Implementation and design issues for using Bluetooth low energy in passive keyless entry systems

Passive Keyless Entry (PKE) systems have embarked to define the market of basic security systems. Low power consumption and maximum data privacy are two parameters that make these setups deployable. With the Bluetooth protocol being enabled with smarter processing and lower energy consumption to create the Bluetooth Low Energy (BLE) segment of peripherals, the focus of this research is to investigate keyless entry systems using this technology. The system has been prototyped using the Programmable System on Chip (PSoC-4 BLE) from Cypress Semiconductors with a BLE peripheral as the host and the user smartphone as the client. The user will advertise through the smartphone BLE and a predefined whitelist at the client end decides which host is granted access. Development was concentrated on taking maximum advantage of the power saving modes available in BLE. There were a considerable number of design issues and tradeoffs that needed to be considered were and looked into. Design issues and tradeoffs between parameters such as optimal scan duty cycle, scan range, power consumption and minimum authentication time have been discussed with implementation results.