Femtocell

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A femtocell (engl. Femto cell) is a radio cell with minimal spatial extent. It is a small transmitting and receiving station that is used in relatively small, sometimes private areas, such as in one's own apartment or individual rooms within buildings, and extends the network of the respective mobile phone provider .

Femtocells are used in the following radio networks , among others :

It can be used with any subscriber device as long as the corresponding standard is supported. The benefit of femtocells lies in the development of locations that are difficult to reach by radio, but above all in the expansion of capacity in areas already served. Femtocells are often installed in the shops of the mobile phone providers in order to establish or improve the network supply for the purpose of demonstrating the end devices offered.

Femto cells can be accessible for general use ( CSG-open femto cell / open access femto cell ) or reserved for a closed group of users ( CSG-closed femto cell / closed access femto cell ).

The femtocell is also integrated into public cellular networks, so that connections between the cell and neighboring cells are transferred without interruption . The connection to the core network of the mobile operator takes place via a private broadband internet connection. The femtocell is connected to the private Internet gateway (usually in the form of a DSL or cable modem ) using a cable . The data transmission between femtocell and the core network is encrypted.

Since the connection to the core network of the mobile operator is established via existing private broadband connections (mostly ADSL / VDSL or cable connections), the UMTS provider saves the costs of leased lines, which it could pass on to the customer.

Products

Since August 2007 the following companies have announced products for private users:

  • Vodafone GmbH: Vodafone Sure Signal in Germany (since August 2012, only for business customers)
  • Telefónica Germany GmbH : Signal Box S and Signal Box M (since May 2013, only for business customers)
  • Sunrise Switzerland has been offering this service for business customers since May 2011. Free of charge for private customers since February 2014.

Vodafone is now stopping the operation of femtocells in Germany.

Hacker attack

In Great Britain in 2010, femtocell technology created an enormous security problem for Vodafone UK. Hackers from The Hacker's Choice (THC) group managed to crack the Vodafone UK network using femtocells, which Vodafone sells in Great Britain under the name “Sure Signal”. This made it possible to make phone calls at the expense of a victim or to send out their caller ID instead of your own. You were also able to listen to the user's mobile box and receive his SMS. What weighed most heavily, however, was that it would have been possible for an operator of a hacked femtocell to eavesdrop on and record all telephone calls being made via "his" network. This was an abuse of femtocell technology. As described above, this provides for expanding the mobile network of a provider with its own small cells. The traffic of the mobile subscriber then runs completely via their own connection (femtocell box & ADSL line), which makes eavesdropping very easy if the encryption is cracked. The problem was solved with the help of a security patch.

The version of the femtocell, which has meanwhile been introduced in Germany, is based on the hardware of another manufacturer and has been checked through multi-stage security audits and penetration tests by various external security service providers.

Picocells

Private base stations, picocells , already exist in business customers for better cell phone coverage in large buildings.

Naming

The prefix femto is an SI prefix meaning Billiardstel.

credentials

  1. ↑ Vodafone now also offers UMTS femtocells for private customers . In: article . tarifetarife.de. February 22, 2013. Retrieved March 5, 2013.
  2. ↑ Henning Gajek: Sure Signal: Vodafone wants to offer femtocells from summer . In: article . teltarif.de. July 21, 2012. Retrieved February 1, 2013.
  3. ↑ O2 brings femtocell for business customers . In: computerwoche.de . August 29, 2013. Retrieved July 27, 2013
  4. ↑ heise online: Vodafone switches off UMTS femtocells. Retrieved on May 2, 2018 (German).
  5. ↑ http://www.coolsmartphone.com/2011/07/15/vodafone-sure-signal-hack-problems-fixed/

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