Analysis of Jamming Attacks on Wireless Sensor Networks

Wireless Sensor Network (WSN) is a wireless-oriented form of communication largely used for outdoor applications, such as environmental monitoring and military surveillance. Therefore, a jamming attack is one of the denial of service attacks (DOS) that may take place by jamming the communication channel, making communication between genuine sensor nodes difficult or even impossible. Several studies have been carried out to develop countermeasures against jamming attacks, utilising parameters such as Packet Delivery Ratio (PDR), Packet Send Ratio (PSR), Received Signal Strength Indication (RSSI) and Clear Channel Assessment (CCA). The accuracy of the parameters used is very important for developing successful countermeasures against jamming attacks. Consequently, the focus in this study is to examine the effect of a jamming attack that was generated by one or more wireless sensor network nodes on PDR, PSR and RSSI, and look at the enhancements that can be made on Packet Delivery Ratio by altering the value of CCA on sender nodes. The experiment was performed using XBee RF and K-mote devices configured as jammers by disabling the CSMA protocol. It was performed in a non-isolated room in order to emulate a real-life environment. Two scenarios were carried out in this study. The first scenario aimed to study RSSI, PSR and PDR values with a fixed CCA value, and the second scenario studied the effect of CCA on PDR value. The experiment showed that the RSSI value measured by XBee RF inflated in the presence of noise. This fact has to be considered when RSSI is utilised in jamming attack counter measures. Further, it has been observed that the PDR value is distressed by jamming because genuine packets collide with jammers’ packets and increase the power of the sent packets without considering that the distance will not be enough to enhance the PDR value. This study demonstrates that changing the CCA threshold value on the XBee RF module influences the Packet Delivery Ratio (PDR) value in the presence of jamming

Ocupación espectral de la banda ISM de 2.4 GHz para aplicaciones de radio cognoscitivo

La tecnología de radio cognoscitivo representa una prometedora solución al problema de escasez de espectro electromagnético, dado que una gran parte del espectro asignado se utiliza de forma esporádica, existiendo una subutilización del mismo. En la banda industrial, científica y médica (ISM, por sus siglas en inglés) de 2.4 GHz, varias campañas de mediciones se han realizado para determinar la ocupación real del espectro. En este trabajo se describe una metodología para obtener la ocupación espectral de la banda ISM de 2.4 GHz, en las instalaciones de la Facultad de Ciencias en la Universidad Autónoma de San Luis Potosí. Se presentan los resultados de la densidad espectral de potencia y el ciclo de trabajo. Estos resultados indican claramente que la utilización del espectro es baja, a pesar de que muchas tecnologías de comunicación inalámbrica comparten este recurso.Palabras Claves: banda ISM, ciclo de trabajo, ocupación espectral, radio cognoscitivo

Belaidžio ryšio tinklų terpės prieigos valdymo tyrimas

Over the years, consumer requirements for Quality of Service (QoS) has been growing exponentially. Recently, the ratification process of newly IEEE 802.11ad amendment to IEEE 802.11 was finished. The IEEE 802.11ad is the newly con-sumer wireless communication approach, which will gain high spot on the 5G evolution. Major players in wireless market, such as Qualcomm already are inte-grating solutions from unlicensed band, like IEEE 802.11ac, IEEE 802.11ad into their architecture of LTE PRO (the next evolutionary step for 5G networking) (Qualcomm 2013; Parker et al. 2015). As the demand is growing both in enter-prise wireless networking and home consumer markets. Consumers started to no-tice the performance degradation due to overcrowded unlicensed bands. The un-licensed bands such as 2.4 GHz, 5 GHz are widely used for up-to-date IEEE 802.11n/ac technologies with upcoming IEEE 802.11ax. However, overusage of the available frequency leads to severe interference issue and consequences in to-tal system performance degradation, currently existing wireless medium access method can not sustain the increasing intereference and thus wireless needs a new methods of wireless medium access. The main focal point of this dissertation is to improve wireless performance in dense wireless networks. In dissertation both the conceptual and multi-band wireless medium access methods are considered both from theoretical point of view and experimental usage. The introduction chapter presents the investigated problem and it’s objects of research as well as importance of dissertation and it’s scientific novelty in the unlicensed wireless field. Chapter 1 revises used literature. Existing and up-to-date state-of-the-art so-lution are reviewed, evaluated and key point advantages and disadvantages are analyzed. Conclusions are drawn at the end of the chapter. Chapter 2 describes theoretical analysis of wireless medium access protocols and the new wireless medium access method. During analysis theoretical simula-tions are performed. Conclusions are drawn at the end of the chapter. Chapter 3 is focused on the experimental components evaluation for multi-band system, which would be in line with theoretical concept investigations. The experimental results, showed that components of multi-band system can gain sig-nificant performance increase when compared to the existing IEEE 802.11n/ac wireless systems. General conclusions are drawn after analysis of measurement results