Simulation Evaluation of the IEEE 802.11ac ad-hoc Network for Voice Communication in Emergency Scenario

The paper presents simulation study of communication system consisting of mobile nodes during crisis situation scenario. Nodes' network interfaces support IEEE 802.11ac standard in ad-hoc mode, while devices operate under control of Google Inc. Android operating system. Overview of current Wi-Fi techniques was described, with an indication of further standard evolution. Limitations of current Wi-Fi ad-hoc mode implementation in Android were addressed, with emphasis on ongoing research projects on overcoming speciflc restrictions: Wi-Fi Peer-to- Peer extension and multi-hop transmission. Evaluation of network e-ciency with Voice over IP service activity during an emergency scenario was performed in simulation environment. Lack of cellular connectivity, external power access and no access to special communication equipment during rescue operation were assumed. Obtained results show insigniflcant impact of service realization on network resources utilization, low maximum end-to-end packet delivery delay and jitter values during continuous telephone conversations. Thus, described assessment shows a high degree of IEEE 802.11ac ad-hoc network applicability in scope of basic voice communication service realization in case of absence of usually ubiquitous cellular infrastructure, with use of typical communication equipment. We face crisis situations everyday and are immediately informed on every such crisis by the mass media. These events take place in both stable and rich countries such as France and unstable, such as Ukraine. The attack on Charlie Hebdo editorial o-ce or the racket attack on Mariupol are difierent examples of accidents, but they have something in common. In both the flrst and second case, the access to mobile telephone services was limited. In the flrst case, due to overload of the mobile network and its subsequent switch-ofi, and in the second case, due to failure of the flxed-line network. Even more severe situations occurred in 2004 in Indonesia and in 2011 in Japan, where the tsunami caused deaths of hundreds of thousands of people, and in the areas covered by the disaster, access could not be provided to telephone services which would be very useful in such a situation. Due to the damages of the power plants operating in an integrated power system over a wide area of Japan (even that not directly afiected by the tsunami), a black-out occurred. Development of the Wi-Fi standards results in their throughput similar to that of Ethernet networks. Today, it is di-cult to imagine a TV, camera or smart phone without Wi-Fi | they are as common as the very telecommunications service. The range of a home-edition of Wi-Fi radio interface is limited to several dozens of meters and ensures a quick exchange of data between difierent devices. The unit price of manufacture of a Wi-Fi transceiver allows for using this solution even as a single-use device (1).