Sprint PCS (NYSE: PCS) is one of the last carriers in the U.S. that does not have real SMS two-way text messaging capabilities on its handsets, and the operator says it might just keep it that way when it launches its upgraded service this summer.

On April 1, Sprint, along with all the other major U.S. carriers, except Nextel Communications Inc. (Nasdaq: NXTL), signed an inter-carrier SMS interoperability agreement. This means that U.S. users on one network can now get text messages of up to 160 characters from their friends on other networks. However, if you are a Sprint customer, it is not simply a matter of pressing "reply" to zap a message back. You can either fire up the ol' WAP browser and mail a reply back or (wait for it, folks...) call the person that sent you the message.

"I know we don't have true SMS," acknowledged Sprint spokesperson Dan Wilinsky. However, he added, the company may not even add proper two-way capabilities when it upgrades its network to CDMA 1xRTT this summer. "Our customers seem to like Instant Messenger," he says.

Of course, there are benefits to IM on a mobile phone, the chief one being that you can communicate with users running IM on their desktop computers. But there are benefits to interoperable SMS as well, like being able to send short messages to just about anyone whose mobile phone number you know. So why not just support both forms of messaging?

By not offering simple SMS services, Sprint -- and Nextel, for that matter -- could be missing out on a simple way to add to its wireless data revenues. Certainly, other carriers are seeing the benefits of true interoperability.

Verizon Wireless said recently that it saw a 25 percent increase in SMS the morning after flipping the inter-carrier switch and is currently seeing more than 2 million SMS messages sent per day (see SMS in the U.S. -- All Upside? ). Worldwide, over 350 billion text messages are expected to be sent this year.

— Dan Jones, Senior Editor, Unstrung
http://www.unstrung.com