[Imported] Unlicensed Radio Frequencies: 2.4ghz frequency spectrum for long range wireless

[sbeadle]

>>Message imported from previous forum - Category:Trio Data Radios<<
User: joelw, originally posted: 2018-10-16 21:17:50 Id:23
This is a re-posting from the obsoleted (October 2018) "Schneider Electric Telemetry & SCADA" forum.

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**_nestbulala:
We have about 66 sites utilizing FM frequency spectrum and are being charged by the government tremendous amount every year for every channel. We are using three (3) channels and we are planning to replace it with unlicensed frequencies using the 2.4 Ghz. One of our site is communicating full duplex with one repeater for 64 sites separated about 1.5 to 15 kms apart. We are planning to replace these with Trio radios with RS232 port and will be connected to ScadaPACK controllers.
One site communicating half duplex about 35 kms apart. We are planning to use Trio radios on RS232 port and will be connected to ScadaPACK ER. We will be utilizing the existing installation except the antenna which might be replaced for incompatibility. These installation is located about 120 kms outside of Riyadh, Saudi Arabia. My question is there any effect on the country's WIFI Communication?_**

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jweder:
The 2.4Ghz ISM band is available in Saudi Arabia. However to the best of our knowledge it is NOT license free when used with products such as ours. The only license free type applications would be WiFi. Even with a license the max. permitted Tx power is 100mW. (20dBm) The Saudi regulatory body is called CITC. They should be consulted before beginning a project of this sort.

There are two issues which arise in this case. First, you will need to find out if the 2.4 GHz ISM band license is cheaper than the license you're currently paying for. Second, it must be understood that 2.4 GHz at 100 mW transmit power is not normally suitable for long range paths. (eg 15 km)

Only if very tall towers are used will you have much hope of 2.4 GHz reaching this far. And other users of the band, such as WiFi, may cause interference stronger than the desired signals if the path is in an urban area.

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**_nestbulala:
Thanks for the information. Therefore we could not get away from paying the license. However, we will just upgrade our radio to a faster transfer rate say 115 kbps. What would be your best recommendations. We are using 5 watts for up to 15 kms and about 10 watts for 35 kms. We were using the FSk format. Can we replace it with RS 232 and connected directly to ScadaPackER? Again, many thanks._**

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jweder:
Unfortunately Control Microsystems does not sell a radio that will match your needs in this case. We do sell 450MHz licensed radios that transmit at 5 watts. (or optionally 20 watts in the 19" rack-mount base station version) But the maximum data rate is 19k2.

We do sell a serial spread-spectrum radio that can do up to 256kbps but it is limited in range, as noted in the discussions above.