Using Asterisk as walke-talkie system


I have a client who wants to set up a smartphone-based (android) walkie-talkie-like system.

It will be used in a shop, where shop assistants often need to talk to each other discreetly. They currently have a analog system that can only be used to call all the other handsets. They want a system that can either be used to call all connected handsets or to call specifically to one of them.

The system should have the following capabilities:

  • Some form of user authentication, only allowing communication within a defined group of handsets.
  • No call-and-answer the phone type delay: Press a button to immediately connect to either all other headsets or one specific one
  • Should be relatively low cost, either based on software that can be purchased or open source software that can be modified without requiring too much development time

Would a client-server system with the smartphone voip clients connected to an asterisk server (probably running on an embedded linux box) be suitable for something like this? I am unsure if the requirement that it work like a walkie-talkie system rather than a call-and-pick-up type system will mean that asterisk is unsuitable.

I don’t see where Asterisk wouldn’t be able to handle this. The hardest part is the client side. In order for a walkietalkie system to work well, you’d have to have a SIP client that auto answers so audio can be sent, but also have a PTT “switch” so you don’t call someone and then get to hear them in an…ahem…compromising situation.

The all-page can be done too. Dial out to all handsets, put them in a conference so everyone gets the audio from the caller, then hangup when done.

I can see how it can be done, but having no Android experience I just don’t have an answer on how to do it on the client side.

Some quick googling shows a few Java based SIP phones for Android that could be modified, but I don’t know if your phones would support the Java apps.

Thanks for your reply.

The headsets would all be android-based and will support an app written in Java.

The client wants the project to be low-cost, so an existing open-source Android-based SIP phone application that can be modified with relatively little extra programming required would be ideal. Pointers are welcome, I also have very little Android experience.