Project 25
[2][3] Based on the recommendations, to find solutions that best serve the needs of public safety management, in October 1989 APCO Project 25 came into existence in a coalition with:[2][4] A steering committee consisting of representatives from the above-mentioned agencies along with FPIC (Department of Homeland Security Federal Partnership for Interoperable Communication), Coast Guard and the Department of Commerce's National Institute of Standards and Technology (NIST), Office of Law Enforcement Standards was established to decide the priorities and scope of technical development of P25.
[4] Interoperable emergency communication is integral to initial response, public health, community safety, national security and economic stability.
Of all the problems experienced during disaster events, one of the most serious is poor communication due to lack of appropriate and efficient means to collect, process, and transmit important information in a timely fashion.
[6] Non-operability occurs due to use of outdated equipment, limited availability of radio frequencies, isolated or independent planning, lack of coordination, and cooperation, between agencies, community priorities competing for resources, funding and ownership, and control of communications systems.
[7] Recognizing and understanding this need, Project 25 (P25) was initiated collaboratively by public safety agencies and manufacturers to address the issue with emergency communication systems.
[8] P25 was established to address the need for common digital public safety radio communications standards for first-responders and homeland security/emergency response professionals.
The Telecommunications Industry Association's TR-8 engineering committee facilitates such work through its role as an ANSI-accredited standards development organization (SDO) and has published the P25 suite of standards as the TIA-102 series of documents, which now include 49 separate parts on Land Mobile Radio and TDMA implementations of the technology for public safety.
Phase 1 radio systems operate in 12.5 kHz digital mode using a single user per channel access method.
Of this 9,600, 4,400 is voice data generated by the IMBE codec, 2,800 is forward error correction, and 2,400 is signalling and other control functions.
In addition, the P25 suite of standards provides an open interface to the radio frequency (RF) subsystem to facilitate interlinking of different vendors' systems.
However it proved more advantageous to use existing 12.5 kHz frequency allocations in Time Division Multiple Access (TDMA) mode for a number of reasons.
Three of the possible NACs have special functions: Adoption of these standards has been slowed by budget problems in the US; however, funding for communications upgrades from the Department of Homeland Security usually requires migrating to Project 25.
Both P25 and TETRA can offer varying degrees of functionality, depending on available radio spectrum, terrain and project budget.
The difficulties inherent in developing P25 networks using features such as digital voice, encryption, or trunking sometimes result in feature-backlash and organizational retreat to minimal "feature-free" P25 implementations which fulfill the letter of any Project 25 migration requirement without realizing the benefits thereof.
Additionally, while not a technical issue per se, frictions often result from the unwieldy bureaucratic inter-agency processes that tend to develop in order to coordinate interoperability decisions.
The United States DHS's Project 25 Compliance Assessment Program (P25 CAP)[27] aims for interoperability among different vendors by testing to P25 Standards.
The OP25 project was founded by Steve Glass in early 2008 while he was performing research into wireless networks as part of his PhD thesis.
The report did not find any breaks in the P25 encryption; however, they observed large amounts of sensitive traffic being sent in the clear due to implementations problems.
One design choice was to use lower levels of error correction for portions of the encoded voice data that are deemed less critical for intelligibility.
An optimal spread spectrum system can require an effective jammer to use 1,000 times as much power (30 dB more) as the individual communicators.
The authors developed a proof-of-concept jammer using a Texas Instruments CC1110 single chip radio, found in an inexpensive toy.
[37] Certain metadata fields in the Project 25 protocol are not encrypted, allowing an attacker to perform traffic analysis to identify users.
[38] The report's authors concluded by saying "It is reasonable to wonder why this protocol, which was developed over many years and is used for sensitive and critical applications, is so difficult to use and so vulnerable to attack."
[39] These include disabling the secure/clear switch, using Network Access Codes to segregate clear and encrypted traffic, and compensating for the unreliability of P25 over-the-air rekeying by extending key life.
