[FEATURE REQUEST] Call service

Is your feature request related to a problem? Please describe.

In the taxi domain, it is common that whenever a taxi is heading in your direction (5 minutes before arrival), an (automated) phone call is made to the end-user, so the waiting time is marginalized.

Urgency

Major, because it is not specified how this should work with the TOMP-API.

Describe the solution you'd like

A possibility is that the ancillaries can be used for this. Therefore the CROW traveler's dictionary has to be extended and an ancillary can be added to the inquiry or offer request: travelers.requirements[].abilities. This is of course not a very trusted way to handle personal information because it is already in the planning phase, where you don't want to exchange personal information.

Another possibility is to use the current specification: the phone number can be requested in the inquiry/offer result, there can be a conditionRequiredBookingData { "requiredField": ["PHONE_NUMBERS"] }. In the booking request, the phone number must be supplied customer.phones[].number. If the end-user is not willing to expose the phone number, this service won't be offered. The only thing is that it is not yet possible to indicate that this taxi service gives this service.
We could handle this by extending the /operator/information result.

TOMP-WG / TOMP-API