Intro
I am Goran, and I am playing with LoRa for some time...
I decided to buy and build one lora gateway so people around my house can use it (that includes me)
I have done this succesfully and spread the word about magic LoRa in my makerspace Radiona.
Other members asked is it posible to test LoRa without spending days in car in front of my house.
Members asked!
Radiona delivers!!!
But first things first...
What is LoRa.
LoRa
LoRa is technology used for LPWAN Low Power Wide Area Network
LoRa is IP block that describes modulation LoRa PHY
Lora is Proprietary modulation :(
LoRa is using chirp spread spectrum
(helps to get signal from noise better).
A chirp is a signal in which the frequency increases (up-chirp)
or decreases (down-chirp) with time.
LoRa works great in a noisy environment
Long range Great battery life
Low transmit power (25mW) Consumption (40mA TX, 10mA RX) In sleep, chip is using under 1uA
Main LoRa Advantages
Low data rate
Air time limits
Main LoRa Disadvantages
Nodes (or single chanel gateway)
SX Chips from Semtech for different frequencies
EU uses 868MHz Band SX1276(433Mhz option with SX1278)
Gateway SX1301/SX1308 for gateway
Can receive 8 bands at the same time
Has better sensitivity then node chips
SX1301 -40*C - great sensitivity
SX1308 0*C - less sensitive in receiving
Chips are SPI controlled
LoRaWAN
LoRaWAN is a media access control (MAC) protocol for wide area networks. It is designed to allow low-powered devices to communicate with Internet-connected applications over the long range wireless connections.
https://stackforce.github.io/LoRaMac-doc/group___l_o_r_a_m_a_c.html
868MHz has Airtime limits
868MHz is a license-free band :)
125kHz bandwidth
Check gr-LoRa on git
Time spendt on air depends of SF and message lenght
LoRaWAN Protocol is supporting 3 classes
Class A
Sends msg - opens RX1 - waits for msg - opens RX2 - waits for msg - go to sleep
Class B
Sends and receives in adjusted time slots
Class C
Sends msg - opens RX1 - waits for msg - opens RX2 - waits for msg
Sends back message on same frequency, message has arrived RX1, or on special frequency RX2
Gateway has same airtime limits as the node - ( downlink depends on band )
Two way for node to attach to a network
Two keys, one for network server and one for data (application)
OTAA
Handshaking
Device sends request
Gateway calculates the session key
Node calculates session keys
Note that no key is sent by node nor by gw
Gateway sends accept (settings) encrypted with new keys
ABP
Authorisation by personalisation
You just set the session key on both sides
(keys never change so it is less secure)
Gateway is just Forwarder just forwarding messages
NODE <> Network
Packet forwarder - runs on gateway
Network architecture
Complete opensource solution on your servers
Gateway bridge broker
Network server broker
Application server broker
or use TTN - https://www.thethingsnetwork.org/ v3 should be
easier to deploy on your servers
Remember LoRa is all about compromise
LoRa is not for a lot of data, and not for time-critical data
Think a byte, not Kilobyte!
TTNZagreb by radiona (SmartZG)
Radiona had two LoRa workshops for now:
- Build your GW
- All about nodes - mapping the city
Our newest gateway by: Prizma
Coverage of our gateways
Our LoRa distance records
Zagreb - Karlovac - 54.5km - SF8
Zagreb - Maribot - 74.2km - SF12
Use cases
- IRNAS has few great ones
- Count penguins
- power on - take pic - OpenCV count penguins - lora send no of penguins - power off
- Pit stop for turtles
- Trap for poachers
- Smart birdhouse
- Intrudes alarm in distant house - or boat...
- Public scale
- Pager
- GPS for pets
- Polution detector
- If something bad detected send a warning
- Agriculture
- Distant plant soil moisture
So many other
Warning:
Do not put your GW near a working chimney
...text ...text
...text ...text
Thank you!
http://radiona.org/wiki/project/lora_gateway
http://radiona.org/wiki/project/lora_nodes
http://lemilica.com
https://ttnmapper.org/
https://www.thethingsnetwork.org/community/zagreb/
http://irnas.eu/