LoRa / LoRaWAN
LoRa (an abbreviation for Long Range) is a wireless communication technology based on spread spectrum modulation techniques derived from chirp spread spectrum (CSS) technology while LoRaWAN defines the media access (MAC) protocol (open networking protocol) and the system architecture for a wide area network. Transmission takes place in the license-free sub-gig ISM bands. Long range is achievable thanks to a correlation mechanism based on band spreading methods. This mechanism allows even extremely small signals disappearing in the noise, to be successfully de-modulated by the receiver. LoRa signals are Highly Robust, Multipath / Fading Resistant, and Doppler Resistant and enable an enhanced network capacity as orthogonal spreading factors enable multiple transmissions with different data rates at the same time and on the same channel. Ideal to manage high capacity demand. The LoRaWAN network architecture is deployed in a star-of-stars topology in which gateways relay messages between end-devices and a central network server.
LoRaWAN® system overview (source: LoRa Alliance)
Bluetooth Low Energy (Bluetooth LE, colloquially BLE, formerly marketed as Bluetooth Smart) is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group (Bluetooth SIG). Compared to Classic Bluetooth, Bluetooth Low Energy is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range. Bluetooth Low Energy technology operates in the same spectrum range (the 2.400–2.4835 GHz ISM band) as classic Bluetooth technology, but uses a different set of channels. Instead of the classic Bluetooth 79 1-MHz channels, Bluetooth Low Energy has 40 2-MHz channels. Within a channel, data is transmitted using Gaussian frequency shift modulation, similar to classic Bluetooth's Basic Rate scheme. The bit rate is 1 Mbit/s (with an option of 2 Mbit/s in Bluetooth 5), and the maximum transmit power is 10 mW (100 mW in Bluetooth 5).
Wirepas is another key wireless connectivity software which focuses more on applications where a mesh network is necessary. The wirepas software runs on any radio hardware. The logic is de-centralized, with all intelligence sitting over the device.With the multi-hop feature integrated and the possibility of multiple gateways without subnets, Wirepass finds its use in applications where there is a need for scalability and a large network. The connectivity layer has built-in 128-bit AES security, suggesting Wirepass to be a good fit in IOT implementations in the near future. Wirepass provides for a throughput of 150 packets per second with a 102 byte payload, providing communication latencies as low as 10 seconds. As Wirepas has been developed by an independent private company, the user faces a per unit license payment with no recurring fees on the connectivity front. The main advantages of Wirepas are: scalability, reliability and low latency . While including all the above parameters, the ideal application for Wirepas is smart city solutions which includes smart meters, smart lighting and smart waste management. Wirepas also might find its way into agricultural IoT implementations where there is a need for low power and scalability in terms of number of devices and area coverage.
NB-IoT technology has seen a recent push from telecom operators across the globe, with its coverage spreading over the map at a rising pace. There are three methods NB-IoT operates through:
• On an independent spectrum
• On unused 200kHz band that were previously used by GSM networks and
• LTE base stations with an additional network block for NB-IoT operations.
The main advantages of NB-IoT are in terms of power and coverage. NB-IoT provides for deeper building penetration through higher bit rates and process gain-improvements. NB-IoT devices are also very power-light as they are usually in the sleep mode while the devices are not operating. However, there are a challenges with regards to NB-IoT.
There is a lot of innovation happening everyday in the field of IoT. Newer technologies are rendering many older ones obsolete. However, a few of these are showing great potential of shaping the future. The technologies discussed in this post are some such technologies. Each of them has unique characteristics which make them suitable for specific requirements. LoRa can be used for implementations where small amounts of data are required at a low periodicity from devices which are located far away from the central gateway. BLE 5 is good for implementing a variety of use cases including mesh, connectable and non-connectable profiles. The ability to change the roles of devices allows for a dynamic architecture where a device can carry out high data rate transfers on detecting some event, thus enabling dynamic power profiles. Wirepas is a proprietary software which uses the 2.4 GHz radio, similar to BLE. It is promoted as a very robust technology with a self-healing network that has the capability to send large amounts of data over a mesh network. The licensing can be a limitation for users looking at keeping a low capex. NB-IoT offers all the advantages of a cellular network with very low power consumption. However, the advantage of low power consumption can be lost if the architecture is not designed properly. Also, the opex involves the cost of subscription paid to the cellular operator. With the complexity of IoT systems increasing, a combination of all of the above technologies might be required for a successful implementation. Check out CASCADEMIC’s IIoT gateway, which can support various combinations of communication technologies in a single device.