Learn more about LoRa and LoRaWAN from a few questions

Question 1: What is LoRa?

LoRa is the abbreviation of Long Range Radio. From the name, we can see that its feature is long transmission distance. Under the same power consumption conditions, it can transmit farther than other wireless methods, achieving the unity of low power consumption and long distance. Under the same power consumption, it can transmit 3-5 times farther than traditional wireless radio frequency communication. It is a low-power LAN wireless standard created by Semtech Corporation of the United States.

Question 2: What is LoRaWAN?

LoRaWAN (Lora Wide Area Network) is the abbreviation of LoRa wide area Internet of Things, which is a communication protocol based on LoRa technology. It mainly consists of three entities (LoRa terminal, LoRa gateway, LoRa server). If we talk about it by protocol layering, LoRaWAN is the MAC layer and LoRa is the physical layer.

Question 3: What are the advantages of LoRa?

Long distance: Ultra-long transmission distance, using spread spectrum gain, its transmission distance is about three times that of FSK. Especially in indoor and underground environments where ordinary wireless transmission signals are weak, LoRa technology has obvious advantages.

Low power consumption: Although its communication distance can reach 5KM, it still has good energy-saving characteristics.

Free: Unlike NB-IOT introduced in our previous article, LoRa works in the free ISM frequency band, so users can complete the deployment of LoRa network without relying on operators, which is not only faster but also cheaper. This opens a convenient door for ordinary users to use this wireless network.

Question 4: What are the shortcomings of LoRa?

Low transmission rate: Because the communication bandwidth after spread spectrum is narrow, it is generally only suitable for networks with low transmission information volume such as sensors. It is not applicable to applications with high data volume (such as image transmission).

Too much concentration of technology: LoRa technology is too concentrated in Semtech companies, which is not conducive to the development of the industry.

New networks are needed: During the deployment of LoRa, new signal towers, industrial base stations and even portable home gateways need to be built. This is difficult for ordinary users. Therefore, there are basically no projects with millions of connections in the industry.

Question 5: What are the LoRa chips?

Currently, most of the terminal chips that support the LoRa communication technology protocol are launched by Semtech or produced under its authorization. The most mainstream in the industry are SX1276 and SX1278, which have the same packaging and slightly different application circuits. The former is aimed at the European and American markets (frequency band 137-1020MHz), and the latter is aimed at the Chinese market (frequency band 137-525MHz). In addition, SX1262 is also a popular LoRa terminal chip. It is smaller than the above two, supports a frequency band of 150-960MHz, has a higher transmission power, and is chosen by many users.

In addition to the terminal chip, a gateway chip is also required to form LoRaWAN. SX1301 is the LoRa gateway chip launched by Semtech. It has 8 LoRa channels and 1 FSK channel. It can be regarded as FPGA + 8-way LoRa modem. This chip is the core interest module of Semtech. From the data sheet to the software driver to the protocol algorithm, it is not open to the public.

Question 6: What is the difference between LoRa and other wireless communication technologies?

Our common wireless communication methods currently include WiFi, Bluetooth, 2G-GSM, 3G\4G, NB-IOT, ZigBee and common small wireless (sub 1G), etc. The figure below is a classification comparison made by the author based on the relevant characteristics of these wireless communication methods. You can see that LoRa has great advantages in many aspects, such as communication distance and communication cost.

Summarize

Last year, I conducted in-depth research and used LoRa, a communication technology, including its hardware design and software driver. If it is simply used to transmit sensor data, LoRa is a very suitable choice. It is much better than ordinary small wireless devices such as Ti's CC1101, Silicon Labs' SI4432 and SI4463 (I actually found that these products have bugs, and the official has admitted it). If they form LoRaWAN, other small wireless devices are incomparable.

At present, NB-IOT is its most intense competitor. Friends who need to know about NB-IOT can read my previous article. Compared with NB-IOT, although they are not in competition with each other in some segments, they are competing in many common fields. LoRa is closed due to its technology monopoly, unlike NB-IOT which is open. This is undoubtedly undesirable for the huge field of wireless communications.

The competition between LoRa and NB-IOT has just begun. It is still unknown who will become the leader in the IoT communication industry. As users, we are both participants and referees in this competition. I hope they will bring more convenience and surprises to our lives in the future!