Underground fare payment cards Those of us, who use the services of the underground, for example, of the Moscow underground, are familiar with the method of payment for these services.From 2008, a method of non-contact fare deduction from the cards is used. We can buy these cards at the booking offices.How does it work?In general, the method is used, which is called RFID, in other words Radio Frequency IDentification. As you might guess, here we could not go without radio-waves. Yes, with their help the data, stored in the so-called transponders or RFID tags, are read and re-recorded. They are a major part of our payment cards.In general, tags can be different. Speaking of smart cards, which are used for fare payment, first of all, they can be referred to passive tags, since they do not have their own source of power. The power current that is induced by a signal from a reading unit is enough for the operation of such cards.Further, underground smart cards are referred to the type “Mifare”, more precisely “Mifare Ultralight”. Their operating frequency is 13.5MHz. The developer is the company “NXP Semiconductors”. It is the chip of this company which is installed in each card.Unlike other RFID systems, this type of cards can be read only at a short distance, namely a few centimetres. That is why we put the card to a reading device, not just pass by it.The reading unit is a validator, a device that is a part of the turnstile. It emits radio waves and when a smart card enters a working area, the process of re-recording of the memory content of its chip takes place and the data are returned. In practice, one trip is deducted and the residue is displayed on the validator panel.Let’s take a look inside an ordinary card for a travel on the Moscow subway.It looks like this, if you try to remove a paper layer.The memory storage capacity of EEPROM for ultralight is 512 bits. That is enough. The chip has no cryptographic protection. In general, for manufacturing this is the easiest and the cheapest card of “Mifare” type. That is why it is produced in large quantities for quick and convenient fare payment. Around the world, more than a billion of these cards have already been sold. And the systems, similar to that of the Moscow underground, are used, for example, in Korea, England, Ukraine and the Netherlands.
- Post Time: 03-31-16 - By: http://www.rfidang.com