FirstNet prepares to marry its 3GPP mission-critical push-to-talk to Motorola Solution's Critical Connect

11 September 2021: Analysis revised to reflect updated information supplied by AT&T executives.

The latest round of periodic FirstNet service and product updates brings a future option for agencies considering mission-critical push-to-talk (MCPTT). Along with a laundry list of other new functionality on the horizon this year, FirstNet will collaborate with Motorola Solutions to add a second MC-PTT service offer and enable public safety agencies to use Motorola's Critical Connect.

In March 2020, AT&T announced the controlled introduction of an MCPTT service, and the offer went live later in 2020. Until recently, AT&T did not identify the supplier of the MCPTT infrastructure. That changed with a recent blog post, with Samsung saluted as the original vendor. With a July 2021 announcement, AT&T expanded its FirstNet's MCPTT options available to agencies by launching support for Motorola Solutions' Kodiak Networks platform. This Motorola Solutions platform is a seasoned PTT over cellular (PTToC) platform enhanced to support 3GPP MCPTT.

Critical Connect is a separate Motorola Solution cloud service offer supporting Motorola's Kodiak Network's architecture. Currently hosting Motorola's proprietary push-to-talk over cellular (PTToC) clients, the platform also serves as an interoperability hub that links disparate land mobile radio systems. Agencies can use a Project 25 ISSI link to secure peer connectivity with one or more peer Project 25 networks linked to Critical Connect.

The July press release does not describe the planned FirstNet interoperability topology. We believe the solution will provide FirstNet-hosted 3GPP mission-critical push-to-talk clients with configured membership in talkgroups accessed via the Critical Connect hub. Not surprisingly, the solution extends to non-3GPP PTToC offered via the legacy AT&T Enhanced Push-to-Talk (EPPT) service. The EPPT service has always been hosted on the Kodiak Networks platform.

Other announced elements of the FirstNet ecosystem expansion include:

• NetMotion by Absolute: A mobile-first VPN solution.
• MissionKeeper from KSI Data Sciences: Streaming software for access to live-streamed video and data from IoT devices such as drones.
• FirstNet Messaging: Group notification and messaging.

FirstNet Impact

• Stronger interoperability story: The move helps buttress FirstNet's claim as an interoperability solution for public safety agencies. By providing links from its standards-based PTToC offer to systems attached via the Motorola Solutions Critical Connect platform, FirstNet immediately gains sweeping interoperability prospects with legacy Project 25 systems.
• An answer to Verizon's support for Kodiak Network's Critical Connect: The announcement by Verizon that it will support Motorola's Critical Connect as a gateway to LMR created pressure on AT&T to match the capability. With this announcement, FirstNet goes beyond the Verizon offer to include 3GPP MC-PTT clients. Verizon is limited to Motorola's proprietary clients.
• Dilutes the FirstNet argument for zero interoperability with other MC-PTT systems: FirstNet has famously rejected moves to allow a mixture of critical communications users hosted on different service providers. But Critical Connect does just that with support for FirstNet, AT&T EPTT, and Verizon Group Response.

Ecosystem Impact

• Verizon: The recently announced Group First Response offer enables smartphones equipped with the Motorola Solutions client to connect into Motorola's Critical Connect hosted service. Unfortunately, the capability does not extend to Verizon's Push-to-Responder service for 3GPP MC-PTT clients. Verizon will need to bridge the two service offers.
• T-Mobile: T-Mobile has no 3GPP MC-PTT offer. Its PTToC capabilities are based on the ESChat framework that offers a wide range of gateway support to Project 25 and other legacy land mobile radio systems.
• Motorola Solutions: Motorola Solutions' Critical Connect gains an important place in the interoperability story between FirstNet and Project 25 networks. However, the question remains as to how much interoperability. It is not clear if non-Motorola Project 25 systems have been successfully connected to Critical Connect. That said, this announcement cements Motorola Solutions' leadership as an interoperability enabler. Who would have thought that was possible?
• L3Harris: With its proven BeOn client and XL series of LTE/LMR hybrid devices, L3Harris should be in an excellent position to leverage PTToC. But the L3Harris to FirstNet interconnect story remains a work-in-progress. The company needs to develop a means to interconnect customer's legacy Project 25 systems with FirstNet's 3GPP MC-PTT.
• Samsung Networks: With AT&T acknowledging Samsung's MCPTT solution as the heart of its initial 3GPP-based solution, Samsung gains an important public reference customer. As the pace of 3GPP MCPTT deployments quickens in Europe, the AT&T reference solidifies Samsung's market position at a pivotal time.

End User Impact

• End users are still in early days: With limited device form factors available for 3GPP MC-PTT, few agencies are in a position to deploy the capability. But we expect additional 3GPP MC-PTT (and eventually push-to-data, push-to-video for a full "Push-to-X" suite) devices to arrive in the market in the coming years. The FirstNet interoperability with Motorola's Critical Connect is an easy way to gain experience bridging the two technologies.
• More devices now support MC-PTT: While once limited to the Samsung X-Cover Field Pro, AT&T now points to a broad set of devices with MC-PTT clients. The AT&T 3GPP-based MCPTT client is now on the rugged, PTT-centric Sonim XP8 and Kyocera DuraforcePro 2, as well as a set of consumer devices that include the Samsung Galaxy S21 series.
• Future procurement needs to factor in LTE/LMR interoperability: As agencies plan for procurement in the coming years, they must factor in a hybrid world that includes links between LTE clients and legacy land mobile radio systems. RFIs, RFPs, and contracts must ensure a smooth process that speeds integration.
• ISSI links are expensive and painful to configure: Vendor support for Project 25 ISSI links requires costly licenses. Talkgroup linkages established on Motorola's Critical Connect bring further license fees. Agencies may find the cost of interoperability puts the goal out of reach, leaving less capable approaches such as radio-over-IP as the go-to solution. While Motorola's Critical Connect may be a cost burden, it eliminates the need for mesh ISSI links to surrounding jurisdictions. With ISSI configuration a complicated process and ISSI link cost consideration, the use of Motorola's Critical Connect may deliver a superior total cost of ownership.
• Headaches loom: Some poor soul will have to map talkgroups and devices between MC-PTT and the legacy system. We hope vendors step up with tools to make this process automatic.

Bottom Line

AT&T announced a suite of valuable additions to its FirstNet offering. Collaborating with Motorola Solutions to link FirstNet MC-PTT users with legacy systems over Motorola's Critical Connect is a shrewd move that bolsters the interoperability claims made by FirstNet/AT&T. But the action also calls into question FirstNet's aggressive push-back on interoperability with Verizon. After all, if Verizon's users connect to Critical Connect and FirstNet's users connect to Critical Connect, then why can't Verizon MC-PTT users be readily hosted on MC-PTT talkgroups with FirstNet users? It is early days, and the interoperability story has many chapters to go.