When integrated into smartphones, ultra-wideband technology can enable new functions, such as secure passive entry. UWB complements the existing short-distance radio standards in keyless vehicle access. It helps to avoid unauthorized access via relay (man-in-the-middle) attacks and therfore makes keyless vehicle access more secure. In a relay attack the radio signal of the vehicle key is extended by radio technology in order to make the vehicle detect the driver to be in close proximity, which is not the case. With UWB technology the driver’s location is reliably pinpointed almost to the centimeter.