Design and implementation of device-to-device communications in next generation mobile networks to counter terrorism in shopping malls

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Mwashita, Weston
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Vaal University of Technology
In this research study, a scheme to minimise interference in converged mobile cellular networks (MCNs) and wireless sensor networks (WSNs) was designed and implemented. The focus was the mitigation of interference that arises when proximity service (ProSe)-enabled sensors engage in a device-to device (D2D) communication to alert smartphone users upon the detection of explosives at highly crowded areas like shopping malls. D2D is a technology that academia and industry experts believe will play a prominent role in the implementation of the next generation of mobile networks, specifically, the fifth generation (5G). However, the full roll out of D2D is being impeded by the interference that the technology introduces to the cellular network. D2D devices cause a significant amount of interference to the primary cellular network especially when radio resources are shared. In the downlink phase, primary user equipment is likely to suffer from interference emanating from a D2D transmitter. On the other hand, the immobile base station is affected by interference caused by the D2D transmitter in the uplink phase. This type of interference can be avoided or reduced if radio resources are allocated intelligently under strict coordination of the base station. An NP-hard optimisation problem was formulated and finding a solution to this problem in 1 ms is not possible. 5G has a frame structure duration of 10 ms with 10 subframes of 1 ms each. Heuristic algorithms were then developed to mitigate the interference affecting the primary network that could carry out resource allocation within the fast-scheduling period of 1 ms. Smartphones have progressed into devices capable of generating massive volumes of data. The challenge is that battery technology is not keeping up with the pace of smartphone technology, so any additional feature that designers want to add, is met with a lot of contempt from customers who are concerned about their smartphone batteries depleting rapidly. In this context, the strategy must be energy-efficient for smartphone users to embrace it. A system level simulator was developed using MATLAB to evaluate the efficacy of the proposed design. Extensive simulation results showed that ProSe-enabled sensors can safely be integrated into cellular networks participating in D2D communication with smart phones, without introducing significant harm to the primary cellular network. The results showed that after implementing the proposed strategy, overall user throughput decreased by 3.63 %. In cellular networks, this is a modest figure since a reduction of up to 5% is acceptable to both users and network providers. The figure generally capped in service level agreements signed between network providers and users is 5%. The proposed technique also resulted in a 0 % reduction in SINR of CUEs in a cellular network, according to the findings. In terms of D2D link throughput for different D2D transmit levels, the method proposed in this research work surpassed a similar scheme proposed in literature by an average of 18.3%.
D. Tech. (Department of Process Control and Computer Systems, Faculty of Engineering and Technology), Vaal University of Technology.
Mobile networks, Smartphones, D2D devices, Cellular network, Next generation, Shopping Malls