What is LoRa® modulation?
LoRa ™ (Long Range acronym) is a modulation technique devised by Semtech that guarantees long-range communications that are competitive with today's technologies. The modulation is based on spread-spectrum techniques and on the frequency variation (chirp) of the spectrum, with correction of FEC errors. LoRa® significantly improves receiver sensitivity and like other spread-spectrum modulation techniques uses the entire channel band to broadcast a signal; this makes it robust to noise and insensitive to frequency offsets caused by the use of internal oscillators in low-priced devices. LoRa ™ can demodulate signals with power up to -19.5 dB while many FSK systems (frequency shift keying) need a power of at least 8-10 dB to be correctly demodulated. LoRa modulation is the physical layer (PHY) that can be implemented on different network topologies and protocols such as Mesh, Star, 6lowPAN, etc.
What is a LoRa® gateway or concentrator?
LoRa ™ gateways or concentrators are designed to be used in star and long-range network architectures and are used in LoRaWAN ™ systems. They are multimodem and multichannel transceivers that can demodulate multiple channels simultaneously or multiple signals on the same channel, due to the properties of LoRa® modulation.
What is LoRaWAN ™?
LoRa® modulation is the physical layer (PHY), while LoRAWAN ™ is the MAC protocol that guarantees high channel capacity of the star and long range networks that the LoRa Alliance has standardized as a Low Power Wide Area Network (LPWAN). The LoRaWAN ™ protocol is optimized to use sensors with reduced battery consumption and includes different classes of end points depending on the need to favor network latency rather than battery life. It is entirely bidirectional and has been designed by security experts to ensure reliability and protection. The LoRaWAN ™ architecture has also been designed to locate and follow mobile data tracking objects, which is one of the fastest steps in the Internet of Things (IoT) applications.
For LoRa® devices, what is the current transmit power that can be achieved with the antenna?
The output power from the device pin is + 20dBm but that of the antenna, after filtering and matching becomes + 19dBm + /? 0.5 dB.
Is LoRa a mesh network, a point-to-point or a star network?
LoRa modulation is the physical layer so it can be used in multiple network topologies. A mesh network increases the spatial extent of the network but reduces capacity, increases synchronization overhead and lowers battery life due to synchronization between network nodes. Thanks to the characteristics of LoRa modulation, a mesh topology is not necessary to increase the range of users, so a star network is sufficient. The LoRaWAN protocol was chosen to optimize capacity, battery life and ease of installation.
What are the differences between the SX1272 transceiver and the SX1276?
The SX1272 has three programmable LoRa bandwidths: 500 kHz, 250 kHz and 125 kHz. It covers only the 850 MHz to 1GHz band. The SX1276 has 500 kHz to 7.8 kHz bandwidths and offers slightly higher reception sensitivity. It covers the bands 150 MHz, 433 MHz and 0.85-1 GHz
LORA Module from RadioControlli ----> RC-SM1276-868
Module LONG RANGE
Radio Modem LONG RANGE IoT Application