Why APRS using LoRa? In short, because we can. Experimentation is the primary justification of Amateur Radio. As radio amateurs, within the confines of our international, national and sometimes local regulations, we can improve technology. APRS works well. But it can be drastically improved. LoRa APRS represents the next step forward in evolving APRS. Amateur radio is also an almost ideal solution to the problem of back up emergency communications. Depending on the type of equipment you choose, Amateur Radio radio can be portable, it can provide both short range and long range communication, and it can continue to work even when local infrastructure goes down. LoRa APRS can provide location, weather information and texting over a longer distance than conventional APRS. LoRa APRS is on the same frequency world-wide: 433.775 MHz. Low-cost, consumer off the shelf (COTS) hardware The LoRa Trackers and iGates can be built from readily available consumer off the shelf hardware. Low Power LoRa APRS is low-power. LoRa trackers transmit at 100mW. They can be run with off the shelf 2W amplifiers for a bit more range. Range LoRa is a chirp spread spectrum technology. As a result of this novel modulation having process gain LoRa can receive signals far below the noise floor. Conventional APRS is limited by having to signals above the noise floor. Ten miles is typical in a wooded urban environment. Battery power LoRa APRS trackers require little power and can run for hours on a Li-ion battery Read more here: https://github.com/lora-aprs/LoRa_APRS_Tracker/wiki https://github.com/lora-aprs/LoRa_APRS_Tracker/wiki I'm working on creating and/or translating the documentation into several foreign languages. Let me know what you think. --Konrad Roeder, WA4OSH Bellevue, WA
Here is a map showing LoRa APRS iGates the world over. The site focuses in on your location. Zoom out to see the rest of the world. We need your help for hosting more iGates. http://lora-aprsdirect.sarimesh.net/
There's a February 2016 article on RTL-SDR that suggests that SDRs can be programmed to decode the LoRa protocol. I've not tried it. https://www.rtl-sdr.com/decoding-the-iot-lora-protocol-with-an-rtl-sdr/ Here is a YouTube video that suggests that an SDR can be used with an FPGA to decode the LoRa protocol. (105) LoRa Transceiver with FPGA and SDR - YouTube Also, this related YouTube video was of interest. (105) How To Decode 433Mhz Low Power Devices Using RTL433 And A RTL-SDR Receiver - YouTube IMHO, it's much easier to encode and decode LoRa protocol with a suitable chip. Eg. SX1278 Here are the parameters that you would need: 433.775 MHz SF=12 CR=5 BW=125kHz
Carolyn K6CLS, I just tried to order several of these TTGO ESP32 LoRa OLED V2.0 boards from Amazon to build more iGates. It does not matter what software they come loaded with. What does matter is the operating frequency. Apparently they're temporarily unavailable, so I ordered them from AliExpress instead. Amazon did have these TTGO T-Beam LoRa OLED V1.1 boards. But I ordered these from AliExpress as well Once you have an iGate up and running, you can see all sorts of details about your Tracker's packets on http://aprs.fi Also, this video might interest you:
Did a lot in our Area, now it is "full" of LoRa Take a look to this Video. With this combination of LoRa, you have a great mesh network for emergency communications! He is using the 868 MHz, but it runs of course with the 433MHz version.
Thanks for sharing. I've tried out Mestastic on 915MHz. Meshtastic is OK for low-powered ISM transmissions. There is no ISM band 433.05-433.79MHz in ITU region 2 (North and South America). We only have 902-915MHz here in Region 2 for ISM (shared with Amateur Radio) Meshtastic is encrypted, so I'm not going to run that on 433MHz here.
So you can do APRS with LoRa on 433MHz, right, why not Meshtastic or other "Tools". It´s just another type of modulation and we´re doing experimantal radio stuff. . Anyway, with this ESP32 Boards, we have so any other options as well 73!
I remember getting a presentation on LoRa 10 years ago when Semtech acquired Cycleo, the French company that developed the technology. At the time I wondered if hams in the U.S. would ever take advantage of the serendipitous availability of LoRa parts for 70 cm. Fair to say that Semtech has never gotten the volume of sales from LoRa that they hoped for, but they still seem to be committed to it. For those of us in relatively flat terrain that is filled with 75-foot trees, an inline amp for 2 watts isn't going to accomplish much. Maybe 20 watts.
tr Keep in mind that LoRa has about 15dB of process gain. It can receive signals that are SNR -13dB without problems. That's below the noise level. It really does not need a 20W amp like conventional APRS does. I'm in the Seattle, WA east-side (Kirkland, Bellevue, Redmond) area. We have 90-125ft fir trees and hilly terrain. We have deployed a few iGates in several less than optimal locations. I regularly get 8-10 miles tracking a T-Beam tracker with a 2W antenna into a roof top mag mount antenna on the way to and from my work in Redmond. I've also built a mobile iGate using a T-Beam where the iGate is tethered to either a public WiFi location or to a cellphone. As the location changes, the iGate updates its lat-lon location from the GPS.
