A FRAMEWORK FOR MOBILE CLOUD COMPUTING

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10 Δεκ 2013 (πριν από 3 χρόνια και 8 μήνες)

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A FRAMEWORK FOR MOBILE CLOUD COMPUTING

R. LAKSHMAN NAIK*, PROF. S. S. V. N. SARMA

Department of CSE, Vaagdevi College of Engineering,Warangal, A.P
.
, India

ABSTRACT

Mobile Cloud Computing (MCC) which combines mobile computing and cloud computing, has become

one of
the indus
try buzz words and a major discussion thread in the IT world since 2009. As MCC is still at the early stage
of development, it is necessary to grasp a thorough understanding of the technology in order to point out the
direction of future r
esearch.

MCC has been introduced to be a potential technology for mobile services. MCC
integrates the cloud computing into the mobile environment and overcomes obstacles related to the performance;
environment and security were discussed in mobile computin
g. This paper presents a brief account on the
background of MCC: from mobile computing to cloud computing and then followed with a discussion on recent
research work. The rest of the paper analyses the challenges of mobile cloud computing. Finally points o
ut
promising future research scope and summary of this study.

KEYWORDS:

-

cloud, mobile, mobile cloud, PaaS, SaaS, IaaS.

INTRODUCTION

Over the past few years, advances in the field of network based computing and applications on demand have led
to an explos
ive growth of application models such as cloud computing, software as a service, community network,
web store, and so on. As a major application model in the era of the Internet, Cloud Computing has become a
significant research topic of the scientific and

industrial communities since 2007. Commonly, cloud computing is
described as a range of services which are provided by an Internet
-
based cluster system. Such cluster systems
consist of a group of low
-
cost servers or Personal Computers (PCs), organizing th
e various resources of the
computers according to a certain management strategy, and offering safe, reliable, fast, convenient and transparent
services such as data storage, accessing and computing to clients. According to the top ten strategic technology
trends for 2012 [1] provided by Gartner (a famous global analytical and consulting company), cloud computing has
been on the top of the list, which means cloud computing will have an increased impact on the enterprise and most
organizations in 2012.

Cloud
computing (CC) has been widely recognized as the next generation’s computing infrastructure. CC offers
some advantages by allowing users to use infrastructure (e.g., servers, networks, and storages), platforms (e.g.,
middleware services and operating syste
ms), and softwares (e.g., application programs) provided by cloud providers
(e.g., Google, Amazon, and Salesforce) at low cost. In addition, CC enables users to elastically utilize resources in
an on
-
demand fashion.

Meanwhile, Mobile devices (e.g., smartph
one, tablet pcs, etc) are increasingly becoming an essential part of
human life as the most effective and convenient communication tools not bounded by time and place. Mobile users
accumulate rich experience of various services from mobile applications (e.
g., iPhone apps, Google apps, etc),
which run on the devices and/or on remote servers via wireless networks.


The rapid progress of mobile computing
(MC) [2] becomes a powerful trend in the development of IT technology as well as commerce and industry fiel
ds.
However, the mobile devices are facing many challenges in their resources (e.g., battery life, storage, and
bandwidth) and communications (e.g., mobility and security) [3]. The limited resources significantly impede the
improvement of service qualities
.

smartphones are considered as the representative for the various mobile devices as they have been connected to
the Internet with the rapidly growing of wireless network technology. Ubiquity and mobility are two major features
in the next generation netw
ork which provides a range of personalized network services through numerous network
terminals and modes of accessing. The core technology of cloud computing is centralizing computing, services, and
specific applications as a utility to be sold like water,

gas or electricity to users. Thus, the combination of a
ubiquities mobile network and cloud computing generates a new computing mode, namely Mobile Cloud
Computing (MCC). As a result, mobile applications can be rapidly provisioned and released with the mi
nimal
management efforts or service provider’s interactions. With the explosion of mobile applications and the support of
CC for a variety of services for mobile users, MCC is introduced as an integration of cloud computing into the
mobile environment. Mob
ile cloud computing brings new types of services and facilities for mobile users to take full
advantages of cloud computing.

BASIC CONCEPT OF MC, CC & MCC

As a development and extension of Cloud Computing and Mobile Computing, Mobile Cloud Computing, as a
new phrase, has been devised since 2009. In order to help us grasping better understanding of Mobile Cloud
Computing, let’s start from the two previous techniques: Mobile Computing and Cloud Computing.

Mobile Computing

Mobility has become a very popular wo
rd and rapidly increasing part in today’s computing area. An incredible
growth has appeared in the development of mobile devices such as, smartphone, PDA, GPS Navigation and laptops
with a variety of mobile computing, networking and security technologies.
In addition, with the development of
wireless technology like WiMax, Ad Hoc Network and WIFI, users may be surfing the Internet much easier but not
limited by the cables as before. Thus, those mobile devices have been accepted by more and more people as th
eir
first choice of working and entertainment in their daily lives.

So, what is Mobile computing exactly? In Wikipedia, it is described as a form of human
-
computer interaction by
which a computer is expected to be transported during normal usage. Mobile co
mputing is based on a collection of
three major concepts: hardware, software and communication. The concepts of hardware can be considered as
mobile devices, such as smartphone and laptop, or their mobile components. Software of mobile computing is the
num
erous mobile applications in the devices, such as the mobile browser, anti
-
virus software and games. The
communication issue includes the infrastructure of mobile networks, protocols and data delivery in their use. They
must be transparent to end users. Th
us the framework of mobile computing is as shown in
below
Fig. 1.

Cloud Computing

Cloud Computing has become a popular phrase since 2007. However, there is no consensual definition on what a
Cloud Computing or Cloud Computing System is, due to dozens of de
velopers and organizations described it from
different perspectives. C. Hewitt [4] introduces that the major function of a cloud computing system is storing data
on the cloud servers, and uses of cache memory technology in the client to fetch the data. Tho
se clients can be PCs,
laptops, smartphones and so on. R. Buyya [5] gives a definition from the perspective of marking that cloud
computing is a parallel and distributed computing system, which is combined by a group of virtual machines with
internal links
. Such systems dynamically offer computing resources from service providers to customers according
to their Service level Agreement (SLA). However, some authors mentioned that cloud computing was not a
completely new concept. L. Youseff [6] from UCSB argue

that cloud computing is just combined by many existent
and few new concepts in many research fields, such as distributed and grid computing, Service
-
Oriented
Architectures (SOA) and in virtualization.




Fig. 1:

The Framework of Mobile Comp
uting


Fig.

2:
The Framework of Cloud Computing

In this paper, we consider the cloud computing is a large scale economic and business computing paradigm with
virtualization as its core technology. The cloud computing system is the development of parallel
processing,
distributed and grid computing on the Internet, which provides various QoS guaranteed services such as hardware,
infrastructure, platform, software and storage to different Internet applications and users.

Cloud computing systems actually can b
e considered as a collection of different services, thus the framework of
cloud computing is divided into four layers, which are data centers layer, infrastructure layer, platform layer, and
application layer is as shown in Fig. 2.

Data centers layer:
Thi
s layer provides the hardware facility and infrastructure for clouds. In data center layer, a
number of servers are linked with high
-
speed networks to provide services for customers. Typically, data centers are
built in less populated places, with high pow
er supply stability and a low risk of disaster.

Infrastructure layer:

it includes resources of computing and storage. In this layer, physical devices and
hardware, such as servers and storages are virtualized as a resource pool to provide computing storage

and network
services to users, in order to install operation system (OS) and operate software application. Thus it is denoted as
Infrastructure as a Service (IaaS). IaaS enables the provision of storage, hardware, servers and networking
components. The cl
ient typically pays on a per
-
use basis. Thus, clients can save cost as the payment is only based on
how much resource they really use. Infrastructure can be expanded or shrunk dynamically as needed. Services of
this layer such as Elastic Computing Cloud (E
C2) of Amazon and S3 (Simple Storage Service).

Platform layer:

this layer is considered as a core layer in the cloud computing system, which includes the
environment of parallel programming design, distributed storage and management system for structured m
ass data,
distributed file system for mass data, and other system management tools for cloud computing. Program developers
are the major clients of the platform layer. All platform resources such as program testing, running and maintaining
are provided by
the platform directly but not to end users. Thus, this type of services in a platform layer is called
Platform as a Service (PaaS). PaaS offers an advanced integrated environment for building, testing and deploying
custom applications. The typical services

are Google App Engine, Azure from Microsoft and Amazon Map
Reduce/Simple Storage Service.

Application layer:

this layer provides some simple software and applications, as well as costumer interfaces to
end users. Thus we name this type of services in the
application layer as Software as a Service (SaaS). SaaS supports
a software distribution with specific requirements. In this layer, the users can access an application and information
remotely via the Internet and pay only for that they use. Users use clie
nt software or a browser to call services from
providers through the Internet, and pay costs according to the utility business model (like water or electricity). The
earliest SaaS is the Customer Relationship Management (CRM) from Salesforce, which was dev
eloped based on the
force.com (a PaaS in Salesforce). Some other services provided by Google on
-
line office such as documents,
spreadsheets, presentations are all SaaS.

Although the cloud computing architecture can be divided into four layers as shown in F
ig. 2, it does not mean
that the top layer must be built on the layer directly below it. For example, the SaaS application can be deployed
directly on IaaS, instead of PaaS. Also, some services can be considered as a part of more than one layer. For
exampl
e, data storage service can be viewed as either in IaaS or PaaS. Given this architectural model, the users can
use the services flexibly and efficiently.

Mobile Cloud Computing

Nowadays, both hardware and software of mobile devices get greater improvement
than before, some
smartphones such as iPhone 4S, Android serials, Windows Mobile serials and Blackberry, are no longer just
traditional mobile phones with conversation, SMS, Email and website browser, but are daily necessities to users.
Meanwhile, those sm
artphones include various sensing modules like navigation, optics, gravity, orientation, and so
on. This brings a convenient and intelligent mobile experience to users. In 2010, Google CEO Eric Schmidt
described mobile cloud computing in an interview that
’based on cloud computing service development, mobile
phones will become increasingly complicated, and evolve to a portable super computer’ [15]. In the face of various
mobile cloud services provided by Microsoft, Apple, Google, HTC, and so on, users may b
e confused about what
mobile cloud computing exactly is, and what its features are.

The Mobile Cloud Computing Forum defines MCC as follows: “Mobile Cloud Computing at its simplest refers to
an infrastructure where both the data storage and the data proces
sing happen outside of the mobile device. Mobile
cloud applications move the computing power and data storage away from mobile phones and into the cloud,
bringing applications and mobile computing to not just smartphone users but a much broader range of mo
bile
subscribers”.

Aepona [7] describes MCC as a new paradigm for mobile applications whereby the data processing and storage
are moved from the mobile device to powerful and centralized computing platforms located in clouds. These
centralized applications

are then accessed over the wireless connection based on a thin native client or web browser
on the mobile devices.

Similar with Cloud Computing, there are a lot but no consensual definitions on what mobile cloud computing is.
In this paper, we consider it

is a novel computing mode consisting of mobile computing and cloud computing, which
provide cloud based services to users through the Internet and mobile devices. On one hand, the mobile cloud
computing is a development of mobile computing, and an extensi
on to cloud computing. In mobile cloud computing,
the previous mobile device
-
based intensive computing, data storage and mass information processing have been
transferred to ’cloud’ and thus the requirements of mobile devices in computing capability and re
sources have been
reduced, so the developing, running, deploying and using mode of mobile applications have been totally changed.
On the other hand, the terminals which people used to access and acquire cloud services are suitable for mobile
devices like s
martphone, PDA, Tablet, and iPad but not restricted to fixed devices (such as PC), which reflects the
advantages and original intention of cloud computing. Therefore, from both aspects of mobile computing and cloud
computing, the mobile cloud computing is
a combination of the two technologies, a development of distributed, grid
and centralized algorithms, and have broad prospects for application.

As shown is the Fig. 3, mobile cloud computing can be simply divided into cloud computing and mobile
computing.
Those mobile devices can be laptops, PDA, smartphones, and so on. This connects with a hotspot or
base station by 3G, WIFI, or GPRS. As the computing and major data processing phases have been migrated to
‘cloud’, the capability requirement of mobile devic
es
is limited
, some low
-
cost mobile devices or even non
-
smartphones can also achieve mobile cloud computing by using a cross
-
platform mid
-
ware. Although the client in
mobile cloud computing is changed from PCs or fixed machines to mobile devices, the main
concept is still cloud
computing. Mobile users send service requests to the cloud through a web browser or desktop application, and then
the management component of cloud allocates resources to the request to establish connection, while the monitoring
and
calculating functions of mobile cloud computing will be implemented to ensure the QoS until the connection is
completed.













Fig. 3:

The Framework of Mobile Cloud Computing

CHALLENGES AND SOLUTIONS

The main objective of mobile cloud computing is
to provide a convenient and rapid method for users to access
and receive data from the cloud, such convenient and rapid method means accessing cloud computing resources
effectively by using mobile devices. The major challenge of mobile cloud computing come
s from the characters of
mobile devices and wireless networks, as well as their own restriction and limitation, and such challenge makes
application designing, programming and deploying on mobile and distributed devices more complicated than on the
fixed c
loud devices [16]. In mobile cloud computing environment, the limitations of mobile devices, quality of
wireless communication, types of application, and support from cloud computing to mobile are all important factors
that affect assessing from cloud comp
uting. Table 1 gives an overview of proposed challenges and some solutions
about mobile cloud computing.

Table 1
:

Challenges and Solutions of Mobile Cloud Computing

Challenges

Solutions

Limitations of mobile devices

Virtualization and Image,

Task migratio
n

Quality of communication

Bandwidth upgrading,

Data delivery time reducing

Division of applications services

Elastic application division

mechanism


Limitations of mobile devices

While discussing mobile devices in cloud the first thing is resource
-
cons
train. Though smartphones have been
improved obviously in various aspects such as capability of CPU and memory, storage, size of screen, wireless
communication, sensing technology, and operation systems, still have serious limitations such as limited compu
ting
capability and energy resource, to deploy complicated applications. By contrast with PCs and Laptops in a given
condition, these smartphones like iPhone 4S, Android serials, Windows Mobile serials decrease 3 times in
processing capacity, 8 times in me
mory, 5 to 10 times in storage capacity and 10 times in network bandwidth.

Normally, smartphone needs to be charged everyday as dialing calls, sending messages, surfing the Internet,
community accessing, and other internet applications. According to past
development trends, the increased mobile
computing ability and rapid development of screen technology will lead to more and more complicated applications
deployed in smartphones. If the battery technology cannot be improved in a short time, then how to eff
ectively save
battery power in smartphone is a major issue we meet today.

The processing capacity, storage, battery time, and communication of those smartphones will be improved
consistently with the development of mobile computing. However, such enormous
variations will persist as one of
major challenges in mobile cloud computing.

Quality of communication

In contrast with wired network uses physical connection to ensure bandwidth consistency, the data transfer rate in
mobile cloud computing environment is
constantly changing and the connection is discontinuous due to the existing
clearance in network overlay. Furthermore, data centre in large enterprise and resource in Internet service provider
normally is far away to end users, especially to mobile device
users. In wireless network, the network latency delay
may 200 ms in ’last mile’ but only 50 ms in traditional wired network.

Some other issues such as dynamic changing of application throughput, mobility of users, and even weather will
lead to changes in b
andwidth and network overlay. Therefore, the handover delay in mobile network is higher than
in wired network.

Division of application services


In mobile cloud computing environment, due to the issue of limited resources, some applications of compute
-
inte
nsive and data
-
intensive cannot be deployed in mobile devices, or they may consume massive energy resources.
Therefore, we have to divide the applications and use the capacity of cloud computing to achieve those purposes,
which is: the core computing task
is processed by cloud, and those mobile devices are responsible for some simple
tasks only. In this processing, the major issues affecting performance of mobile cloud computing are: data
processing in data centre and mobile device, network handover delay,
and data delivery time.

For a given standard, providing a quality guaranteed cloud service should consider the following facts: optimal
division of application between cloud and mobile device, interaction between low
-
latency and code offload, high
-
bandwidt
h between cloud and mobile device for high speed data transmission, user
-
oriented cloud application
performance, self
-
adaptation mechanism of mobile cloud computing, and optimal consumption and overhead of
mobile devices and cloud servers. The following st
rategies can be used to response to the challenges:



Upgrade bandwidth for wireless connection, make the web content more suitable for mobile network using
regional data centers.



Deploy the application processing node at the ’edge’ of cloud in order to redu
ce data delivery time.



Duplicate mobile devices to cloud using virtualization and image technologies, to process Data
-
Intensive
Computing (DIC) and Energy
-
Intensive Computing, such as virus scanning in mobile devices.



Dynamically optimize application push
in cloud and the division with mobile terminals.

ADVANTAGES OF MOBILE CLOUD COMPUTING

Cloud computing is known to be a promising solution for mobile computing due to many reasons (e.g., mobility,
communication, and portability). In the following, we descri
be how the cloud can be used to overcome obstacles in
mobile computing, thereby pointing out advantages of MCC.

Extending battery lifetime

Battery is one of the main concerns for mobile devices. Several solutions have been proposed to enhance the
CPU perfo
rmance [8] and to manage the disk and screen in an intelligent manner [9] to reduce power consumption.
However, these solutions require changes in the structure of mobile devices, or they require a new hardware that
results in an increase of cost and may n
ot be feasible for all mobile devices. Computation offloading technique is
proposed with the objective to migrate the large computations and complex processing from resource
-
limited
devices (i.e., mobile devices) to resourceful machines (i.e., servers in c
louds). This avoids taking a long application
execution time on mobile devices which results in large amount of power consumption.

[10, 11] evaluate the effectiveness of offloading techniques through several experiments. The results demonstrate
that the r
emote application execution can save energy significantly. Especially, [18] evaluates large
-
scale numerical
computations and shows that up to 45% of energy consumption can be reduced for large matrix calculation. In
addition, many mobile applications take
advantages from task migration and remote processing. For example,
offloading a compiler optimization for image processing [12] can reduce 41% for energy consumption of a mobile
device. Also, using memory arithmetic unit and interface (MAUI) to migrate mob
ile game components [13] to
servers in the cloud can save 27% of energy consumption for computer games and 45% for the chess game.

Improving data storage capacity and processing power

Storage capacity is also a constraint for mobile devices. MCC is develop
ed to enable mobile users to store/access the
large data on the cloud through wireless networks. First example is the Amazon Simple Storage Service (Amazon
S3) which supports file storage service. Another example is Image Exchange which utilizes the large
storage space
in clouds for mobile users. This mobile photo sharing service enables mobile users to upload images to the clouds
immediately after capturing. Users may access all images from any devices. With cloud, the users can save
considerable amount of

energy and storage space on their mobile devices since all images are sent and processed on
the clouds. Facebook is the most successful social network application today, and it is also a typical example of
using cloud in sharing images.

MCC also helps red
ucing the running cost for compute
-
intensive applications that take long time and large
amount of energy when performed on the limited
-
resource devices. Cloud computing can efficiently support various
tasks for data warehousing, managing and synchronizing
multiple documents online. For example, clouds can be
used for transcoding [14], playing chess [13, 15], or broadcasting multimedia services [16] to mobile devices. In
these cases, all the complex calculations for transcoding or offering an optimal chess m
ove that take a long time
when perform on mobile devices will be processed quickly on the cloud. Mobile applications also are not
constrained by storage capacity on the devices because their data now is stored on the cloud.

Improving reliability

Storing da
ta or running applications on clouds is an effective way to improve the reliability since the data and
application are stored and backed up on a number of computers. This reduces the chance of data and application lost
on the mobile devices. In addition, M
CC can be designed as a comprehensive data security model for both service
providers and users. For example, the cloud can be used to protect copyrighted digital contents (e.g., video, clip, and
music) from being abused and unauthorized distribution [17].
Also, the cloud can remotely provide to mobile users
with security services such as virus scanning, malicious code detection, and authentication [18]. Also, such cloud
-
based security services can make efficient use of the collected record from different us
ers to improve the
effectiveness of the services.

In addition, MCC also inherits some advantages of clouds for mobile services as follows:

Dynamic provisioning

Dynamic on
-
demand provisioning of resources on a fine
-
grained, self
-
service basis is a flexible
way for service
providers and mobile users to run their applications without advanced reservation of resources.

Scalability:

The deployment of mobile applications can be performed and scaled to meet the unpredictable user
demands due to flexible resource p
rovisioning. Service providers can easily add and expand an application and
service without or with little constraint on the resource usage.

Multi
-
tenancy:

Service providers (e.g., network operator and data center owner) can share the resources and
costs t
o support a variety of applications and large number of users.

Ease of Integration:

Multiple services from different service providers can be integrated easily through the cloud
and the Internet to meet the users’ demands.

FUTURE RESEARCH SCOPE OF THE WORK

Although some projects of mobile cloud computing has already been deployed around the world, there is still a
long way for business implementation, and some research aspects should be considered in further work. However,
there are still some issues which
need to be addressed. This section presents several open issues and possible
research directions in the development of MCC.

Low Bandwidth

Bandwidth is one of the big issues in MCC since the radio resource for wireless networks is much scarce as
compared wi
th the traditional wired networks. Although many researchers propose the optimal and efficient way of
bandwidth allocation, the bandwidth limitation is still a big concern because the number of mobile and cloud users is
dramatically increasing.

Data delive
ry

Due to the feature of resource
-
constrains, mobile devices have potential challenges in cloud accessing, consistent
accessing, data transmission, and so on. Such challenges can be solved using: special application (service) and
middle
-
ware (provide a pl
atform for all mobile cloud computing systems).

Network Access Management

An efficient network access management not only improves link performance for mobile users but also optimizes
bandwidth usage. Cognitive radio can be expected as a solution to achiev
e the wireless access management in
mobile communication environment [19]. Cognitive radio increases the efficiency of the spectrum utilization
significantly, by allowing unlicensed users to access the spectrum allocated to the licensed users. When this
te
chnique is integrated into MCC, the spectrum can be utilized more efficiently, the spectrum scarcity can be solved
and thus millions of dollars for network providers can be saved [20]. However, cognitive radio is defined as wireless
communication technolog
y in which each node communicates via an optimal wireless system based on recognition
of radio resource availability in heterogeneous wireless communication environment. Therefore, mobile users in
MCC must be able to detect this radio resource availability

(through spectrum sensing) while ensuring that the
traditional services will not be interfered.

Task division

Researchers divide tasks (applications) from mobile devices into multiple sub
-
tasks and deliver some of them to
run in cloud, which is a good sol
ution to the resource limited mobile devices. However, we do not have an optimal
strategy or algorithm on how to divide these tasks, which one should be processed by cloud and which one by
devices.

Quality of Service

In MCC, mobile users need to access to
servers located in a cloud when requesting services and resources in the
cloud. However, the mobile users may face some problems such as congestion due to the limitation of wireless
bandwidths, network disconnection, and the signal attenuation caused by mo
bile users’ mobility. They cause delays
when users want to communicate with the cloud, so QoS is reduced significantly. Two new research directions are
CloneCloud and Cloudlets that are expected to reduce the network delay.


Better service

The original pur
pose of mobile cloud computing is providing PC
-
liked services to mobile terminals. However, as
the existing different features between mobile devices and PCs, we cannot directly transplant the services from PCs’
platform to mobile devices. Therefore, furth
er research should try to identify the method on how to provide suitable
and friendly interactive services for mobile devices.

Pricing

Using services in MCC involves with both mobile service provider (MSP) and cloud service provider (CSP).
However, MSPs an
d CSPs have different services management, customers’ management, methods of payment and
prices. Therefore, this will lead to many issues, i.e., how to set price, how the price will be divided among different
entities, and how the customers pay. For exampl
e, when a mobile user runs mobile gaming application on the cloud,
this involves the game service provider (providing a game license), mobile service provider (accessing the data
through base station), and cloud service provider (running game engine on dat
a center). The price paid by the game
player has to be divided among these three entities such that all of them are satisfied with the division. It is clear that
the business model including pricing and revenue sharing has to be carefully developed for MCC
.

Standard Interface

Interoperability becomes an important issue when mobile users need to interact and communicate with the cloud.
The current interface between mobile users and cloud are mostly based on the web interfaces. However, using web
interfaces m
ay not be the best option. First, web interface is not specifically designed for mobile devices. Therefore,
web interface may have more overhead. Also, compatibility among devices for web interface could be an issue. In
this case, the standard protocol, si
gnaling, and interface for interacting between mobile users and cloud would be
required to ensure seamless services. In the future, HTML5 is expected as a promising technique to address this
issue. HTML5 WebSockets offer a interface. However, an extensive
performance evaluation and feasibility study
have to be performed to ensure that it will work in MCC efficiently.

Service Convergence

The development and competition of cloud service providers can lead to the fact that in the near future these
services wil
l be differentiated according to the types, cost, availability and quality. Moreover, in some cases, a single
cloud is not enough to meet mobile user’s demands. Therefore, the new scheme is needed in which the mobile users
can utilize multiple clouds in a
unified fashion. In this case, the scheme should be able to automatically discover and
compose services for user. One of the potential solution of this issue is the sky computing, which will be the next
step of cloud computing. Sky computing is a computing

model where resources from multiple clouds providers are
leveraged to create a large scale distributed infrastructure [21]. Similarly, the mobile sky computing will enable
providers to support a cross
-
cloud communication and enable users to implement mobi
le services and applications.
However, to offer a service to mobile user in a unified way, the service integration (i.e., convergence) would need to
be explored.


CONCLUSION

1.

With the high increasing of data computation in commerce and science, the capacity

of data processing has
been considered as a strategic resource in many countries.

2.

Mobile cloud computing (MCC), as a development and extension of mobile computing (MC) and cloud
computing (CC), has inherited the high mobility and scalability, and become
a hot research topic in recent
years.

3.

Mobile cloud computing is one of mobile technology trends in the future since it combines the advantages of
both mobile computing and cloud computing, thereby providing optimal services for mobile users.

4.

According to
a recent study, more than 240 million business will use cloud services through mobile devices
by 2015. That traction will push the revenue of mobile cloud computing to $5.2 billion. With this
importance, this article has provided an overview of mobile clou
d computing in which its definitions,
architecture, and advantages have been presented.

5.

The applications supported by mobile cloud computing including mobile commerce, mobile learning, and
mobile healthcare have capability of wide range of mobile services.


6.

The quality of communication in wired network is better than in wireless network, so reducing the proportion
of data delivery in wireless environment is an effective way to improve the quality. In addition, upgrading
bandwidth is envisaged to be a simple

way to increase performance but it i
ncurs additional cost to users.

7.

Deploying an effective elastic application division mechanism is deemed to be the best solution to guarantee
the application service in MCC, its complicated, but promising high impact res
ults.

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