LoRa and LoRaWAN
Why LoRa and LoRaWAN ?
LoRa stands for Long Range and it is a radio system. The wave form of LoRa, its frequency makes it ideal for sending and receiving short messages, just as notification, using extreme low power signals, that is because LoRa operates below the 1Ghz band (Each region or country will define the band, see yours here), that means below the noise line, so nothing can cause interference (less process needed, less power consumption). It is a narrow band system and it is not useful for broadcasting pictures or videos. Sigfox is a similar technology but it has a limitation that makes it not suitable for Big Cat Brother however it could be useful for other use cases where larger windows between messages is acceptable.
Besides the low power consumption, LoRa is a great technology due to its flexibility and the use of unlicensed frequency bands. Depending on what you are willing to do, LoRa can be used for sending some messages or more complex schemes to deploy over the air updates for your devices. Needless to say, the infrastructure needed to create a solution around LoRa can be near to zero. LoRa has evolved a lot during the last years, a huge community was built around it and the technology itself shifted from being just another radio transceiver to a complete stack of software that is called LoRaWAN.
I won’t give the details yet about the use of LoRa in the context of Big Cat Brother but what I am going to say is that BCB uses both configurations, this allows to keep the OpEx (the cost of operating the system) quite low which is very important to implement this kind of projects were funds are really hard to get.
If you read about the high-level description of Big Cat Brother then you know that it is composed of several types of intelligent and autonomous devices, they communicate between each other using a scheme called LoRa Mesh. Most implementation of LoRa Mesh are proprietary, like mine, it is hard to find a Standardized Mesh configuration. The basic idea is that messages captured by one device can be forwarded until it reaches the intended listener. Most BCB devices are based on GPS enabled boards running RTOS (Real Time Operating Systems) and that is a key point to play with time division frames. This communication scheme is great to synchronize devices, there is a special device called BCB Regional Core that is responsible for maintaining things they way they should be, for instance, every device on a particular region could be at a higher level of attention when a given situation is suspected to be happening.
While the former description is great for device to device communications, BCB is also built to interact with the outer world, that means that some information needs to be communicated outside the secrecy of BCB devices. A good example of that is the need to alert park rangers that an ongoing situation is really happening.
Technology without its context is useless, concepts are important and they can have a very different meaning in different scenarios, for instance, if a BCB device is suspected to be broken, it could mean that a poacher broke it and that is a “business” event, not just a technical failure. Many IoT application monitor equipment failures and report them to the technical staff on a device status console (A typical use of LoRaWAN), when you are dealing with crimes against nature most things acquire a different meaning and require different actions.
To add LoRa capabilities to a device you will need to integrate some LoRa or LoRaWAN compliant module, there are several companies providing these modules, Semtech (The inventors of LoRa), Microchip and many others. See here a description of the module BCB devices are using. There are some already made Hats, Add-ons or shields that will provide LoRa connectivity to your device, it is not necessary to start building your own circuits.
As almost any communication technology, you can use low level commands to set up things (such as configuring the module as a simple radio for sending a number of bytes) or high level APIs to send and receive messages like mqtt and others. If you decide to go the LoRaWAN way some additional infrastructure will be needed, like Gateways. Gateways are provided by operators and there are a few open source Gateway implementations you can use too.
I will be covering the details soon.