Cloud-based, open standard capabilities provide flexible, cost effective and highly secure connectivity

First responders, transportation agencies and public departments depend on interoperable Land Mobile Radio (LMR) solutions to connect and communicate.

AT&T* understands this need and now supports Inter-RF Subsystem Interface (ISSI), an IP-based, open-standard connection – APCO Project 25 (P25).  APCO P25 is the standard for connectivity among public sector and public safety networks.

This follows closely on the heels of our support for CSSI. Announced earlier this year, CSSI lets customers connect dispatch console systems.

Customers can connect their LMR networks to AT&T Enhanced Push-to-Talk to extend coverage and communications nationwide. AT&T Enhanced Push-to-Talk also meets the requirements of the Federal Information Processing Standard (FIPS) Publication 140-2. FIPS is a U.S. government computer security standard used to test and validate product security.

The end-to-end solution also integrates AT&T Dynamic Traffic Management to provide priority call treatment and network access based on Quality of Service network technology.

“With ISSI, the geographic and technological restrictions of LMR are a thing of the past,” said Walt Rivenbark, associate vice president of Advanced Mobile Solutions, AT&T. “We’re the first major U.S. wireless carrier to offer ISSI and CSSI connectivity to more than 2,500 public safety networks.”

“We expect this solution to change how public entities think about their radio services. They can now communicate virtually whenever, wherever they need to. And the solution complements their existing systems with Enhanced Push-to-Talk’s cost-effective and user-friendly functionality,” Rivenbark said.

We’re piloting ISSI with several customers, including the city of Richardson. The Texas city is deploying LMR interoperable EPTT devices to its mission support teams. 

“AT&T’s unique offering is simple, scalable and reliable,” said Steve Graves, chief information officer, City of Richardson, Texas. “It’s the next evolution of Land Mobile Radio.  It’s a cost effective solution that’s removing the most expensive part of the radio system, the radio itself!  ISSI is empowering us to communicate on an open standard interface and making it easier to integrate AT&T Enhanced Push-to-Talk."

Customers can also use Radio over IP to achieve interoperability. It’s also built into our Enhanced Push-to-Talk network to further support IP interoperability.

For more information, visit You can also catch a demonstration of ISSI at the AT&T booth (#1363) at APCO. 

*AT&T products and services are provided or offered by subsidiaries and affiliates of AT&T Inc. under the AT&T brand and not by AT&T Inc.

About AT&T

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