Vehicle access system

A control unit arranged to control an access system for a vehicle, the control unit comprising:

• one or more inputs for receiving a first communication signal from a first communications device and a second communication signal from a second communications device;
• a processor arranged to manage a vehicle access process;
• and
• an output arranged to output vehicle access control signals;
• wherein the processor is arranged to:
• scan for a first communication signal from a first communications device using a first communication channel of a first communications system;
• initiate a vehicle access process based on detecting the first communication signal from the first communications device, the vehicle access process comprising comparing a received signal strength indication, RSSI, of the received first communication signal to a predetermined threshold signal strength value and, in the event that the RSSI of the received first communication signal exceeds the threshold signal value, sending from the output a challenge signal for a second communications device using a second communication channel of a second communications system;
• and
• wherein the output is arranged to output a vehicle access control signal to control the vehicle access system based on a response signal received from the second communications device, the response signal having been sent in response to the challenge signal.