A method, comprising: determining a first device identifier for a portable electronic device of a user, the determining being performed in response to the portable electronic device entering a first area and the first device identifier being sent using a first communications channel by the portable electronic device and received through a sensor (160, 220) by an access system control unit, wherein the first device identifier is for the first communications channel; as a result of determining the first device identifier from the portable electronic device, sending the first device identifier from the access system control unit to a database and receiving by the access system control unit a second device identifier for the portable electronic device from the database, the second device identifier having been determined based on the first device identifier and being for a second communications channel, whereby the first and second communication channels are different types of communication channels; and sending an access code determined by the access control unit based on the second device identifier for the portable electronic device from the access control unit to the portable electronic device using the second communications channel, wherein sending the access code includes instructing by the access system control unit a wireless communication network to send the access code to the portable electronic device, and sending by the wireless communication network the access code to the portable electronic device; reading the access code from the portable electronic device at a second area using an access terminal (180, 250); and granting access to the user as a result of reading the access code from the portable electronic device. determining a first device identifier for a portable electronic device of a user, the determining being performed in response to the portable electronic device entering a first area and the first device identifier being sent using a first communications channel by the portable electronic device and received through a sensor (160, 220) by an access system control unit, wherein the first device identifier is for the first communications channel; as a result of determining the first device identifier from the portable electronic device, sending the first device identifier from the access system control unit to a database and receiving by the access system control unit a second device identifier for the portable electronic device from the database, the second device identifier having been determined based on the first device identifier and being for a second communications channel, whereby the first and second communication channels are different types of communication channels; and sending an access code determined by the access control unit based on the second device identifier for the portable electronic device from the access control unit to the portable electronic device using the second communications channel, wherein sending the access code includes instructing by the access system control unit a wireless communication network to send the access code to the portable electronic device, and sending by the wireless communication network the access code to the portable electronic device; reading the access code from the portable electronic device at a second area using an access terminal (180, 250); and granting access to the user as a result of reading the access code from the portable electronic device.