chapter 6

5 major m-commerce applications

location-based services mobile financial applications intrabusiness applications accessing information telemetry

MiFi

- a small, portable, wireless device that provides users with a permanent Wi-Fi hotspot wherever they go - range is about 10m - still quite expensive though - provides broadband activity anywhere there is a 3G cellular network coverage

war driving

- act of locating WLANs while driving/walking around a city or elsewhere - if a WLAN range extends beyond the building then an unauthorized user could intrude into the network - intruder could then gain free internet connection and possibly gain important or other resources

wide-area wireless networks

- connects users to the internet over geographically dispersed territory - include cellular telephones and wireless broadband cellular telephones: provide two-way radio communications over a cellular network of base stations with seamless handoffs wireless broadband (WiMAX): has a wireless access range of up to 50km - can provide long-distance broadband wireless access to rural areas and remote business locations

intrabusiness applications

- consist of m-commerce application that are used within organizations - companies can use non-voice mobile services to assist in dispatch functions; assign jobs to employees, along with detailed informations about the job

eavesdropping

- efforts by unauthorized users to access data travelling over wireless networks

accessing information

- facilitated by mobile ports and voice portals designed to aggregate and deliver content in a form that will work within limited space available on mobile devices - portals provide information to users anywhere and anytime

medium-range wireless

- include Wireless Fidelity (Wi-Fi), Wi-Fi Direct, MiFi and mesh networks

mobile financial applications

- include banking , wireless payments and micropayments, money transfers, wireless wallets, and bill-payment services - makes it more convenient for customers to transact business no matter the time or place

pervasive computing

- is "invisible", everywhere computing is embedded in the object around us two technologies provide the infrastructure for pervasive computing: - radio-frequency identification (RFID) - wireless sensor networks (WSNs)

Internet over Satellite (IoS)

- many places, IoS is the only option to receive internet connections because using cables are either too expensive or physically impossible - IoS enables users to access internet via GEO satellites from a dish mounted on the side of their homes Disadvantage: - GEO satellites have propagation delay and can be disrupted by environmental influences

4 main types if wireless transmission media

- microwave transmission - satellite transmission - radio transmission - infrared light

medium-earth-orbit (MEO)

- move relative to earth (10-12 of them) - require medium powered transmitters - negligle transmission delay - less expensive to build and launch - moderate orbital life (6-12 years) - uses GPS

commercial/business use of GPS

- navigating, mapping and surveying, and in remote areas - cellphones in USA must have GPS embedded in them so that the location of a person making an emergency call can be detected immediately

wireless sensor networks (WSNs)

- networks of interconnected, battery-powered, wireless devices placed in the physical environment to collect data from many points over an extended space

Wi-Fi Direct

- new generation of wifi - enables peer-to-peer communications so devices can connect directly - can transfer content among devices without a wireless antenna (unlike WiFi) - similar type of compatibility to bluetooth but with a greater range and much faster data transfer

radio-frequency jamming

- occurs when a person or a device, intentionally or unintentionally, interferes with wireless network transmissions - can result in a wireless system going down, disrupting operation

location-based services

- provide information specific to a location ex. mobile user can 1) request nearest business or service (ATM or restaurant) 2) receive alerts, such as warning of traffic jam, accident 3) find a friend location based advertising: marketers can integrate the current location and preferences of mobile users - can send user-specific advertising messages about nearby shops, restaurants etc.

infrared light

- red light that usually is not visible to human eyes common applications: used in remote controls for tvs, VCRs, DVDs, and CD players advantage: does not penetrate walls and so does not interfere with other devices in adjoining rooms - low-to-medium bandwidth - used only for short distances disadvantage: infrared signals can easily be blocked by furniture - must have unobstructed line of sight

geostationary (GEO)

- remain stationary relative to earth (8 of them) - few satellites needed for coverage - transmission delay - most expensive - longest orbital life - uses TV signal

low-earth-orbit (LEO)

- satellites move rapidly relative to the earth - large number needed for global coverage - negligible transmission delay - shortest orbital life (as low as 5 years) - can pick up low-power (weak) transmitters - uses telephone

short range wireless networks

- simply the task of connecting one device to another, eliminating wires and enabling users to move around while they use the devices- - in general, have a range of 30m or less - ex. Bluetooth, ultra-wideband, near-field communications Bluetooth: industry specific used to create small personal are networks - is a PAN (personal area network) - can link up to 8 devices within 10m - low power consumption, radio waves transmitted in all directions from a transmitter ex. wireless headset etc. Ultra-wideband (UWB): high-bandwidth wireless technology with transmission speeds in excess of 100 Mbps - good application for streaming multimedia (ex. from personal computer to a television), also real-time location (valuable for health care environments, where mobile equipment is critical) near-field communications (NFC): has the smallest range of any short-range wireless network - designed to be embedded in mobile devices such as cell phones or credit cards (ex. can swipe your device or card within a few cm of point-of-sale terminals to pay for items

satellite transmission

- systems make use of communication satellites, and they receive and transmit data via line-of-sight - 3 types of satellites around earth, geostationary (GEO) furthest from earth, medium-earth-orbit (MEO), low-earth-orbit (LEO) - higher the satellites orbit the greater is their footprint advantage: their enormous footprint, the area of the earths surface reached by a satellite's transmission - overcomes the limitations of microwave data relay stations - high bandwidth - can broadcast transmissions, which signals many receivers at one time disadvantage: - expensive - must have unobstructed line of sight - signals experience propagation delay - must use encryption for security propagation delay: the amount of time it takes for the head of the signal to travel from the sender to the receiver

radio-frequency identification (RFID)

- term for technologies that use radio waves to automatically identify the location of individual items equipped with tags that contain embedded microchips

microwave transmission

- transmit data via electromagnetic waves - because must communicate line of sight, microwave towers usually cannot be spaced more than 50km apart (due to the curvature of the earth) - used for high-volume, long-distance, line-of-sight communication advantage: the high volume, high bandwidth, relatively inexpensive disadvantage: is that microwave transmissions are susceptible to environmental interference during severe weather such as heavy rain or storms

rogue access points

- unauthorized access point to a wireless network - once the attacker is in, can send the users a web page asking for confidential information - more effective with public hotspots

Mesh Networks

- use multiple Wi-Fi access points to create a wide area network that can be quite large - essentially a series of interconnect local area networks

radio transmission

- uses radio-wave frequencies to send data directly between transmitters and receivers advantage: is that radio waves travel easily through normal office walls - high bandwidth - signals pass through walls - inexpensive and easy to install disadvantage: that radio transmissions are susceptible to snooping by anyone who has similar equipment that operates on the same frequency - creates electrical interference problems

telemetry

- wireless transmission and receipt of data gathered from remote sensors - company technicians can use telemetry to identify maintenance problems in equipment ex. car manufacturers use telemetry applications for remote vehicle diagnosis ex. can help find your phone if you loose it

3 other GPS satellites

GLONASS: Russian satellite, complete 1995. fell into disrepair with the fall of the Soviet economy. achieved 100% coverage of Russian territory Galileo: EU, finished in 2015 Beidou: China, meant to be completed 2020

types of satellite

geostationary (GEO) medium-earth-orbit (MEO) low-earth-orbit (LEO)

GPS

global positioning system - a wireless system that uses satellites to enable users to determine their position anywhere on earth - 3 satellites gives 2D (two dimensional location) - 4 satellites gives 3D (three dimensional location) - can find the location of any receiving station or user within a range of 3m - can convert users latitude and longitude into a electronic map

Wi-Fi

provides fast and easy internet or intranet broadband access from public hotspots located at airports, hotels, cafes etc. - medium-range wireless local area network (WLAN), basically like a wired LAN but without the cables - transmitter with an antenna (called wireless access point), connects to a wired LAN or to a satellite dishes that provide an internet connection - wireless access point provides service to a number of users within a small geographical perimeter (up to 60m), known as a hotspot

- 4 major threats to wireless networks - wireless security issues

rogue access points war driving eavesdropping radio-frequency jamming