——Question 1: What is LoRa——
LoRa is the abbreviation of Long Range Radio. It can be seen from the name that its characteristic is that it has a long transmission distance. Under the same power consumption condition, it has a longer transmission distance than other wireless methods, realizing the unification of low power consumption and long distance. Under the same power consumption condition, it is 3 to 5 times longer than the traditional wireless radio communication distance. It is a low-power LAN wireless standard created by Semtech Company of the United States.
– Question 2: What is LoRaWAN? –
LoRaWAN (Lora Wide Area Network) is a communication protocol based on LoRa technology. It is mainly composed of three entities (LoRa terminal, LoRa gateway and LoRa server). If LoRaWAN is the MAC layer according to protocol hierarchy, LoRa is the physical layer.
– Question 3: What are the advantages of LoRa? –
Long distance: ultra long transmission distance, with spread spectrum gain, whose transmission distance is about three times of FSK. In particular, LoRa technology has obvious advantages in indoor and underground environments where the wireless transmission signal is weak.
Low power consumption: Although its communication distance can reach 5km, it still has good energy-saving characteristics.
Free: Different from the NB-IOT described in our last article, LoRa works in the free ISM band, and users can complete LoRa network deployment without relying on the operator, which is not only faster but also cheaper. This opens a convenient door for ordinary users to use the wireless network.
– Question 3: What are the disadvantages 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 such as sensors. It is not applicable to applications with high data volume (such as image transmission).
Technology concentration: LoRa technology is too concentrated in semtech. It is not conducive to the development of the industry.
New network is required: During LoRa deployment, new signal towers, industrial base stations and even portable home gateways are required. This is difficult for ordinary users. Therefore, there are almost no projects with millions of connections in the industry.
– Question 4: What are LoRa chips? –
At present, most of the terminal chips supporting LoRa communication technology protocols are launched by or licensed by Semtech. The most mainstream in the industry is SX1276 and SX1278. The packages of the two are the same, and the application circuits are slightly different. The former is oriented to the European and American markets (frequency band 137-1020MHz), while the latter is oriented to the Chinese market (frequency band 137-525MHz). In addition, SX1262 is also a popular LoRa terminal chip. Its size is smaller than the above two models. It supports a frequency band of 150-960MHz and has higher transmission power, which is chosen by many users.
In addition to terminal chips, if you want to form LoRaWAN, you also need gateway chips. SX1301 is the LoRa gateway chip launched by Semtech. It has eight LoRa channels and one FSK channel. It can be seen as FPGA+8-way LoRa modem. This chip is a core interest module of Semtech. From data manuals to software drivers to protocol algorithms, it is not disclosed.
– Question 5: LoRa and other wireless –
——What is the difference between communication technology——
At present, our common wireless communication methods include WiFi, Bluetooth, 2G-GSM, 3G 4G, NB IOT, ZigBee and common small wireless (sub 1G). The following figure is the classification and comparison of the author according to the relevant characteristics of these wireless communication modes. We can see that LoRa has great advantages in many aspects, such as communication distance and communication cost.
| Wireless technology | distance | rate | energy consumption | Laying cost | Communication cost | Adapt to occasions |
| LoRa | Extremely far | slow | low | low | Free Admission | Internet of Things |
| WiFi | short | Extremely fast | Extremely high | low | Free Admission | Home Network |
| Bluetooth | Extremely short | commonly | Extremely low | low | Free Admission | Intelligent hardware |
| 2G-GSM | far | commonly | high | high | charge | Call Internet |
| 3G/4G | far | fast | high | high | charge | Call Internet |
| NB-IOT | Far away | slow | low | high | charge | Internet of Things |
| ZigBee | short | Very ordinary | low | low | Free Admission | Networking equipment |
| Other small wireless | far | slow | low | low | Free Admission | Outdoor sensor |
——Summary——
Last year, the author made in-depth research and used LoRa, a communication technology, including its hardware design and software driver. LoRa is a very suitable choice if it is simply used to transmit sensor data, which is much better than ordinary small wireless devices, such as Ti’s CC1101, SI4432 and SI4463 in the core laboratory (I unexpectedly found that there is a bug in this product, which has been officially recognized). If LoRaWAN is composed, other small wireless networks are incomparable.
At present, NB-IOT is more competitive than NB-IOT. Friends who need to know NB-IOT can see my last article. Compared with NB-IOT, although they do not compete in some segments, they compete in many common fields. LoRa Because the monopoly of its technology has led to its blocking, rather than the openness of NB-IOT, this is undoubtedly not pleasing to the huge field of wireless communication.
The competition between LoRa and NB-IOT has just begun, and it is still unknown who will become the leader of the Internet of Things communication industry in the end. As users, we are the participants and judges of this competition. I hope they will bring more convenience and surprises to our life in the future!