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"Those things" about LoRa, how many LoRa terminal devices do you know?
What is lora? LoRa must be familiar to everyone. It is an ultra-long-distance wireless transmission scheme based on spread spectrum technology developed by Semtech in the United States. Due to its unique modulation method,bluetooth Wireless Module it has low power consumption, long distance and high flexibility. , so the name "LoRa" (Long Range, meaning long distance). At present, LoRa devices mainly operate in the global free frequency bands, including 433, 868, 915 MHz and so on.
In addition, we also need to understand the concepts related to lora. Today we will talk about LoRa's "those things." LoRa modulation technology LoRa is a modulation technology from a technical point of view. Compared with similar technologies, Provide longer communication distance. LoRa modulation is based on spread spectrum technology, a variant of linear modulation spread spectrum (CSS), with forward error correction (FEC). LoRa significantly improves receiver sensitivity and, like other spread spectrum techniques, uses the entire channel bandwidth to broadcast a signal, making it more robust to channel noise and insensitivity to frequency offsets due to the use of low-cost crystals. LoRa can modulate the signal 19.5dB below the noise floor, while most frequency shift keying (FSK) requires a signal power of 8-10dB above the noise floor to be correctly modulated.
LoRa modulation is a physical layer (PHY) that can be used for different protocols and different network architectures - Mesh ad hoc network, Star, point-to-point transmission, etc. The difference between LoRa and LoRaWAN is that LoRa modulation is PHY, and LoRaWAN is MAC protocol, which is used for high-capacity, long-distance and low-power star network. The LoRa Alliance is standardizing WiFi Wireless Module Low Power Wide Area Network (LPWAN). The LoRaWAN protocol is optimized for low-power, battery-powered sensors, including different levels of end nodes to optimize the balance between network latency and battery life. The LoRaWAN protocol is fully bidirectional, built by security experts to ensure reliability and security. The LoRaWAN architecture also easily locates moving objects for asset tracking, the fastest growing application in the IoT. Major telecom operators are deploying LoRaWAN as a nationwide network, and the LoRa Alliance is standardizing LoRaWAN to ensure that different national networks are interoperable.
LoRa Gateway LoRa Gateway is designed for long-distance star architecture and used in LoRaWAN system, multi-channel, multi-modulation transceiver, multi-channel demodulation at the same time, due to the characteristics of LoRa, it can even demodulate multiple signals on the same channel at the same time. The LoRa gateway uses RF devices different from terminal nodes, has higher capacity, and acts as a transparent bridge to relay messages between terminal devices and central network servers. LoRa gateways are connected to network servers through standard IP connections, and LoRa end devices use single-hop wireless communication to one or more gateways. The communication of all terminal nodes is generally two-way, but it also supports multicast function operations, software upgrades, wireless transmission or other mass release of messages, which reduces the wireless communication time. Depending on the required capacity and the installation location (home or tower), there are different gateway versions. LoRa Concentrator The terms LoRa Gateway and LoRa Concentrator are both used, but they are equivalent components in a LoRa system. In other industries, the definitions of gateway and concentrator mean different components.
LoRa Anti-interference Capability The LoRa modem can suppress co-channel GMSK interference up to 19.5dB, or in other words, it can accept a signal 19.5dB lower than the interference signal or the noise floor. Because of such strong anti-interference, the LoRaTM modulation system can not only be used in frequency bands with high spectrum utilization, but also in mixed communication networks to expand coverage when the original modulation scheme in the network fails. LoRa's data rate LoRaWAN defines a specific set of data rates, but the end chip or PHY can have multiple options. The SX1272 chip supports data rates from 0.3 to 37.5kbps, and the SX1276 chip supports 0.018 to 37.5kbps. LoRa End Node A LoRa End Node is the part of the LoRa network that performs sensing or control. They are battery powered at a distance. These end nodes establish communication with LoRa gateways (concentrators or base stations) using the LoRaWAN network protocol. LoRa Adaptive Data Rate (ADR) ADR is a method that changes the actual data rate to ensure reliable packet delivery, optimal network performance, and capacity scaling. For example, nodes closer to the gateway use higher data rates (reducing transmission time) and lower output power. Only nodes at the very edge of the link budget use the lowest data rate and maximum output power.
The ADR method can adapt to changes in the network infrastructure and support varying path losses. In order to maximize the battery life of end devices and the overall network capacity, the LoRa network infrastructure manages the data rate and RF output of each end device individually by implementing ADR. LoRa has quickly been recognized by the market due to its low power consumption, long-distance and high flexibility. Many representative products of Ebyte are based on LoRa spread spectrum technology. In order to further reduce costs, Ebyte also launched A new generation of LoRa solution, more cost-effective, welcome new and old friends to buy!
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