I came to know that India's Ministry of Communication has assigned the 865-867 MHz band for radio frequency devices.
http://www.rfidjournal.com/articles/view?1703
Most of the RF devices in India operates on 2.4GHz frequency even though the range is major concern. The frequency is inversely proportion to distance, so range get shorted if go for 2.4Ghz.
I started searching on internet for any existing provider which have a solution of my application particular on RF band 865-867Mhz and result was no one exist. Finally, I decided to design and started looking for available option for RF transceiver which can support RF band 865-867Mhz and my search was end at Microchip. I finalized the RF chip MRF89XA and MiWiPro stack and started work on that and got success in communication between transceiver. Nowhere any accurate data available for range covered by this module even i had many mail correspondence with microchip support but no fruitful result. After some toughed experiment in field, got range data covered by MRF89XA chip.
So, I published here that data which i got during my testing and you can trust on that.
Consider Parameter:
Tx Power : +12.5 dbm
LNA gain : -13.5 dbm
Data rate : 40kbps
Results for clear RF LOS Horizontal ------------------------------------------------------------------------------------------------------
PAN coordinator (Node-1) Coordinator (Node -2 )
Received Signal Strength Received Signal Strength
100m 150m 200m 250m 300m 100m 150m 200m 250m 300m
1F 21 1B 1D Connection Fail 20 1E 18 0F Connection Fail
1E 21 1D 1B 21 1F 18 14
1D 21 19 1A 1C 1E 16 18
1F 23 19 1D 1E 20 18 17
1D 1F 1B 1E 1E 1E 14 18
Note: All RSSI results are in HEX Value
Results shows that the distance increase beyond 250 meter, connection gets broken.
http://www.rfidjournal.com/articles/view?1703
Most of the RF devices in India operates on 2.4GHz frequency even though the range is major concern. The frequency is inversely proportion to distance, so range get shorted if go for 2.4Ghz.
I started searching on internet for any existing provider which have a solution of my application particular on RF band 865-867Mhz and result was no one exist. Finally, I decided to design and started looking for available option for RF transceiver which can support RF band 865-867Mhz and my search was end at Microchip. I finalized the RF chip MRF89XA and MiWiPro stack and started work on that and got success in communication between transceiver. Nowhere any accurate data available for range covered by this module even i had many mail correspondence with microchip support but no fruitful result. After some toughed experiment in field, got range data covered by MRF89XA chip.
So, I published here that data which i got during my testing and you can trust on that.
Consider Parameter:
Tx Power : +12.5 dbm
LNA gain : -13.5 dbm
Data rate : 40kbps
Results for clear RF LOS Horizontal ------------------------------------------------------------------------------------------------------
PAN coordinator (Node-1) Coordinator (Node -2 )
Received Signal Strength Received Signal Strength
100m 150m 200m 250m 300m 100m 150m 200m 250m 300m
1F 21 1B 1D Connection Fail 20 1E 18 0F Connection Fail
1E 21 1D 1B 21 1F 18 14
1D 21 19 1A 1C 1E 16 18
1F 23 19 1D 1E 20 18 17
1D 1F 1B 1E 1E 1E 14 18
Note: All RSSI results are in HEX Value
Results shows that the distance increase beyond 250 meter, connection gets broken.
HI Saurabh,
ReplyDeleteI am using the same RF module, with following stetting are:
Consider Parameter:
Tx Power : +10 dbm
LNA gain : 0 dbm
Data rate : 10kbps
Here the application is string current monitoring in Solar farm.
Basically i am using microchip proprietary mesh stack, but in solar farm many obstacles will be there in the path of wireless module such string of panels, groung levels, etc..
Because of that i am not seeing even 40m range, but in normal testing keeping LOS maximium range i obtained was 80 to 90 meters.
My question is how to increase the range? And how did you get more than 200metres of range with same mrf89xa RF module?
Datasheet itself says that maximum range is up to 120 meters..
In my study as you decrease the bit rate will get more range that's why i kept it as 10kbps and tx power as 10 db.