Available at: https://digitalcommons.calpoly.edu/theses/1873
Date of Award
MS in Electrical Engineering
As wireless protocols become easier to implement, more products come with wireless connectivity. This latest push for wireless connectivity has left a gap in the development of the security and the reliability of some protocols. These wireless protocols can be used in the growing field of IoT where wireless sensors are used to share information throughout a network. IoT is being implemented in homes, agriculture, manufactory, and in the medical field. Disrupting a wireless device from proper communication could potentially result in production loss, security issues, and bodily harm. The 802.15.4/ZigBee protocol is used in low power, low data rate, and low cost wireless applications such as medical devices and home automation devices. This protocol uses CSMA-CA (Carrier Sense Multiple Access w/ Collision Avoidance) which allows for multiple ZigBee devices to transmit simultaneousness and allows for wireless coexistence with the existing protocols at the same frequency band. The CSMA-CA MAC layer seems to introduce an unintentional gap in the reliability of the protocol. By creating a 16-tone signal with center frequencies located in the center of the multiple access channels, all channels will appear to be in use and the ZigBee device will be unable to transmit data. The jamming device will be created using the following hardware implementation. An FPGA connected to a high-speed Digital to Analog Converter will be used to create a digital signal synthesizer device that will create the 16-tone signal. The 16-tone signal will then be mixed up to the 2.4 GHz band, amplified, and radiated using a 2.4 GHz up-converter device. The transmitted jamming signal will cause the ZigBee MAC layer to wait indefinitely for the channel to clear. Since the channel will not clear, the MAC layer will not allow any transmission and the ZigBee devices will not communicate.
Digital Communications and Networking Commons, Electrical and Electronics Commons, Electromagnetics and Photonics Commons, Hardware Systems Commons, Signal Processing Commons, Systems and Communications Commons