Ch 8 - CIS 3700

Active RFID

tags use internal batteries for power, and they broadcast radio waves to a reader. Because active tags contain batteries, they are more expensive than passive RFID tags, and they can be read over greater distances. Therefore, they are used primarily for more expensive items.

Radio-frequency identification (RFID)

technology allows manufacturers to attach tags with antennas and computer chips on goods and then track their movement through radio signals.

A QR code

A QR code is a two-dimensional code, readable by dedicated QR readers and camera phones.

pervasive computing (or ubiquitous computing).

Pervasive computing is invisible "everywhere computing" that is embedded in the objects around us-the floor, the lights, our cars, the washing machine, our cell phones, our clothes, and so on

Two systems are being developed to replace bar codes:

QR (for quick response) codes and RFID systems.

One downside of smartphones

that people can use them to copy and pass on confidential information.

Line-of sight means

that the transmitter and receiver are in view of each other

One major limitation of CEO satellites is

that their transmissions take a quarter of a second to send and return. This brief pause, one kind of propagation delay, makes two-way telephone conversations difficult. Also, CEO satellites are large and expensive, and they require substantial amounts of power to launch

Mobile computing refers

to a real-time connection between a mobile device and other computing environments, such as the Internet or an intranet

loS enables users

to access the Internet via CEO satellites from a dish mounted on the side of their homes. Although loS makes the Internet available to many people who otherwise could not access it, it has its drawbacks. Not only do CEO satellite transmissions involve a propagation delay, but they also can be disrupted by environmental influences such as thunderstorms.

These two characteristics, mobility and broad reach, create five value-added attributes that break the barriers of geography and time: UCIPL

ubiquity, convenience, instant connectivity, personalization, and localization of products and services

RFID systems

use tags with embedded microchips, which contain data, and antennas to transmit radio signals over a short distance to RFID readers. The chip in the RFID tag is programmed-with information that uniquely identifies an item. It also contains information about the item such as its location and where and when it was made.

Radio transmission

uses radio-wave frequencies to send data directly between transmitters and receivers.

Microwave transmission systems transmit data

via electromagnetic waves. These systems are used for high-volume, long-distance, line-of-sight communication. Line-of sight means that the transmitter and receiver are in view of each other

mobile refers to

something that changes its location over time

RFID was developed to replace bar codes

Bar codes have worked well, but they have limitations. First, they require a line of sight to the scanning device. This system works well in a store, but it can pose substantial problems in a manufacturing plant or a warehouse or on a shipping/receiving clock. Second, because bar codes are printed on paper, they can be ripped, soiled, or lost. Third, the bar code identifies the manufacturer and product but not the actual item.

three basic short range networks

Bluetooth, ultra wideband (UVB), and near field communications (NFC).

Individuals are finding wireless devices convenient and productive to use, for several reasons.

First, people can make productive use of time that was formerly wasted-for example, while commuting to work on public transportation. Second, because people can take these devices with them, their work locations are becoming much more flexible. Third, wireless technology enables them to schedule their working time around personal and professional obligations.

radio transmission has its drawbacks.

First, radio media can create electrical interference problems. Also, radio transmissions are susceptible to snooping by anyone who has similar equipment that operates on the same frequency. Another problem with radio transmission is that when you travel too far away from the source station, the signal breaks up and fades into static

Radio transmission has several advantages.

First, radio waves travel easily through normal office walls. Second, radio devices are fairly inexpensive and easy to install. Third, radio waves can transmit data at high speeds

Location-based services provide information that is specific to a given location.

For example, a mobile user can ( 1) request the nearest business or service, such as an ATM or a restaurant; (2) receive alerts, such as a warning of a traffic jam or an accident; and (3) find a friend.

Satellite

High bandwidth. Large coverage area. Expensive. Must have unobstructed line ,of sight. Signals experience propagation delay. Must use encryption for security.

Microwave

High bandwidth. Relatively inexpensive. Must have unobstructed line of sight. Susceptible to environmental interference.

Radio

High bandwidth. Signals pass through walls Inexpensive and easy to install Creates electrical interference problems. Susceptible to snooping unless encyrpted

MEO satellites disavantage

However because MEO satellites move with respect to a point on Earth's surface, receivers must track these satellites. (Think of a satellite dish slowly turning to remain oriented to a MEO satellite).

LEO satellites move

Like MEO satellites, however, LEO satellites move with respect to a point on Earth's surface and therefore must be tracked by receivers. Tracking LEO satellites is more difficult than tracking MEO satellites because LEO satellites move much more quickly relative to a point on Earth Unlike CEO and MEO satellites, LEO satellites can pick up signals from weak transmitters. This feature makes it possible for satellite telephones to operate via LEO satellites, because they can operate with less power using smaller batteries. Another advantage of LEO satellites is that they consume less power and cost less to launch.

Infrared

Low to medium bandwidth. Used only for short distances. Must have unobstructed line of sight.

Satellite transmission systems make use of communication satellites.

Satellite transmission systems make use of communication satellites.

Geostationary earth orbit (CEO)

Satellites stationary relative to point on Earth • Few satellites needed for global coverage • Transmission delay (approximately .25 second) • Most expensive to build and launch • Longest orbital life (many years) orbit 22,300 miles Number 8 Use :TV signal

There are four major threats to wireless networks: RWER

rogue access points, war driving, eavesdropping, and radio-frequency jamming.

Short-range wireless networks

Short-range wireless networks simplify the task of connecting one device to another. In addition, they eliminate wires and enable users to move around while they use the devices. In general, short-range wireless networks have a range of 100 feet or less .

Smartphones are now present in U.S. jury boxes, raising serious questions about juror impartiality and the ability of judges to control courtrooms

Smartphones are now present in U.S. jury boxes,

satellites use broadcast transmission, which sends signals to many receivers at one time.

So, even though satellites are line-of-sight like microwave, they are high enough for broadcast transmission, thus overcoming the limitations of microwave.

the enormous footprint-the area of Earth's surface reached by a satellite's transmission overcomes the limitations of microwave data relay stations.

The most basic rule governing footprint size is simple: The higher a satellite orbits, the larger its footprint. Thus, medium-earth-orbit satellites have a smaller footprint than geostationaly satellites, and low-earth-orbit satellites have the smallest footprint of all.

near-field communications (NFC).

This process uses a contact-free technology

Mobile computing has two major characteristics that differentiate it from other forms of computing:

mobility and broad reach

War driving

War driving is the act of locating WLAN s while driving (or walking) around a city or elsewhere. To war drive or walk, you simply need a Wi-Fi detector and a wirelessly enabled computer. If a WLAN has a range that extends beyond the building in which it is located, then an unauthorized user might be able to intrude into the network. The intruder can then obtain a free Internet connection and possibly gain access to important data and other resources.

Worldwide lnteroperability

Worldwide lnteroperability for Microwave Access, popularly known as WiMAX, is the name for IEEE Standard 802.16. WiMAX has a wireless access range of up to 31 miles, compared to 300 feet for Wi-Fi. Wi:tv'IAX also has a data-transfer rate of up to 75 Mbps. It is a secure system, and it offers features such as voice and video.

In radio-frequency (RF) jamming,

a person or a device intentionally or unintentionally interferes with your wireless network transmissions

Wireless

a term that is used to describe telecommunications in which. electromagnetic waves, rather than-some from of wire or cable, carry the signal between communicating devices such as computers, smartphones, and iPads.

There are two basic types of RFID tags: of the tags.

active and passive. . In contrast, passive RFID tags rely entirely on readers for their power. They are less expensive than active tags, but they can be read only up to 20 feet. For these reasons they are generally applied to less-expensive merchandise. Problems with RFID include expense and the comparatively large size of the tags.

A mobile portal

aggregates and provides content and services for mobile users. These services include news, sports, and e-mail; entertainment, travel, and restaurant information; community services; and stock trading.

Pervasive computing

also called ubiquitous computing, means that virtually every object has processing power with either wireless or wired connections to a global network.

Mobile commerce

also known as m-commerce-refers to e-commerce (EC) transactions conducted with a mobile device.

Another vital function of mobile technology is to help users obtain and utilize information. Two types of technologies-mobile portals and voice portals-

are designed to aggregate and deliver content in a form that will work within the limited space available on mobile devices. These portals provide information to users anywhere and at any time.

The major benefits of Wi-Fi are

are its low cost and its ability to provide simple Internet access. It is the greatest facilitator of the wireless Internet- that is, the ability to connect to the Internet wirelessly.

Wireless sensor networks (WSNs)

are networks of interconnected, battery powered, wireless sensors called motes that are placed into the physical environment. The motes collect data from many points over an extended space. Each mote contains processing, storage, and radio-frequency sensors and antennas. Each mote "wakes up" or activates for a fraction of a second when it has data to transmit. It then relays those data to its nearest neighbor. So, instead of eve1y mote transmitting its data to a remote configures 8.6 Barcodes, RFID puter at a base station, the data are moved mote by mote until they reach a central computer where they can be stored and analyzed. An advantage tags, and QR codes. of a wireless sensor network is that if one mote fails, then another one can

Medium-range wireless networks

are the familiar wireless local area networks (WLANs). The most common type of medium-range wireless network is Wireless Fidelity, or Wi-Fi.

Modern smartphones provide capabilities that include

cellular telephony, Bluetooth, Wi-Fi, a digital camera for images and video, global positioning system (CPS), an organizer, a scheduler, an address book, a calculator, access to e-mail and Short Message Service (SMS, sending and receiving short text messages up to 160 characters in length), instant messaging, text messaging, an MP3 music player, a video player, Internet access with a full-function browser, and a QWERTY keyboard

Wireless technologies enable individuals and organizations to

conduct mobile computing, mobile commerce, and pervasive computing.

Wi-Fi Direct

enables peer-to~peer communications, so devices can connect directly. It allows users to transfer content among devices without having to rely on a wireless antenna. It can connect pairs or groups of devices at Wi-Fi speeds of up to 250 Mbps and at distances of up to 800 feet. Further, devices with Wi-Fi Direct can broadcast their availability to other devices just as Bluetooth devices can. Finally, Wi-Fi Direct is compatible with the more than 1 billion Wi-Fi devices currently in use.

The term wireless means

exactly what it says: without wires.

Currently, there are three types of satellites circling Earth:

geostationary (CEO), medium-earth-orbit (MEO), and low-earth-orbit (LEO).

Near-field communications (NFC)

has the smallest range of any short-range wireless networks. It is designed to be embedded in mobile devices such as cell phones and credit cards.

Wireless technologies include

include both wireless devices, such as smart1Jhones, and wireless transmission media, such as microwave, satellite, and radio

A voice portal

is a Web site with an audio interface. Voice portals are not Web sites in the normal sense because they can also be accessed through a standard phone or a cell phone. A certain phone number connects you to a Web site, where you can request information verbally.

personal area network

is a computer network used for communication among computer devices-for example, telephones, personal digital assistants, and smartphones-located close to one person.

Mesh networks

multiple Wi-Fi access points to create a wide area network that can be quite large. Mesh networks could have been included in the long-range wireless section, but you see them here because they are essentially a series of interconnected local area networks

Ultra-wideband (UWB)

is a high-bandwidth wireless technology with transmission speeds in excess of 100 Mbps.

Wireless fidelity (Wi-Fi)

is a medium-range WlAN, which is a wired LAN but without the cables. In a typical configuration, a transmitter with an antenna,called a wireless access point (see Figure 8.3), connects to a wired LAN or to satellite dishes that provide an Internet connection. A wireless access point provides service to a number of users within a small geographical perimeter (up to a couple of hundred feet), known as a hotspot. Multiple wireless access points are needed to support a larger number of users across a larger

MiFi

is a small, portable wireless device that provides users with a permanent Wi-Fi hotspot wherever they go.

Super Wi-Fi

is a term coined by the U.S. Federal Communications Commission(FCC) to describe a wireless network proposal that creates long-distance wireless Internet connections. Super Wi-Fi uses the lower-frequency white spaces between television channel frequencies. These lower frequencies enable the signal to travel further and penetrate walls better than normal Wi-Fi frequencies

The global positioning system (CPS) is

is a wireless system that utilizes satellites to enable users to determine their position anywhere on Earth. CPS is supported by 24 MEO satellites that are shared worldwide.

Bluetooth (www.bluetooth.com)

is an industry specification used to create small personal area networks.

rogue access point

is an unauthorized access point to a wireless network.

Location-based mobile commerce

is called location-based commerce (or L-commerce)

Telemetry

is the wireless transmission and receipt of data gathered from remote sensors. Telemetry has numerous mobile computing applications. For example, technicians can use telemetry to identify maintenance problems in equipment

Mobility

means that users carry a device with them and can initiate a real-time contact with other systems from wherever they happen to be.

The major types of wireless media are MSRI

microwave, satellite, radio, and infrared

Satellite radio (or digital radio)

offers uninterrupted, near CD-quality transmission that is beamed to your radio, either at home or in your car, from space. In addition, satellite radio offers a broad spectrum of stations, including many types of music, news, and talk

passive RFID tags

passive RFID tags rely entirely on readers for their power. They are less expensive than active tags, but they can be read only up to 20 feet. For these reasons they are generally applied to less-expensive merchandise. Problems with RFID include expense and the comparatively large size of the tags.

Cellular telephones (cell phones)

provide two-way radio communications over a cellular network of base stations with seamless handoffs

The final type of wireless transmission is infrared transmission. Infrared light is

red light that is not commonly visible to human eyes. Common applications of infrared light are found in remote control units for televisions, VCRs, and DVD and CD players

Mobile computing

refers to a real-time, wireless connection between a mobile device and other computing environments, such ·as the Internet or an intranet. c

Eavesdropping

refers to efforts by unauthorized users to access data that are traveling over wireless networks.

mobile commerce (or m-commerce)

refers to electronic commerce (EC) transactions that are conducted in a wireless environment, especially via the Internet.

Broad reach

refers to the fact that when users carry an open mobile device, they can be reached instantly, even across great distances

Three factors are preventing the commercial Wi-Fi market from expanding even further:

roaming, security, and cost.

Cellular technology is quickly evolving, moving toward higher transmission speeds and richer features. The technology has progressed through several stages:

• First generation (1 G) cellular used analog signals and had low bandwidth (capacity). • Second generation (2G) uses digital signals primarily for voice communication; it provides data communication up to 10 Kbps • 2. 5 G uses digital signals and provides voice and data communication up to 144 Kbps. Third generation (3G) uses digital signals and can transmit voice and data up to 384 Kbps when the device is moving at a walking pace, 128 Kbps when it is moving in a car, and up to 2 Mbps when it is in a fixed location. 3G supports video, Web browsing, and instant messaging Fourth generation (4G) is still under development, and it is not one defined technology or standard

A QR codes have several advantages over bar codes:

• QR codes can store much more information than bar codes. • Data types stored in QR codes include numbers, text, URLs, and even Japanese characters. • The size of QR codes is small because these codes store information horizontally and vertically. QR codes are more resistant to damage than bar codes. • QR codes can be read from any direction or angle, so they are less likely to be misread.

LEO

• Satellites move rapidly relative to point on Earth 400-700 miles Many Telephone • Large number needed for global coverage • Requires only low-power transmitters • Negligible transmission delay • Least expensive to build and launch • Shortest orbital life (as low as 5 years) orbit 400-700 miles Number Many use Telephone

MEO

• Satellites move relative to point on Earth 6,434 miles 10-12 GPS • Moderate number needed for global coverage • Requires medium-powered transmitters • Negligible transmission delay • Less expensive to build and launch • Moderate orbital life (6-12 years) orbit 6,434 miles channel 10-12 use GPS

Wireless devices provide three major advantages to users:

• They are small enough to easily carry or wear. • They have sufficient computing power to perform productive tasks. • They can communicate wirelessly with the Internet and other devices.

The development of m-commerce is driven by the following factors:

• Widespread availability of mobile devices. • Declining prices. The price of wireless devices is declining and will continue to decline. • Bandwidth improvement.