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A GSM/UMTS network is provided and operated by Osmocom during the conference.

You can use the GSM/UMTS network to place calls or send SMSs for free on the GSM/UMTS network as well as to the on-site DECT, ISDN, POTS and VoIP networks of the POC. To use the network you require a congress SIM card.

GPRS/UMTS for internet or data traffic might be provided occasionally, but the bandwidth is likely insufficient for anything beyond an IRC client.

To operate the GSM/UMTS network the free software implementation osmocom is used. If you want to know more about it, talk to the GSM team located at CCH 0, near the POC.


the network is work in progress (e.g. highly unstable)

what works:

  • you can buy a SIM card at the POC
  • the GSM network is running (currently with low power)
  • the UMTS network is running (currently at only one location)
  • phones can register to the GSM/UMTS network
  • get your extension by dialing *#100#
  • send SMSs between phones
  • register your extension using your GSM token ("call ended" means it failed while "call finished" means it succeeded; wait up to 15 min or toggle airplane mode to take effect)
  • voice calls over GSM (also to and fron DECT)

what does not yet work:

  • voice calls over UMTS
  • GPRS is unstable (and very slow)

what will never work:

  • high speed GPRS

SIM card, registration

To be able to use the GSM network, you require a SIM Card dedicated for this network. It is required to encrypt the traffic over the air:

  1. use a SIM card from past CCC events, or acquire a new one at the POC for 2 euros
  2. Register/log-in on eventphone
  3. Register a new extension with phone type "GSM". Give the system a couple of minutes to synchronise with our in-house GSM provider. Relax. Maybe have a nip of your favorite caffeinated beverage.
  4. Dial the GSM token shown in the details view of your extension. This step completes the registration process and pairs your device/SIM with the event's GSM network. If you ever feel like switching devices or SIM cards, then just redial this number on your new device.

note: the SIM card also works without using the token, but only within the GSM network.


To use data over GRPS or UMTS you need to set up an APN.

Under Android go to Settings -> Wireless & Networks -> More -> Cellular networks -> Access Point Names. You only need to set the APN to "internet" and the APN protocol to IPv4.


The UMTS network operates on Band V (850 MHz). Most feature phones and some smartphones do not support this band. You can check on phone databases such as PhoneArena or phonedb.

Additional information

  • To get your extension, dial *#100#.
  • You can be called from the outside. For more information and outside phone number visit the Static:Linux-Call-Router project.
  • You can re-use the GSM token you got when creating an extension with any SIM for this network.
  • The MCC (Mobile Country Code) is 262 (Germany), the MNC (Mobile Network Code) is 42.
  • Our network use the following bands:
    • GSM (DCS 1800)
    • UMTS (850 / band 5)

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