8 A] With a neat diagram explain the deployment and communication architecture of LoRa.
• LoRa or long range is a patented wireless technology for communication developed by Cycleo of Grenoble, France for cellular-type communications aimed at providing connectivity to M2M and IoT solutions.
• It is a sub-GHz wireless technology that operationally uses the 169 MHz, 433 MHz, 868 MHz, and 915 MHz frequency bands for communication.
• LoRa uses bi-directional communication links symmetrically and a spread spectrum with a 125 kHz wideband for operating.
• Applications such as electric grid monitoring are typically suited for utilizing LoRa for communications.
• Typical communication of LoRa devices ranges from 15 to 20 km, with support for millions of devices.
• LoRa achieves high receiver sensitivity by utilizing frequency-modulated chirp coding gain.
• LoRa devices provide excellent support for mobility, which makes them very useful for applications such as asset tracking and asset management.
• In comparison with similar technologies such as NB-IoT, LoRa devices have significantly higher battery lives, but these devices have low data rates (27 to 50 kbps) and longer latency times.
• LoRa devices make use of a network referred to as LoRaWAN, which enables the routing of messages between end nodes and the destination via a LoRaWAN gateway.
• Unlike Sigfox, LoRaWAN has a broader spectrum resulting in interference, which is solved using coding gains of the chirp signals. Additionally, unlike Sigfox LoRaWAN end nodes and the base stations are quite inexpensive.
• The LoRaWAN protocol is designed for WAN communications and is an architecture that makes use of LoRa, whereas LoRa is used as an enabling technology for a wide area network.
• Messages transmitted over LoRaWAN is received by all base stations in proximity to the device, which induces message redundancy in the network. However, this enhances the resilience of the network by ensuring more messages are successfully delivered between entities in the network.
A LoRa network follows the star topology and is made up of four crucial entities: end points/nodes, gateways, network server, and a remote computer (Figure 4.21).
The end nodes deal with all the sensing and control solutions. The gateways forward messages from end nodes to a backhaul network. The LoRa network can comprise both or either of wired and wireless technologies. The gateways themselves are connected to the network server utilizing IP-based connections (either private or public).
The LoRa network server is responsible for scheduling message acknowledgments, modifying data rates, and removing message redundancies. Finally, the remote computers have control over the end nodes and act as data sinks for data originating from these nodes.
The LoRa network security is achieved through various mechanisms such as unique network key, which ensures security on the network level, unique application key, which ensures an end-to-end security on the application level and device specific key.