Communications in Emergency and Crisis Situations

Abstract. In emergency and crisis situations (ECS) like earthquakes, tsunamis, terrorist attacks, it is very important that communication facilities are operative to provide services both to rescue teams and civilians. In ECS it is very common that communication premises are often unable to provide services, either due to physical damages or traffic overload. In such a case there is the need for rapid reestablishment of communication services. In this paper the communication services that can be exploited for ECS mitigation are discussed. The usage scenarios of such services are studied. Following that and looking from a network perspective view an ECS communication network architecture is presented. This architecture aims to provide seamless interoperability of varies communication technologies often present in EC

UDC 004.735, DOI: 10.2298/CSIS0901169M Co-existence Performance Evaluation of Wireless Computer Networks in a Typical Office Environment

Abstract. The Wireless Local Area Networks (WLANs) are often used as a wireless extension to the typical office network infrastructure providing mobility to the users. In addition Wireless Personal Area Networks (WPANs) serve interconnection to computer and mobile phone peripherals as headsets, input devices, printers etc. Thus it is common that WLANs and WPANs have to operate in the same area. IEEE 802.11b/g is the most popular WLAN technology operating in the 2.4GHz Industrial Medical and Scientific (ISM) band. On the other hand Bluetooth (BT) is the technology often used to support WPANs. As BT also uses the 2.4GHz ISM band, there an issue of interference between WLANs and PANs. In this work the performance degradation in Wireless Local Area Networks and Wireless Local Area Networks due to coexistence is examined by real measurements. Both 802.11 to 802.11 and 802.11 to Bluetooth coexistence is addressed

Lightweight & secure industrial IoT communications via the MQ telemetry transport protocol

Summarization: Massive advancements in computing and communication technologies have enabled the ubiquitous presence of interconnected computing devices in all aspects of modern life, forming what is typically referred to as the 'Internet of Things'. These major changes could not leave the industrial environment unaffected, with 'smart' industrial deployments gradually becoming a reality; a trend that is often referred to as the 4th industrial revolution or Industry 4.0. Nevertheless, the direct interaction of the smart devices with the physical world and their resource constraints, along with the strict performance, security, and reliability requirements of industrial infrastructures, necessitate the adoption of lightweight as well as secure communication mechanisms. Motivated by the above, this paper highlights the Message Queue Telemetry Transport (MQTT) as a lightweight protocol suitable for the industrial domain, presenting a comprehensive evaluation of different security mechanisms that could be used to protect the MQTT-enabled interactions on a real testbed of wireless sensor motes. Moreover, the applicability of the proposed solutions is assessed in the context of a real industrial application, analyzing the network characteristics and requirements of an actual, operating wind park, as a representative use case of industrial networks.Presented on