Context-aware Mobile Computing - a Literature Review

1. 2014 October Context-aware
Mobile Computing
Literature review
T. A. Makumburage
Index No: 13440481

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● Abstract
The purpose of this study is to explore the world of context-aware mobile computing. From the roots of
the context-awareness and mobile computing paradigm, the questions focused on this review are what
technology has evolved with the context-awareness and how those technologies effect to the modern
day society.
● Introduction
Computer applications usually executed in a static controlled environment. But when it comes to mobile
platforms the environment is constantly changing. These context aware systems can sense their physical
environment and adapt their behavior accordingly. So the mobile applications can take advantage of
contextual information to provide a better service to the end user. Although location is a primary
capability of a context-aware system, location does not necessarily capture things of interest that are
mobile or changing. Context-aware in contrast is used more generally to include nearby people, devices,
lighting, noise level, network availability, etc…[1] [21] [24]
Today’s mobile hardware are quite capable of sensing users and their current state by gathering
contextual information, which significantly reduce demands on human attention. This leads to a smooth
interaction between human and technology. The hand held devices are becoming increasingly valuable
to the users. Thus the smartphones are getting cheaper, as well as more powerful and battery hungry.
Secondly there are emerging de facto standards for mobile communication such as Bluetooth, Wi-Fi and
NFC, which allows users to share information. So the modern research about mobile computing focuses
on the development of the technologies for context-awareness as well as the design of context-aware
mobile applications.[22] [23]
● History
Context-aware systems are a part of a pervasive computing paradigm. The concept emerged from
ubiquitous computing research at Xerox PARC in the early 1990s. Three important aspects of context are
[1]
:
● where you are
● who you are with
● what resources are nearby
The term 'context-aware' was first used in paper ‘Disseminating Active Map Information to Mobile
Hosts’, by Bill Schilit and Marvin Theimer in 1994. They have described a model of computing in which
users interact with many different mobile and stationary computers. Context-aware systems were

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classified as systems which can adapt according to its location of use, the collection of nearby people
and objects, as well as the changes to those objects over the time.[2]
● Mobile Computing
In recent years mobile software and hardware grew in leaps and bounds towards new innovation.
Newest smartphones have the processing power equal to a desktop computer with the added
advantage of being fit into a hand. Following are some key things that spiced up the mobile innovation.
● Tough competition to grab the market share (Apple vs. Android).
● Flagship smartphones by competitors in each year.
○ Google’s Nexus Line
○ Apple’s iPhone
○ Samsung’s Galaxy Series
○ LG’s G series
○ Motorola’s Moto series
○ HTC’s HTC One Series
● Patent wars.
○ Apple vs. Google court case for Android APIs
○ Apple vs. Samsung patent infringement
○ Google buying Motorola for patents and selling it to Lenovo
● Upcoming new mobile operating systems.
○ Android 5.0
○ Apple iOS 8
○ Microsoft Windows Mobile 8.1
○ Ubuntu Mobile Operating System
○ Mozilla Mobile Operating System
● The fall of mobile giant, Nokia.
● Android One project, a 100$ smartphone.
● Introduction of 64 bit Mobile Computing.

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When it comes to getting contextual information from the mobile user, there are a wide range of
sensors available on modern smartphone.
▪ GPS/GLONASS
The Global Positioning System (GPS) is a space-based satellite navigation system that provides location
and time information in all weather conditions, anywhere on or near the Earth where there is an
unobstructed line of sight to four or more GPS satellites[13]
.
In modern smartphones there are two GPS options available, A-GPS and GLONASS. GLONASS is acronym
for "Globalnaya navigatsionnaya sputnikovaya sistema" or "Global Navigation Satellite System". It is
also space-based satellite navigation system operated by the Russian Aerospace Defense Forces. It
provides an alternative to Global Positioning System (GPS) and is the second alternative navigational
system in operation with global coverage and of comparable precision[14]
.
These technologies are the main pillars of the location tracking in mobile computing. Many applications
like Google Maps use these technologies to track user location and provide context-aware information
to provide better services to the user.
▪ Wi-Fi
Using nearby Wi-Fi, software can gather contextual information of the users with great accuracy. As per
the Research implementation conducted using the Wi-Fi LAN of Carnegie Mellon University by Asim and
David on 2002. Their implementation is based on signal strength and access point information from the
IEEE 802.11b Wave LAN. This is contrast to the GPS based approach, which has poor indoor accuracy and
consumes lot of power.[10]
In 2013 we could see the results of these kind of researches, When Android
Figure 1: Smartphone OS Market Share, Q2 2014[12]

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operating system introduces Wi-Fi always scanning option to get the accurate location information to
Google location services[11]
.
Apart from these main sensors, there are many more along the list. Such as,
▪ Gyroscope - a device for measuring or maintaining orientation[15]
▪ Accelerometer - a device that measures proper acceleration ("g-force")[16]
▪ Barometer - a device to measure atmospheric pressure[17]
▪ Pedometer - a device for count steps[18]
▪ Heart rate monitor
▪ Fingerprint sensor
▪ NFC (Near Field Communication)
● Implementing Context-awareness
o Smartphones
▪ Location sensing
Smartphones use GPS/GLONASS or any other tracking mechanism to get hold of the user context data.
Those data will be used by the mobile operating system to assist the user on decision making and to
learn about user behavior. Currently there are thousands of software which uses location sensing to
provide a better service to the user.
▪ Project Tango
In real life people use visual clues to navigate and understand the world around us. They observe the
size and shape of objects, and learn their position and layout almost effortlessly over time. This
awareness of space and motion is fundamental to the way people interact the environment and each
other. People are physical beings that live in a 3D world. Yet, the mobile devices assume that physical
world ends at the boundaries of the screen.[5]
Project Tango is an effort from Google’s Advanced Technology and Projects group (ATAP) with the
collaboration of partners across nine countries, to develop context-aware mobile devices which runs
their famous open source operating system, Android. There are two devices are already out in the open
for developers, a smartphone and a tablet, to build applications on top of this amazing hardware
platform. The prototype is an Android smartphone-like device which tracks the 3D motion of the device,
and creates a 3D model of the environment around it, which applications can use to gather information
about the context. [4]

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The goal of the Tango team is to give mobile devices a human-scale understanding of space and motion.
Which means the mobile device may able to gain knowledge about what context it is in and how fast the
context is changing. Thus they concentrated modern research in robotics and computer vision
knowledge to achieve the target.[5]
o Google Glass
Google Glass was developed by Google X, the facility within Google devoted to advanced technological
advancements. Google Glass is a type of wearable technology with an optical head-mounted display
(OHMD). It was developed with a goal of producing a mass-market ubiquitous computer. Google Glass
displays information in a smartphone-like hands-free format in the head-mounted display. Wearers
communicate with the Internet via natural language voice commands.[6]
The engineers behind Google Glass have created a mini-projector that blasts information into a prism
that redirects imagery directly toward your retina, much of which depends on the placement of Glass on
your head. [7]
The hardware setup behind Google Glass, includes a battery, CPU, 2GB RAM, 16GB storage
,speakers, microphone, 5MP camera and various context-aware sensors which you would see in a
smartphone.[7] [6]
Google Glass also uses many existing Google applications, such as Google Now, Google Maps, Google+,
and Gmail. Many developers and companies have built applications for Google Glass, including news
apps, facial recognition, exercise, photo manipulation, translation, and sharing to social networks.[6]
The
facial recognition ability of the Google Glass become a hot topic since the introduction, because some
scientific movies we saw in our childhood became a reality. With the support of the many utility
applications Google glass will provide the wearer context-related accurate data instantaneously.
Figure 2: Project Tango [5] Figure 3: Project Tango [5]

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Figure 4: How Google Glass Works [7]
o Software
▪ Google Now
Google Now carried the tag line “The right information at just the right time” [9]
. It is a context-aware
intelligent personal assistant software built by Google, to work with Android and iOS mobile operating
systems. Google Now was named the "Innovation of the Year" for 2012 by Popular Science magazine.
Google Now uses a natural language processing to answer questions, make recommendations, and
perform actions by delegating requests to a set of web services. Along with answering user-initiated
queries, Google Now proactively delivers information to the user that it predicts they will want, based
on their search habits and context[8]
.
Google Now displays cards with information pulled from the user's Gmail account, such as flight
information, package tracking information, hotel reservations and restaurant reservations. Other
additions were movies, concerts, stocks and news cards based on the user’s location and search history
[8]
. For example Google Now could tell you if you if you are late to office, based on the contextual
information from the road you are in, using the traffic information pulled from the Google Maps. Google
Now is implemented as a part of the Google Search application. It recognizes and uses repeated actions
that a user performs on the device (common locations, repeated calendar appointments, search queries,
etc.) to display more relevant information to the user in the form of "cards". The system leverages
Google's Knowledge Graph project, a system used to assemble more detailed search results by analyzing
their meaning and connections, which is user context[8] [9]
.

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▪ Google Maps
Another implementation of context awareness is generating traffic related information in Google Maps.
Google Maps uses location data from android devices around the area to generate travelling patterns
and travelling time of the people. Location history of the devices are stored in the servers and analyzed
to provide the travelling time between two waypoints in the Google map[19]
.
● Advantages
There are many advantages of context-aware systems. Following are some of them.
o Accurate & relative information
Context-aware systems always provide accurate and relative information to the user, because of the
location sensing. Mobile applications will have existing user location to filter out relevant data and
provide accurate information to the user.
o Information at your fingertips
Because of the context-awareness of the modern smartphones, you would not been needed to inform
the device of your context. The devices are capable enough to provide you the context-aware
information instantaneously. Weather information is a very common type of such a service.
o Personal Assistance
Personal assistance built-in to the mobile operating systems are a quite a hot topic in these days. Apple
Siri, Google Now are among the favorites. Those personal assistance applications will collect huge
amount of data via your interactions with the phone, from natural language processing and location
sensing. Services provided by personal applications are in the variety of simply making a call to booking
you an Airplane ticket.[9] [20]
o Less Human Interaction
When the mobile applications are getting more automated and context-aware, the human interaction
need to do a task using a device is getting lesser by the day. Reminders, important notifications, traffic
information are some examples.

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● Disadvantages
o Security
When there is so many sensors that can resolve your identity, security became a huge factor in mobile
computing. Hardware manufacturers needed to make sure their hardware used for context-awareness
are not hack able by a third party. Also software vendors needed to test their applications thoroughly to
check whether there are any gaping holes which will allow some unauthorized person to steal the data
from users. Even with the consent from the users sharing some critical information may cause harm to
the user. Example if a robber found out a certain user is at work in an exact time, he will rob the user’s
home knowing that no one is at the targeted home.
o Privacy
It is clear to the community that mobile operating systems tend to cache user location to give a better
context-aware services to the user. At sometimes these location data may cause violation of their
privacy rights. Because of the reason most operating systems and applications ask for user consent for
collecting any kind of data related to user privacy.
o Accuracy
If an application is heavily based on the context information to provide services, then there is always a
possibility of data fabrication. Inaccurate data will lead to incorrect context information been pushed to
the user.
o Infrastructure
Not every person has and access to the mobile devices with context-sensing hardware and software.

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● References
1. Wikipedia: Context-aware pervasive systems [Online] 25 June 2014. [Cited: October 18,
2014.] http://en.wikipedia.org/wiki/Context-aware_pervasive_systems
2. Bill Schilit and Marvin Theimer, Disseminating Active Map Information to Mobile Hosts :
[Cited: October 18, 2014.] https://impact.asu.edu/~cse591uc/papers/00313011.pdf
3. Bill Schilit, Norman Adams, Roy Want, Context-aware computing applications : [Cited:
October 18, 2014] http://graphics.cs.columbia.edu/courses/mobwear/resources/schilit-
mcsa94.pdf
4. Wikipedia : Project Tango [Online] 2 July 2014 [Cited: October 18, 2014]
http://en.wikipedia.org/wiki/Project_Tango
5. Project Tango [Online] 18 October 2014 [Cited: October 18, 2014]
https://www.google.com/atap/projecttango
6. Wikipedia : Google Glass [Online] 18 October 2014 [Cited: October 18, 2014]
http://en.wikipedia.org/wiki/Google_Glass
7. This is How Google Glass Works [Info graphic] [Online] 09 April 2013 [Cited: October 18,
2014] http://www.droid-life.com/2013/04/09/this-is-how-google-glass-works-infographic
8. Wikipedia : Google Now[Online] 21 September 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Google_Now
9. Google Now [Online] 20 October 2014 [Cited: October 20, 2014.]
http://www.google.com/landing/now/
10. Asim Smailagic and David Kogan,Location Sensing and Privacy in a Context-aware
Computing Environment: October 2012 [Cited: October 20, 2014]
http://diuf.unifr.ch/pai/education/2002_2003/seminar/winter/telecom/01043849.pdf
11. Stop Android 4.3 from always scanning for Wi-Fi networks [Online] 02 August 2013 [Cited:
October 20, 2014] http://www.cnet.com/how-to/stop-android-4-3-from-always-scanning-
for-wi-fi-networks/
12. Smartphone OS Market Share, Q2 2014 [Online] 20 October 2014 [Cited: October 20, 2014]
http://www.idc.com/prodserv/smartphone-os-market-share.jsp
13. Wikipedia : Global Positioning System[Online] 29 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Global_Positioning_System
14. Wikipedia : GLONASS[Online] 20 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/GLONASS
15. Wikipedia : Gyroscope[Online] 20 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Gyroscope
16. Wikipedia : Accelerometer[Online] 13 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Accelerometer
17. Wikipedia : Barometer[Online] 20 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Barometer
18. Your Nexus 5 Has a Real Pedometer Built In-Here's How You Use It [Online] 20 October
2014 [Cited: October 20, 2014.] http://nexus5.wonderhowto.com/how-to/your-nexus-5-
has-real-pedometer-built-in-heres-you-use-0151267/

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19. How Google Tracks Traffic [Online] 20 October 2014 [Cited: October 20, 2014.]
http://www.theconnectivist.com/2013/07/how-google-tracks-traffic/
20. Wikipedia : Siri[Online] 20 October 2014 [Cited: October 20, 2014.]
http://en.wikipedia.org/wiki/Siri
21. D. Schall, C. Dorn and S. Dustdar, Context-aware Mobile Computing: [Cited: October 28,
2014.]
http://pdf.aminer.org/000/247/251/deferred_systems_software_model_for_semantic_info
rmation_sharing_in_context.pdf
22. Louise Barkhuus and Anind Dey, Is Context-Aware Computing Taking Control Away from
the User? Three Levels of Interactivity Examined 2003 [Cited: October 28, 2014.]
www.itu.dk/people/barkhuus/barkhuus_ubicomp.pdf
23. Brown, P.J.Bovey, J.D.,Context-aware applications: from the laboratory to the
marketplace 1997 [Cited: October 28, 2014.]
http://www.researchgate.net/publication/3343988_Context-
aware_applications_from_the_laboratory_to_the_marketplace
24. Chen, Guanling, Kotz, David A Survey of Context-Aware Mobile Computing Research[Cited:
October 28, 2014.] www.cs.dartmouth.edu/reports/TR2000-381.pdf