Telecommunication Network for IoT devices: Sigfox, LoRa and CAT M1

IoT devices are being used for monitoring, tracking and controlling several systems now everywhere. When it comes to Machine to Machine (M2M) communication using constrained IoT devices, power consumption is a big deal. Most of the constrained devices do not have direct power connection and they are operated using battery power. Using standard high power consuming networks (3G, 4G, Wifi ) for communication with these devices is not feasible in this case. To operate IoT devices there are several separate networks are used now a days. Sigfox, LoRa and CAT M1 are these type of networks. Each of them has their strength and weaknesses. Telstra has launched country wide CAT M1 network recently which can put a big impact in Australia to expand the IoT networks.

LoRa is a spread-spectrum technology with a wider band (usually 125 kHz or more). Its frequency-modulated chirp utilizes coding gain for increased receiver sensitivity. However, because it's looking for a very specific type of communication, the elevate noise due to a larger receiver bandwidth is mitigated by the coding gains.

French company Sigfox also has a wide coverage in Australia (Recently I participated a IoT Challenge completion using Sigfox network and the project won the prize as well. Competition projects link : https://www.hackster.io/contests/sigfoxuniversities/projects , My project link: https://www.hackster.io/zaidul/forest-sense-get-the-heartbeat-of-the-forest-1a2d7d ). Sigfox is a narrowband (or ultra-narrowband) technology. It uses a standard radio transmission method called binary phase-shift keying (BPSK), and it takes very narrow chunks of spectrum and changes the phase of the carrier radio wave to encode the data. This allows the receiver to only listen in a tiny slice of spectrum, which mitigates the effect of noise. It requires an inexpensive endpoint radio and a more sophisticated basestation to manage the network. Sigfox communication tends to be better if it’s headed up from the endpoint to the basestation. It has bidirectional functionality, but its capacity going from the basestation back to the endpoint is constrained, and you’ll have less link budget going down than going up. This is because the receiver sensitivity on the endpoint is not as good as on the expensive basestation. Sigfox Network coverage can be checked from the below link: https://www.sigfox.com/en/coverage

Category M1 (Cat M1) is a technology that functions on a 1.4 MHz (reduced from 20 MHz) spectrum, has a transmit power of 20Bm, and provides average upload speeds between 200kpbs and 400 kpbs. This technology can extend battery life, potentially by up to 10 years. Cat M1 is important because it extends LTE’s market reach. By allowing LTE to cost-effectively support lower data-rate applications, Cat M1 is being touted as a good fit for low-power sensing and monitoring devices such as health and fitness wearables, utility meters, and vending machines, among many others. Telstra launched their CAT M1 network recently and their CAT M1 network coverage can be found from the below link: https://www.telstra.com.au/business-enterprise/solutions/internet-of-things/iot-coverage

While uses of IoT devices are increasing now a days, a widespread, power efficient and reliable telecommunication network will be required to add all these devices. We can expect, more companies will come to this market with new efficient technologies as a competitor of Sigfox, LoRa and CAT M1 in coming days. 

References:

1. https://www.link-labs.com/blog/sigfox-vs-lora

2. https://dzone.com/articles/what-is-quotcat-m1quot-and-what-does-it-mean-for-i

3. https://www.zdnet.com/article/telstra-turns-on-cat-m1-for-4gx-network/