Home/Support/Support Forum/Why am i getting Very less LOS range for Xbee 802.15.4 RF Module?

Why am i getting Very less LOS range for Xbee 802.15.4 RF Module?

0 votes
I am using Xbees' with part no XB24-AWI-001. One Xbee was connected to an Arduino powered by battery and the other Xbee to laptop though Sparkfun Xplorer board.

I started losing packets once the LOS distance between the two Xbee exceeded 12 m. The standard LOS range should be near to 90m for Xbee 802.15.4.

Is there any setting which i need to configure in the Xbee for getting the standard range.
asked Feb 22, 2016 in IEEE 802.15.4 by Ajith New to the Community (4 points)

Please log in or register to answer this question.

1 Answer

0 votes
How high are the antennas for both radios above all obstructions?
answered Feb 22, 2016 by mvut Veteran of the Digi Community (11,302 points)
Both are Whip Antennas and they are 2cm above all obstructions.
2cm above obstructions is Not LOS.  That is Non RF LOS conditions in which case your range will be very limited. I would suggest reading over http://knowledge.digi.com/articles/Knowledge_Base_Article/Maximizing-range/?q=maximizing+range&l=en_US&fs=Search&pn=1 to help you get a better understanding as to why.
Thank you for referring to that wonderful article.

Still is there any additional settings in Xbee which we can configure to increase Transmitter power ,Receiver sensitivity and antenna gain.
No, the output power and receiver sensitivity are at the maximum values by default. The only setting that you can adjust is the output power which as I have stated is at the highest by default.

You do not have the ability to increase antenna gain on the module you have chosen. You would need to use one of the external antenna options to be able to do that.  Even then, at the antenna height you are at, you would need to add at least 12dB of additional antenna gain to your existing system to double what range you are currently getting. Instead, if you were to simply raise the antenna a few meters above the obstructions, you would see your range skyrocket with the existing antennas.
But default Xbee comes with antenna of small height. Like Whip antenna is about 2cm approx. Then what do you mean when you say we must raise the antenna a few meters above all obstructions. Even when the Xbee is above all obstruction the antenna height will still be 2cm.

Forgetting LOS range, our range is still poor ie 12m, considering that indoor range mentioned in datasheet is about 30m.
The wire whip antenna should be about 1 1/4" long and should be perpendicular to the top of the XBee module.

The antenna height I am referring to is that in this case, the radio would need to be mounted so that the antenna is pointed up and that the radio is above all obstructions.

The indoor range is an Up To distance and is greatly dependent upon what is located between the two antennas. The more obstructions, the more walls or even the type of walls will greatly reduce the range.
...