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Nextivity Launches New CEL-FI DUO Smart Signal Booster

T-Mobile the first mobile provider to offer the all-new 4G/LTE smart signal booster to subscribers. New dual-band signal booster ensures crystal-clear voice services and lightning fast LTE data speeds for T-Mobile customers.

SAN DIEGO – September 17, 2014Nextivity Inc. today announced the launch of the CEL-FI DUO, a new dual-band smart signal booster designed for use on 3G, 4G LTE (including VoLTE) and UMTS networks. In Un-carrier™ fashion, T-Mobile is the first wireless provider in the world to offer the all-new CEL-FI DUO to customers, allowing them to extend their 4G LTE network experience indoors where traditional cellular networks hit walls.

Despite the fact that it is smaller than any of its predecessors, the DUO is packed with features. In addition to added support for 4G/LTE (including VoLTE), the CEL-FI DUO offers dual-band support for up to 35MHz of boosted bandwidth, allowing it to operate with the expanding set of channels used on the T-Mobile network. It also provides 10 times the gain of earlier versions for a bigger and better coverage footprint than ever, and uses patented echo-cancellation algorithms for stronger signals in the coverage area. It is the only dual-band smart signal booster designed to simultaneously boost UMTS/WCDMA voice as well as LTE (including VoLTE) signals on the T-Mobile network. The T-Mobile variant of the CEL-FI DUO will be available to customers starting September 17, 2014.

“With the launch of Nextivity’s new 4G/LTE signal booster, we are continuing to deliver on our promise to our customers,” said Jason Young, senior vice president of product marketing at T-Mobile. “This is another example of how we offer innovative ways to experience our network no matter where our customers are.”

Addressing the Indoor Coverage Challenge
According to recent survey data, more than half of mobile subscribers in the U.S. experience dropped calls, poor voice quality, or poor data rates inside their homes or offices. The all-new, all-digital CEL-FI DUO being launched today is a plug-and-play booster; simply plug it in and it works – no cabling, no external antennas, and minimal configuration necessary. It can be set up quickly and easily to deliver up to five bars of 3G or 4G/LTE coverage in just minutes.

The CEL-FI DUO is comprised of two units. The window unit captures the signal from a nearby T-Mobile cell tower and brings it inside. The coverage unit creates a large coverage bubble that automatically adapts to a subscriber’s indoor environment to maximize coverage in homes and small offices.

“T-Mobile’s continued support of our smart signal booster across its network is testament to the smarts we’ve built into our award-winning CEL-FI booster,” said Werner Sievers, president and CEO of Nextivity Inc. “T-Mobile continues to solve customer pain points by delivering new services to customers. We are proud that CEL-FI is part of the T-Mobile toolkit, and look forward to continued success as T-Mobile makes our all-new CEL-FI DUO technology available to customers.”

Changing the Booster Landscape in the U.S.

T-Mobile and Nextivity worked together with the FCC to craft the recently regulated CFR20.21 rules concerning the use of consumer signal boosters on mobile networks. T-Mobile was also the first wireless provider to request approval for a carrier specific signal booster under these new rules. The CEL-FI DUO was the first carrier specific signal booster to be approved in the U.S. under these new FCC rules.

While analog signal boosters (repeaters) have been available for sale in the U.S. for many years, prior to the adoption of the 47 CFR 20.21 rules, it has been illegal to install and use them because of network interference. As an all-digital smart signal booster, CEL-FI was designed and developed by Nextivity using some of the most advanced radio frequency and signal processing technology in the market today.

CEL-FI DUO for T-Mobile

T-Mobile customers interested in learning more can contact T-Mobile Customer Service or visit a T-Mobile retail store. Subscribers that are not eligible to receive a 4G/LTE signal booster from T-Mobile can purchase CEL-FI DUO directly from Nextivity.

About Nextivity Inc.

Headquartered in San Diego, Nextivity Inc. develops the CEL-FI Smart Signal Booster, which is authorized by more than 160 leading global carriers in 83 countries for use on their networks. Nextivity’s engineering team has leveraged advanced signal processing and intelligent antenna design to develop the world’s only self-configuring, environmentally aware indoor coverage systems. Additional information is available at, on Twitter @5bars, and on Facebook (

Nextivity, the Nextivity logo, and CEL-FI are registered trademarks of Nextivity Incorporated in the United States and/or other countries. All other trademarks are the property of their respective owners.

Media Contact
Marisa Marzano
Echo Communications (for Nextivity)
[email protected]