Define downlink gateway for multicast device as device configuration

[ezamp]

Summary

Add in the configuration of multicast devices the possibility to enter the list of gateway ids to be used for sending downlink messages.

Current Situation

Currently, gateway ids must be added as a parameter in downlink submission requests. Whenever you want to send a downlink message to a multicast "device" you need to specify all the gateways.

Why do we need this? Who uses it, and when?

Many platforms schedules downlink messages without knowing which gateway to use as a path for the downlink. In this case the platform is unable to send downlinks to the multicast devices because it does not know which gateways to use. If the gateway list is associated (as a configuration) to the multicast device, then it is no longer necessary to specify this gateway list as a parameter in the downlink request.

Proposed Implementation

add a new field in "General settings" in which to insert the gateway ids.

Contributing

• [ ] I can help by doing more research.
• [ ] I can help by implementing the feature after the proposal above is approved.
• [X] I can help by testing the feature before it's released.

Code of Conduct

• [X] I agree to follow TTN's Community Code of Conduct.

[adriansmares]

It is indeed the case that for multicast devices we currently cannot schedule any downlinks via the Console, as the fixed downlink paths cannot be provided. We should consider adding some UX for this, including grouping logic for simulcast downlinks.