Multimedia in 4G mobile communication

systems
Harishkumar N , Abhimanyu Rajan
II-year M.V.J. College of Engineering, Bangalore

ABSTRACT software market. In the near future, third-generation

The popularity and evolution of mobile devices like mobile communication systems will extend the scope
laptops, mobile phones and Personal Digital of today’s Internet streaming solutions by introducing
Assistants (PDA), and the evolution of fast mobile standardized streaming services, targeting the mobile
networks in the last decade, have made it possible to user’s specific needs. By offering higher data-
increase the complexity of mobile applications and transmission rates up to 20 Mbps more than 3G for
services provided to end-users. It is also a wide-area coverage and local-area Coverage, 4G
spectacular growth in multimedia communication systems will be able to provide high quality streamed
especially via the World Wide Web. This paper content to the rapidly growing mobile market. In
explore some of the current technology of mobile addition to higher data rates, these systems also will
devices, mobile networks and multimedia systems, offer value-added applications supported by an
and is based on the exploration outline some underlying network that combines streaming services
issues for design and development of mobile with a range of unique mobile specific services such
multimedia systems in 4G Mobile Communication as Multimedia content, geographical positioning,
System. Fourth-generation mobile communication user profiling, and mobile payment. Mobile cinema
systems will combine standardized streaming with a ticketing is one example of such a service. First, the
range of unique services to provide high-quality mobile network or a terminal integrated
content (Multimedia) that meets the specific needs positioning system such as GPS would determine
of the rapidly growing mobile market By offering the user’s geographical location. Then, the service
higher data-transmission rates up to 20 Mbps more would access a cinema database to generate a list of
than 3G for wide-area coverage and local-area nearby movie theatres and a user profile database to
coverage, 4G systems will be able to provide high determine what kind of movies the user likes best.
quality streamed content to the rapidly growing Based on the geographical location information and
mobile market. user-defined preferences, the service would offer the
user a selection of available movies and show times.
INTRODUCTION The user would then have the option of using the
Many portal sites offer streaming audio and video mobile device to view corresponding movie trailers
services for accessing news and entertainment through a streaming service. Upon choosing a film,
content on the Internet from a PC. The term the user could purchase a ticket through payment
multimedia streaming means that there are more than software on the mobile device. This and other mobile
one media type involved in the communication, e.g. application scenarios present numerous challenges,
text and graphics, voice, animations, video and audio. such as how to provide spectrum efficient streaming
We define multimedia to denote the property of services over varied radio-access networks to
handling a variety of representation media in an different types of end-user terminals. Our standard-
integrated manner. This means that the various based Interactive Media platform addresses these
sources of media types are integrated into a single challenges by using an architecture that fits
system framework. Currently, three incompatible seamlessly into 4G mobile communication systems.
proprietary solutions offered by Real Networks, An integral part of this architecture is a streaming
Microsoft, and Apple dominate the Internet streaming proxy, which acts on both the service and transport
levels. It is flexible enough to deal with different 3.Increased interaction between corroborating
operator requirements and that it can provide technologies; the smart card in your phone will
high-quality streaming services in a mobile automatically pay for or will tell your car to warm up
application environment. in the morning as your phone has noted you leaving
the house. We can use new technology such as
4G MOBILE COMMUNICATIONS CDMA wireless access technology, advanced
SYSTEMS antenna systems, next-generation mobile Internet,
International Mobile Telecommunications (IMT- quality of service, power amplifier technology, and
2000) and the Universal Mobile Telecommunications wireless access networks in 4G mobile
System (UMTS) will be among the first 3G mobile communication system.4G applications include
communication systems to offer wireless wideband high-performance streaming of multimedia content
multimedia services using the Internet protocol. Two based on agent technology and scaleable media
important technological changes will facilitate this coding methods.4G will solve problems like limited
advancement. The first change is a shift from last- bandwidth in 3G when people are moving and
generation radio-access technologies such as the uncertainty about the availability of bandwidth for
global system for mobile (GSM) communication, streaming to all users at all times. The 4G networks
CDMA One (an IS-95 code division multiple access will also provide access to support services such as
standard), and personal digital cellular (PDC) toward authentication, security, and billing mechanisms as
more sophisticated systems with higher data-transfer well as mobile-specific services such as mobility
rates such as the enhanced data. Fourth-generation management and location-based computing.
mobile communication systems will combine
standardized streaming with a range of unique MOBILE STREAMING CHALLENGES
services to provide high-quality content that meets The widespread implementation of mobile streaming
the specific needs of the rapidly growing mobile services faces two major challenges: access network
market. GSM environment (EDGE), wideband and terminal heterogeneity, and content protection.
CDMA (WCDMA), and cdma2000. As Figure 1
illustrates, the second important technology shift is HETEROGENEITY
from a vertically integrated to a horizontally layered In the future, we will have access to a variety of
service environment. A horizontally layered 4G mobile terminals with a wide range of display sizes
service network seamlessly integrates Internet and capabilities. In addition, different radio-access
protocol transport into a mobile service environment networks will make multiple maximum-access link
with a variety of access networks, opening up many speeds available. Because of the physical
new opportunities for IP-based mobile applications. characteristics of cellular radio networks, the quality
For example, mobile terminals will be able to access and, thus, the data rate of an ongoing connection will
existing Internet content through protocols and also vary, contributing to the heterogeneity problem.
markup languages such as WAP and WML that are One way to address heterogeneity is to use
optimized for wireless application scenarios. appropriately designed capability exchange
4Gmobile communications will have transmission mechanisms that enable the terminal and media
rates up to 20 Mbps_ higher than of 3G. The server to negotiate mobile terminal and mobile
technology is expected to be available by the year network capabilities and user preferences. This
2010. 4G is being developed with the following approach lets the server send multimedia data
objectives: 1. Speeds up to 50 times higher than of adapted to the user’s mobile terminal and the
3G. However, the actual available bandwidth of 4G is network. For example, a user accessing a specific
expected to be about 10 Mbps. service via a WCDMA network could get the content
2. Three-dimensional virtual reality imagines delivered at a higher bit rate than someone using a
personal video avatars and realistic holograms, and general packet radio service or GSM network.
the ability to feel as if you are present at an event Similarly, when a person using a mobile multimedia
even if you are not. People, places, and products will terminal with a built-in low quality speaker plugs in a
be able to interact as the cyber and real worlds merge. high-fidelity headphone, a dynamic capability takes
place, upgrading the transmission to a high-quality deliver premium content over digital networks
audio stream for the remainder of the session. A without DRM mechanisms in place to prevent
related problem is how to efficiently deliver streamed widespread illegal copying of valuable multimedia
multimedia content over various radio-access content such as music and movies.
networks with different transmission conditions. This
is achievable only if the media transport protocols STREAMING STANDARDIZATION
incorporate the specific characteristics of wireless Several organization and industry groups including
links, such as delays due to retransmissions of the Internet Streaming Media Alliance (ISMA) and
corrupted data packets. Here, proxies are a suitable the Wireless Multimedia Forum (WMF) have
approach for caching data packets and optimizing the recognized the need for standardization of streaming
data transport over the wireless links to a mobile services. Mobile streaming services in particular
terminal. require a common standardized format because it is
unlikely that mobile terminals will be able to support
all proprietary Internet streaming formats in the near
future. Using standardized components such as
multimedia protocol stacks and codecs_video and
audio compression/decompression software in end-
user equipment will help reduce terminal costs.
Furthermore, preparing and providing content in one
standardized format is less time consuming and
expensive than setting up content for several
proprietary streaming solutions individually. We
Figure 1. The shift from a vertically integrated to a must to address mobile streaming standardization.
horizontally layered mobile service environment. 4G Streaming services as an important building block of
network seamlessly integrate Internet protocol 4G multimedia applications. In addition to mobile
transport with a variety of access networks. streaming standardization, it is also require to
addresses other applications such as
videoconferencing and services for composing and
receiving multimedia messages. Multimedia
messaging services can include text, images, and
audio, short video clips, or video-stream URLs. We
have to use the mobile packet-switched streaming
service. This service integrates simultaneously
playing video, audio, images, and formatted text into
mobile multimedia applications. The protocols and
Figure 2. The protocols integrate simultaneously terminals for streaming applications are less complex
playing video, audio, images, and formatted text than for conversational services, which require media
into mobile multimedia applications input devices and encoders. There are some standard
specifies both protocols and codecs. The protocols
CONTENT PROTECTION and their applications, illustrated in Figure 3, are
At the application level, controlling what users can “Real-time streaming protocol (RTSP) and session
do with content is an important challenge. The description protocol (SDP) for session setup and
simplest form of content protection is simply control,” Synchronized Multimedia Integration
disallowing the storage of received content. Content Language (SMIL) for session layout description,
protection is part of the much broader digital rights “Hypertext transfer protocol (HTTP) and
management (DRM) concept, which uses techniques transmission control protocol (TCP) for transporting
such as encryption and conditional access based on static media such as session layouts, images, and text,
usage rules to protect and manage access to and " Real-time transfer protocol (RTP) for
multimedia data. Content providers are reluctant to transporting real-time media such as video, speech,
and audio. The codecs and media types are " H.263 and formatted text play at the same time. SMIL, an
video," MPEG-4 simple visual profile video XML-based presentation language developed by the
(optional), " AMR (adaptive multirate) speech, " World Wide Web Consortium, is the glue that
MPEG-4 AAC low complexity (AAC-LC) audio combines these different elements to create an
(recommended but optional), " JPEG and GIF interactive multimedia presentation. SMIL is HTML
images, and " XHTML-encoded, formatted text. with additional notions of time and temporal
behavior. Thus, it can describe a media screen and
control the placement of media elements in space and
time. The streaming client interprets the SMIL scene
description and uses it to control the spatial layout
and synchronization in the multimedia presentation.
The standard specifically uses the SMIL 2.0 Basic
Language Profile as well as the Event Timing, Meta
Information, and Media Clipping modules. The
additional modules add functionality such as changes
in the presentation schedule based on user interaction
(EventTiming), sending metainformation about the
multimedia data (MetaInformation), and rendering
only parts of a transmitted media stream (Media-
Clipping). In addition, a streaming client can
support the Pre fetch Control module, which lets the
content creator include hints about when to start a
media stream.

INTERACTIVE MEDIA PLAT-FORM

The Interactive Media system, illustrated in Figure 4,
Figure 3. Overview of streaming client is a software platform for mobile streaming
applications. Designed as an end-to-end solution, the
To enable interoperability between content servers, system consists of Dedicated content creation
especially when inter working with MMS, the machines, A player application that runs on widely
standard specifies using MPEG-4 as an optional file used operating systems such as Windows CE and
format for storing media on the server. The EPOC, Content servers that hold the newly created
standardization process selected individual codec’s multimedia content, and A proxy, which builds the
on the basis of both compression efficiency and interface between the player application and other
complexity. When combined using the SMIL parts of the platform.
presentation description language, the codecs enable
rich multimedia presentations and applications,
including video, audio, slideshows, and
Multilanguage subtitling. Figure 3 shows the logical
components and data flow in a block diagram of a
Streaming Standardization mobile-streaming
terminal, including the individual codecs and
presentation control. The network transmits the data
and passes it to the application from Standard
format link Layer. The application demultiplexes
the data and distributes it to the corresponding video
and audio decoders. The streaming standard offers
the possibility of creating presentations in which
several media elements such as video, audio, images, Figure 4. Interactive Media platform.
 The client uses HTTP to request a SMIL application can have several skins. For example, a
presentation from a Web server. Within the SMIL branding application implements the skin as images
presentation, the client finds links to the streaming mapped on the side of the players display and control
content, which it acquires from the streaming servers. elements. Selecting a different set of images for the
Static content , such as an image, is fetched from a skin brands the application for various customers.
Web server via HTTP. The chosen protocols are fully After launching the player application separately, the
compliant with existing standards. HTTP provides user can select a SMIL presentation or a single
access to static content through a TCP connection, stream to navigate through a hierarchy of SMIL
while RTP packets transport streaming content via presentations. An alternative is to click a hyperlink in
UDP connections. RTSP manages streaming a standard Web browser that anchors a SMIL
sessions. As the Streaming standardization standard presentation. In either case, the player fetches the
requires, the system uses SDP via an RTSP SMIL file from a Web server via the proxy. The
connection to access stream descriptions. Introducing players SMIL engine interprets the contents of the
a proxy is necessary to fulfill the requirements of a SMIL file and fetches the streams (using the RTSP
mobile Internet application using off-the-shelf protocol) and the static content (using HTTP)
components designed for the fixed Internet. It also according to the storyboard the SMIL file describes.
shields the core network from the back-end The engine launches the content-specific codecs to
components and vice versa. Additionally, the back- render the information. Each of the elements in the
end components can be located outside the operator SMIL file can have an underlying hyperlink. When
domain, using the proxy with a firewall extension. the user clicks on a region of the screen that is
This leads to a truly distributed architecture that puts associated with a hyperlink, the SMIL engine fetches
the components into locations where they operate the anchored file and interprets its content.
most effectively.
Content Servers
CONTENT CREATION MACHINES Two kinds of back-end servers store the content the
The content creation machines depicted in Figure 4 player renders: Off-the-shelf Web servers hold the
host the applications needed for creating both live SMIL pages, images, and other static content, and
and offline content. They are used to prepare dedicated streaming servers store streaming content
streaming content, for example, to edit videos and and related information. On reception of an HTTP
images and encode them in the appropriate formats GET request for an SMIL file from the proxy or the
for mobile streaming. Additionally, these machines player, the Web server processes the request and
create the SMIL files, which are a kind of storybook fetches the appropriate content. Subsequent HTTP
for the interactive presentation. They upload the GET requests fetch the associated static content, or
content to the streaming servers for dynamic content the user can click on a hyperlink in a SMIL file to
and to the Web servers, which hold the static content fetch the new presentation. The player application
and the SMIL files. uses the RTSP protocol to control the operation of
the streaming server. After fetching the description of
Player Application a streaming session, which it transports using the
The player application renders multimedia content session description protocol, the player application
and lets users navigate through the SMIL sets up the streams of this session, for example, the
presentations. Each multimedia element can be video and audio track. When it receives an RTSP
hyperlinked to other presentations. The players PLAY request, the server starts sending out RTP
SMIL implementation is fully standard-compliant as packets that transport the streaming content. Each
are the supported codecs, which decode multimedia stream can be in a different state for example, being
data and render it on the output devices. Plug-in set up, playing, paused. Therefore, the streaming
capabilities simplify extending the player with servers must keep track of all active sessions. The
additional codecs. Applying skins changes the player server uses the real-time control protocol to provide
applications appearance. A skin is a structure that the player, proxy, and streaming server with
adapts the look of an applications user interface. An additional information about the session such as
packet loss. Each stream that the server sends out has and combine it with off-the-shelf products. The proxy
an RTCP connection. itself is fully scalable at the machine level, using
Telco standard load-balancing solutions when
Proxy multiple machines use the same IP address. The
The proxy is the systems interface to both the radio proxy’s major task is to adapt the streaming
network and the back-end components. This central multimedia to the mobile network links continuously
components major task is to adapt the streaming changing conditions.
multimedia on the fly to the mobile network links
continuously changing conditions. When a client CONCLUSION
requests an interactive multimedia presentation, the Standardization of mobile services is being
streaming proxy initially loads the SMIL file. The developed to overcome the challenges of streaming
proxy’s basic HTTP functionality optimizes the client multimedia content in 4G mobile communication
connection according to the mobile IP networks systems. The streaming standard specifies protocols
characteristics. The client fetches the SMIL file and and codecs that address streaming multimedia
interprets it on the client, then the client requests both challenges such as the transmission characteristics of
static and streaming content from the back-end wireless links and the heterogeneity of radio-access
servers. Acquiring static content such as images and networks and mobile terminals. The Interactive
text files is very straightforward, but the proxy’s Media streaming platform, based on the standard,
value becomes more apparent when it transmits provides interfaces that application developers can
streaming data to the client. During transmission of use for charging and billing functions as well as
streaming data, the proxy dynamically adapts the network operation and maintenance. Ongoing
delivered quality of service in accordance with developments concentrate on optimizing mobile
available bandwidth. To achieve this dynamic content applications by supporting additional codes
adaptation, the proxy uses feedback information from and offering a broader range of interfaces for proxy
the player application, radio network, and IP management and operation. Eventually, the
network. The user, content-provider, and operator use platform will include extensions for capability
the proxy to configure preferences. A content exchange to allow negotiation of terminal capabilities
provider can specify a minimum bandwidth to ensure during session setup and digital rights management.
acceptable video-stream quality. If this bandwidth is
not available, a slide show is presented instead. If the REFERENCES
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Mobile network operators can easily integrate the
Interactive Media platform into existing structures