How to Make a Phone into a Walkie Talkie
By Eric Lin, Thu Oct 30 05:00:00 GMT 2003

Without giving more than a nod to new Push To Talk (PTT) technologies, Popular Mechanics has an explanation on how Nextel's Direct Connect works, and what makes it so much faster.


According to the article, Nextel's has 3 secrets to fast voice delivery. The first is that the phone spends more idle time communicating its position to the network in preparation for an incoming PTT request. The second is that since Direct Connect is transmitted as packet data, Nextel has built a data layer into their network including a separate data channel at each tower. The last is that PTT calls are transmitted peer to peer- once set up, they are not transmitted through central gateways like typical cellular data.

Like Nextel, FastChat and other new 2.5G PTT applications send their audio as packet data. Obviously other networks are not optimized for handset to handset data transmission and so cannot provide as speedy an experience. They can, however, provide a more pervasive one, as these applications can run on handsets on any packet data network, not just Nextel's. Drew Caplan, VP of Network Services at Nextel, compared Direct Connect to IM- perfect for discussing little bits of data instantaneously. Like AIM or other instant messengers, Nextel is fast, but it is not interoperable. We'd then extend the metaphor and compare new operator independent systems to SMS. It's not instant, but it is timely, and it is accessible on any network.

It's only fair to point out what looks to be Mac vs Windows style holy war brewing at the end of the article, where Popular Mechanics finally mentions new push to talk applications. In a very mid-90's Apple statement, Nextel said they are more concerned about user experience than interoperability. Both would be nice, but what about courtesy too? We're concerned about the all-too-annoying walkie-talkie chirps emanating from pockets and hands everywhere, and the loud talking into speakerphones that often follows them.