Telepocalypse

OPINION://Voicemail: don't phone home

Circuit-switched thinking runs deep. Because the only thing the PSTN can do is make a phone call, every problem is solved by making a phone call.

Take voicemail, for instance. Whilst trying not to bore you with the obvious, let’s recap how traditional voicemail works. The phone network intercepts unanswered calls using a time-out, and re-directs them to a voicemail server. The caller talks to the voicemail server, and that server stores the message. The callee receives a message waiting indicator, and later on makes a phone call to the voicemail system. Everything’s a phone call.

We’re all so used to this paradigm, we never question whether any other mechanism is possible, or whether the current approach makes sense. We seem to assume that future technologies like multi-modal phones and CDMA EV-DV (simulaneous circuit voice and packet data) are needed before we will break out of this mess. That isn’t necessarily so.

Assume a phone call requires an (extremely generous) 3Kb per second of audio. One hour of stored audio is about 10Mb of data. This is a pretty modest amount by the standards of modern flash memeory. Your mobile phone is perfectly capable of storing all your voicemail. The network is perfectly capable of transmitting the data in a sensible amount of time. Unlike email, most voicemail is listened to - the amount of wasted download is small.

Of course, the handset cannot be the voicemail server itself, because it may be out of signal range or turned off. Store-and-forward is still necessary.

You should be able to listen to voicemails on your plane journey home. You should be able to reply to them on a store-and-forward basis, even when you’re not connected to the network. And most of all, you shouldn’t have to use a clunky telephony user interface to navigate a message queue. And you shouldn’t be restricted to one device for accessing your own data.

How often have you returned a call in voicemail, spoken to the caller, and then finished the call by closing your phone or pressing ‘end’? You find yourself dumped out of the voicemail system (hey, you ended the call to the voicemail server - the phone couldn’t tell the difference!). To go back and delete the message, you have to re-dial and navigate the whole voicemail user interface again. Yet there’s a prefectly adequate 2 inch screen that could have been used to list the entries, just like an email inbox.

Or have you ever had the experience of someone calling you from their cell phone, leaving you a voicemail, but you can’t quite pick out the critical number they dictated because their connection dropped out for a moment? But if their message had been recorded locally, and forwarded over a TCP connection, it would have been crystal clear.

Taking this further, why on earth is it the recipient’s carrier that decides when and where to redirect me? Why can’t my handset just look up in a directory where you want voice messages sent?

The technology to make the end points smart is here today. We might not be able to do reliable wireless VoIP on wide-area networks with the deployed technology of today. There is a usability gap still to be filled, and profit to be made from filling it.

The abandonment of the circuit-switched world for all communication that isn’t both real-time and two-way is seriously overdue.