Mobile Computing

2015-08-27T09:13:26Z

Phamnhatkhanh: /* Further reading */

{{mergefrom|Mobile Internet device|date=June 2012|discuss=Talk:Mobile_device#Merge_with_mobile_internet_device}}
{{mergefrom|Mobile device|date=June 2012}}
{{expert-subject|Technology|ex2=Computing|date=May 2009}}

[[File:Galaxy Nexus smartphone.jpg|thumb|upright|The [[Galaxy Nexus]], capable of web browsing, e-mail access, video playback, document editing, image editing, among many other tasks common on smartphones. A smartphone is a tool of mobile computing.]]
[[File:Telxon PTC-710 with MP 830-42.jpg|thumb|Telxon PTC-710 is a 16-bit mobile computer PTC-710 with MP 830-42 micro[[Printer (computing)|printer]] 42-column version. ]]

'''Mobile computing''' is [[human–computer interaction]] by which a [[computer]] is expected to be transported during normal usage. Mobile computing involves [[mobile communication]], mobile hardware, and mobile software. Communication issues include ad hoc and infrastructure networks as well as communication properties, [[communications protocol|protocols]], data formats and concrete technologies. Hardware includes [[mobile device]]s or device components. [[Mobile software]] deals with the characteristics and requirements of mobile applications.

==Definitions==

Mobile Computing is "taking a computer and all necessary files and software out into the field and the system".<ref>[http://www.blm.gov/wo/st/en/prog/more/bea/Glossary.html#m Glossary]</ref> There are several different dimensions under which mobile computers can be defined:
(1) in terms of physical dimensions;
(2) in terms of how devices may be hosted;
(3) in terms of when the mobility occurs;
(4) in terms of how devices are networked;
(5) in terms of the type of computing that is performed.<ref name="Poslad">{{cite book |last = Poslad | first = Stefan | title = Ubiquitous Computing Smart Devices, Smart Environments and Smart Interaction | publisher = Wiley | year = 2009 | pages=115–133 | isbn = 978-0-470-03560-3 | url = http://www.eecs.qmul.ac.uk/people/stefan/ubicom/index.html}}</ref>

In terms of dimensions, mobile computers tend to be planar and tend to range in size from centimeters to decimeters. Mobile computer may themselves be mobile, e.g., it is embedded into a [[Robot]] or [[Vehicle]] that is mobile or itself may not be mobile, but is carried by a mobile host, e.g., the mobile phone is not mobile but it is carried by a mobile human. The most flexible mobile computer is one that can move during its operation or user session but this depends in part on the range of any wireless network it is connected to. A [[tablet computer|tablet]] or [[laptop]] computer connected via [[Wi-Fi]] can move while staying connected within the range of its [[WLAN]] transmitter. To move between multiple different located [[WLAN]]s, the device must interrupt, suspend, or close its current user session before connecting to another [[WLAN]] transmitter in another session. A device such as a tablet or mobile phone can move much further while staying connected within the range of a GSM network as it can seamlessly move between multiple GSM transmitters or [[Base station]]s. Mobile computers may also support or form part of a more local network that moves as the devices, i.e., mobile computers may also be used as part of a [[WPAN|''Wireless Body Area Network'']], [[WPAN|''Wireless Personal Area Network'']] or a [[piconet]]. Depending on the type of application the mobile computer runs, the computation of the applications may run only locally, e.g., a [[Computer game|PC game]]. The majority of mobile computers for personal use tends to be used for communication or for remote data downloads such as remote Web access (see [[Mobile Internet device]]). As some mobile computers contain an array of sensors, microphones and cameras, these can be used for local data capture, filtering tagging and remote uploads. Increasing mobile computers are also being used to access services such as travel, payment or for access to controlled physical spaces.

==Devices==
Some of the most common forms of mobile computing devices are as follows.
* [[personal computers|''portable computers'']], compacted lightweight units including a full character set keyboard and primarily intended as [[computer terminal|host]]s for software that may be parametrized, as laptops, notebooks, notepads, etc.
* [[mobile phone|''mobile phones'']] including a restricted key set primarily intended but not restricted to for vocal communications, as cell phones, smart phones, phonepads, etc.
* [[Smart cards]] that can run multiple applications but typically payment, travel and secure area access
* [[wearable computing|''wearable computers'']], mostly limited to functional keys and primarily intended as incorporation of [[software agent]]s, as watches, wristbands, necklaces, keyless implants, etc.

The existence of these classes is expected to be long lasting, and complementary in personal usage, none replacing one the other in all features of convenience.

Other types of mobile computers have been introduced since the 1990s including the:
* [[Portable computer]] (discontinued)
* [[Personal digital assistant]]/[[Enterprise digital assistant]] (discontinued)
* [[Ultra-Mobile PC]] (discontinued)
* [[Laptop]]
* [[Smartphone]]
* [[Robots]]
* [[Tablet computer]]
* [[Wearable computer]]
* [[Carputer]]
* [[Application-specific computer]]

==Limitations==
* '''Range & Bandwidth''': Mobile Internet access is generally slower than direct cable connections, using technologies such as [[GPRS]] and [[EDGE]], and more recently [[HSDPA]] and [[HSUPA]] [[3G]] and [[4G]] networks and also upcoming [[5G]] network. These networks are usually available within range of commercial cell phone towers. High speed network [[wireless LAN]]s are inexpensive but have very limited range.
* '''Security standards''': When working mobile, one is dependent on public networks, requiring careful use of [[virtual private networks|VPN]]. Security is a major concern while concerning the mobile computing standards on the fleet. One can easily attack the VPN through a huge number of networks interconnected through the line.
* '''Power consumption''': When a power outlet or portable generator is not available, mobile computers must rely entirely on battery power. Combined with the compact size of many mobile devices, this often means unusually expensive batteries must be used to obtain the necessary battery life.
* '''Transmission interferences''': Weather, terrain, and the range from the nearest signal point can all interfere with signal reception. Reception in tunnels, some buildings, and rural areas is often poor.
* '''Potential health hazards''': People who use mobile devices while driving are often distracted from driving and are thus assumed more likely to be involved in traffic accidents.<ref>http://www.distraction.gov/stats-and-facts/</ref> (While this may seem obvious, there is considerable discussion about whether banning mobile device use while driving reduces accidents or not.<ref>{{cite web|url=http://handsfreeinfo.com/study-handheld-cell-bans-have-no-effect|title=Hands Free Cell Phones No Safer, Insurance Study Claims|publisher=|accessdate=16 July 2015}}</ref><ref>{{cite web|url=http://news.cnet.com/8301-30686_3-10444717-266.html|title=Study: Distractions, not phones, cause car crashes|publisher=CBS Interactive|work=CNET|accessdate=16 July 2015}}</ref>) Cell phones may interfere with sensitive medical devices. Questions concerning [[mobile phone radiation and health]] have been raised.
* '''Human interface with device''': Screens and keyboards tend to be small, which may make them hard to use. Alternate input methods such as speech or handwriting recognition require training.

==In-vehicle computing and fleet computing==
Many commercial and government field forces deploy a ruggedized portable computer with their fleet of vehicles. This requires the units to be anchored to the vehicle for driver safety, device security, and [[ergonomics]]. [[Rugged computer]]s are rated for severe vibration associated with large service vehicles and off-road driving and the harsh environmental conditions of constant professional use such as in [[emergency medical services]], fire, and public safety.

[[Image:Compaq portable.jpg|thumb|The [[Compaq Portable]] - Circa 1982 pre-[[laptop]]]]

Other elements affecting function in vehicle:
* [[Operating temperature]]: A vehicle cabin can often experience temperature swings from -20F to +140F. Computers typically must be able to withstand these temperatures while operating. Typical fan-based cooling has stated limits of 95F-100F of ambient temperature, and temperatures below freezing require localized heaters to bring components up to operating temperature (based on independent studies by the SRI Group and by Panasonic R&D).
* Vibration can decrease the life expectancy of computer components, notably rotational storage such as [[Hard disk drive|HDDs]].
* Visibility of standard screens becomes an issue in bright sunlight.
* Touchscreen users easily interact with the units in the field without removing gloves.
* High-temperature battery settings: Lithium ion batteries are sensitive to high temperature conditions for charging. A computer designed for the mobile environment should be designed with a high-temperature charging function that limits the charge to 85% or less of capacity.
* External antenna connections go through the typical metal cabins of vehicles which would block wireless reception, and take advantage of much more capable external communication and navigation equipment.

Several specialized manufacturers such as First Mobile Technologies, National Products Inc ([[Ram Mounts]]), Gamber Johnson and [http://www.havis.com Havis] (formerly LedCo) build mounts for vehicle mounting of computer equipment for a wide range of vehicles. The mounts are built to withstand the harsh conditions and maintain ergonomics.

Specialized installation companies design the mount design, assembling the parts, and installing them in a safe and consistent manner away from [[airbags]], vehicle HVAC controls, and driver controls. Frequently installations will include a [[Wireless Wide Area Network|WWAN]] modem, power conditioning equipment, transceiver antennae mounted external to the vehicle, and WWAN/WLAN/GPS/etc.

==Security issues involved in mobile==
'''Mobile security''' or '''mobile phone security''' has become increasingly important in mobile computing. It is of particular concern as it relates to the [[Information security|security]] of personal information now stored on the [[smartphone]].

More and more users and businesses use smartphones as communication tools but also as a means of planning and organizing their work and private life. Within companies, these technologies are causing profound changes in the organization of [[information systems]] and therefore they have become the source of new risks. Indeed, smartphones collect and compile an increasing amount of sensitive information to which access must be controlled to protect the [[Information privacy|privacy]] of the user and the [[intellectual property]] of the company.

All smartphones, as computers, are preferred targets of attacks. These attacks exploit weaknesses related to smartphones that can come from means of communication like [[SMS]], [[Multimedia Messaging Service|MMS]], [[wifi|wifi networks]], and [[GSM]]. There are also attacks that exploit software vulnerabilities from both the web browser and operating system. Finally, there are forms of [[malware|malicious software]] that rely on the weak knowledge of average users.

Different security counter-measures are being developed and applied to smartphones, from security in different layers of software to the dissemination of information to end users. There are good practices to be observed at all levels, from design to use, through the development of [[operating system]]s, software layers, and downloadable apps.

==Portable computing devices==
{{main|Mobile device|Portable computer}}
{{Cleanup|section|date=February 2009}}

Several categories of portable computing devices can run on batteries but are not usually classified as laptops: portable computers, PDAs, ultra mobile PCs (UMPCs), tablets and smartphones.

* A [[portable computer]] (discontinued) is a general-purpose computer that can be easily moved from place to place, but cannot be used while in transit, usually because it requires some "setting-up" and an AC power source. The most famous example is the [[Osborne 1]]. Portable computers are also called a "transportable" or a "luggable" PC.

* A [[personal digital assistant]] (PDA) (discontinued) is a small, usually pocket-sized, computer with limited functionality. It is intended to supplement and to synchronize with a desktop computer, giving access to contacts, address book, notes, e-mail and other features.[[Image:PalmTX.jpg|thumb|right|A [[Palm TX]] PDA]]

* An [[ultra mobile PC]] (discontinued) is a full-featured, PDA-sized computer running a general-purpose operating system.

* A [[tablet computer]] that lacks a keyboard (also known as a non-convertible tablet) is shaped like a slate or a paper notebook. Instead a physical keyboard it has a [[touchscreen]] with some combination of [[virtual keyboard]], stylus and/or [[handwriting recognition]] software. Tablets may not be best suited for applications requiring a physical keyboard for typing, but are otherwise capable of carrying out most of the tasks of an ordinary laptop.

* A [[smartphone]] has a wide range of features and install-able applications.

* A [[carputer]] is installed in an automobile. It operates as a wireless computer, sound system, GPS, and DVD player. It also contains word processing software and is bluetooth compatible.<ref>{{cite web|url=http://www.engadget.com/tag/carputer/|title=Carputer Articles on Engadget|publisher=AOL|work=Engadget|accessdate=16 July 2015}}</ref>

* A |Pentop (discontinued) is a computing device the size and shape of a pen. It functions as a writing utensil, MP3 player, language translator, digital storage device, and calculator.<ref>{{cite web|url=http://www.geardiary.com/2007/10/07/the-fly-fusion-pentop-computer-review/|title=Gear Diary » The FLY Fusion Pentop Computer Review|date=7 October 2007|publisher=|accessdate=16 July 2015}}</ref>
* An application-specific computer is one that is tailored to a particular application. For example, [[Ferranti]] introduced a handheld application-specific mobile computer (the [[Ferranti MRT|MRT-100]]) in the form of a [[clipboard]] for conducting [[opinion polls]].<ref>G Rowley, K Barker and V Callaghan “''The Questronic Project and the Ferranti MRT 100 A Boon For Survey Research''”, The Professional Geographer, Volume 37, Issue 4, pages 459–463, November 1985</ref>

Boundaries that separate these categories are blurry at times. For example, the [[OQO]] UMPC is also a PDA-sized tablet PC; the [[EMate 300|Apple eMate]] had the clamshell form factor of a laptop, but ran PDA software. The [[HP Omnibook]] line of laptops included some devices small more enough to be called ultra mobile PCs. The hardware of the [[Nokia 770]] internet tablet is essentially the same as that of a PDA such as the [[Sharp Zaurus|Zaurus]] 6000; the only reason it's not called a PDA is that it does not have [[Personal information manager|PIM]] software. On the other hand, both the 770 and the Zaurus can run some desktop Linux software, usually with modifications.

==Mobile data communication==
[[Wireless]] data connections used in mobile computing take three general forms so.<ref name="Ositech">[http://www.ositech.com/downloads/123dwnlod_1.html "Wireless Data Communications for Beginners"], ''Ositech''</ref> [[Cellular network|Cellular]] data service uses technologies such as [[GSM]], [[Code division multiple access|CDMA]] or [[General Packet Radio Service|GPRS]], [[3G]] networks such as [[W-CDMA (UMTS)|W-CDMA]], [[Enhanced Data Rates for GSM Evolution|EDGE]] or [[CDMA2000]].<ref>Lachu Aravamudhan, Stefano Faccin, Risto Mononen, Basavaraj Patil, Yousuf Saifullah, Sarvesh Sharma, Srinivas Sreemanthula. [http://www.informit.com/articles/printerfriendly.aspx?p=98132 "Getting to Know Wireless Networks and Technology"], ''InformIT''</ref><ref>[http://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdf "What really is a Third Generation (3G) Mobile Technology"], ''ITU''</ref> and more recently [[4G]] networks such as [[LTE (telecommunication)|LTE]], [[LTE-Advanced]].<ref>[[LTE Advanced]]</ref> These networks are usually available within range of commercial [[Cell site|cell towers]]. [[Wi-Fi]] connections offer higher performance,<ref>Gier, Jim. [http://www.wireless-nets.com/resources/downloads/wireless_industry_report_2007.pdf "Wireless Network Industry Report"], ''Wireless Nets, Ltd.''</ref> may be either on a private business network or accessed through public [[Hotspot (Wi-Fi)|hotspots]], and have a typical range of 100 feet indoors and up to 1000 feet outdoors.<ref>[http://www.hotrecruiter.com/resources/technical-tutorials/35-freelance-tips-a-tutorials/893-wi-fi "Wi-Fi"]</ref> [[Satellite Internet access]] covers areas where cellular and Wi-Fi are not available<ref>Mitchell, Bradley. [http://compnetworking.about.com/od/internetaccessbestuses/g/bldef_satellite.htm "Satellite Internet"]</ref> and may be set up anywhere the user has a [[Line-of-sight propagation|line of sight]] to the satellite's location,<ref>[http://www.compassroseintl.com/pubs/Intro_to_sats.html "Introduction to Global Satellite Systems"], ''CompassRose International Publications''</ref> which for satellites in [[geostationary]] orbit means having an unobstructed view of the southern sky.<ref name="Ositech" /> Some enterprise deployments combine networks from multiple cellular networks or use a mix of cellular, Wi-Fi and satellite.<ref>[http://www.netmotionwireless.com/resources/case_studies.aspx Case studies], ''netmotionwireless.com''</ref> When using a mix of networks, a [[mobile virtual private network]] ([[mobile virtual private network|mobile VPN]]) not only handles the [[Computer security|security]] concerns, but also performs the multiple network [[login]]s automatically and keeps the [[Application software|application]] connections alive to prevent [[Crash (computing)|crashes]] or data loss during network transitions or coverage loss.<ref>Phifer, Lisa. [http://searchmobilecomputing.techtarget.com/tip/0,289483,sid40_gci1210989_mem1,00.html "Mobile VPN: Closing the Gap"], ''SearchMobileComputing.com'', July 16, 2006. </ref><ref name="Cheng">Cheng, Roger. [http://online.wsj.com/article/SB119717610996418467.html "Lost Connections"], ''[[The Wall Street Journal]]'', December 11, 2007. </ref>

==See also==
{{commons category|Mobile computers}}
* [[Enterprise digital assistant]]
* [[Location-based service]]
* [[Mobile ad hoc network]]s
* [[Mobile cloud computing]]
* [[Mobile Computing and Communications Review]]
* [[Mobile development]]
* [[Mobile device management]]
* [[Mobile identity management]]
* [[Mobile interaction]]
* [[Mobile phone]]
* [[Mobile software]]
* [[Mobileer]]s (users of [[mobile rig]]s)
* [[PDA]]
* [[Smart card]]
* [[Smart device]]
* [[Ubiquitous computing]]

== References ==

=== Citations ===
{{Reflist|2}}

=== Bibliography ===
* GH Forman, J Zahorjan - Computer, 1994 - doi.ieeecomputersociety.org
* David P. Helmbold, "A dynamic disk spin-down technique for mobile computing", citeseer.ist.psu.edu, 1996
* MH Repacholi, "health risks from the use of mobile phones", [[Toxicology Letters]], 2001 - Elsevier
* Landay, J.A. Kaufmann, T.R., "user interface issues in mobile computing", Workstation Operating Systems, 1993.
* T Imielinski, BR Badrinath "mobile wireless computing, challenges in data management- Communications of the ACM, 1994 - portal.acm.org
* Roth, J. "Mobile Computing - Grundlagen, Technik, Konzepte", 2005, dpunkt.verlag, Germany
* Pullela, Srikanth. "Security Issues in Mobile Computing" http://crystal.uta.edu/~kumar/cse6392/termpapers/Srikanth_paper.pdf
* Zimmerman, James B. "Mobile Computing: Characteristics, Business Benefits, and Mobile Framework" April 2, 1999. http://ac-support.europe.umuc.edu/~meinkej/inss690/zimmerman/INSS%20690%20CC%20-%20Mobile%20Computing.htm
* Koudounas, Vasilis. Iqbal, Omar. "Mobile Computing: Past, Present, and Future" http://www.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/vk5/report.html

==Further reading==
* {{cite book | title=Mobile Computing Principles: Designing and Developing Mobile Applications with UML and XML | first=Reza | last=B'Far | publisher=Cambridge University Press | year=2004 | isbn=0-521-81733-1}}
* {{cite book | title=Ubiquitous Computing: Smart Devices, Environments and Interactions | first=Stefan | last=Poslad | publisher=Wiley | year=2009 | isbn=0-470-03560-9}}
* {{cite book | title=The Wireless Internet Explained | publisher=Digital Press | year=2001 | first=John | last=Rhoton | isbn=1-55558-257-5}}
* {{cite book | title=Mobile Computing: Technology, Applications, and Service Creation | first=Asoke | last=Talukder | first2=Roopa | last2=Yavagal | publisher=McGraw-Hill Professional | year=2006 | isbn=0-07-147733-0}}

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Mobile Computing