GNURadio is an open-source software for making Software Defined Radio. It can be used to model a radio transmission or the process a real radio communication.
Scapy is a python tool set able to interact with GNURadio. Basically GNURadio will receive an signal from a SDR key and process it to get a digital sequence. Scapy will process this sequence and potentially generate a new sequence to be process by GNURadio to be transmitted.
There are plenty of example of GNURadio/Scappy usage to hack, simulate, learn many radio protocols like WiFi, GSM, Bluetooth… I want to play a little with Sigfox also so that’s why I started to investigate on this tool.
As this tool is a bit complicated, this post details the key element having helped me to getting started with this tool.
After making LoRaWan test in a city environment, I make some test in a rural environment with the objective of evaluating the capability for being used in connected farming environment.
The result is really like what we have got in a city, eventually better in a way as the antenna position was on altitude. The following map makes with 6kbps communication shows the coverage. You can see that the coverage is really limited on the Eastern direction. This is due to higher mountains this way. Mountain are the main limiting elements and as you can see, even on short distance communication they are blocking any signal.
In a try to connect my LoRa gateway to a standard backend, I started to install TheThingsNetwork software stack. Even if I did not finish it because it was not compatible to my gateway protocol, here are my starting notes … May be completed later.
After spending some time reading and writing about LoRa it was a good time to make some real test of this technology.
As actually there is no network for LoRa, as much as I know, in my town, I expected to start a simple LoRa test (point to point and not as part of a WAN). I just bought some RN2483 LoRa module from Microchip online and also get some from Avnet (thank you Guillaume)
The module is easy to solder on a prototype board and get its command over a serial port. I choose to make two modules :
The first one is connected to a FTDI cable and will stay at home as a basestation
The second one is connected to an Arduino and will be a mobile device for my test
Telecom Design LAN capability is a 9600bps rf 868 transmission you can use with the sigfox modem to communicate between multiple TD120x devices. One of the main use is to have multiple sensors communicating to a sigfox gateway. The communication get benefit of the nice ultra narrow band RF transceiver included in the chip.
TD LAN is based on GFSK modulation on 25kHz channels working at 9600bps.
I did really remember where but I read it could reach long distance in the best conditions, so as it could open many opportunities, I wanted to test it in real conditions to see what we could get from it.
If you want to create a company like infrastruture on Azure you could expect to create a VPN to have a secured access to it and have an internal lan to protect you servers against external access. Basically the system provides all that you need but, as usual in the closed world of MicroSoft. The VPN server based on SSTP protocol sound hard and not documented to be used with MacOsX or Linux.
I’ll describe in this post how I fixed this issue par using an OpenVpn gateway server.
Internet is providing more and more bandwidth to transfer files and files are bigger and bigger. One thing is not changing, it is latency as distance still the same over the time. When a protocol requires acknowledgment between blocks of transfer this latency is limiting the throughput like explained in this post.
The throughput is really different depending on the protocol in use to transfer the file. As I did not found something giving a lot of data to compare the existing protocol, i’ll try to get figures myself and detail here.