Introduction to LoRa and Features

[Guide] What is LoRa LoRa? LoRa is a low-power LAN wireless standard created by Semtech. Low power consumption is generally difficult to cover long distances. Long distances generally have high power consumption. It seems that it is impossible to run a horse far without eating grass. LoRa's name is Long Range Radio.

What is LoRa

LoRa is a low-power LAN wireless standard created by Semtech. Semtech develop LoRaWan and a series of LoRa chips. Low power consumption is generally difficult to cover long distances. Long distances generally have high power consumption. It seems that it is impossible to run a horse far without eating grass. The name of LoRa is Long Range Radio. Its biggest feature is that it can spread farther than other wireless methods under the same power consumption. It realizes the unification of low power consumption and long distance. Its distance is 3-5 times larger than that of traditional radio frequency communication under the same power consumption.

Characteristics of LoRa

Transmission distance: 2-5 km in towns and 15 km in suburbs.

Operating frequency: ISM frequency band includes 433, 868, 915 MHZ, etc.

Standard: IEEE 802.15.4g.

Modulation mode: based on spread spectrum technology, a variant of linear modulation spread spectrum (CSS), with forward error correction (FEC) capability, a proprietary technology of semtech.

Capacity: One LoRa gateway can connect thousands of LoRa nodes.

Battery life: up to 10 years.

Security: AES128 encryption.

Transmission rate: hundreds to dozens of Kbps. The lower the rate, the longer the transmission distance. This is much like a person picking things. If you pick more, you can go far.

LoRa and LoRaWan

As can be seen from the above figure, LoRa is a subset of LoRaWan. LoRa only includes the physical layer definition, and LoRaWan also includes the link layer.

This picture shows the network architecture of LoRaWan. On the left is a variety of application sensors, including smart water meters, smart trash cans, logistics tracking, vending machines, etc. On the right is the LoRaWan gateway, which converts the data of the LoRa sensor into TCP/IP format and sends it to the Internet. LoRa gateway is used for long-distance star architecture, which is multi-channel, multi modulation transceiver, and multi-channel simultaneous demodulation. Due to the characteristics of LoRa, multiple signals can be demodulated simultaneously on the same channel. The gateway uses RF devices different from the terminal node, with higher capacity, and acts as a transparent bridge to relay messages between the terminal equipment and the central network server. The gateway is connected to the network server through standard IP connection, and the terminal equipment uses unicast wireless communication message to one or more gateways.

In fact, LoRaWan is not a complete communication protocol, because it only defines the physical layer and the link layer. The network layer and the transport layer do not have such functions as roaming and networking management.