An investigation into jamming GSM systems through exploiting weaknesses in the control channel forward error correction scheme

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Masters of Science in Engineering (Electrical), 2017The ability to communicate effectively is of key importance in military scenarios. The ability to interfere with these communications is a useful tool in gaining competitive advantages by disrupting enemy communications and protecting allied troops against threats such as remotely detonated explosives. By reducing the number of corrupt bits required by using customised error patterns, the transmission time required by a jammer can be reduced without sacrificing effectiveness. To this end a MATLAB simulation of the GSM control channel forward error correction scheme is tested against four jamming methodologies and three bit corruption techniques. These methodologies are aimed at minimising the number of transmitted jamming bits required from a jammer to prevent communications on the channel. By using custom error patterns it is possible to target individual components of the forward error correction scheme and bypass others. A ran dom error approach is implemented to test the system against random errors on the channel, a burst error approach is implemented to test the convolutional code against burst errors, and two proposed custom error patterns are implemented aimed at exploiting the Fire code’s error detection method. The burst error pattern approach required the least number of transmitted jamming bits. The system also shows improvements over current control channel jamming techniques in literature.XL201

Standard interface definition for avionics data bus systems

Data bus for avionics system of space shuttle, noting functions of interface unit, error detection and recovery, redundancy, and bus control philosoph

Applications of satellite technology to broadband ISDN networks

Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about $190M whereas the second architecture would be about$250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

The 30/20 GHz flight experiment system, phase 2. Volume 2: Experiment system description

A detailed technical description of the 30/20 GHz flight experiment system is presented. The overall communication system is described with performance analyses, communication operations, and experiment plans. Hardware descriptions of the payload are given with the tradeoff studies that led to the final design. The spacecraft bus which carries the payload is discussed and its interface with the launch vehicle system is described. Finally, the hardwares and the operations of the terrestrial segment are presented

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression