Board Thread:Speculation House/@comment-34553226-20180516224055/@comment-4010415-20180516225845

Like 73 said... Local communications are still up.

The purpose of the CCT was to amplify communication technology to be capable of connecting worldwide.

As explained in World of Remnant: Cross Continental Transmit System, they already had technology that allowed them to communicate from long distances, but it was local only. The video even showed a visual representation of local comms between Patch and the City of Vale. Here's the screenshot, to the right.

So, although the CCT is down, Vale and Patch still have their local comm systems, so that people within the capital and on the island of Patch can still communicate with each other over long distances. They just can't call someone who is too far away from the capital. As long as Jaune, Ren, and Nora were still within that range, Ruby was able to call them.

We saw them using local comms in the Volume 4 Character Short, and Ruby's Scroll quite literally said "Local Area Only" on it.

In Welcome to Haven, Qrow even says to Lionheart: "Local comms are still up. Keep in touch." while waving his Scroll at him. The City of Mistral still has its local comm system, hence how Lionheart was able to call Qrow later in Volume 5.

Basically, the CCT was not their only way of being able to call people. It's just that, without it, they're only able to call locally.