On Oct. 20, 2010, in Charleston, S.C., another core Project 25 Phase 2 definition document was approved for publication. This is a significant milestone because manufacturers now have the necessary information required to develop P25 Phase 2 time division multiple access (TDMA) products.

Because spectrum is a limited commodity, the P25 Phase 2 TDMA standard allows government agencies to do more with the same number of allocated frequencies. Agencies utilizing a P25 trunked system with Phase 2 TDMA operation will be able to double their voice capacity from current Phase 1 implementation, which will allow more users to operate on their system. For users who need more functionality on their systems, the addition of TDMA operation can help an agency free up spectrum for advanced data capabilities such as location service, text messaging and over-the-air rekeying or programming, while maintaining the same number of simultaneous voice calls.

As agencies move to the future, it is important to understand that the P25 Phase 2 TDMA operation does not replace Phase 1 operation, but rather augments it. The P25 Phase 2 TDMA standard is needed by agencies across the country that want increased voice capacity with the benefits of an interoperable, standard-based solution. Agencies now will have the flexibility to choose the operation that is best-suited for their organizations, with the confidence that they can transition in the future while maintaining the interoperability required for effective emergency response.

Several manufacturers, including Motorola, already have filed P25 Phase 2 TDMA modulation schemes with the FCC and have been working for the past few years to prepare their products for TDMA operation. In some cases, TDMA-capable equipment purchased today will be software upgradable to P25 Phase 2 TDMA.

Completing the core documents, which are now approved, allows manufacturers to develop equipment to the standard. To complete the TDMA suite of standards, testing documents need to be finalized. These documents, which currently are in development, establish defined tests that allow manufacturers to verify their implementations relevant to the core documents and test interoperability with other manufacturers. This is important for public-safety agencies to ensure compliance to the standard and interoperability among multiple manufacturers.

The completion of the Project 25 Phase 2 TDMA trunked core definition documents was a team effort. This accomplishment is a direct result of the dedication of the Project 25 Steering Committee, the public-safety community, Telecommunications Industry Association and P25 manufacturers who, like Motorola, have invested engineering resources to accelerate and complete this important suite of standards documents. The result is a vibrant standard that continues to support the public-safety community’s requirement to have state-of-the-art, interoperable communication systems so that first responders can achieve their mission of keeping our communities safe.

Bob Schassler is senior vice president, radio solutions, for Motorola Solutions.