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Cel-Fi DUO+ 3G/4G/LTE Smart Signal Booster for T-Mobile

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Item Number: 7921



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The Nextivity Cel-Fi DUO+ is the next generation of intelligent repeater kits for home and business users looking to boost their cellular network performance. This LTE signal booster is for T-Mobile network users and works with LTE bands 2, 4 and 12. Each all-in-one cell booster kit can provide high-gain coverage improvements for up to 15,000 square feet. The coverage area makes this all-in-one T-Mobile repeater kit a smart choice for large households and small businesses that need to pull in a better signal for data, voice and SMS texting.
The T-Mobile Cel-Fi signal booster is completely wireless both in and out. Furthermore, it automatically sets itself up and adjusts itself based on signal strength. As long as there is at least one bar of signal, the network unit will pick it up, boost it, and relay the signal to the coverage unit via an encrypted wireless link. A software-based coverage pattern analysis is used to optimize gain. With a peak gain of 100 dBi, it can turn even a weak signal into a robust connection. The stronger signal enhances the performance of every device in range with a T-Mobile LTE SIM card, including smartphones, jetpacks and routers with embedded modems.
We are ready to answer your questions here by phone or email. Here at 5GStore, we are dedicated to providing the best customer service.

Amplifier Features:

  • Coverage area*: up to 15,000 square feet
  • All-in-One Kit? YES
  • Compatibility: T-Mobile 3G/4G/LTE/AWS (LTE bands 2, 4, 12) ONLY - does not work with other carriers
  • Installation: Cel-Fi doesn't require the installation of external antennas, bulky coaxial cables, handset registration, or a configuration setup by the user. In fact, Cel-Fi intelligently and automatically senses and adapts to its environment-including to changes made by your carrier, or to changes caused by nearby equipment like Wi-Fi, or other Cel-Fi devices. Multiple Units of Cel-Fi can be deployed in large offices and will not interfere with coverage strength.

*Many factors will influence the actual coverage area you will see from a repeater, including layout/floorplan, construction, and original un-amplified signal strength. Depending on your situation, you may see more or less coverage than the estimates listed here. It is not possible to guarantee coverage area.

celfi pro install

Installation notes:

  • There must be at least one bar of usuable signal at the window in which you install the Network Unit. 

Features & Benefits:

  • Wirelessly linked Network and Coverage Units (5GHz U-NII band).
  • Peaceful coexistence with adjacent 802.11( 2.4GHz&5GHz), and femtocell devices.
  • Max EIRP: 10 dBm downlink per 5 MHz and up to 22 dBm uplink, per band.
  • Software-based optimization of integrated antenna coverage pattern which maximizes system gain and provides improved
  • Automatic Gain Control (AGC) based on real-time echo-cancellation.
  • Seamless call handovers between Cel-Fi systems and the macro network.
  • Subscriber devices enjoy improvements in battery life.
  • Bluetooth communications between a mobile handset and Cel-Fi via our Cel-Fi WAVE Mobile App provides software update
    capability and advanced information for technical support.
  • Adaptive signal equalization.
  • Includes Nextivity's 3rd-generation (ARES) chipset with 6 core processor.
  • Up to 3 cellular bands supported; relaying two simultaneously
  • Supports E-UTRA bands 2, 4, and 12 for T-Mobile
  • Support for 3GPP Rel. 10 features.
  • Network-Safe software prevents uplink system gain from exceeding path loss between Network Unit and closest tower,
    thus eliminating unnecessary rise in base station noise level.
  • Uplink Muting Mode automatically shuts down uplink cellular transmissions when no active user equipment is detected.
  • Secure and ciphered provisioning for only T-Mobile’s channels based on network broadcasted PLMN ID.
  • Full Band Scan feature discovers newly deployed and re-farmed spectrum

As you will see in nearly every T-Mobile signal booster review, this system can provide a significant increase in speed, reliability and battery life for multiple devices at once. The Cel-Fi DUO+ system is designed so it can function around other RF signal emitters or Wi-Fi devices without interference to the booster technology. In addition to self-adjustments for signal, it will also adapt to T-Mobile carrier changes or new equipment installations. Using a Smart T-Mobile signal booster will vastly improve the coverage area even in larger homes and offices, and you won’t need to add antennas or coaxial cables for your phones or other devices to benefit from the boosted signal.

Managing your T-Mobile Cel-Fi wireless repeater is easy as well. Their Cel-Fi WAVE mobile app supports Bluetooth communication on compatible handsets for software updates. When there are no active devices in range, the Uplink Muting Mode will automatically shut down signal transmissions to help conserve electricity. Cel-Fi software also automatically manages gain levels to prevent over-gain and interference. If a user travels out of the signal booster range while on a call, Cel-Fi seamlessly transfers the call over to the main T-Mobile network without interruption.

With this cell booster, T-Mobile reception can improve at an affordable price and with easy installation. It takes just five minutes to set up and can be used in the Americas, Europe, Africa and anywhere else that T-Mobile utilizes bands 2, 4 and 12. Read a T-Mobile 4G/LTE signal booster review in the Customer Reviews tab to decide if this device is right for you. We are ready to answer your questions here by phone or email. Here at 5GStore, we are dedicated to providing the best customer service and include a year of free tech support with each purchase.

Package Includes:

  • Network Unit
  • Coverage Unit
  • 2 Power Supplies
  • 2 Mounting Brackets
  • Quick Start Guide


  • RF Specifications:
    • Radio 1: Band 2
      • Frequency DL: 1930-1990 MHz
      • Frequency UL: 1850-1910 MHz
    • Radio 2: Band 4
      • Frequency DL: 2110-2155 MHz
      • Frequency UL: 2110-2155 MHz
    • Radio 3: Band 12
      • Frequency DL: 729-746 MHz
      • Frequency UL: 699-716 MHz
  • Environmental:
    • Operating temperature: 0° to 40°C
    • Storage temperature:-25° to 60°C
    • Relative humidity: 5% to 95%, noncondensing
    • RoHS II 2011/65/EU
    • WEEE (2002/96/EC)
    • ErP 2009/125/EC
  • Power:
    • 12VDC via external supply (two included)
    • External Supply: 100 to 240 VAC, 47-63Hz
    • Power consumption less than 25W per unit
  • Physical Specification:
    • Network Unit: 158.5 x 146 x 59mm, Weight 19.75oz.
    • Coverage Unit: 158.5 x 146 x 59mm, Weight 13.75oz.
  • Standards:
    • FCC Parts 15, 20, 22, 24, 27
    • EN 301 489 -1, 17, 23
    • EN 301 893
    • EN 301 908-1, 11, 15
    • EN 300-328
    • EN 62311
    • UL 62368-1
    • CSA C22.2#62368-1 IEC/EN 62368-1
    • 3GPP TS 25.143 Rel.10
    • 3GPP TS 36.143 Rel.10
    • EN 50566/62209-2/62479 (SAR) Bluetooth SIG

This is a CONSUMER device.
BEFORE USE, you MUST REGISTER THIS DEVICE with your wireless provider and have your provider's consent. Most wireless providers consent to the use of signal boosters. Some providers may not consent to the use of this device on their network. If you are unsure, contact your provider.
You MUST operate this device with approved antennas and cables as specified by the manufacturer. Antennas MUST be installed at least 20 cm (8 inches) from any person.
You MUST cease operating this device immediately if requested by the FCC or a licensed wireless service provider.
WARNING. E911 location information may not be provided or may be inaccurate for calls served by using this device.
Please note, the four largest carriers - AT&T, T-Mobile, Verizon and Sprint - and more than 90 regional carriers have given blanket consent for use of all boosters certified to the new FCC standards.

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All Reviews (14)

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Only customers who bought this item from 5Gstore can write a review - these are all verified 5Gstore purchases

Date Added: 10/09/2020 by Glen G. (Rockford, AL)
Works as advertised. Get 3 bars now and I can talk and FaceTime.

Date Added: 06/22/2020 by Matthew D. (Winneconne, WI)
Signal in house is better but not what u would have expected for the price.

Date Added: 06/07/2020 by Steve M. (LAKE OSWEGO, OR)
Works perfectly as advertised

Date Added: 05/29/2020 by Aaron P. (Success, MO)
If I'm just holding the phone with 1 hand connection is a tad slow but still stable. However if I use both hands to play a game in landscape mode it still frequently drops connection. Voice had slight static. There are 2 bars in the window.

Date Added: 05/16/2020 by Robert K. (Littleton, NC)
This is replacing a unit that failed just before the end of the 1 year warranty. I tried to get the filed unit returned but 5g would not provide voice support and the trouble shooting they were insisting on was preposterously ludicrous over email. I have 50 years of experience working in complex systems and this experience was intolerable. I reordered a new unit because I like them(this is my 3rd) but I did because it is somewhat unique albeit fragile.

5Gstore Comments:
We're sorry you weren't able to get the original unit working! Unfortunately your warranty had already expired when you contacted us, which limited the options available, and troubleshooting is always required by the manufacturer to get a replacement approved. Please let us know if you have any issues in the future and we will be happy to help.

Date Added: 10/09/2018 by Brian P. (Bremerton, WA)
Got Verizon signal into building interiors that never had it before.

Date Added: 09/16/2018 by Ted. (SHELBY TOWNSHIP, MI)
Works great for 700mhz band on T-Mobile!

Date Added: 04/06/2018 by Randall R. (Rocky River, OH)
Seemed to improve the signal significantly for us to use air cards in our new warehouse while we wait for our network to be installed.

Date Added: 11/22/2017 by Jackie H. (Wausa, NE)
Works as advertised. Where we were getting 1x service we now get 3 & 4 bars LTE.

Date Added: 07/31/2017 by Richard M. (Westlake Village, CA)

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Will the Cel-Fi DUO+ work with 5G?

No, the Cel-Fi DUO+ only supports LTE signals.

Can an external antenna be connected to the Cel-Fi DUO+?

The Cel-Fi Duo+ does not support external antennas.