AT&T today announced the availability of its Enhanced Push-to-Talk (PTT) service, which runs over the company's LTE network.

The carrier also announced a pair of ruggedized PTT devices that support the new service, including the Samsung Rugby III and Sonim XP5560 Bolt, as well as a pair of BlackBerry devices.

AT&T's Enhanced PTT service includes features such as the ability to combine PTT services and mobile applications, supervisory override and talk group scanning, and sub-second call setup.

AT&T offers a pair of Enhanced PTT plans. Organizations can choose from $5 per month when added to existing AT&T voice and data plans, or $30 per month for a PTT-only rate plan (no voice or non-PTT data included).

Both plans include unlimited PTT, and data used by the Enhanced PTT application will not count against the customer’s monthly data totals or incur pay-per-use charges.

The new offering from AT&T is aimed squarely at attracting customers coming off of Sprint's iDEN network, which that carrier is decommissioning for use in its rollout of LTE. In September, Sprint said its PTT service, which runs on its CDMA network, now has more than 1 million customers.

Sprint has said its iDEN network is slated to be decommissioned as early as June 30, 2013. Sales of most iDEN devices have been discontinued, and the company is working to move those customers still using the phones to its new service.

About 9,600 of Sprint's iDEN cell sites had been taken down by the middle of 2012. The replacement PTT service has a broader footprint than iDEN, more than doubling coverage to 2.7 million square miles, including the addition of 2G and roaming service.

Sprint plans to use the 800 MHz spectrum left over from iDEN to supplement its LTE network on the 1900 MHz band. The PTT overhaul is part of Sprint's broader network upgrade project, which has it ripping out old base stations and replacing them with new equipment that supports LTE. Sprint CEO Dan Hesse said in June that the company's vendors were on track to have 12,000 of the new sites on air by year-end.