There are a lot of things to unbox while exploring the LoRaWAN technology. Each and every part is crucial & exciting to know more about. The LoRaWAN Gateway is one of them, which communicates over multi-channels with multi-spreading factors.
A gateway typically refers to the physical box or encasement housing the hardware and application software that performs essential tasks to connect IoT devices to the cloud. IoT devices use a gateway as a central hub to drop sensed knowledge and connect that data to external networks hence also termed a “Data Concentrator”.
A gateway is much like a Wi-Fi router. It has a LoRa concentrator, which allows it to receive RF signals sent out by LoRaWAN devices, which get converted to a signal compatible with a server, such as Wi-Fi, to send data to the cloud.
With this technique, end devices simultaneously communicate with the gateway using different channels and data rates without pre-negotiation, enabling the gateway to accommodate about 10,000 end-devices simultaneously. However, in the multi-data rate channel mode, the gateway is limited to a 125 kHz bandwidth with eight channels, even if the maximum bandwidth of LoRa is 500 kHz.
The IP traffic from a gateway to the network server can be backhauled via Wi-Fi, hardwired Ethernet, or a Cellular connection. LoRaWAN gateways operate entirely at the physical layer and, in essence, are nothing but LoRa radio message forwarders.
For LoRaWAN downlinks, a gateway executes transmission requests coming from the LNS without any interpretation of the payload. Since multiple gateways can receive the same LoRa RF message from a single end device, the LNS performs data de-duplication and deletes all copies. Based on the RSSI levels of the identical messages, the network server typically selects the gateway that received the message with the best RSSI when transmitting a downlink message because that gateway is the one closest to the end device in question.
