Early radio: Mute the receiver; switch the antenna; key the transmitter. Unkey the transmitter; switch the antenna; unmute the receiver. Back and forth, back and forth, and you have a conversation with the radio operator on the other end.

Big advance: Press one button, and control circuitry mutes the receiver and switches the antenna as the transmitter keys. Push to talk. Honestly, it was a big deal when it first came out — when, in the 1940s?

Today's radio communications users take push-to-talk for granted. But guess what? What's old is new again.

Nextel Communications promoted push-to-talk as an extra benefit to business users who subscribed to its cellular telephone service. One of the company's early descriptions called push-to-talk “executive intercom.” The current description calls it “direct connect.” Direct connect not only rhymes, it doesn't exclude employees and family members.

Customers didn't care why Nextel could offer push-to-talk and other cellular or PCS companies could not. Radio communications specialists understood that Nextel offered push-to-talk because the company actually had radio communications licenses, not cellular or PCS wireless telephone licenses. Until a change in FCC regulations, cellular and PCS carriers were not allowed to offer the feature.

And why should they want to? Two reasons — money and money.

The first reason, money, has to do with Nextel's success in keeping its average monthly revenue above $70 while cellular and PCS carriers draw monthly customer dollars in the $40 range. It seems as though business customers really like push-to-talk, and they use more of the costlier peak-period airtime than consumer customers.

The second reason, money, has to do with the ability to serve dispatch customers such as utilities and public safety agencies. Although Nextel's penetration into these markets has been minimal, incremental revenue is welcome at any time and is especially welcome in times of recession and slowing market growth.

Combine push-to-talk with priority access, and you have a package that is both attractive to public safety users and potentially unsatisfactory (if not dangerous) to consumers during emergencies.

Priority access moves public safety users to the top of the call queue so their calls connect before others are served. The feature helps to overcome an objection that some agencies have about relying on Nextel as a primary mobile voice communications medium. When an officer, firefighter or medical technician wants push-to-talk radio communications during an emergency, he wants it immediately. When he wants to use a handset to make a mobile phone call, he wants the call to be connected right now.

But during an emergency that affects many people and draws news coverage, Nextel, cellular and PCS networks fill with people calling public safety agencies to ask for help or to tell what they have seen. The networks fill with people calling friends and relatives to reassure them about their health and welfare. And they fill with reporters calling news editors.

Priority access would add traffic to the networks, making it somewhat less likely that calls for help would be connected as they compete for the remaining capacity. The question is whether priority access would serve public safety agency communications at the possible expense of calls for the help that the agencies provide.

Meanwhile, Nextel, Motorola and Qualcomm have inked a deal to develop push-to-talk for CDMA technology in a way that is compatible with Nextel's IDEN-technology push-to-talk. Plus, Nextel gains exclusive rights for several years to deploy CDMA push-to-talk in North America and several overseas markets. Nextel can transition to CDMA without losing its push-to-talk advantage to CDMA competitors.

Nexteland is a place where public safety agencies can pay Nextel to carry their dispatch communications. It's where Nextel bills dispatch calls by the number of units called, plus airtime. It's where Nextel's radio interference to public safety communications is overcome because, well, by golly, radio interference by Nextel may have contributed to a decision to buy radio service from Nextel.

Nexteland is a world where a possible frequency swap with public safety agencies might give Nextel radio spectrum for third-generation cellular service using — guess what? — CDMA in the 2,100MHz band with exclusive push-to-talk service.

It's a beautiful world, isn't it?

All thanks to that little thing that most carriers left alone during the wireless boom days — push-to-talk.