With the Internet of Things becoming an unavoidable force in the world of Electronics, it seems this topic can't be discussed without the mention of LoRa™ - the low power, long-range wireless protocol developed by Semtech. LoRa™ gives an incredible performance compared to other competing technologies. Based on spread-spectrum and other technology and other techniques, result in LoRa™ being a robust and reliable technology.
Below are 5 interesting points about LoRa™ and what to know before working with it:
1. Operating in the sub-gigahertz spectrum LoRa™ chips achieve very long distance transmissions with less interference than existing FSK (FM) solutions. LoRa™ does this by using the entire channel bandwidth to broadcast a signal. Instead of operating on a single channel which is often highly populated by traditional FSK frequencies. This makes it incredibly reliable and robust against co-channel noise, and insensitive to frequency offsets caused from the use of low cost crystals in fixed frequency solutions.
2. Prior to sending a message, the LoRa™ transmitter will send out a 'chirp' signal. This is sent to check that the band is free to send the message. Allowing the message to be sent without interference.
Semtech LoRa Preamble (Image from www.link-labs.com)
Once the LoRa™ receiver has picked up the preamble 'chirp' from the transmitter, the end of the preamble is signalled by the 'reverse chirp' which tells the transmitter that is it clear to begin transmission.
3. LoRa™ protocol is the primary layer of the technology - there is also LoRaWAN™. LoRaWAN™ can connect multiple LoRa™ devices into a "network" and allow them to cross-communicate within their group. Due to the long range able to be achieved from LoRa™. This can be a network within a building, a town, nationally or globally. If the transmission needs to travel a long distance, using the LoRaWAN™ it can simply pass the transmission down a 'daisy-chain' of LoRa™ devices until it reaches its intended recipient.
LoRaWAN Diagram (Image taken from www.lora-alliance.org)
4. IoT devices (sensors and smart machines) only need to send small packets of data at regular intervals which makes LoRa™ an ideal solution. Traditional solutions such as Bluetooth or WiFi have added overhead constraints. LoRa™ overcomes these and it does not matter where these devices are located.
5. A number of modules are now available with the Semtech LoRa™ technology built-in, such as our RF-LORA module. These modules are available in various styles to allow long range communication perfect to be utilised in the LoRa™ network. Our RF-LORA and GAMMA modules provide LoRa™ solutions as a low cost LoRa™ engine, or with on-board operating systems providing a straight forward digital/serial interface requiring no knowledge of LoRa™ or even RF design. This offers a simple method of adding wireless communication into a product design.
Click to see RF-LORA RS
Click to see GAMMA-868 RS
Click to see GAMMA-868-SO RS