Expected range in Xbee Pro S1

Wireless & IoT
1

Hi, I’ve tested the range of a couple of Xbee Pro S1 today. In the datasheet, it’s said that the Xbee Pro has a range (outdoors and in line of sight conditions) up to 1600 meters, however I’ve only achieved to send data without losing any packet at 70m. At 100m I receive data but I lose a 15% of the sent packets, and at 150m I lose almost every packet.

Is that normal? I guess I won’t have a range up to 1.5km but I expected to have at least around 300m. ¿Am I doing anything wrong?

More details. I’m using the Xbee version with the wire antenna. What comes to the configuration, I’ve only changed the baudrate to 57600. The rest is the default configuration (point to point connection…). I’m powering my xbees with my laptop through FTDI Basic Breakout (https://www.sparkfun.com/products/9716).

For my tests I’m not using any software. I’m just sending 36 byte length packets and then I’m checking how much of them arrive without errors to the other Xbee.

Thanks in advance

2

What setting is in the power register? More than likely, it defaults to a lower power setting and you will get limited range.

Quote from the product’s comments:

You can use a utility like XCTU from Digi to check(and set) if your module is set to work at max power or not.

3

If you mean the Power Level (PL) setting, it’s set up to highest by default.

What range do you think I should get with the wire antennas?

The only thing that I think I could have done better is to power my Xbee with a battery and a switching regulator instead of the FDTI adapter but I didn’t have a battery at that moment. Maybe my laptop or the FDTI adapter can’t source all the current that the Xbee needs or maybe the power signal isn’t continuous at all and there’s some noise… Anyway, has anyone tested the Xbee range through my conditions?

Thanks

4

PabloAG:
Hi, I’ve tested the range of a couple of Xbee Pro S1 today. In the datasheet, it’s said that the Xbee Pro has a range (outdoors and in line of sight conditions) up to 1600 meters, however I’ve only achieved to send data without losing any packet at 70m. At 100m I receive data but I lose a 15% of the sent packets, and at 150m I lose almost every packet.

Is that normal? I guess I won’t have a range up to 1.5km but I expected to have at least around 300m. ¿Am I doing anything wrong?

More details. I’m using the Xbee version with the wire antenna. What comes to the configuration, I’ve only changed the baudrate to 57600. The rest is the default configuration (point to point connection…). I’m powering my xbees with my laptop through FTDI Basic Breakout (https://www.sparkfun.com/products/9716).

For my tests I’m not using any software. I’m just sending 36 byte length packets and then I’m checking how much of them arrive without errors to the other Xbee.

Thanks in advance

That's the 2.4GHz XBee S1, we assume.

Range is all about (1) line of sight and lack thereof; (2) antenna gain at each device; (3) transmitter power; (4) given IEEE 802.15.4’s fixed modulation mode and channel width largely determine receiver sensitivity; (5) transmitter power; (6) frequency which is given at 2.4GHz. With the Xbee, the baud rate choice does not affect the RF - that’s fixed by 802.15.4.

Antenna gain: such as omni vs. yagi vs. dish. At the extreme, a dish on a chimney in clear line of sight to a like-kind, can provide a few miles. The XBee S1 Pro with a little on-board wire antenna, if elevated and line of sight - about 1000-2000m. It’s all about antenna gain. Xbees have an option for an RP-SMA connector to which you can attach a variety of types of antennas.

In line of sight, you need higher elevation as the “Fresnel zone” applies. Imagine a football shaped object between the two antennas. At the middle of the path, this zone can hit the earth or terrain, buildings, trees, even with elevated antennas. That attenuates. In clear line of sight, earth curvature affects things with high gain antennas to achieve a long path.

There are tools to calculated all this, called RF link budget tools. One is a simple spreadsheet I often use. Others are on line.

The unknown is the amount of non-line-of-sight and the specifics therein.

You should have the XBee setup with ACKs enabled. That’s a config item. If so, there will be retransmissions for possible error correction. You should receive zero frames with errored bits/bytes because there is a CRC check. If retransmission fails to correct (weak signal/interference), you should see a lost packet, not an errored bit.