Our awareness of the LoRaWAN technology is the key to the developments & innovations in the field. This ensures the way forward to a Smart & Secure future. Let us dive into why LoRaWAN technology is trending & drifting all of us to a higher level. LoRa is basically an RF wireless modulation technique & essentially a way of manipulating radio frequency waves with Chirp Spread Spectrum (CSS) technology. It encodes information similar to the way dolphins and bats communicate! LoRa-modulated transmission is robust against disturbances and can be received across great distances. Therefore, the main advantages of LoRa are its long-range capability and its affordability. For example, a general use case for LoRa in industrial space and smart cities, where low-powered and inexpensive internet of things devices (typically sensors or monitors) spread across a large area sends small packets of data sporadically to a central administrator. These are not alarming words but are essential to be familiar with. The feasibility & flexibility of the technology depends on some factors, illustrated below:
Spreading Factor (SF) The chirp spread spectrum technology uses so-called “chirps”. The spreading factor (SF) determines the speed of a chirp. In general terms, the amount of spreading code applied to the original data signal is termed the “Spreading Factor”. A lower spreading factor means faster chirps & therefore higher data transmission rate at the same bandwidth & time. And a high SF means a broadcast has a higher range, at the cost of increased power consumption. Lower SF means more chirps are sent per second; hence, you can encode more data per second. Higher SF implies fewer chirps per second; hence, there are fewer data to encode per second. Compared to lower SF, sending the same amount of data with higher SF needs more transmission time, known as airtime (Time On Air). LoRa modulation has a total of 6 spreading factors from SF7 to SF12 and it influences the data rate, time on air, battery life & receiver sensitivity. The below table shows how spreading factors affects the receiver sensitivity.
Data Rate (Spreading Factor)
Sensitivity
Time On Air
SF7
-123.0 dBm
41 ms
SF8
-126.0 dBm
72 ms
SF9
-129.0 dBm
144 ms
SF10
-132.0 dBm
288 ms
SF11
-134.5 dBm
577 ms
SF12
-137.0 dBm
991 ms
Larger spreading factors mean larger processing gain, and so a signal modulated with a larger spreading factor can be received with fewer errors compared to a signal with a lower spreading factor, and therefore travel a longer distance. It uses unlicensed ISM (Industrial, Scientific, Medical) radio bands for network deployments. From a security point of view, an end device can connect to a network with LoRaWAN in two ways:
Over-the-air Activation (OTAA): A device has to establish a network key and an application session key to connect with the network.
Activation by Personalization (ABP): A device is hard coded with keys needed to communicate with the network, making for a less secure but easier connection.
Hence, concluding that LoRaWAN benefits are undeniable in today’s IoT landscape.
