Technologies
Related Technologies
Radio Frequency Identification
RFID is a generic technology concept that refers to the use of radio waves to identify objects
(Auto-ID Center, 2002). RFID tags have both a microchip and an antenna. The microchip is used to
store object information such as a unique serial number. The antenna enables the microchip to
transmit object information to a reader, which transforms the information on the RFID tag to a
format understandable by computers. RFID is part of a range of technologies (such as barcodes,
biometrics, machine vision, magnetic stripe, optical card readers, voice recognition, smart
cards, etc.). RFID is considered a significant improvement over the conventional barcode,
which needs to be read by scanners in “line-of-sight” fashion and can be stripped away if the
paper product labels get ripped or damaged.
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Real Time Location System
This system is a wireless radio frequency solution that continually monitors and reports the
location of tracked resources in real time. RTLS is based on wireless devices such as active RFID
tags which send a wireless signal to location receivers that are then relayed to a location processing
engine. The latter uses various types of algorithms, such as Time Difference of Arrival (TDOA), Received
Signal Strength (RSS), Fingerprint and telemetry message retrieval to determine the position
of the tracked object.
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Wi-Fi Technology
IEEE 802.11 is a standard developed for the wireless LAN/WLAN networks. "Wi-Fi" defines specifically the
group 802.11a, b, and g. It uses six over-the-air modulation techniques. Using the 2.4 gigahertz (GHz) band
with a data rate up to 11 Mbit/s, 802.11b is the one widely accepted wireless networking standard. 802.11b
operates under Part 15 of the FCC Rules and Regulations.
802.11b uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) as the media access method
to improve the reliability of data transmissions. The standard uses Complementary Code Keying (CCK) as its
modulation technique, which is a variation on CDMA. It supports point-to-multipoint configuration, wherein
an access point communicates via an omni-directional antenna, or it can also be used in fixed
point-to-point arrangements. Wi-Fi also includes the security standard Wi-Fi Protected Access or
WPA. 802.11g works in the 2.4 GHz band and operates at a maximum data rate of 54 Mbit/s.
802.11g is compatible with 802.11b hardware. 802.11g uses an orthogonal frequency-division multiplexing
(OFDM) modulation technique for the data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts
to CCK for 5.5 and 11 Mbit/s and DBPSK/DQPSK+DSSS (direct-sequence spread spectrum) for 1 and 2 Mbit/s.
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Mesh Network Technology
This technology is gradually maturing to a point where it cannot be ignored when considering various
wireless networking technologies for deployment. While the first large-scale community mesh deployments
are yet to be seen, existing lab-level implementations and feasibility tests have demonstrated
enough advantages to motivate further experimentation.
In this type of architecture, the access points - traditional Wi-Fi stations - are connected by
radio links. They are authenticated gradually to establish transit bonds and a routing
table. If one of them breaks down, the others will avoid the traffic towards this failing point. As
a result, a very reliable network is formed. Architecture is also able to absorb peaks of traffic
with a balancing of dynamic head.
In a mesh network, it’s possible to shorten the distance between nodes, which dramatically increases
the link quality. By reducing the distance by a factor of two, the resulting signal is at least four
times more powerful at the receiver. This makes links more reliable without increasing transmitter
power in individual nodes. In a mesh network, you can extend the reach, add redundancy, and improve
the general reliability of the network simply by adding more nodes.
Voice Transmission Option
The use of two frequency bands avoids interference. Signal reception employs the 2.4GHz
band (802.11b). Signal transmission is carried out using the 5 GHz band (802.11a), recently
opened to the public, and can be used indoors or outdoors. Although it was developed for
relaying data, a mesh network can also be used for voice transmission. However algorithms
will need to be established to limit the number of jumps between reception nodes in order
to avoid extreme latency periods.
Organization and Business Models
The decentralized nature of mesh networks lends itself well to a decentralized ownership model
wherein each participant in the network owns and maintains their own hardware, which can greatly
simplify the financial and community aspects of the system. However, the chief drawback of a mesh
topology is expense, because of the large number of cables and connections required.
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Microwave Technology
The analysis of electromagnetic signals is a fundamental problem for many engineers and scientists.
A wide range of systems and applications incorporate RF, microwave and wireless devices and signals
which may be indistinguishable to the layman. Traditionally, RF has defined radio frequencies ranging
from a few kHz to several GHz. However, it is true that RF has become synonymous with wireless and
high-frequency signals, describing all signals with wavelengths below far infrared (~300GHz).
Microwaves correspond to the highest radio frequencies inside the RF band, which translates into
wavelengths above one GHz. Applications using microwaves are described below:
- Microwave radiation is used by radar to detect the range, speed, and other characteristics
of remote objects.
- Microwaves pass easily through the earth's atmosphere. That’s why they are used
for broadcasting transmissions. There is also much more bandwidth in the microwave spectrum than in
the rest of the radio spectrum.
Wireless LAN protocols, such as Bluetooth and the IEEE 802.11g and b specifications, also use
microwaves in the 2.4 GHz ISM band, although 802.11a uses an ISM band in the 5 GHz range. Metropolitan
Area Networks (MAN) protocols, such as WiMAX. The IEEE 802.16 specification was designed to operate
between 2 GHz and 11 GHz. The commercial implementations are in the 2.5 GHz, 3.5 GHz and 5.8 GHz ranges.
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Wireless Sensor Technology
Wireless sensor networks are constituted from clusters of devices using sensor technologies deployed over a
specific area, wirelessly communicating data to a central system. Sensor networks continually monitor
physical properties, processes, chemical or magnetic properties, using viable and emerging communication
infrastructures. With a range of software which enhances business intelligence through data extraction and mining,
sensor networks will allow an entire class of systems to be designed and deployed with breakthrough results in
diverse marketplaces.
Wireless sensor networks rely on emerging technologies such as communication technologies
(RF communication, ad hoc networking routing), semiconductor technologies (MEMS CMOS microprocessor),
embedded systems and micro sensor technologies.
Wireless sensor networks possess the potential to revolutionize business in a similar way to the emergence
of the internet by providing a large number of users with various forms of information. In fact,
sensor networking enjoys an enormous application potential in various fields, including:
- Environmental and healthcare: sensing ocean temperature, gathering information about a patient's condition
- Critical industrial areas: monitoring oil containers, verifying chemical gas substance concentration
- Warehouse and supply chain: monitoring currents states and history of goods with critical
conservation conditions
- Military: surveillance and reconnaissance
A wireless sensor network consists of a large number of tiny sensor nodes, each of which is equipped
with a radio transceiver, a small microprocessor and a number of sensors. These nodes are able to
autonomously form a network through which sensor readings can be propagated. Since the sensor nodes
have some intelligence, data can be processed as it flows through the network.
Given the hardware limitations and physical environment in which the nodes must operate, along
with application-level requirements, the algorithms and protocols must be designed to provide a robust
and energy-efficient communications mechanism. Design of physical-layer methods such as modulation,
and source and channel coding also fall in this category. Channel access methods must be devised,
and routing issues and mobility management solved.
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