Position-based access verification method

A vehicle comprising:

• an access system, wherein the access system comprises a transmission unit arranged in the vehicle and a transponder unit arranged in a portable device, wherein
• the transmission unit is configured to emit request signals at regular intervals in an active state;
• the transponder unit is configured, in response to a triggering event, to store current position of the vehicle and to determine the transponder unit's own position at regular intervals;
• the transponder unit is further configured to deactivate the transmission unit when the transponder unit detects, based on the determined position, that the transponder unit has left a first zone, wherein the first zone is arranged around the vehicle, and wherein the transmission unit does not emit any request signals while the transmission unit is deactivated;
• the transponder unit is further configured to activate the transmission unit when the transponder unit detects, based on the determined position, that the transponder unit has entered an adjusted first zone, wherein the adjusted first zone is arranged around the vehicle.