Hi there,

LoraWan or Sigfox might be your solution you are looking for. However, note that their data bit rate might be considered to be low for high data rate streams.

You can use short range UHF or VHF transceivers such as CCII01 or CC1200 from texas instrument from TEXAS Instrument and extend its range by using the suitable RF power amplifiers and increasing its sensitivity by by adding an appropriate low noise amplifier. Such transceivers configuration can be used for long distance even for cube satellites with low orbit of 400 km.

Such transceivers can be configured for different carrier frequencies, data rates and modulation techniques. They are basically thought for wireless sensor networks.

Best wishes

I assume you are looking for fixed-point to fixed-point, 10 km data link.

VHF/UHF narrow-band for low-speed (MURS or the equivalent in your country) and Long-range WiFi (2.4 GHz ) for high-speed data link would be suitable. The equipments are cheap and easy to obtain and both allow (in the USA) the use of high-gain directional antenna. The VHF/UHF band will be affected less by bad weather conditions than the 2.4 GHz WiFi.

The key here is to figured out what's allowed (license free) in your country/region.

You may start by hot-wire a pair of hand-held MURS radio (search "MURS radio" at amazon.com).

reference link: "https://en.wikipedia.org/wiki/Multi-Use_Radio_Service;" "https://en.wikipedia.org/wiki/Long-range_Wi-Fi".

For this kind of application, the higher the frequency, the better.

Your antenna height is dictated by the curvature of the earth and the

need to keep the first fresnel zone from the ground.

- Curvature of the earth (2 equal height poles)

h = sqrt(R*R+d*d/4) - R ; (pythagoras)

with R: the curvature of the earth

d : distance between the towers

-> h = 2 m

- first fresnel zone:

h = sqrt(landa*d/4)

1. For 5.7 Ghz : landa = 0.053 , h = 11.5 m

-> the required antenna height for 5.7 Ghz band is the sum of both numbers, so 13.5 m.

-> You can also use other bands, check for yourself.

You need to size antenna gain such that you have enough link budget. It will mean, the lower the frequency, the higher the towers and the larger the antenna. It is also true you can have rain fading, and this is worse for higher frequency.

Best Regards,

Henri.

Dear Edmund Nurellari,

Even I was thinking of using SigFox but I need to interface this module with my sensor so that I can transmit sensor data to the ground station. This interface programming part will be tricky in SigFox, I guess.

Dear Xiao Qing Zhou,

MURS is limited in its power (approx 2 W) and also in modulation formats. I feel long range WiFi will be a better choice but again interfacing it with sensor data could be an issue?

With directional antenna, every 3dB gain is equivalent of doubling the transmission power in the direction. So 2W over 10 km is achievable. The MURS allows FSK modulation for data, you'd need a Modem for hot wiring a handheld MURS radio for experiment.

Assuming your data come out in serial format, you need to design a communication protocol such as a host polling on a set time interval, and the sensor end(s) send back a burst of transmission with a pre-defined data packet structure;

There're MURS data link modules on the market that support serial link. You just need to learn a handful of commands to control the module (modem controls + radio controls such as set channel; turn on receiver; check signal level; read data; turn on transmitter; send data; turn off transmitter etc.).

With WiFi, there also are modules on the market that support serial, but the handling is a bit more complicated for the IP protocol.

For a full featured WiFi connection, you need to choose a platform that has the IP support and/or capable to compile/implement the library code for the module.

Almost all LoRaWAN modules work in 868-900 MHz range. But the unlicensed band in India is 865-867 MHz. Is it possible to configure any LoRaWAN module in this frequency range so that it can be used in India?

Does CC1310 from Texas Instruments support a full duplex communication?