Ng Yuen Lam, Stephanie 200565297 (ECEN2802Q)
“Doot” through life with Octopus
With a growth rate of 0.9%, Hong Kong recently has had a growing population of over
6.9 million people (Census and Statistics Department 2006). To accommodate the rapid
pace of life and need for expediency, the “Octopus” (see figure 1) is now considered a
daily necessity. This name is familiar amongst locals and is in fact a rechargeable card
used for contact-less electronic payments. The Octopus system was first launched in
September 1997 with currently over 14
million cards in circulation (Octopus Holdings
Limited 2005). Initially, use of the Octopus
was introduced primarily only to public
transport such as the mass transit railway
(MTR). However over the past decade, usage
has swiftly spread throughout the city ranging
from vending machines to fast food chains
providing a “simple way” (Octopus Cards
Figure 1: The Octopus Card. This is a Limited 2005) to pay. Dependent on the
personalised card e.g.) student card. The highly popular radio frequency identification
combination of colours used are from the
(RFID) technology that is also used in the EZ-
colour scheme for the children (red), adult
(yellow) and elderly (green) cards. Link card in Singapore, the Octopus is
undeniably an ingenious idea.
The principle of RFID
Figure 2: The RFID system. The reader sends out signals via radio waves which the Octopus card
reflects when in proximity. This reflected data can be collected at the antenna and either stored in
the portable reader for uploading at a later time or directly sent to the host computer for data
RFID represents technology using radio waves to automatically identify people or objects
(RFID Journals 2007). In the case of Octopus, RFID in the card recognizes a designated
reader installed such as those on buses. To be precise, the most frequently used method of
identification is through storage of a serial number capable of identifying information
(EPIC 2007). The Octopus card is an RFID tag storing data in a microchip attached to an
antenna. For Octopus, the chip is provided by Sony and referred to as FeliCa using the
Manchester bit coding scheme to minimize interference ensuring reading efficiency
(Sony Corporation 2007). Despite the chip’s small storage size of 2kB, it is sufficient in
performing the Octopus’ function mainly involving payment (Sieberg 2006). Very
importantly, it is the antenna that allows the chip to transmit signals and thus information
to the reader (Sony Corporation 2007) (see figure 2). A field is created by the reader and
power is extracted from it to facilitate the chip’s circuits. The reader communicates with
the tag through radio wave transmission with reflected signals from the tag then
converted into digital instructions for the computerized reader (EPIC 2007).
Octopus readers installed at various places demonstrate their
widespread applications in Hong Kong. The most significant
use of the Octopus is in payment with the main advantage of
convenience through a “touch and go” system. The card only
needs to be placed in close proximity with the reader (see
figure 3) to allow recognition confirmed by the sound “doot”.
The system is easy to use with the chip able to be read even
through materials such as leather, reducing the hassle of having
to take it out of one’s belongings (see figure 3). The ease of
usage makes it suitable for all ages as reflected in recent
Figure 3: The Octopus card
is placed on or within close developments including Octopus watches (see figure 4), phone
range to the reader. It can be covers and key chains, each catering to the users’ preference
detected even through small (Octopus Cards Limited 2005). This proves that the Octopus’
personal items such as use of RFID technology can be expanded to many areas owing
wallets. to its small size.
Using Octopus, consumers are able to pay for a
variety of utilities. Transportation fares for example
on the MTR can be paid through a simple tap of the
card on the reader. The Octopus can also be used for
making purchases in major supermarkets and
convenience stores including PARK ‘n’ SHOP, 7-
Eleven and Watson’s. In the last few years, Octopus
payments have been introduced to fast food chains
and eateries such as Maxim’s Express, McDonalds
and Starbucks Coffee. To this date, over 10 million Figure 4: An Octopus watch. This
transactions using Octopus have been estimated accessory functions like an Octopus
(Octopus Cards Limited 2006). In response, usage of card with a built in RFID microchip
coins and even notes can be replaced by the Octopus acting as a tag for the reader.
which can store up to HK$1000. Recharging can be
done conveniently at add-value machines located in MTR stations (see figure 5), at
dealers accepting Octopus transactions or even from a designated bank account known as
the automatic add value service (AAVS) (Octopus Cards Limited 2005). Not only does
the card allow payment simplicity, it is also able to store transaction records and indicate
remaining values (see figure 6).
Figure 5a, b, c (right): a) The add-value machine. b)
To add value to the card, insert the card into the b)
machine. c) Select “add value” action and choose top
up mode either by case or an electronic payment
system (EPS) card.
a) b) Figure 6a, b (left); a) Balance
checking at MTR entry points. b)
Balance and transaction checking
at electronic kiosks in MTR
Aside from payment, Octopus can also be used in other ways. Through registration with
an assigned management, access control in residential areas and offices can be enforced
(Octopus Cards Limited 2007). This allows only authorized residents or personnel into a
given area acting as an additional security measure. Furthermore, school campuses can
also use the Octopus as a means of keeping track of student attendance, administrative
work and purchases at school canteens and kiosks (Octopus Cards Limited 2007). This
system is helpful in ensuring that students do not bring too much cash to school and at the
same time allowing parents to monitor their expenditure.
The various applications demonstrate the use of RFID technology being able to fully
expand Octopus’ ability ranging from simple payment to a more complex level of access
control and management. Evidently, this simple looking piece of plastic plays an
important role, enhancing the efficiency of the otherwise troublesome payment process
and is an invaluable asset.
Census and Statistics Department 2006. Hong Kong Statistics. The Government of the
Hong Kong Special Administrative Region. Available on
Accessed 1st March 2007.
EZ-Link 2007. The Card: Products. Available on http://www.ezlink.com.sg/theCard.htm.
Accessed 3rd March 2007.
Octopus Cards Limited 2007. Octopus. Available on
http://www.octopuscards.com/consumer/en/index.jsp. Accessed 10th February
RFID Journal 2007. Frequently Asked Questions. Available on
http://www.rfidjournal.com/faq. Accessed 10th February 2007.
Sieberg D. 23rd October 2006. Is RFID tracking you? CNN. Available on
http://www.cnn.com/2006/TECH/07/10/rfid/index.html. Accessed 3rd March
Sony Electronics Global 2007. The FeliCa System. Available on
http://www.sony.net/Products/felica/index.html. Accessed 13th February 2007.