Mobile Cloud Computing

splashburgerInternet and Web Development

Oct 22, 2013 (4 years and 2 months ago)

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Mobile Cloud Computing

Kommineni, venkata Rajesh

Abstract:

Mobile Cloud computing is widely accepted concept that is used to improve the user experience
when accessing through mobile devices. Mobile cloud computing is the extended application of
Cloud
computing, which refers to both the applications delivered as a service over the internet and
hardware and system software in the datacenters that provide these services.

By removing the
limitations of the mobile cloud computing like storage, computing cap
abilities, and providing some
additional features to the mobile cloud like increased security, we can expect the growth of mobile
computing and find its broad acceptance.
Some challenges like mobility, heterogeneity and low
band
-
width will hinder the advan
cement of this incorporation. Here we deal with the abstraction of
mobile agent and universal mobile service cell to shield the un
-
equivalence of heterogeneous
distributed systems. Meanwhile, pirates and illegal distribution of digital contents are becomin
g a
serious concern in these days. So Cloud based SIM DRM scheme is presented for mobile internet.


1)

Introduction:

In the recent years, the main aim of IT industry is to lower the computational costs and
achieve high productivity. This can be done by impro
ving the utility of computing resources,
reducing administrative costs and avoiding large amount of investments to provide a service. The
main goal of any computing model is to make a better use of resources, put them together in order
to achieve high thro
ughput and able to tackle large computation problems and provide better
results. Cloud computing is the recent technology, which was growing in popularity, which enables
these functions. Cloud computing is coined recently and gained popularity in 2007, whi
ch can be
also called as Internet based Distributed Computing. The roots of cloud computing can be traced to
early stages of Grid computing and Distributed Computing. Cloud computing is a combination of
utility computing (on
-
demand computing), Software as
a service, and distributed computing. Utility
computing and Software as a service are two services that are provided by cloud computing,
whereas distributed computing is one of the underlying technologies for implementing cloud
computing. “Cloud Computing
refers to both the applications delivered as a service over the
internet and hardware and system software in the datacenters that provide these services.” [1].


Mobile cloud computing intends to make the advantages of cloud computing for mobile
users. It
will also provide some additional functionality to the cloud as well. Mobile cloud
computing helps to overcome the limitations of mobile devices in particular of the processing
power and data storage.
Mobile cloud computing helps to extend battery life by
transferring the
execution of computation intensive application to the cloud.


Mobile
Cloud computing is regarded as the next generation computing infrastructure
. Here
the information is permanently stored in servers on internet and cached temporarily on clients
through mobile devices. Although the wireless network brings us many benefits, there are many
challenges that will hinder the growth of mobile computing.

With the growth of mobile industry, a
considerable amount of mobile applications and services are available. Now a days users are
capable sharing and distributing digital media contents easily through internet. Here only
authorized users who have obtained

the license should access the information.


The rest of the paper deals with the Definition of cloud computing in section 2, motivation
towards cloud computing in section 3, Support available for cloud computing in section 4, mobile
cloud computing in se
ction 5, how energy is saved using section 6, mobile cloud architecture in
section 7, mobile service scheduling in section 8, cloud based SIM DRM scheme in section 9 and
concluded in section 10.

2)

Definition

of Cloud Computing
:

Cloud computing is the recent
trend that moves

computing and data away from the desktop,
portable PCs into large datacenters. The term “cloud” refers to the datacenters. Cloud computing
takes the benefits of cyberinfrastructure and is developed on the research of virtualization,
distri
buted computing, grid computing and more recently networking, web and software services.
According to R Buyya [2] “
A cloud is a type of parallel and distributed system consisting of a collection
of interconnected and virtualized computers that are dynamica
lly provisioned and presented as one or
more unified computing resources based on service
-
level agreements established through negotiation
between the service provider and consumers
”.


The more general definition of the cloud is a collection of servers a
nd computers that can be
accessed by the public through internet. These servers and computers are operated and owned by
the third party at multiple locations. Cloud computing is a user friendly version of grid computing.
Cloud computing is platform indepen
dent, where the data and software resides in the cloud and we
can access them not only through our PCs but also through cloud
-
friendly devices like smart phones
and PDAs.

Terminology:


Cyberinfrastructure:

It was used to develop and deploy applications e
asily, thus expanding the
scope of applications within budget. It also helps to shift the scientist’s and engineer’s effort on to
the research without concerning on the information technology development.

Virtualization:

This feature enables the abstracti
on of lower
-
level functionalities and underlying
hardware. This enables the portability of higher
-
level functions and sharing and/or aggregation of
physical resources. [3].

Distributed Computing
: is the computing environment, in which multiple autonomous c
omputers
are connected through a communication network, interact with each other to achieve common goal.

There are two types of clouds

Public cloud:

it is the cloud that can be accessed to public over internet.

Private cloud:

The cloud which is owned by th
e organization and can only be accessed to individuals
in the organization


3)

Motivation towards Cloud computing:

Cloud computing is evolved from grid computing. The evolution has been the result of shift in
market focus from an infrastructure that delivers
storage and compute resources to the one that is
economy based, aiming to deliver more abstract resources and services. They share lots of common
features like vision, architecture and technology but also differ in the various aspects like security,
progra
mming model and applications.


Both grid computing and cloud computing are used to reduce the cost of computing,
increase reliability, and flexibility. Due to the increase in demand for large computing, analyzing of
massive data, we need to shift from grid

computing to cloud computing. The main reason for this
shift is to reduce the cost of building multiple systems and enabling security to each system. In
cloud computing the data and software resides with the third party, so that it can be accessed by
the
required client without using more resources in his local machine. In recent days companies are
looking to cut their costs on building systems which they don’t need for a long time, in this scenario
the cloud computing is helpful for the achievement. In ca
se of distributed computing, the enterprise
has to build entire systems and install the applications in every system, which results in the cost of
buying the entire equipment. This resulted in the transformation from grid computing to cloud
computing.


The

Cloud computing is a specialized distributed computing paradigm. It differs in the grid
computing in following ways

1)

Scalability: it is largely scalable

2)

Virtualization: It can be abstracted as an entity and delivers services to customers outside
cloud

3)

Serv
ices: the services can be dynamically configured and delivery on demand.

Advantages of cloud computing:

1)

The cloud provider completely manages the service. The client needs to have only PC or a
Smartphone and internet to access the cloud, where as in grid c
omputing, the client needs to
use his local resources.

2)

The cloud is not just a collection of computer resources like grid, it has more than that.
Cloud provides mechanism to manage these resources like, monitoring, work load
rebalancing, changing requests
.

3)

There will be a rapid decrease in hardware cost, increase in computing power and storage
capacity.

4)

Cloud computing infrastructure can be located in areas with lower costs of space and
electricity.

5)

Cloud computing eliminates the cost of download and insta
ll of the software.

Some Concerns:

1)

On long term, the subscription fee may exceed the cost of the service provided.

2)

Constant Internet connection is required.

3)

Data security and Availability are main concerns. Since the data is located at the single
source, c
rash of servers may be harmful to the users. Efficient backup and recovery
mechanisms are to be implemented.


4)

Support for Cloud computing:

Cloud computing is a term that can be used for anything that involves delivering hosted services
over the internet in

real time. The forms of services that a cloud can offer are broken into different
categories such as infrastructure, software, hardware, platform etc.

Software as a Service (SaaS):

Software or application is hosted as a service and can be accessed to
the

client over internet, until the client needs software. SaaS is commonly referred as Application
Service Providers (ASP), where the application is run in datacenter and its functionality is provided
to the client through the internet. This service eliminat
es the user’s need to install the software on
his local machine and decreases the cost of maintenance and purchase of software.

Enterprise SaaS vendors are salesforce.com (SDFC), NetSuite, Oracle/Siebel (CRM applications),
Workday. SaaS desktop applicatio
ns for end users, include Google Apps (Google Talk, Google
Calendar, Google docs), Microsoft WindowsLive etc.

Hardware as a Service (HaaS)
:

Due to the rapid advancements in hardware virtualization, IT
automation, and pricing, users can buy IT hardware or e
ven the entire datacenter as
-
a
-
pay
-
as
-
you
-
go subscription service, means the clients can access the hardware support needed for the
application as long as he needs the application and willing to pay for it, instead of buying the total
hardware. The HaaS sh
ould be flexible, scalable and manageable to meet the needs of clients. It is
useful to enterprise users, because they do not need to invest money in building and managing
datacenters. HaaS providers have to face the problems like efficiency, ease and spee
d of
provisioning such large systems

Examples of Haas Service are



Morgan Stanley’s

[4]

lease contract with IBM in 2004.



GridLayer

Cloud Provider. A service by Layered Technologies that delivers Virtual Private
Datacenters and virtual private servers
from grids of commodity servers

Platform as a Service (PaaS)
:

This is the important service of clouds, providing the developers
with the platform to run their applications. The allotment of hardware resources for applications is
abstracted by the help of t
his service. This service helps to reduce burden to developers by
developing, testing, deploying and hosting of sophisticated web applications. PaaS gradually
decreases the project development time by providing all the available resources.

The main vendor
s are Google (Google App Engine), Yahoo (pipes), Coghead, and Microsoft’s Azure.



Amazon's Elastic Compute Cloud, or EC2
,

[5]

is probably the most generalized and best
-
known of the cloud computing service offerings.



IBM Computing on Demand or Blue Cloud

[6]

is a highly enterprise
-
focused cloud computing
offering platform as a service, which is sold to enterprises, can cross over between public
and private cloud applications.


Infrastructure as a Service (IaaS):

IaaS is the delivery of the infrastructure of c
omputer as a
service. I.e. hardware resources (storage) and computing power (CPU and Memory) are offered as a
service.
The goal of these services is to replace a company’s entire server room and network
through virtualization technology. These offerings a
re designed to cut costs and improve flexibility.

This service allows the clients to pay as they grow. HaaS also allows the clients to access to the new
technologies so that he can achieve a much faster delivery time of the project.

Examples are GoGrid, F
lexiscable, Layered Technologies, Joyent and Mosso/Rackspace etc.


5)


Mobile Cloud
Computing
:



In the recent times the term “cloud computing” is being discussed in the context of “future
of web”, but it doesn’t gain its full potential until it is transform
ed from computer platform to a thin
client


mobile platform. The recent research report says that Mobile Cloud Computing is going to
become the disruptive force in mobile world, which leads to become a dominant way in which
mobile applications operate.


Mobile computing refers to an
infrastructure where both the data storage and the data
processing happen outside the mobile device. In recent days there are numerous examples of
mobile cloud computing applications include Mobile Gmail, Google Maps, and some

navigation
apps. However in recent times most data storage and processing are done on mobile devices, not in
cloud. In coming years this trend will change. With the advent of more smart phones, the market is
turning towards building smart phone with more
apps, which leads to the growth of mobile cloud
computing.


There are two main reasons why cloud computing will be a disruptive force in the mobile
world. First is the number of users the technology has the power to reach, far more than the
number of smart
phone users alone. The second reason has to do with how applications are
distributed today. Today, mobile applications are tied to a carrier, but with the mobile cloud
computing applications, as long as you have the access to the web, you can have the acce
ss to the
mobile applications.


"mobile cloud computing" is the future doesn't mean phones will be filled with links to
websites that work in any browser instead of special, downloadable applications, some of which
you can even purchase. Instead, mobile ap
plications will exist in both formats. As for the
downloadable applications themselves, they will still appear to be your typical mobile app
-

end
users won't even notice a difference. However, there

will be

a difference
-

it will just be on the back
-
end.
Mobile applications will begin to store your data in the cloud as opposed to on the mobile
device, and the applications will become more powerful as processing power is also offloaded to the
cloud.

The first mobile apps powered by the cloud will likely be
business
-
focused mobile
productivity applications where collaboration, data sharing, multitasking, and scheduling are key
factors. For consumers, though, navigation and mapping applications will be the most obvious
examples of the trend. Plus, there are so
me specialty applications today which already function as
mobile cloud apps
-

for example,

Schlage

offers a remote keyless entry system which lets you
mobilely control your home from a distance. You can let

someone into your house, manage your
lights, your thermostat, your camera system, etc. There are also a few applications in the iPhone
app store that let you

remotely mana
ge your PC

and your

DVR
, too.


Potential problems:


There are some issues that could be barriers to this shift in mobile computing.

1)

The main problem is the lack of speedy mobile internet accesses
everywhere.

2)

The wireless environment is subjected to many obstacles like lower bandwidths, high error
rates, and more frequent
spurious disconnections.

3)

T
he character of mobile environment, mobility causes the fast address migration and
dynamic
configuration which makes it more difficult for the system to answer the

queries
from users efficiently and timely.

4)

T
he portable device in the mobile environment always can’t have powerful computing
ability and storage ability. That means the mobile host c
an’t support enough computing and
storage ability for

some complex services which are needed by users

5)

Some technologies like HTML 5, does local caching, that could help mobile cloud apps get
past those sorts of issues.


6)

How Mobile Cloud Computing Save Ene
rgy
:


With all the advantages of the cloud computing the primary constraints for mobile cloud
computing are limited energy and wireless bandwidth. Cloud computing can prove energy savings
as a service to the mobile users, through it also poses some unique
challenges. Many applications
are too computation intensive to perform on a mobile system. If mobile user wants to perform such
applications, he can run on the cloud. However some applications like Image retrieval, voice
recognition, etc., should run on th
e mobile system which consumes lot of energy, which can be
offloaded to save lots of energy and extend battery life time. some basic approaches for saving
energy are

Adapting new generation of semiconductor technology: we need to use small transistors, wh
ich
results in better performance.

Avoiding wastage of

energy
: we need to reduce the wastage of energy by turning off the mobile.

Execute the programs slowly
: which decreases the processors clock speed, so power consumption
decreases

Eliminate computation
:

which means move computation away from the mobile device.


By sending the computation to other environment effectively the processor cycles reduces,
which results in the reduction of power usage. V
irtualization allows cloud vendors to run arbitrary
applic
ations from different customers on virtual machines.

Cloud vendors thus provide computing
cycles, and users can use these cycles to reduce the amounts of computation on mobile systems and
save energy. Thus, cloud computing can save energy for mobile users
through computation
offloading.


The minimum bandwidth required for offloading to save energy is B0= 577.777x(d/c)

[7]

Where c is the number of instructions and d is the bytes of data exchanged between
server and
mobile system.


The application that is
benefited from offloading computation is Chess. The amount of
computation of chess is very large. The complexity of chess exceeds the number of atoms in
universe. By offloading the chess, we can make the computation with cloud which reduces the
computation

power. However there are some possible challenges for this offloading


Privacy and Security:

The shifting of data and computation to the cloud causes the problem of
privacy and security. The cloud services are provided by the third party and there is no
guarantee
as how these vendors assure the security to the data. Some strict rules
have

to be ensured by the
vendors to provide the security to the
user’s

data. Efficient Encryption Algorithms should be
implemented to provide additional security.


Reliabil
ity
: During the network outages, the data of the user should be protected. The retrieval of
the data should be reliable.


Real time data
: The real time data scenarios should be effectively implemented, without the loss of
data.


A
nalysis suggests that
cloud computing can potentially save energy for mobile users. However, not
all applications are energy efficient when migrated to the cloud. Mobile cloud computing services
would be significantly different from cloud services for desktops because they must

offer energy
savings. The services should consider the energy overhead for privacy, security, reliability, and data
communication before offloading.





7)

Mobile Cloud Architecture:

The mobile environment is divided into lots of cell

regions.

Every cell reg
ion has several
cloud units which

act as mobile support station to support services for mobile

users in this region.
Cloud units in every cell region and

remote cloud units are connected to be the mobile cloud,

which
supports computing ability and storage
ability. The mobile cloud lessens

the mobile host from
complex computing and the mobile hosts

can just concentrates on the interaction with users. For
the

transmission between mobile host and cloud units, Universal Mobile Service Cell which acts as
an

abst
raction of the mobile agent to solve the influence of

unstable network
.

[8]



The main aspects of this architecture are

Mobile cloud:


With the advent of cloud computing, the cost of computation has been drastically
reduced as the computations are done by cloud. Here for the mobile environment, mobile cloud acts
as the media to accept requests from the client and send the responses back t
o the client. With this
the mobile host doesn’t need to pay much computing time for complex services.

Mobile cloud has two types of cloud units:

1)

Cloud units in every cell region: deals with the user’s requests directly. Which sends
requests to remote clou
d units

2)

Remote cloud units: Deals with the key computing service.


Universal

Mobile Cell:

It acts as the mediator between mobile cloud and mobile host, which sends the requests of
mobile host to mobile cloud and gets the request back from mobile cloud to
mobile host. It has two
kinds of cell

User Mobile Service cell: collects the requests from the users and migrates it to cloud
mobile service cell. It gets backs the response from cloud mobile service cell and sends it to mobile
host

Cloud Mobile Service
cell: collects the requests from user mobile service cell, checks the
request with the mobile cloud and handovers the responses to user mobile service cell.


When the mobile user turns off his mobile after sending the request to the mobile cloud,
then the system should react to this situation. Here cloud units in certain region keep a list of
connection information between each MH and MB. When the cloud mobile
service cell completes
searching, if the connection is not present, cloud units use proxy system to save the information
until connection is established again. Using the IP Mobility support, clouds can know the change of
mobile host, where cloud mobile cel
l migrates the corresponding cloud units and repeats the above
process.
The Universal Mobile Service Cell makes the

mobility transparent to users and also
minimizes the bad

influence of the unstable wireless network
.



Mobile Host:

The cloud computing pro
vides us with

unlimited resources, great capacity for storage and
the

computing ability theoretically. We can combine the CPU and

the memory to one component
named CM, moreover an

important new component called Mobile Cloud is attached to

the new
architect
ure.


8)

Mobile Service Scheduling
:



Mobile Service scheduling is the main problem for mobile cloud computing. There
are two scheduling methods. Heuristic, which assigns each task a priority and sort them in
decreasing order. The meta
-
heuristic, a genetic
algorithm is guided by random search method
which mimics the principles of evolution and natural genetics. The genetic algorithms search
optimal solutions from entire solution space; they often obtain reasonable solutions in all
situations.

T
here are a hug
e

difference concerning about the capability of computing of

mobile
device and the cloud. The solution is to provide an

abstraction over the heterogeneous environment

[8]
.


Universal Mobile Service cell is represented as a triple of (arrival time, priority
, state). Some
constraints are imposed like Precedence (C1 must be completed before C2 is initialized), Integrality
(sum of each cells leads to result), Uniqueness (precedence of cells identify service).


The genetic algorithm for scheduling is of five tu
ple

π (
N, R, C, D, G
). N is a set of clouds which
performs computation, R is matrix which represents migration time between nodes. C is the matrix
which represents computation time when cell Ci is executed. D is matrix representing transmitting
time of dat
a between cell Ci and Cj. G is DAG used to denote precedence graph.


First we need to represent the scheduling problem in a genetic way (Ci, Nj). Then initial population
is calculated, which is the set of solutions. We randomly initialize the population w
hile due to the
precedence of cells and efficiency of computing. Here better way is chosen to initialize it. The fitness
function, which is minimization of computational time for scheduling is calculated as

F(SOLUTION) = C+D+R.

Here we want to maximize t
he value of fitness function, so we can change it into


fitness (solution) = S
-

F ( Solution).

Crossover means that two possible solutions from a new solution via GA operators, select the
method which can cut the genetic representations into two halves a
nd exchange the halves. We
need to prove the new solution satisfies the given constraints.


Mutation is considered as the occasional random alternation of genetic algorithm. Here we will
choose genetic representations Gi, search the genetic representation

Gj having same precedence Gi
and exchange them.


Overall architecture is

Initailize()

compute fitness values

repeat


crossover()


mutation()


compute the fitness values


preserve the best string

until convergent


In this way we can schedule the mobile cloud environment, which is an NP problem.


9)

A Cloud based
SIM DRM S
cheme

F
or

M
obile

I
nternet
:



With the rapid growth of the mobile industry, a considerable

amount of mobile applications and
services are available.

Meanwhile, pirates and illegal distributions of digital

contents have become
serious issues. Digital Rights Management

(DRM) aims at protecting digital contents from

being
abused through regulating the usage of digital contents.



There are two categories
of DRM Schemes

Device based DRM:

Security comes from enforcing unique identifiers to the devices. This is
inflexible to mobile internet

Smart card based DRM:

The security comes from key generation algorithms and protocols protected
by smart card. There a
re some security attacks like imposter attacks, and they are uneconomical.

So,

cloud based SIM DRM scheme, called

CS
-
DRM, is proposed for the mobile Internet.
The usage of
SIM card instead of smart card not only reduces the unnecessary cost but provides h
igher security.



In a system implementing a CS
-
DRM scheme

[9]
, only customers

who have purchased the
corresponding licenses can

use or access the digital contents by a frontend, i.e., a cloud

client. The
backend of the system contains kinds of
application

services based on cloud computing, which are
charge

of generating, storing and transmitting encrypted digital

contents and corresponding
licenses. Communication protocols

support the licenses acquisition and verification between

cloud
clients a
nd servers. Besides, algorithms for encrypting/decrypting secret keys and digital contents
are also

necessary parts in CS
-
DRM schemes.




In CS
-
DRM, digital content is encrypted by a content key Kc. Inorder to decrypt and render
the digital content a DRM client must obtain the corresponding license
l

which contains Kc from the
license server. Here Kc is encrypted with
l

and so malicious user

can’t acquire the content of Kc
even he gets the license. In order to protect Kc, a simcard is used as a client entity in the frontend.
The secret key Ki, which is used to decrypt Kc in
l

is stored in SIM card, the algorithm used to
decrypt Kc is implemen
ted as a hardware module inside the SIM card. License State Word (LSW), is
stored in the file system of SIM card to prevent
l

from being tampered. Every time when cloud client
applies Kc, the SIM card verifies the LSW by comparing the LSW value stored in S
IM card with the
hash value of
l.
If the verification is successful, SIM card decrypts Kc in
l

and Kc can be used to
decrypt the digital content. Else the Kc application is denied.



SIM card can be used to safely store the value of Ki, because it is diff
icult to crack due to its
well defined standards. The data abstraction approaches in file system of SIM card makes LSW
secure, and the interaction between SIM card and DRM is protected by LSWP. There can be several
types of attacks

Tamper License: If any u
ser tries to tamper the License, the hash value calculated in LSW with the
stored value in LSWP. The modification is noticed and license is not available anymore.

Tamper or Detect the LSW: There are several wants to scan the SIM card file system, or an
aut
horized user can access the file system and use the LSW value. But the efficient Data abstraction
techniques are applied in SIM card makes it impossible to identify LSW value even if SIM card is
scanned.


The cost of SIM card based DRM schemes are less co
mpared to other DRM schemes. As the smart
card is replaced with the sim, the data protection mechanisms are applied which increases the
security to the data.


10)

Design of Intelligence Mobile Cloud Service Platform based context
-
area:


Mobile Cloud Computing

provides new chance for IT industry by allowing the superiority and
economic of Cloud Computing to meet the mobility and convenience of mobile and draws a synergy
effect for both. Mobile devices used in mobile environment include personal information and
enable
to provide the environment that collects a variety of context
-
aware information. Therefore Context
-
aware reasoning technique has been studied to provide a suitable service for user by using user’s
context and personal profile information in mobile e
nvironment. In context
-
aware system, Formal
context model has to be provided to offer information needed by application as well as store
context and manage. Due to the limited mobile resources context

aware reasoning technique
cannot be applied to the mob
ile platforms.


There are context
-

aware information modeling techniques like Key
-
value model, Markup scheme
model, Graphical model, Object oriented model, and ontology based model which are used in
existing ubiquitous environment and web environment. Ont
ology model enables to express
concepts and interactions easily, which has been studied recently to Semantic Web study based on
OWL (Web Ontology Language). Provisioning Technology refers to technology related to activities
and procedure that prepares know
ledge needed in advance to find optimized resources among
multiple resources and supplies by request. It makes users and enterprises use the system by
allocating, arranging and distributing IT infrastructure resources according to the need of user or
busin
ess. Storage provisioning identifies the unused or waste storage and creates a common pool,
which is used by the administrator when needed. Thin Provisioning Method, announced by 3par
storage which is a joint company by Sun, Oracle and Symantec is a manage
ment method of store
resources, which limited IT administrators to allocate Physical storage through virtualization. The
Hadoop Technique sets up software required or generates basic configuration files by loading data
in advance and operates Hadoop work a
utomatically. The main disadvantage of Provisioning
technique is they do not consider important personal information like context information because
of provisioning by using simple information of resources.



Here author [10] suggested Context
-
aware bas
ed intelligence model cloud service platform for
efficiently managing resource to use context
-

aware information





As shown in Figure 1, The system has intelligence agent, responsible for understanding a variety of
context
-
aware information and inferrin
g it, it consists of sub
-
modules like service module, context
-
aware processor, personal profile, context
-
aware information modeling database. The system has
Intelligence middleware, which provides services and efficiently manages IT resources by users’
req
uest. Context
-
aware processors on intelligence agent include process for collecting context
-
aware information and modeling it, inferring context
-
aware information, and responsible for
understanding what user’s situation was. Service model was responsible
for sending context
-
aware
information to intelligence middleware, providing services that suitable to user. Personal profile
was a repository used to store information. Context
-
aware modeling DB is used to store
information which was modeled by using onto
logy.


Intelligence middleware consisted of interaction interface for communicating to agent, resource
manager(allocating and managing service information for processing user’s request and has
Monitoring module, provisioning module and scheduler), service manager
, service catalog,
provisioning rule database. Monitor module crawled information of IT resource utilization.
Provisioning module set up plan for providing best service to analyze context
-
aware information
which was transferred by user and utilization of s
ervice and resource by plan which was
established to provisioning module.


Service catalog was used to store service information for which user used, provisioning rule
database was stored rule for providing best provisioning process to use context
-

aware
information
and utilization of resource. Service module was responsible for executing service and using
distributed IT resource to provide service to user. Synchronization module is responsible for
synchronizing resource which user was using on cloud compu
ting.



11)

Advantages and Disadvantages of Mobile Cloud Computing:


T
here are numerous advantages of cloud computing on mobile hardware such as:



The growth of enterprise mobile cloud computing will create new revenue streams for both
IT and mobile suppliers
serving businesses. Reasons for this include an evolving IT supply
chain, business adoption of cloud platforms for IT services and greater business use of
handsets and smartphones. In the longer
-
term opportunity is in mobile devices accessing IT
services
from the cloud and paying for access on a per
-
use basis.



Developers can also greatly benefit from mobile cloud computing. Advantages include
access to a bigger market, the chance to make applications that cost less, and keep a larger
share of the revenue.



Mobile data such as sensor logs and multimedia data are immediately available and can be
processed in
-
place or another node that is nearby in the network. Processing data in this
way eliminates the need to expensively transfer data to remote, centralized s
ervices.



Data can often be shared more quickly and/or less expensively among mobile devices
through local
-
area or peer
-
to
-
peer networks. Data sharing is inherently useful in some
applications, and it is needed for collaborative computing jobs.



Services suc
h as websites that use mobile data can be created with little extra computing
infrastructure. Instead of hosting data and services on an expensive server farm or utility
computing service, work can be distributed among mobile devices.



A mobile
-
cloud comput
ing infrastructure could potentially be scaled to many more
machines than a traditional cloud computing infrastructure simply because of the number
of these devices that are in use.



Ownership of the cluster hardware is distributed. By using mobile hardware

owned by
many different people, risks that arise when proprietary cloud services are used, such as
data lock
-
out and dependence on external entities for data privacy, are avoided.


Disadvantages of Mobile Cloud Computing
:


When it comes to mobile cloud co
mputing there are several inherent obstacles that currently limits
its growth and prevalence. Most of these have to do with restrictions related to mobile networks,
namely variable data rates, intermittent connectivity and longer network latencies, compare
d to
fixed broadband.

A major hurdle faced by cloud computing is the availability of networks and intermittency. A cloud
program requires a constant internet connection. However as mobile internet capabilities continue
to get better, chances are high that
solutions to such a problem will become apparent.

At the same time it is obvious that mobile cloud computing is not going to be the best solution for
every need. It poses challenges due to the intrinsic nature and constraints of wireless networks and
devices. This is especially true when it comes to rich
-
internet (RIA) and immersive mobile
applications, e.g. online gaming and augmented reality that require high
-
processing capacity and
minimum network latency. These will most probably continue to be pro
cessed locally on powerful
smartphones and mobile tablets. Mobile broadband networks generally require longer execution
times for a given application to run in the cloud and network latency issues may deem certain
applications and services unfit for the mo
bile cloud. In summary, some of the most critical issues
related to mobile cloud computing includes:

• Network latency and limited bandwidth in the mobile network

• Limitations towards bandwidth
-
hungry apps/services

• Restrictions in utilizing
handset features, e.g. GPS, Bluetooth


M
obile cloud computing is also facing many challenges such as the dependency on continuous
network connections, data sharing applications and collaboration, and security. These problems
must be carefully investigated
before mobile cloud computing can become the next big thing.
Several key aspects of mobile cloud computing, include:

• Architecture of mobile applications in cloud environments

• Thin client layer on mobile devices

• Delay tolerance application
s

• Software structure for mobile cloud application

• Collaborative operations in mobile cloud computing

• Mobile social network

• Security in mobile cloud computing

• Business model for mobile cloud

• Design tool

• Data sharing

and collaboration

• New applications




12)

Conclusion:


Cloud computing is the emerging technology for delivering IT services as computational
utilities. Mobile cloud computing is used to move the computation away from the mobile
devices into the cloud. Many limitations hinder the growth of mobile cloud computi
ng like
limited power, and storage facilities. In this paper we show how mobile cloud computing can
increase the battery life time. Since wireless network pose some concerns related to the
mobility of the devices, we discussed mobile cloud architecture and

scheduling scheme for
scheduling the actions between mobile cloud and mobile host. However efforts are being made
to improve the efficiency of this scheduling algorithm. With the advent of mobile cloud
computing, the growth of mobile applications has enha
nced. Cloud based SIM DRM scheme is
proposed for mobile internet. The SIM card is used in this technique, which not only reduces the
cost but also increases the security.





















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