Embodiments of a system and method for determining an angle-of-arrival of signals received from a transmitting device are shown. The first side panel has a first seating portion that is continuous with one of the end side portions to extend the main seat adjacent the wheel arch. Due to the remarkable edge smoothness achieved with the present invention, the gaps can be quite small, which provides marked advantages in terms of test accuracy, speed and the number of different functionalities that can be packed into a single biosensor. The cipher is communicated to the receiver and decoded to recover a message m\u2032. Pits or grooves also may be formed in the optical device.