Example Applications - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 346

successes can be seen at Lufthansa and AirPlus, above all due to the self service
of customers, which significantly reduces labour intensive handling and verification
tasks. Furthermore, the ability to accept short notice bookings is increased by the
time saving on the ground, thus increasing competitiveness compared to alternative
travelling options (according to Giesecke & Devrient, 1997).
13.3.2 Ski tickets
Anyone entering a ski lift has to be in possession of a valid daily or weekly pass. These
tickets were originally made of cardboard and validated by a date stamp. Checking
paper tickets is very labour intensive because each ticket must be checked visually for
validity. Furthermore, it is inconvenient for individual skiers to have to fish around in
their anoraks for a sodden paper ticket with cold fingers before every journey on the lift.
RFID technology offers an ideal alternative by replacing paper tickets with contact-
less smart cards or disk transponders (Figure 13.14). When the transponder is sold a
deposit of 5-10 euros is usually retained. After use, the transponder can be returned
and the deposit refunded. The lift operator can revalue the transponder using special
readers and it can thus be reused.
The read range of the system is designed to be great enough that the transponder
tickets no longer need to be held in the hand, but can remain in an anorak pocket.
All ski lift entrances are protected by a turnstile, which is released by the read elec-
tronics upon detection of a valid transponder. In order to read the skier's transponder,
however it is carried, every entrance is monitored by two antenna opposite each other.
The size of the magnetic antenna is a problem, because it must be very large
due to the desired read range. The resulting magnetic coupling between the two reader
antennas is so great at a distance of several metres that the resulting mutual interference
makes it impossible to read a transponder. To circumvent this problem, ski ticket
Figure 13.14 Contactless reader as access control and till device at a ski lift (reproduced by
permission of Legic Identsystems, CH-Wetzikon)