Editing Project 25 (section)

===Introduction===
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. In some cases, radio communication systems are incompatible and inoperable not just within a jurisdiction but within departments or agencies in the same community.<ref>{{cite web|url=http://www.safecomprogram.gov/NR/rdonlyres/3FFFBFBA-DC53-440E-B2EF-ABD391F13075/0/SAFECOM_Statement_of_Requirements_v1.pdf |title=SOR.book |access-date=2010-09-26}}</ref> Non-operability occurs due to use of outdated equipment, limited availability of radio frequencies, isolated or independent planning, lack of coordination, and cooperation, between agencies, community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.<ref>{{Cite web|url=http://www.ncjrs.gov/pdffiles1/nij/204348.pdf|title=Why Can't We Talk?<!-- Bot generated title -->}}</ref> Recognizing and understanding this need, Project 25 (P25) was initiated collaboratively by public safety agencies and manufacturers to address the issue with [[emergency communication system]]s. P25 is a collaborative project to ensure that [[two-way radio]]s are interoperable.  The goal of P25 is to enable public safety responders to communicate with each other and, thus, achieve enhanced coordination, timely response, and efficient and effective use of communications equipment.<ref>{{cite web|url=https://www.motorola.com/staticfiles/Business/Solutions/Business%20Solutions/Mission%20Critical%20Communications/ASTRO%2025%20Trunked%20Solutions/_Document/Project%2025%20Whitepaper.pdf?localeId=33 |title=A Google Company |publisher=Motorola |access-date=2014-06-06}}</ref>

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 [http://tiaonline.org/all-standards/committees/tr-8 TR-8] engineering committee facilitates such work through its role as an ANSI-accredited [[standards organization|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.<ref>[http://global.ihs.com/search_res.cfm?currency_code=USD&customer_id=2125402A4E0A&oshid=2125402A4C0A&shopping_cart_id=292558332D4B20484B5B3D5B220A&country_code=US&lang_code=ENGL Search Results | IHS Standards Store<!-- Bot generated title -->]</ref>

{{cquote|Project 25 (P25) is a set of standards produced through the joint efforts of the [[Association of Public Safety Communications Officials International]] (APCO), the National Association of State Telecommunications Directors (NASTD), selected federal agencies and the National Communications System (NCS), and standardized under the [[Telecommunications Industry Association]] (TIA)... The P25 suite of standards involves digital Land Mobile Radio ([[Land Mobile Radio System|LMR]]) services for local, state/provincial and national (federal) public safety organizations and agencies...

P25 is applicable to LMR equipment authorized or licensed, in the U.S., under NTIA or FCC rules and regulations.

Although developed primarily for North American public safety services, P25 technology and products are not limited to public safety alone and have also been selected and deployed in other private system application, worldwide.<ref>Codan LTD., [https://cdn.codancomms.com/general-downloads/Products/User-Guides/Codan_TG-001-4-0-0-P25-Training-Guide.pdf P25 Radio Systems] Training Guide</ref>}}

P25-compliant systems are being increasingly adopted and deployed throughout the United States, as well as other countries. Radios can communicate in [[analog signal|analog]] mode with legacy radios, and in either [[Digital signal (signal processing)|digital]] or analog mode with other P25 radios. Additionally, the deployment of P25-compliant systems will allow for a high degree of equipment interoperability and compatibility.

P25 standards use the proprietary [[Improved Multi-Band Excitation]] (IMBE) and [[Advanced Multi-Band Excitation]] (AMBE+2) voice codecs which were designed by Digital Voice Systems, Inc. to encode/decode the analog audio signals. It is rumored that the licensing cost for the voice-codecs that are used in P25 standard devices is the main reason that the cost of P25 compatible devices is so high.<ref>{{cite web|url=http://forums.radioreference.com/general-scanning-discussion/146947-why-digital-scanners-so-expensive.html |title=p25expence |date=31 May 2009 |access-date=5 October 2016}}</ref>

P25 may be used in "talk around" mode without any intervening equipment between two radios, in conventional mode where two radios communicate through a repeater or base station without trunking or in a [[Trunked Radio Systems|trunked]] mode where traffic is automatically assigned to one or more voice channels by a [[Repeater]] or Base Station.

The protocol supports the use of [[Data Encryption Standard]] (DES) encryption (56 bit), 2-key [[Triple-DES]] encryption, three-key [[Triple-DES]] encryption, [[Advanced Encryption Standard]] (AES) encryption at up to 256 bits keylength, [[RC4]] ([[40-bit encryption|40 bits]], sold by Motorola as ''Advanced Digital Privacy''), or no encryption. 
The RC4 Advanced Digital Privacy can withstand casual attackers. It is supposed to offer 40-bit security, where an attacker must test the 2 to the power of 40 possible keys to find the right one. This level of encryption offers no real protection and there is software that allows you to find the key.<ref>{{cite web|title=P25 ARC4 ADP key finder|url=https://archive.org/details/p25arc4keyfinder}}</ref>

The protocol also supports the ACCORDION 1.3, [[BATON]], [[Firefly (protocol)|Firefly]], MAYFLY and [[SAVILLE]] [[Type 1 encryption|Type 1]] ciphers.