, guess you can use that channel.
You don't need to measure C/N, you know what signal level you can expect based on calculations. Noise is kTB + NF.
C/I you don't measure directly. Instead you can measure CINR. Shut off transmission on other side, and measure your interference+noise. Subtract noise + noise factor and you get interference alone. Turn on transmission, and measure signal level (it's probably dominant, so there's no need for any subtractions).
Like I said, be a more specific about what you exactly want, and you might get a more detailed answer.

[proy1_10]

No doubt, there is a Government Agency. But sometimes, we can propose a sub-band as preferred (material re-used, spares working in same sub-band,etc...). So ideally, sometimes we need to define areas where material is practically the same.

As you say, we only need to know if a channel is available (free) or not, to group free sub-bands from geographic areas (to have similar material in the same zone) and propose these bands to Government.

I would like to know how to characterize a Microwave signal to measure it in a Spectrum Analyzer. I think, there are signals occuping 28 MHz, 54 MHz and everyone have different properties respect to others, but how to measure every signal respect to noise?... (i.e. signal BW28MHz, configuration in Spectrum Analyzer: SPAN=XX MHz, Resolution BW=XX Hz Video BW=XX kHz,...)

If you want, keep posting...

Thank you for your reply, Byja.
BR

[byja]

No doubt, there is a Government Agency.

Great, then let them deal with available frequencies and internetwork interference. The only problem left to you is intranetwork interference.


But sometimes, we can propose a sub-band as preferred (material re-used, spares working in same sub-band,etc...). So ideally, sometimes we need to define areas where material is practically the same.I know, it is a problem. Fortunately, I don't work with Siemens eq. anymore, so I don't have to bother with subbands, specific channel ODUs and etc. For me, one XCVR covers the whole band, one IDU chasis for almost every radio configuration, one radio interface unit for every bandwidth and modulation, etc... :)


I would like to know how to characterize a Microwave signal to measure it in a Spectrum Analyzer. I think, there are signals occuping 28 MHz, 54 MHz and everyone have different properties respect to others, but how to measure every signal respect to noise?... (i.e. signal BW28MHz, configuration in Spectrum Analyzer: SPAN=XX MHz, Resolution BW=XX Hz Video BW=XX kHz,...) There are even more channel spacings (channel bandwidths) than those mentioned, as well as different modulation and coding types.
But what I'm really interested in is what exactly are you trying to accomplish?
There are two types of measurements/tests. First one is performed on the very site (location), and it's mostly basic measurement, like presence of radios operating in desired band, etc.
Second type of measurement is verification testing. For the equipment you plan to use there are documents issued by the manufacturer that state tons and tons of typical and guaranteed characteristics. Unless the client or some sort of government agency requires you to do it, I don't see the reason why you should measure such things. Just go with the characteristics that are stated in technical description.
However, if that's what you want, I can be of a help. Last three weeks I've been doing verification testing of our Evolution series of radio terminals. We measured following:
1. output power
2. received threshold level
3. power consumption
4. normal operation within guaranteed voltage range
5. RF spectrum mask compliance
6. channel bandwidth
7. spurious emission
8. cochannel interference sensitivity (for likewise interferer only)
9. adjacent channel interference sensitivity (same)
10. Tx and Rx frequency accuracy
11. RSSI
12. traffic measurements

...and many more, varying voltage of power supply over the entire range, as well as exposing ODUs to nominal (+25C), minimum (-33C) and maximum (+50C) temperatures.

A good start for measurements are ETSI specifications, freely available on their website. EN 302 217 family of specifications is probably the most important one.

[proy1_10]

Thank you very much!
I'm a newby and you're a real expert. I can't disturb you, so before ask, I need to read tons and tons of documents. I have downloaded ETSI document (A first step, to walk a large route...).
I'm really interested in your work.
BR

[byja]

I have some sort of protocol for measurement of radio characteristics, but it's in Serbian, and I don't have much time to translate it.
Instead, if there's anything specific you need help, ask and I'll help you out as much as I can.

[proy1_10]

Maybe Mr. magic google can translate it. If you can send me original docs...

Thank you for your interest, Byja.

BR

[proy1_10]

Sorry admin double post

[Cost_Reducer]

in this doc. Hope this is helpfull:p

[yudi_tnd]

hi Cost_Reducer....
I'm interesting on your attachment, but got difficulties to download it.
Could you send your attachment to my email ??

Thanks
yudi_tnd@yahoo.com

[anhakeem]

thanks Cost_Reducer for posting but how to download attachment

[tt1dks]

in this doc. Hope this is helpfull:p
please upload to other place like Rapidshare or MediaFire because I can not get it here.
Thanks

[nieckyz]

what a great post..
but I got the problem to dowload it..
please share with rapidshare, please.
thanks very much..

[anhakeem]

I think jest click on thanks in the corner left in Cost_Reducer post

[Cost_Reducer]

.... i read this post to late.
Here (http://www.4shared.com/file/91985393/82ee2c7b/Frequency_Survey_Sets.html) you can download this doc

please feel free to contact me if you have any Q`s....