Genuine P25 Interoperability: Tips and Traps When Moving to Digital Radio www.taitradio.com Scott Skibness Tait Communications

Learning Objectives An update on the latest standards, interfaces and certification bodies and their implications for procurement decisions Understand why the P25 Compliance Assessment Program matters to you With all of this why don’t all P25 radios work on all P25 networks?

Project 25: History Designed for public safety by public safety Developed in partnership between APCO and TIA Initial P25 standards were released in 1995 P25 is a suite of mobile radio standards and bulletins which define interoperable communications for emergency services They are continuing to evolve; Phase 2 trunking is in progress The result? True multi-source procurement and interoperability Smooth migration from analog

Project 25/TIA 102 Standards Suite The standards suite allows for some features that are: Mandatory Standard options: where if offered they must follow the standard Manufacturer’s extensions to the standard: these can fit within the framework of the standard Caveat: watch out for manufacturer extensions that are similar to standard options 4

Project 25: More Than An Air Interface

Project 25 Standards: Roll-out Phases P25 requirements and standards for a digital Common Air Interface (CAI) using FDMA 12.5 kHz channels and for the supporting system Must be backwards compatible with FM analog Phase 2 P25 requirements and standards for a digital CAI using 6.25 kHz channels or equivalent and for the supporting system Must be backwards compatible with Phase 1 digital only The primary improvement in Phase 2 is spectral efficiency Note: Phase 2 is sometimes interpreted as referring to P25 requirements and standards supporting both Phase 1 and Phase 2 systems, such as the ISSI, Fixed Station, and Console Interfaces Spectral efficiency is primarily a focus for US. Currently there is no good reason for TAP to move to Phase 2 6

Project 25 Standards Status: Phase 2 Most vendors are offering P25 Phase 2 upgradable equipment today A number of test documents are still to be started Uses half rate vocoder in 2-slot TDMA Conventional Phase 2: work will commence on conventional 2-slot TDMA What does this mean for you? People are only now starting to understand Phase 1!! There is no need/regulatory push for Australia to adopt Phase 2. We do not know of any vendor publically committing to availability dates for Phase 2 What does this mean for you? Phase 2 standards are currently being worked on, but the equipment is a way off… 7

P25 Compliance Assessment Program (CAP) CAP Test Bulletins Lab Assessments Multi-Vendor CAP Testing Suppliers Declaration of Compliance Responder Knowledge Base Posting Department of Homeland Security (DHS) DHS recognised manufacturers’ & independent test laboratories Equipment tested against the specifications Assurance of interoperability between manufacturers’ equipment DHS recognised manufacturers’ test laboratories Interoperability testing between vendor’s subscribers and infrastructure – Strongest test around: Competitor tested for P25! User has the freedom to choose in a multi-vendor environment (many systems have more than one vendor on the system) Buyers of Phase 1 P25 equipment can be certain they will work seamlessly with other equipment and conform to P25 standards Proof that Phase 1 P25 is a good long-term investment Performance specs: type approval tests ++ The Project 25 Compliance Assessment Program (P25 CAP) A voluntary program that allows P25 equipment suppliers to formally demonstrate their products’ compliance with a select group of requirements within the suite of P25 standards Purpose: is to provide emergency response agencies with proof that their equipment meets P25 standards for performance, conformance and interoperability Supplier’s Declaration of Compliance (SDoC) Summary Test Reports (STR) SDoCs/STRs on the Responder Knowledge Base (RKB) 8

Responder Knowledge Base (RKB) Website Who is FEMA? Benefit to the customer is that they can choose a selection of products that will work together. They are no longer tied to just one manufacturer. Benefit is choice. www.rkb.us → Other Content → Certifications and Declarations → P25 SDoCs 9

Why Do We Need The CAP? Choice for buyers Multiple users on a single network can use the P25 technology and various vendors’ P25 products on that network Users can purchase the right fit for their needs with more options Security to buyers The CAP offers a formal assurance program Confidence in interoperability P25 equipment meeting the CAP standards Federal grant money in the US is dependant on interoperable products … but the CAP is still of interest in other regions P25 CAP - consistency of technology Emphasis on Tait’s laboratory as the first outside US Phase 1 only currently: many people are only starting to understand Phase 1 – only USA has the push to go to Phase 2 No room for proprietary signalling at the moment What does this mean for you? Implications = potential for no interoperability User has the freedom to choose in a multi-vendor environment (many systems have more than one vendor on the system) P25 CAP tests are still evolving and the focus is more on Phase 1 (with mature products) as opposed to Phase 2 which is not till later The main benefit for people in the US to worry about Phase 2 is spectral efficiency. If this issue doesn’t concern you, neither should Phase 2. Multiple vendors with mature Phase 1 products Few vendors with Phase 2 products (not mature) – there is lots of testing to come behind the CAP testing Phase 2 standards are still evolving: they are close to defining the standards, but the compliance standard has not even begun yet. Caution that Phase 2 products released now may not be interoperable once the standards are defined. No strong reason to use Phase 2 in TAP as there is no mandate from regulators for narrowbanding here (unlike the FCC in the US) 10

Who Defines The CAP? Approved by the CAP Governing Board Comprised of representatives from US Government agencies Generally follows the TIA recommendations for compliance assessment tests References standard tests Published in Compliance Assessment Bulletins (CAB) ********* Be aware of the following*********** Disagreements between the manufacturers and NIST, re performance tests. NIST want to add conformance tests, but manufacturers want to test against themselves, not against a stub (test protocol vs test stub?). This allows room for interpretation says NIST and possible un- interoperability if interpretations exist between manufacturers No manufacturers on CAP governing board 11

Four Vendors with P25 CAP Recognized Labs Worldwide Standard test process to become recognized Vendor hosted CAP interoperability testing in a recognized lab Tait, Motorola, EF Johnson and Harris Other CAP testing such as performance testing is also completed After testing, SDoCs and STRs are published to the RKB website Goal: cooperation between P25 vendors for interoperability Vendor hosted CAP testing events: Motorola, EFJ, Tait, Harris have hosted… Motorola twice (evolving the process – not all manufacturers need to retest if changes are minimal – can claim “interoperability” based on minor changes not affecting test outcomes. APCO 25 Interface Committee (APIC): A P25 committee, comprised of P25 users and equipment manufacturer representatives, which develops initial drafts of P25 standards. 2.4.3 Compliance Assessment Bulletin: A Compliance Assessment Bulletin is the primary product created by the P25 CAP/GB. The scope of a CAB can range from policy to guidance, covering issues such as specific test standards to be used for a particular P25 interface, guidelines for the creation of an SDoC, P25 LMR RFP Guidance, etc. 2.4.4 Compliance Assessment Process and Procedures Task Group (CAPPTG): A subcommittee of the APCO 25 Interface Committee, or APIC. The mission of the CAPPTG is to ensure that P25 equipment and systems comply with P25 standards for interoperability, conformance, and performance, regardless of equipment supplier, and in accordance with the User Needs Statement of Requirements. 2.4.5 Declared Equipment: A P25 product which: 1) has been tested at a P25 CAP-recognized laboratory; 2) has been determined by the equipment supplier to be compliant with all current requirements of the P25 CAP; 3) possesses a Supplier’s Declaration of Compliance (SDoC); and 4) has a summary test report that has been reviewed for accuracy and completeness by the P25 CAP Laboratory Program Manager. 4.2 Demonstration of Compliance The test methods used in the program are chosen from P25-approved standards that are customarily drawn from the TIA-102 suite of standards. The intention is for the suite to contain performance, conformance, and interoperability test standards for each interface or major service. A variety of test methods are contained within each test standard. Many but not all of these test methods will be included in the minimal set of tests required for compliance demonstration in this program. A joint group of users and equipment suppliers, in the P25 Compliance Assessment Process and Procedures Task Group (CAPPTG), evaluates each test method within a test standard for suitability and inclusion within the program. CAPPTG then compiles a list of the required test methods drawn from each test standard, and releases them in the form of a draft compliance related Telecommunications Systems Bulletins (TSB). The compliance related TSB is approved by the P25 Steering Committee, and routed to the TR-8 for final editing and publication. The P25 CAP/GB uses these TSBs as the basis for the creation of CAB’s with regard to required testing, but is not limited to the material in the compliance related TSB’s. 12

Trade-offs Interoperability ≠ Total Interoperability Proprietary extensions Performance ≠ Coverage Guarantees Testing Culpability 13

Why don’t all P25 radios work on all P25 networks? Different interpretation of the standards Different implementation of the standards Usability of the radio Requirement for non-standard functionality 14

Interpretation of the P25 standards Different interpretations of the standard Features outlined in the standard that WILL work group calls registration affiliation unit to unit calls However… on most networks there are other features required. Patch Calls Dynamic Regrouping Failsoft 15

Differences in Implementation Not all standards are clearly defined Many of the items in the standards are open to interpretation Control Channel Hunt – items like acquisition, retention, what is a valid CC, and when to leave are detailed but how to find one and select which to use or keep are not. Or deployed with additional capabilities Radio inhibit and uninhibit – The standard defines how this will work but the data is unencrypted as defined so vendors add encryptions within the system for these which limits the functionality to others. 16

Usability of the Radio Differences in features and operation. ‘Usability’ is one of the major obstacles for having multiple vendors on a state-wide network. Acceptance or certification testing is based on an existing terminal and how it operates and not the P25 standard Scan configuration Programming Units Alert sounds and configuration 17

User Misunderstandings About the Standard Largely defined by the individual vendors, or the user when programming. Therefore NOT uniform. Vendor Proprietary Features Defined by the P25 Feature Sets At the 3 levels User Interface: Tones, Display, Lights, Knobs, etc. User Programming: Tones, Channels, Features, etc. Standard Options User Programming Interface: channel lists, pull down menus, Etc.. P25 Air Interface & Signaling: ID, Alarms, Features, etc. Core Features P25 Feature Sets User P25 Experience 18

Non-Standard Functionality Adding functionality that is not available to other suppliers Network suppliers add services that help make its terminals function more efficiently. Dynamic Power Control Providing functionality that limit interoperability with other vendors radios on the network. Non-standard Encryption – insist on AES or DES OTAP Limit what is granted in a license to a few features 19

Lesson Learned Examples from past systems Non-standard frequency splits Failsoft function with unique code words where in some cases it included a specific manufactures ID Unused bits that change states from system to system. Lack of testing on the system means some conditions are not found out until the units are deployed 20

Lessons Learned Limit testing of “proprietary” features Vendors need more than the minimum information to work effectively Willingness of the network owners to work with the other vendors Not all users will need or want the same functionality so make sure you are not limiting their choices with the certification process Test failures are not just a failure for a vendor They are a failure for the P25 standard and interoperability. SAVINGS – customers have seen a 30% to 40% savings or more in the cost of subscriber units when multiple vendors radios are offered on a system. 21

Genuine P25 Interoperability: Tips and Traps When Moving to Digital Radio www.taitradio.com Scott Skibness Tait Communications