Increasing edge device address space while complying with a radio communication protocol

An IoT service of a provider network may be used to increase the edge device address space while complying with a radio communication protocol. This may allow a service provider to manage a much larger number of client devices that use a particular radio communication protocol that specifies a limited address space (e.g., LoRaWAN). When the IoT service receives a join request via a private gateway of the client network, the service determines, based on the private gateway ID, the client ID of the client that owns the private gateway/client network. The service may generate a unique internal ID for the edge device by combining the client ID with an assigned device ID. The internal ID identifies the edge device as an activated device of the edge network.