NIST prototypes technology that connects LMR and wireless broadband networks.
Many of the country’s 4.6 million public safety workers still use traditional analogue radios, in part because of the high cost of switching to digital equipment and the slow adoption of new systems of familiar push-to-talk features on which responders depend.
Now engineers at the National Institute of Standards and Technology have built a low-cost computer system that connects older public safety radios to the latest wireless communications networks. The prototype system can help public safety agencies more easily integrate their radio systems into broadband networks that support voice, text, instant messaging, video and data transmission.
The NIST prototype connects analog mobile radios (LMRs) and towers to an LTE server that manages broadband operations. This mission-critical call push system includes:
- Software-defined radio stations that interact with the LMR signaling interfaces and transmit this data to the next device.
- An open source software environment for software radio control that handles digital signal processing.
- LTE phone user interface that allows LMR radio users to talk to LTE network users as if they were both on the same push-to-talk network.
The physical equipment includes a computer with an Internet connection to the LTE system, appropriate software and an antenna. The entire setup is the size of a video game console plus a laptop or desktop computer, NIST officials said on April 12. news release.
NIST wanted to make sure that the system was robust, inexpensive and in line with existing and future standards.
The NIST system costs less than existing industry and government efforts to connect radio and mobile networks.
“There is no commercial option that can be compared to what we are developing,” said NIST engineer Jordan O’Dell. “The goal here is to create a prototype and accelerate the development of technology in the industry, which will fill a significant gap.”
At present, the connection of radio and cellular networks requires a radio system that supports the interface of the Project 25 radio frequency subsystem, which can be too expensive for many public safety agencies to purchase or retrofit. Another option, which provides a bridge between the headphones and the broadband network, requires investment in specialized radio and donor interfaces.
“We want public safety agencies to have a very cheap option that can interact with old technology when other options are not available,” O’Dell said.
NIST researchers plan to improve the interface to the broadband network, connect to additional types of radio stations and publicly release all features such as open source.
Read the full NIST article here.
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