Repeaters for Coverage and Femtocells for Speed and Capacity

There are several technical solutions for dead zone coverage in your home, ranging from:
  • Chasing your network provider to install extra cell towers near your home, improving signal strength throughout
  • Switching network providers to one with better coverage in your area (always worth checking before taking out a new contract)
  • Installing a repeater to boost the signal between your cellphone and the cell tower
  • Using an operator's dual-mode WiFi/cellphone UMA service, such as T-Mobile's hotspot@home
  • Using a dual-mode WiFi/cellphone, but making calls using a separate internet VoIP program such as Fring or Truphone
  • Using a femtocell, such as Sprint's Airave

Broad Tradeoffs between signal repeaters and femtocells

  • Repeaters are a one-off purchase and can be self-installed.
  • WiFi based solutions may not require any installation (if you already have WiFi at home), but require a WiFi or UMA capable cellphone.
  • Femtocells are self-installed by connecting to your broadband at home - they become part of the wireless operators network and attract a monthly fee.
In particular, there's quite a lot of debate between signal boosters and femtocells.

Signal Boosters are great for poor voice coverage in sparsely populated areas

Fans of signal boosters argue that for a one-off fee, the problem of poor coverage is solved. It benefits all users - there's no additional charge or fees for boosting calls, so owners are happy for anyone to use them. In some cases, they can also boost signals for more than one network (some types of booster are dual band and can handle frequencies from different operators).

WiFi needs a dual-mode cellular/WiFi handset

WiFi/UMA operators highlight that there is usually nothing to be done to install their system in your home - many homes already have WiFi. The issue is buying and configuring the cellphone, and sometimes configuring any security protection on your WiFi network to allow access. There is a small, but growing, range of handsets available to be used in this way. Some models have had VoIP withdrawn recently, with manufacturers citing lack of demand for this feature. Indeed, most people are happy enough to use the standard phone in the normal way and just expect it to work.

Femtocells solve poor coverage but bring increased capacity and data performance too

Femtocell advocates would claim that this is what their solutions offer. Femtocells are fully functional cell-towers, but miniaturised into a unit of similar size to a WiFi access point. They connect to the cellular operator's network using your broadband internet link (cable or DSL). They are compatible with existing phones, although you can restrict whether your femtocell is available for anyone to use for calls, or just accessible from nominated cellphones. When entering your home, the cellphone switches to using your femtocell and calls are sent and received in the normal way - it just uses your own broadband rather than the external celltower. The downside is that your cellular network operator will typically want a monthly fee for you to continue using it, although this can be wrapped up in your overall bill.


In sparsely populated areas, repeaters may well be a good and appropriate solution. I liken them to having a megaphone installed on your rooftop, allowing you to use your normal voice to project further.

But the radio planning teams within network operators find that these devices can cause untold problems in some situations. Imagine a densely populated area where many poeple were shouting through a megaphone - it would affect those who weren't using one. As with any shared resource, those who shout loudest get served first, whilst the ordinary guy gets poorer service. This can make it diffiicult for the radio planning teams to decide the best place to install new cell towers, and how to tune the network by varying power levels and frequency allocations etc.

Another reason to use femtocells is to offset the growing usage of mobile broadband data services. Each femtocell has the capacity today to handle 10 Mbit/s or more, and future versions will have the capability of 100 Mbit/s or more. This is replicated throughout every femtocell installation in the country - if millions of femtocells are deployed, then the total capacity is enormous. Outdoor cellsites have a similar capacity - today's 3G cellsites may have 3 or 6 sectors and therefore somewhere in the region of up to 50Mbit/s maximum; 4G cellsites may be ten times that. But each cellsite is serving something like 1000 subscribers (this includes those with phones switched off, not on a call etc), so the actual capacity per user is much reduced. Femtocells dramatically increase the data carrying capacity of the network, and by offloading traffic that would otherwise be carried on the outdoor network, free up capacity and improve quality for those who need to use the service away from home.

Finally, for data services, the short distance between the laptop and the femtocell will dramatically improve the radio connection and therefore quality and throughput it can offer. By using a femtocell, laptop and mobile data users will get a much better, faster experience which will use less battery power.

Summary: Boosters vs Femtocells

To summarise, in some situations signal boosters are good to solve poor coverage issues in remote areas for voice service only. In urban environments or where 3G data services are required, femtocells or WiFi solutions are needed to achieve best results.

Coverage *** ***
Capacity * ***
Data speed O ***

For more information about Femtocells including technical and commercial business case aspects, visit

David Chambers
Buy Femtocell Primer - the only femtocell book published today

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