Frequent Asked Questions and Answers
The Next Generation of Signal Boosters
Nextivity Cel-Fi RS2 Mobile Signal Booster General and Technical Questions
- What is Cel-Fi?
Cel-Fi is a carrier-grade, consumer-friendly smart signal booster
that maximizes a user’s indoor wireless experience by eliminating
in-building dead zones. It can more than quadruple wireless Internet
data speeds and eliminate dropped calls for wireless subscribers in
their homes or offices by boosting signal strength from one bar to five
- How does Cel-Fi work?
Cel-Fi consists of two units: the Window Unit (WU), and the
Coverage Unit (CU). Users place the WU in an area with the strongest
signal from the carrier network. The CU is then either placed in the
center of the home or office, or in the area where the best signal
quality is most needed.
The two units communicate wirelessly with one
another enabling the CU to effectively produce a “bubble of quality
signal” throughout the home or office, resulting in significantly better
voice quality and greater data throughput. The WU and the CU are placed
at varying distances apart, but in general an indoor distance of up to
20 meters, or 66 feet, is common.
- Who uses Cel-Fi?
Cel-Fi is typically used by residential subscribers or SMB/SMEs
that experience coverage and/or data throughput and performance problems
such as in-building dead-zones and dropped calls.
- Where can I buy Cel-Fi?
Cel-Fi is available through e-NETSource. Cel-Fi is also offered by and authorized for use by 120
global mobile operators, including Telstra, Optus and many
- Why should I use Cel-Fi?
Cel-Fi is used to resolve the issue of poor indoor cellular signal
quality in homes, home offices small business and enterprises. Cel-Fi
is self-learning and self-configuring, making it fast and easy to
install and use. There is no professional installation required, no
drilling, and no cables. Users most often say, “if you can install a
light bulb, you can install Cel-Fi."
- Will Cel-Fi work with my iPhone?
Yes! All versions of the iPhone (including 5S and 5C) are supported on new RS2 Cel-Fi systems sold on this web site.
- Does Cel-Fi require an Internet connection?
- Can Cel-Fi run on batteries?
Cel-Fi does not currently run on batteries and requires a power
outlet to operate. You can install a UPS between Cel-Fi and the power
- I’ve installed Cel-Fi, but my mobile phone’s signal strength is the same.
It is very likely that you are using an iPhone, which measures
your signal differently than other devices. Even if your Cel-Fi booster
is installed correctly and the service you experience is substantially
improved, your iPhone may not show you these improvements in relation to
the number of signal strength bars on the phone.
To learn more about
how iPhones display signal strength, click here.
- Which mobile operators offer Cel-Fi?
In Australia Cel-Fi is currently approved for Telstra Next G network, including Aldi Mobile, Boost Mobile and Kogan Mobile (all on 3G 850MHz network only), and Optus's 3G 900 and 2100 network, including Amaysim, iiNet, TPG and Virgin.
For New Zealand it is approved for 2 Degrees Mobile. Cel-Fi is authorized for use by 120 mobile operators around the
world. Another 65 carriers are currently testing Cel-Fi on their
networks. Of the world’s top 20 mobile operators, 13 have either
implemented or are testing Cel-Fi.
- Is Cel-Fi operator or service provider specific?
Yes, each Cel-Fi system is designed to work only on individual operator network.
- Why do mobile operators like Cel-Fi?
It’s estimated that 17% to 25% of all mobile users worldwide
experience poor quality indoor wireless coverage, translating into well
over 1 billion subscribers globally. As a result, carriers lose more
than $10 billion through customer churn, and lost upsell opportunities.
Cel-Fi immediately increases retention and subscriber satisfaction.
Cel-Fi subscribers buy more services and use more of the ones they have,
resulting in increased monthly revenue for carriers.
- Is it legal to use signal boosters?
Mobile operators have historically adopted an extremely strict
policy against the use of consumer-class boosters on their networks due
to interference and resulting damage caused by legacy repeaters.
However, Cel-Fi is fully compliant with the new Report and Order for
signal boosters as defined by the Federal Communications Commission
In Australia Cel-Fi is currently only approved for:
Telstra Next G Network, including Aldi Mobile, Boost Mobile and Kogan Mobile (all on 3G 850MHz network only).
Optus's 3G 900 and 2100 network, including Amaysim, iiNet, TPG and Virgin.
Please note that once you turn on Cel-Fi it will lock to the towers in your area within 32 hours and will stay locked to those towers. If you change address please contact our office (for those customers that have bought the units from e-NETSource)
- What makes Cel-Fi different from other smart signal boosters?
Cel-Fi relies on intelligent, self-organizing algorithms to
maximize the area of coverage for users while ensuring that it does not
compromise or interfere with mobile operator networks or impede other
subscribers’ signals. Cel-Fi does not require any new equipment or
changes to existing network infrastructure, or mobile devices.
Recognized for its superior design and effectiveness, Cel-Fi is the only
consumer booster authorized and approved in Australia (Telstra Next G, and Optus 3 G Networks), New Zealand (2 Degree Mobile) and the United Kingdom.
- Does Cel-Fi require maintenance or adjustments if changes occur to the serving cellular network?
No. Cel-Fi does not require maintenance, and it will automatically adjust to changing cellular network situations.
- What technologies does Cel-Fi support?
The current version of Cel-Fi supports 3G WCDMA/HSPA+ technology,
commonly referred to as 3G and 4G, but not to be confused with 4G LTE.
- What is IntelliBoost?
The Cel-Fi's IntelliBoost Baseband Processor is the first core
processor designed specifically to optimize the indoor transmission and
reception of 3G wireless signals. With advanced filtering, equalization
and echo cancellation techniques, Nextivity has developed an embedded
architecture which delivers unprecedented in-building data rates and
pervasive 3G connectivity.
The IntelliBoost processor ensures that
Cel-Fi products never negatively impact the macro network while
providing maximum coverage. By continuously monitoring the gain and
making real-time adjustments, the system will never overdrive the base
station or raise the noise floor.
- What frequency is used to communicate between the two units (the Window Unit and the Coverage Unit)?
Cel-Fi uses channels from both the U-NII-1 (either 5.15-5.25 GHz or 5.25-5.35GHz) and the U-NII-2 block (5.47-5.725 GHz) to communicate
between the Window Unit and the Coverage Unit.
- Does a Cel-Fi system have to be activated or provisioned on the mobile operator’s network?
No, Cel-Fi products do not require network activation or
- Experience has shown that traditional repeater products
often cause significant degradation to mobile network quality. How is
Cel-Fi utilizes an intelligent processor to actively adjust to the
network environment. It uses multiple techniques including automatic
gain control, real-time path loss analysis, and uplink signal gating to
ensure that it never degrades the quality of the macro network signal or
artificially raises the noise floor of the Node B.