The global tendencies of IEEE 802.11 and IEEE 802.15.4 wireless or sensor networks have been rapidly deployed in a variety of lifestyle applications, including IoT, smart home systems and critical infrastructures such as industrial, scientific and medical (ISM) sectors. Such networks provide a convenient and flexible environment for data transmission, but using IoT devices is associated with several security and performance issues. The IEEE 802.15.4 standard is the basis for protocols such as Zigbee and has been developed for operation in low-power sensor networks, enabling data transmission in limited environmental conditions. However, low power consumption and low throughput make 802.15.4 networks a little vulnerable to PHY and MAC attacks such as packet injection and denial of service attacks. The Thesis is focused on cybersecurity and throughput aspects of IEEE 802.15.4 networks, focusing on the analysis of attacks and methods to counteract them. The study includes an experimental evaluation of the throughput of the Zigbee network based on Shannon’s theorem, taking into account the factors such as overhead, probability of successful packet transmission and channel utilisation rate. The statistical modelling method based on the Nakagami distribution was used to assess the impact of interference and attacks on the network. The experiments analysed network attacks such as packet injection, DoS attacks, and signal jamming. For network protection, the CC2531 packet monitor module was used, and attack blocking techniques using additional monitoring devices and RF interference generation were used.