Open BTS: Emergency GSM Messaging & Monitoring System for Civil Protection is proposed as a solution ready-to-deploy in the event of natural disaster, in that areas where GSM networks are temporarily down.

1. Luca Bongiorni OpenBTS UNIVERSITY OF OSTRAVA Department of Telecommunication

5. How GSM works !? Mobile Stations Base Station Subsystem Network Management Subscriber and terminal equipment databases BSC MSC VLR HLR EIR AUC OMC BTS BTS BTS

11. Authentication and Encryption Scheme A3 Mobile Station Radio Link GSM Operator A8 A5 A3 A8 A5 K i K i K c K c SIM Challenge RAND m i Encrypted Data m i Signed response (SRES) SRES SRES F n F n

13. Authentication Sequence

14. Authentication Sequence

15. Authentication Sequence

16. Authentication Features

17. A5 Encryption Mobile Stations Base Station Subsystem Network Management Subscriber and terminal equipment databases BSC MSC VLR HLR EIR AUC OMC BTS BTS BTS A5 Encryption

18. A5 Streaming Implementation A5 output is 228 bit for both directions A5 K c (64 bit) F n (22 bit) 114 bit XOR Data (114 bit) A5 K c (64 bit) F n (22 bit) 114 bit XOR Ciphertext (114 bit) Data (114 bit) Mobile Station BTS

21. Smart Card Anatomy

36. Hardware Used

37. Power System

38. GSM Network

40. Emergency GSM Messaging & Monitoring System for Civil Protection It is proposed as a solution ready-to-deploy in the event of natural disaster, in that areas where GSM networks are temporarily down. With the full handvover it also ensures the possibilty, by users, to move they from a BTS cell to another, so as to ensure optimum performance and usability of telephony / messaging system.

41. GSM Messaging & Monitoring System With the graphical interface, web-based, it is possible to reach all users in a given area and with its database will be possible to operate a feedback system to monitor their actual receipt and act accordingly management of emergency vehicles to be sent in a given area.

42. GSM Triangulation Another service implemented, in case are deployed on the ground, at least 3 BTS, is able to triangulate the signal from a particular user, with good approximation.

43. Conclusions In these few slides we saw how could be simple… develop and deploy a low cost GSM network. Infact OpenBTS gives us all we need and as an open source project, we can extend research into all GSM know-how, thanks especially to big community of researchers.

46. Bongiorni Luca – http://www.securitycondition.com These slides are written and distributed under Attribution-NonCommercial 3.0 Unported Thank you for Attention