P25 Systems
APCO Project 25 (P25) is a digital radio standard that has been specified, in
conjunction with the public safety community, to meet the needs of the public safety
community, such as interoperability. Technology compliant with the P25 open
standard is implemented in several phases:
P25 Phase 1:
• The P25 Common Air Interface (CAI) on P25 Phase 1 uses a technology known as
Frequency Division Multiple Access (FDMA), where the channels are divided
according to frequency
• The channel bandwidths for voice and traffic channels are 12.5kHz
• It is backwards compatible with analog.
P25 Phase 2:
• This phase specifies requirements and standards for P25 systems with a CAI
incorporating Time Division Multiple Access (TDMA) technology and providing a
6.25kHz-equivalent channel bandwidth for greater spectral efficiency
• TDMA divides the 12.5kHz into two time slots, effectively giving a 6.25kHz-channel
bandwidth
• The control channel in a P25 Phase 2 system is still a 12.5kHz FDMA channel
• Data channels, to deliver functionality such as OTAR, are still 12.5kHz FDMA
channels
• It is backwards compliant with P25 Phase 1
• This is currently only available for trunked networks.
Our Product: Harris Assured Communications
The Harris P25 system combines the benefits of an IP- based network with industry recognized Project 25 (P25) standards. The result is a single cost-effective IP-based network that is reliable, scalable and secure while providing communications interoperability.
Harris is at the forefront of P25 standards development. Committed to making radio communications interoperability a reality for first responders, Harris has taken a leadership role as a member of the P25 Compliance Assessment Program (CAP). P25 CAP provides a framework and process for demonstrating the compliance and interoperability of P25 equipment. Harris is an industry leader in P25 standards based products with software defined radios that are software upgradable to P25 Phase 2 including portables radios, mobile radios, base stations and repeaters.
The Harris P25 system fully supports the P25 ISSI (Inter-RF Sub-system Interface), allowing the connection of multiple P25 networks, even those from other suppliers. Through this use of the industry- standard interface, continuous interoperability can be established among agencies operating with disparate radio systems, technologies or radios.
