P25 Common Air Interface (CAI) is a standard for digital audio that specifies the type of digital signals that are transmitted by radio. When P25 was launched, the goal was to create a significant amount of interoperability so those who need it, such as public safety officials, could work more efficiently. The CAI standard offers the desired interoperability to those that use radios that offer the interface.
P25, the standards set for optimal interoperability in radio communication, has eight open interfaces; Common Air Interface (CAI), Subscriber Data Peripheral Interface, Fixed Station Interface, Console Subsystem Interface, Network Management, Data Network Interface, Telephone Interconnect Interface, and Inter RF Subsystem Interface. These eight interfaces allow for those using P25 radios to effectively communicate with others using P25 radios, even if they are using the radios of a separate manufacturer.
Of the eight interfaces of P25, none is more widely deployed than CAI. The importance of CAI is that it allows for two separate P25 radios to efficiently communicate or for a P25 radio to efficiently communicate with P25 infrastructure, regardless of the manufacturer. It’s the basis of what P25 is all about. Additionally, it allows for interoperability capabilities for both FDMA, the designation of multiple users to separate frequencies, and TDMA, the subdividing of a channel into time slots when the digital data is transmitted, channel access methods.
P25 is integral for many occupations, such as public safety officials, as it allows for interoperability among other P25 radios and infrastructure, regardless of the manufacturer that supplied it. Of the eight open interfaces of P25 radios, none is more widely deployed than CAI as it is the interface most responsible for interoperability. More and more users of radio communication are switching to P25 radios for the interoperability they desire and RELM Wireless is proud to be a leading supplier of these important communication products.