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Long Range

 

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Do you need more range?

Does up to 1/2 mile through buildings and other urban obstacles sound enough? What about up to 40 miles line-of-sight with high-gain antennas? Both of these distances, with everything shorter and in between, are made possible by Digi's 9XTend® 900 MHz wireless OEM modules.

The laws of physics prevent 2.4 GHz communications from transmitting as far as 900 MHz communications. However, you can still reach up to 3 miles line-of-sight using half-wave antennas with Digi 24XStream™ 2.4 GHz wireless OEM modules.

How is this done?

The high-performance range properties of Digi's wireless OEM modules are achieved by proprietary RF technology coupled with excellent receiver sensitivity properties.

Why does sensitivity matter?

Simply put, the more sensitive your RF solution is to receiving RF transmissions, the farther you can place your device from the transmitter site. In fact every -6 dB of receive sensitivity doubles your range in line-of-sight conditions (-10dB in urban environments). The industry's wireless OEM module averages for receive sensitivity are merely -96 dB to -90 dB for 900 MHz and 2.4 GHz communications, respectively.

At -110 dBm for 900 MHz and -104 dBm for 2.4 GHz Digi dominates the competition, providing over 4 times the range of the industry averages!

Most of our competitors try to increase range by boosting output power. Digi 100 milliWatt wireless OEM modules outperform most 1 Watt solutions while only using 1/10th the power. Portable product designers love the low power and long range provided by Digi products.

RF transmission range

RF transmission range is all about how many dB of fade margin are present in the system. The difference between 1 Watt and 1/10th Watt is 10dB (30dBm vs. 20dBm). Digi wireless OEM modules can detect signals as low as -110dBm, most of our competitors' equipment can only detect signals with a level of -93 dBm on average.

To translate:
Digi transmits 10 dB less power but the receiver can detect 17 dB weaker signals so we out-perform the average competitor by 7 dB. That translates into Digi modules having 2x more range than many 1 Watt transmitters!

Calculating fade margin

Transmit power to antenna + transmit antenna gain + receive antenna gain
- the receive sensitivity - path loss = Fade margin

Competitor example

(900 MHz 100 mW wireless OEM module)
Fade margin of a wireless connection where 20 dBm of transmit power is emitted to a yagi antenna with 6 dBi gain, and the signal received by a 6dBi gain yagi antenna connected to a receiver with -90 dBm receive sensitivity with a total path loss of 150 dB, equals

20 dBm transmit power + 6 dBi yagi + 6 dBi yagi
- (-90 dBm receive sensitivity) - 150 dB path loss = 17 dB fade margin

Same example using Digi

( 9XStreamâ„¢ 900 MHz 100 mW wireless OEM modules )

20 dBm transmit power + 6 dBi yagi + 6 dBi yagi
- (-110 dBm receive sensitivity) - 150 dB path loss = 37 dB fade margin

That is a whopping 20 dB difference in fade margin. With every -6 dB of receive sensitivity doubling your range, the Digi solution has a range over 8 times longer than the example competitor's solution.

Digi has over 8 times the range in this example!

 

 

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