Configure subbands and filtering capabilities of your LoRaWAN gateways

LoRaWAN gateways run a LoRa Basics Station software that enables the gateways to connect to AWS IoT Core for LoRaWAN. To connect to AWS IoT Core for LoRaWAN, your LoRa gateway first queries the CUPS server for the LNS endpoint, and then establishes a WebSockets data connection with that endpoint. After the connection is established, uplink and downlink frames can be exchanged through that connection.

Filtering of LoRa data frames received by gateway

After your LoRaWAN gateway establishes a connection to the endpoint, AWS IoT Core for LoRaWAN responds with a router_config message that specifies a set of parameters for the LoRa gateway's configuration, including filtering parameters NetID and JoinEui. For more information about router_config and how a connection is established with the LoRaWAN Network Server (LNS), see LNS protocol.

{
"msgtype"    : "router_config"
"NetID"      : [ INT, .. ]
"JoinEui"    : [ [INT,INT], .. ] // ranges: beg,end inclusive
"region"     : STRING             // e.g. "EU863", "US902", ..
"hwspec"     : STRING
"freq_range" : [ INT, INT ]       // min, max (hz)
"DRs"        : [ [INT,INT,INT], .. ]   // sf,bw,dnonly
"sx1301_conf": [ SX1301CONF, .. ]
"nocca"      : BOOL
"nodc"       : BOOL
"nodwell"    : BOOL
}

The gateways carry LoRaWAN device data to and from LNS usually over high-bandwidth networks like Wi-Fi, Ethernet, or Cellular. The gateways usually pick up all messages and pass through the traffic that comes to it to AWS IoT Core for LoRaWAN. However, you can configure the gateways to filter some of the device data traffic, which helps conserve bandwidth usage and reduces the traffic flow between the gateway and LNS.

To configure your LoRa gateway to filter the data frames, you can use the parameters NetID and JoinEui in the router_config message. NetID is a list of NetID values that are accepted. Any LoRa data frame carrying a data frame other than those listed will be dropped. JoinEui is a list of pairs of integer values encoding ranges of JoinEUI values. Join request frames will be dropped by the gateway unless the field JoinEui in the message is within the range [BegEui,EndEui].

Frequency channels and subbands

For US915 and AU915 RF regions, wireless devices have choices of 64 125KHz and 8 500KHz uplink channels to access the LoRaWAN networks using the LoRa gateways. The uplink frequency channels are divided into 8 subbands, each with 8 125KHz channels and one 500KHz channel. For each regular gateway in AU915 region, one or more subbands will be supported.

Some wireless devices can't hop between subbands and use the frequency channels in only one subband when connected to AWS IoT Core for LoRaWAN. For the uplink packets from those devices to be transmitted, configure the LoRa gateways to use that particular subband. For gateways in other RF regions, such as EU868, this configuration is not required.

Configure your gateway to use filtering and subbands using the console

You can configure your gateway to use a particular subband and also enable the capability to filter the LoRa data frames. To specify these parameters using the console:

After you've added a gateway, in the AWS IoT Core for LoRaWAN Gateways page of the AWS IoT console, if you select the gateway that you've added, you can see the SubBands and filters NetIdFilters and JoinEuiFilters in the LoRaWAN specific details section of the Gateway details page.

Configure your gateway to use filtering and subbands using the API

You can use the CreateWirelessGateway API that you use to create a gateway to configure the subbands you want to use and enable the filtering capability. Using the CreateWirelessGateway API, you can specify the subbands and filters as part of the gateway configuration information that you provide using the LoRaWAN field. The following shows the request token that includes this information.

POST /wireless-gateways HTTP/1.1
Content-type: application/json

{
"Arn": "arn:aws:iotwireless:us-east-1:400232685877aa:WirelessGateway/
       a11e3d21-e44c-471c-afca-6716c228336a",
"Description": "Using my first LoRaWAN gateway",
   "LoRaWAN": { 
      "GatewayEui": "a1b2c3d4567890ab",
      "JoinEuiFilters": [
        ["0000000000000001", "00000000000000ff"],
        ["000000000000ff00", "000000000000ffff"]
      ],
      "NetIdFilters": ["000000", "000001"],
      "RfRegion": "US915",
      "SubBands": [2]
   },
   "Name": "myFirstLoRaWANGateway"  
   "ThingArn": null,
   "ThingName": null
}

You can also use the UpdateWirelessGateway API to update the filters but not the subbands. If the JoinEuiFilters and NetIdfilters values are null, it means there is no update for the fields. If the values aren't null and empty lists are included, then the update is applied. To get the values of the fields that you specified, use the GetWirelessGateway API.