It's not easy to catch up to John Powell. If the senior consulting engineer isn't participating in standards debates or regional planning meetings, he's jetting to Washington to give advice to the Department of Homeland Security's Office for Domestic Preparedness and to its Project SAFECOM, which is working to advance interoperable communications between first-responder agencies nationwide. Recently, however, MRT did just that and was brought up to date on developments — or lack thereof — concerning APCO's Project 25 Phase 2 standard, emerging 4.9 GHz technologies and software-defined radio.

MRT: The Project 25 standardization process has been slower than expected. What steps are being taken to speed the completion of Phase 2?

Powell: Congress has directed federal agencies to move Phase 2 forward if the Project 25 Standards Committee is not able to do it. We also have a very clear mandate regarding the Inter-RF Subsystem Interface, and we're hoping to have an ISSI — limited to voice trunking — out by the end of the year. That's the commitment manufacturers have made. There are two other pieces that need to be completed so we can leverage multiple vendor systems into a single console: the console interface and the subsystem interface. These three components have languished between Phase 1 and Phase 2.

MRT: When completed, what might the Phase 2 standard look like?

Powell: We have two major contenders for Phase 2 with different proposals, both of which have good features and drawbacks. Both are promoted by substantial companies: Motorola and EADS (European Aeronautic Defense and Space Co.). Both companies have exceptional R&D and engineering support, but their proposals are incompatible over the air. (See “Fighting over the future of P25,” MRT, June for full details on the Motorola and EADS' proposals.)

MRT: What is a realistic timetable for completion of Phase 2?

Powell: We have reached common agreement on a great deal. Everything that we can come to a common agreement on has been reached. The [APCO Project 25 Standards Committee] says it will make a decision on Phase 2 by October. Once that decision is made, the manufacturers will be on board. Each will have a different time to market, which is inherent in the technologies.

MRT: How will the Phase 2 standard affect users?

Powell: We have guaranteed — with the effort to harmonize the two standards — users are really going to benefit because the migration from Phase 1 to Phase 2 is going to be very graceful. Users can migrate systems on a channel-by-channel basis. When the new channel is working, the new additions made with Phase 2 are transparent to Phase 1 users. The new equipment will take advantage of the new channel.

MRT: How long do you believe it will take for equipment to hit the market once the Phase 2 standard is completed?

Powell: I would hope it would be ready in a year. Companies have been watching this, and a lot of R&D has been done by a number of companies. Clearly, they know the way we have to go to speed up product development. I don't think we'll have a long lead time for product.

MRT: Now that the guard band issues have been resolved for the 4.9 GHz band, what technology hurdles will public-safety users of the band face?

Powell: Two things impact us. First, we've never operated a network in that high of a band. Second, we have minimal broadband experience, so there is a huge learning curve. In terms of technology, there are many different solutions on the drawing board for getting ready for delivery. There is the PacketHop type of stuff, and mesh networks have potential. One of the biggest limiting factors is how public safety will use access points. Hot spots are great, but the cost of backhaul is extremely high, so we won't see a lot of access-point systems deployed over wide areas. At the same time, there are other emerging standards that address coverage, such as WiMAX and 802.20. Again, one of the big drawbacks is that in higher frequencies, there are not really any fielded standards out there that support mobility.

MRT: Software-defined radio is a technology in which you are deeply involved. How far do we have to go before we are at a point where it can be used in the field?

Powell: There are so many different issues there. We still have technology hurdles to overcome such as size, cost and the usual problems you run into, especially for portable equipment. Another big concern is cross licensing of intellectual property so we can put all legacy systems into one box. We've moved some. One of the biggest things we did last fall was issue a request for information from public safety to see how various players see the impact of SDR on public safety. That process will define where we are within that space. We're seeking a lot of input not only from the user community, but also from the manufacturers, both in the public-safety space as well as from others that want to enter that space.

MRT: Can you talk about the work you are doing with homeland security agencies?

Powell: A lot of that is very straightforward technical assistance. Probably one of the most successful programs we have going right now is the technical assistance we're providing within the Office for Domestic Preparedness. We have teams supporting the states and the 50 designated areas that received significant grant funding for interoperability. There is separate funding to provide some real high-level technical assistance from a team of state and local folks with significant experience supported by a top-notch engineering team in San Diego. All in all, it has been a very successful program. That's building on the guideline work within the Science and Technology directorate of the Department of Homeland Security through its Project SAFECOM program.


John Powell is a senior consulting engineer to the National Public Safety Telecommunications Council (NPSTC) and the U.S. Departments of Justice and Homeland Security. He currently chairs NPSTC's Interoperability Subcommittee and its Software Defined Radio (SDR) Working Group. Powell also is a member of the SAFECOM Executive Committee and the SDR Forum Board of Directors. He holds a bachelor's degree in electrical engineering from the University of California.