Ch8: Wireless, Mobile Computing, and Mobile Commerce

Wireless Sensor Networks (WSNs)

networks of interconnected, battery powered, wireless sensors called motes that are placed into the physical environment

Wide-Area wireless networks (generations of cellular tech)

First generation (1G): cellular networks 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. 2.5G: 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. It supports video, Web browsing, and instant messaging. Fourth generation (4G): is not one defined technology or standard. The International Telecommunications Union (ITU) has specified speed requirements for 4G: 100 Mbps (million bits per second) for high-mobility communications such as cars and trains, and 1 Gbps (billion bits per second) for low-mobility communications such as pedestrians. A 4G system is expected to provide a secure all-IP-based mobile broadband system to all types of mobile devices. Fifth Generation (5G): expected to be deployed by 2020, 5G networks are predicted to be faster and more intelligent than previous generations of cellular networks. With 5G, wearable computers (e.g., Fitbit), smartphones, tablets, and other devices with sensors that are location- and context-aware will work together with apps and services that you use. Wireless Broadband or WiMAX: Worldwide Interoperability for Microwave Access (WiMAX) is the name for IEEE Standard 802.16 which has a wireless access range of up to 31 miles and a data transfer rate of up to 75 Mbps. It is a secure system, and it offers features such as voice and video.

Four major threats to wireless networks

Rogue access Point: an unauthorized access point connected to a wireless network Evil Twin Attack: the attacker is in a vicinity with a Wi-Fi enabled computer and a separate connection to the internet. Using a hospotteer—a device that detects wireless networks and provides information on them the attacker simulates a wireless access point with the same wireless network name, or SSID, as the one that authorized users expect. If the signal is strong enough, users will connect to the attacker's system instead of the real access point. War Driving: the act of locating WLANs while driving (or walking) around a city or elsewhere Eavesdropping: efforts by unauthorized users to access data that are traveling over wireless networks Radio-Frequency (RF) Jamming: a person or a device intentionally or unintentionally interferes with your wireless network transmissions

Low Earth Orbit (Leo)

Satellites move rapidly relative to point on Earth; 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)

Middle Earth Orbit (MEO)

Satellites move relative to point on Earth; Moderate number needed for global coverage; requires medium-powered transmitters; negligible transmission delay; less expensive to build and launch; moderate orbital life (6-12 rears) *GPS is supported by 24 MEO satelites

Geostationary Earth Orbit (GEO) Satellite

Satellites stationary relative to point on earth; few satellites needed for global coverage; transmission delay of 25 seconds; most expensive to build and launch; longest orbital life

Dematerialization

a phenomenon that occurs when the functions of many physical devices are included in one other physical device. Consider that your smartphone includes the functions of digital cameras for images and video, radios, televisions, Internet access via Web browsers, recording studios, editing suites, movie theaters, GPS navigators, word processors, spreadsheets, stereos, flashlights, board games, card games, video games, an entire range of medical devices, maps, atlases, encyclopedias, dictionaries, translators, textbooks, watches, alarm clocks, books, calculators, address books, credit card swipers, magnifying glasses, money and credit cards, car keys, hotel keys, cellular telephony, Wi-Fi, e-mail access, text messaging, a full QWERTY keyboard, and many, many others.

QR code

a two dimensional code, readable by dedicated QR readers and camera phones

Universal Product Code (UPC)

a typical bar code made up of 12 digit that are batched in various groups. The first digit identifies the item type, the next five digits identify the manufacturer and the next 5 identify the product. The last digit is a check did for error detection

Short Range Wireless Networks

have a range of 100 feet or less Short-Range Wireless Networks: have a range of 100 feet or less (e.g., Bluetooth, ultra-wideband (UWB), and near-field communications (NFC)). Bluetooth: an industry specification used to create small personal area networks. Bluetooth 1.0: can link up to eight devices within a 10-meter area (about 30 feet) with a bandwidth of 700 kilobits per second (Kbps) using low-power, radio-based communication. Bluetooth 4.0: can transmit up to approximately 25 megabits per second (Mbps) up to 100 meters (roughly 300 feet). Personal Area Network: a computer network used for communication among computer devices (e.g., telephones, personal digital assistants, and smartphones) located close to one person. Ultra-Wideband: a high-bandwidth wireless technology with transmission speeds in excess of 100 Mbps which makes UWB a good choice for applications such as streaming multimedia from a personal computer to a television. Near-Field Communications: has the smallest range of any short-range wireless networks, and is designed to be embedded in mobile devices such as cell phones and credit cards.

Internet of Things

scenario in which objects, animals, and people are provided with unique identifiers and the ability to automatically transfer data over a network without requiring human to human or human to computer interaction

Radio-Frequency Identification (RFID)

tech that allows manufacturers to attach tags with antennas and computer chips on goods and then track their movement through radio signals; developed to replace barcodes two types of tags: active (tags that use internal batteries for power, and they broadcast radio waves to a reader) and Passive (tags rely entirely on readers for their power, less expensive than active tags, and can be read only up to 20 feet)

Medium range wireless networks

the familiar wireless local area networks (WLANs) and the most common type of Medium-range network is Wi-Fi Wireless Mesh Networks: networks using multiple Wi-Fi access points to create a wide area network that can be quite large and are essentially a series of interconnected local area networks.

Pervasive/Ubiquitous Computing

visually every object has processing power with either wireless or wired connections too a global network

Satellite

wireless transmission media Advantages: high bandwidth, large coverage area Disadvantages: expensive, requires unobstructed line sight, signals experience propagation delay, requires the use of encryption for security 3 basic types: GEO, MEO, LEO

Radio

wireless transmission media Advantages: high bandwidth, signals pass through walls, inexpensive and easy to install Disadvantages: creates electrical interference problems; susceptible to "snooping" unless encrypted

Infrared

wireless transmission media Advantages: low to medium bandwidth; used only for short distances Disadvantages: requires an unobstructed line of sight

Microwave

wireless transmission media advantages: bandwidth, inexpensive disadvantages: requires an unobstructed line of sight, susceptible to environmental interference