RFID Applications in E-Healthcare - E-Healthcare Systems and Wireless Communications - page 75

need to be used for different applications: low
frequencies can be used to increase the penetration
into materials and water, but they provide shorter
range; while higher frequencies can increase the
range significantly, however they become very
sensitive to environmental conditions. Generally,
low-frequency passive tags have a range of ap-
proximately 30 cm; high-frequency passive tags
have around 1 meter and ultrahigh-frequency
tags have range from 3 - 5 m. Active tags are
used whenever a longer range is required, such
as in container tracking and railway applications,
because they can increase the signal range to 100
m and beyond (Lieshout et al., 2007, p.31).

on RFID technology in 1948 - 'Communication
by Mean of Reflected Power', after which much
attention was given to RFID. 1950s marked an
era of theoretical exploration of RFID techniques
with a number of pioneering research and scientific
papers being published. In 1960s more researchers
and inventors seemed interested in this technol-
ogy and commercial systems like Sensormatic
and Checkpoint were launched with Electronic
Article Surveillance (EAS) equipment to counter
theft of merchandise. By the 1970s, a number of
developers, companies, academic institutions,
government laboratories such as Los Alamos
Scientific Laboratory and Swedish Microwave
Institute Foundation, were aware of RFID and
a considerable amount of development work
was done during this period with applications
intended for animal tracking, vehicle tracking
and factory automation. As time passed, with the
development of personal computers (PC), RFID
also became a well-known topic since the PCs al-
lowed convenient and economical data collection
and management for RFID systems. As a result,
the phase of 1980s became the decade for full
implementation of RFID technology with applica-
tions extended into a number of areas. The 1990s
were significant due to the wide scale adoption of
RFID in electronic toll applications in the United
States; installation of over 3 million RFID tags
on rail cars in North America; toll applications,

Development and Progress of RFID

Radio Frequency Identification is a recent tech-
nology which is gaining momentum and is con-
sidered to become the most persistent computing
technologies in the history (see Table 2 - Decades
of RFID). RFID would not have surfaced if the
Radar technology had not been found in the
early 20 th century. Radar sends out radio waves
to detect and locate objects by the reflection of
the radio waves. The British developed 'Identity
Friend or Foe' system, used in World War II, to
get codes back only from the 'friendly' aircrafts
which were identified by the radar. Later, Harry
Stockman published one of the earliest papers

Figure 1. RFID reader and tag communication flow diagram in an RFID system