Detailed LoRa Networking

　　Detailed LoRa Networking

　　 LoRa is the physical layer or wireless modulation used to establish long-distance communication links. Many traditional wireless systems use frequency shift keying (FSK) modulation as the physical layer because it is a very effective modulation for low power consumption. LoRa is defined by Semtech as a physical layer modulation method, which is a wide area network communication technology based on unlicensed spectrum. Semtech controls LoRa's most important intellectual property rights, chips are almost monopolized, and the LoRa Alliance has been established.

　　How does LoRa achieve low power consumption

　　 We know that distance and power consumption are a natural contradiction in communication systems. When the transmission power drops, the propagation distance must be close. So how does LoRa solve this contradiction? The fundamental reason is that LoRa improves the sensitivity of the receiver, so that it has a super link budget and does not require high transmit power.

　　LoRa technology

　　 LoRa receiver sensitivity is due to direct sequence spread spectrum technology. LoRa uses a high spreading factor to obtain a higher signal gain. Generally, the signal-to-noise ratio of FSK needs 8dB, while LoRa only needs -20dB.

　　 In addition, LoRa also applies forward error correction coding technology to add redundancy to the transmission information to effectively resist multipath fading. Although some transmission efficiency is sacrificed, the transmission reliability is effectively improved. After all, LoRa does not require a high transmission rate.

　　 LoRa network detailed explanation

　　 LoRa network is mainly composed of terminals (with built-in LoRa modules), gateways (or base stations), network servers and application servers. Application data can be transmitted in both directions.

　　LoRa networking

　　 The LoRaWAN network architecture is a typical star topology. In this network architecture, the LoRa gateway is a transparent transmission relay, connecting terminal devices and the back-end central server. The terminal device uses a single hop to communicate with one or more gateways. All nodes communicate with the gateway in both directions.