wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

Radio Frequency Identification 8-21
a private company could be trusted to protect our personal records from illegal use, when we cannot
entrust the government with it. It is also argued that a mobile phone is different because we could return
to anonymity by turning our mobile phones off. Similarly, we need to carry our e-ID if and only if we
want to enter some controlled areas; otherwise it could be safely kept at home. After entry, we could keep
our privacy by hiding the e-ID in a metallic bag, such as a bag for potato chips.
Concern about the loss of privacy goes hand-in-hand with the development of the AIDC from the
issuance of the first EPC bar code. Today, a personal trail could be tracked via one’s use of the credit card,
the vicinity card, the prepaid card, the electronic key, the electronic ticket, the mobile phone, the iPod,
the iPhone, the fixed-line or the wireless network connection, the e-ID, and the e-passport. The RFID is
simply another variation of the same theme. The association of a product brought with a buyer may leave
a faint trace of the whereabouts of the person involved, but it is certainly not a reliable one. However, it
may be the last cue for locating a missing person for rescue. From the technical point of view, the assured
benefits obtained from having a long-range hands-free ID outweigh the potential loss of privacy in absolute
terms [22]. At least, it is a view of an old-fashioned Asian living in a conservative Asian country.
8.29 recent Developments
At the present stage of development, there exist many compatible and incompatible protocols in the
market. To better understand the subsequent discussions, the ISO 18000-6C, an air interface for RFID
at 860–960.MHz, is used as an illustration.
As usual, the memory of an RFID tag is divided into many fields. In addition to the 8 bit header and
the 36 bit serial number, rooms have been reserved for the company (28 bit) and the object class of the
tag (24 bit). With the ever-increasing popularity of the RFID, the memory has been expanded from 64
to 96 bit as illustrated in Table 8.3. For the EPCglobal Class 1 Generation 2 (Gen 2) tag, a 32 bit error
correction was augmented to the 96 bit standard and a kill command was added.
The memory of Gen 2 was later amended to 256 bit [23]. The extra space of 128 bit is undefined, a room
reserved for any nation to define special commands to be used within its jurisdiction for catering to its
specific needs due to its unique cultural heritage, religious background, and level of industrialization.
Nowadays, the trend of development is to further expand the memory while keeping the Gen 2 data
structure intact. Together with a 48 bit overhead, a 304 bit EPC bank is created. It is very likely that the
EPC bank would be used as a common platform for multisystem and multistandard operations. In addition
to the serial number in Gen 2, a bank of 64 bit is added on top of the EPC bank for a unique identification
of the tag (TID) according to the ISO 15963 recommendations. To distinguish this TID from
the ID found in the EPC bank, they are called ISO-TID and EPC-TID, respectively. To address diverse
national needs, an extra 64 bit is included for storage of four passwords for accessing special commands
and the “kill” commands as shown in Table 8.4.
Compared with the 32 bit EPC-TID in the 36 bit serial number, 42 bit in the TID bank are reserved
for the ISO-TID. Hence, the maximum number of identifications has been increased from 4.295 × 10 9 to
4.398 × 10 12 . Assuming that one trillion tags will be consumed annually, the ISO-TID alone could last
for several years. However, if it is used in conjunction with the EPC-TID, the tag could be used almost
indefinitely.
The “kill” command in Gen 2 is a noteworthy new feature that warrants in-depth discussion. This
command enables any operator to disable any tag permanently. It was perhaps created for lessening our
worry on the loss of privacy as it dissociates a product from its new owner. In doing so, it could also
relieve the projected traffic congestion due to the simultaneous arrival of many tags.
TABLE 8.3
Header
8 Bit
The 96 bit EPC Bank
Manager Number
28 Bit
Object Class
24 Bit
Serial Number
36 Bit
A 0 0 1 F B A 3 2 E F 9 7 0 7 3 4 5 A 3 5 1 B E
© 2011 by Taylor and Francis Group, LLC