AT&T, Assured Wireless developing high-powered user equipment (HPUE) to extend effective FirstNet coverage

BALTIMORE—FirstNet users soon may be able use high-power user equipment (HPUE) on 700 MHz Band 14 spectrum that is expected to extend the effective range from a cell site by 80% triple the effective coverage area and enhance in-building coverage—characteristics that AT&T’s FirstNet leader calls a “game changer.”

Chris Sambar, AT&T’s senior vice president for the FirstNet program, said that HPUE is one of several technologies that AT&T is eager to launch on FirstNet.

“HPUE is one [technology] that we’ve really been pushing hard on,” Sambar said yesterday during an interview with IWCE’s Urgent Communications. “Assured Wireless is doing a really nice job. That’s going to be a game changer.”

Typical cellular devices transmit signals using a maximum of about 200 milliwatts of power. However, a unique characteristic of the 20 MHz of Band 14 spectrum licensed to the FirstNet Authority is that devices operating the band are allowed to transmit using the 3GPP standard for HPUE that permits 1.25 watts—six times the normal cellular power level—which greatly enhances the effective range for users.

As with other cellular signals, HPUE devices do not radiate signals at maximum power under all conditions; the power level automatically is adjusted to ensure performance while saving battery life and preventing harmful interference.

Assured Wireless CEO Tom Bilotta said that the company will have HPUE products available by the end of the year.

“Our initial product plans are focused on a combination of a module that can go in other vehicle routers, fixed routers and things like that, as well as a USB modem device that can augment either fixed or vehicle solutions,” Bilotta said during an interview with IWCE’s Urgent Communications.

Bob LaRose, vice president of business development at Assured Wireless, said that the USB product—about the size of a smaller smartphone—likely will have the first one to be noticed in the marketplace.

“The USB device will have early ramifications, because people will be able to plug that into existing routers and get FirstNet HPUE, whereas the embedded path is going to take any of those same companies a little bit longer to integrate inside of their products and get them recertified, as it would with any other module,” LaRose said during an interview with IWCE’s Urgent Communications. “But the USB [version] can be just plugged in, without any further certification, as it will be certified.”

Unlike many USB devices, the Assured Wireless HPUE product will not rely on the battery of a host device to operate, Bilotta said.

“Because of some of our peak [power] draws, we were afraid that not all sourcing devices would be able to support that,” Bilotta said. “We ended up driving an external-supply capability in it, just to make sure that there’s no poor performance encountered.”

Although the Assured Wireless products can be used with antennas directly attached, LaRose said he does not believe that will be typical.

“We think that, for most normal mobile and fixed applications, they’ll be using external antennas—the kind you see on a vehicle,” LaRose said.

Bilotta echoed this sentiment, noting other potential use cases.

“We see this as being useful, whether it’s augmenting vehicle routers or whether it’s in a fixed deployment, where it could be in the streetlight controller or in a camera,” Bilotta said. “It should be pretty easy to integrate for a lot of people.”

Sambar said that AT&T also is exploring the potential use of HPUE technology in handheld devices. Although the 1.2 watts of HPUE transmit power pales in comparison to LMR devices that have maximum power levels of 3 watts and 5 watts, AT&T wants to make sure that users can utilize the device in safe manner.

“It needs to be clear to first responders that that device shouldn’t be held up to your head, because we don’t want to hurt people,” Sambar said. “They need to use it with a remote speaker mic of some sort.”

Sambar said that the availability of HPUE offerings will provide the carrier another flexible tool that can be used to deliver coverage to FirstNet users. Sambar acknowledged that HPUE could impact the carrier’s strategy when assessing the location and timing of deploying new cell sites but did not speculate on any specifics.

While most attention around HPUE coverage gains has been focused on providing coverage in underserved rural areas, the added signal strength of HPUE technology also has the potential to help address in-building communications, which is one of the most vexing problems for public safety in urban and suburban environments.

“Where do firemen go? They go in the stairwells of buildings, and those are the concrete areas that you need the building penetration on,” Bilotta said.