TETRA and Project 25 operations use narrow spectrum channels to serve the voice communications and signaling traffic. Mobile LTE broadband technology now provides similar functionality with Mission Critical Push-to-Talk (MCPTT) in standard implementations. While LTE brings substantial benefits thanks to wide and flexible bandwidth functionality, the technology remains lacking when it comes to supporting user-to-user communication without a network available. In contrast, both TETRA and Project 25 provide these direct mode operations in support of emergency services workers operating out of network range.

The Harris XL-200P is a hybrid ruggedized portable push-to-talk radio that operates on LMR radio systems, an LTE network or a Wi-Fi access point. For land mobile radio (LMR) networks, the XL-200P supports Project 25, EDACS and analog radio access technologies. The unit operates on VHF, UHF and 700/800 MHz frequencies. On LTE networks, the unit supports Verizon and FirstNet's Band 14. Customers may purchase configurations with a single band, dual band, or full spectrum support.

Hardened Push-to-Talk Operation on LTE
When launched two years ago, Harris Corporation touted it as LTE capable. At APCO 2017, Harris Corporation announced the XL-200P capabilities as an LTE communication device are now completed, and its first customers have received equipment. The unit allows the user to select the best network technology for communications.

Wi-Fi Flexibility
In addition to Project 25 and LTE connections, the XL-200P supports IP-based push-to-talk connections over a local Wi-Fi network. This functionality allows an agency to supplement coverage in police stations, jails, hospitals and other difficult-to-serve areas with Wi-Fi.

LTE tethering Means Rich Device Environment and Savings
Emergency services workers assigned XL-200P units have the ability to tether supplemental devices by using the XL-200P as a local hotspot connection when the unit is on an LTE network. The tethered functionality means that a tablet-equipped police officer has full access to LTE-based broadband communications without the need for an additional wireless service account assigned to the tablet.

Strengths

• LTE operation allows an agency with spotty LMR coverage to expand range by using wireless IP networks offered by LTE or Wi-Fi. This means that commercial service from Verizon or a Band 14 network (i.e., FirstNet) or agency Wi-Fi access points naturally expands the LMR coverage. More importantly, it provides a bridge to future interoperable public safety mission critical voice networks based on LTE networks.

• The Harris XL-200P hotspot tether mechanism provides flexible attachment of additional devices supporting richer user interfaces. By tethering through the XL-200P LTE connection, agencies avoid the need to purchase additional service subscriptions for tablets, eCitation printers, etc.

• The Harris XL-200P includes direct mode operation, a critical feature when users are out of range of either the LTE or LMR systems.

• Harris participated in the 2017 ETSI Mission Critical Push to Talk Plugtest event. This shows a commitment to an open mission critical LTE standard for voice communications.

Concerns

• When it comes to LTE, the XL-200P is currently limited to Band 14 and Verizon bands. FirstNet's partner AT&T public statements suggest slow Band 14 adoption may be the case if existing AT&T capacity is adequate. Any agency that signs up for FirstNet will not likely gain the benefits of LTE connectivity provided by the current XL-200P, but Harris’ roadmap includes support for AT&T bands.

• Harris Corporation does not have a presence in the TETRA market. Nations around the world are engaged in modernizing public safety communications systems by adding LTE capability. Without a track record of support for TETRA, Harris Corporation misses an important potential opportunity beyond North America.

CritComm Perspective

The Harris XL-200P is an important contribution to the future of The Harris XL-200P is an important contribution to the future of public safety voice and data communications. Two years ago, Harris Corporation launched the XL-200P as an LTE capable platform. At APCO 2017, the company delivered on the promise of robust LTE connectivity as an alternative to traditional trunked technologies. By serving as an LTE communications device, the unit enables an evolutionary path that starts with Project 25 trunked radio systems and ends with all-IP LTE broadband systems.

Beyond voice support, what stands out is a flexible Wi-Fi tethering mode provided for connecting devices such as tablets or printers. Police Departments gain the best of both worlds: familiar hardened PTT terminals coupled with rich end user application interfaces hosted on tablets, all operating over a single LTE subscription.

Unfortunately, however, the original frequency plan anticipated a combination of LTE bands that may not be available to FirstNet subscribers. The lackluster commitment to Band 14 deployments means that FirstNet subscribers will largely be on AT&T commercial bands not supported by the current XL-200P, but Harris’ roadmap promises support is coming to implement AT&T bands. Of course, what would really make this device shine is fully automatic switching between trunked operations, Wi-Fi and LTE. Nonetheless, the initial suite of shipping LTE capability puts the Harris XL-200P heads-and-shoulders above the competitive pack.