MULTIMEDIA OVER WIRELESS BROADBAND NETWORKS

MULTIMEDIA OVER WIRELESS MULTIMEDIA OVER WIRELESS BROADBAND NETWORKSBROADBAND NETWORKS

BY: NEELIMA PUNJALABY: NEELIMA PUNJALA

Definition:Definition:

Multimedia over wireless broadband is an emerging service Multimedia over wireless broadband is an emerging service that integrates voice, video and data in the same service. For that integrates voice, video and data in the same service. For example songs, movies, games are considered to be different example songs, movies, games are considered to be different forms of multimedia.forms of multimedia.

Example of a wireless handheld device supporting multimedia Example of a wireless handheld device supporting multimedia is a, Personal Data Assistant (PDA), it can integrate voice, is a, Personal Data Assistant (PDA), it can integrate voice, video, and data in one device. A camera mobile phones is video, and data in one device. A camera mobile phones is

another example.another example.

Examples of multimediaExamples of multimedia

Applications using multimedia:Applications using multimedia:

1.1. Remote educationRemote education

2.2. video-on-demandvideo-on-demand

3.3. TeleshoppingTeleshopping

4.4. Home gamesHome games

5.5. Entertainment (Movies, Songs)Entertainment (Movies, Songs)

Multimedia examples:Multimedia examples:

Transmission of real-time data over wireless broadband network Transmission of real-time data over wireless broadband network indicates delivery of multimedia along traditional data traffic which is indicates delivery of multimedia along traditional data traffic which is extremely dense and heavy. extremely dense and heavy.

The system required for this kind of support must be capable of The system required for this kind of support must be capable of providingproviding 1. Quality of Service (QoS) for voice and video packets. 1. Quality of Service (QoS) for voice and video packets. 2. Use the available bandwidth to the maximum 2. Use the available bandwidth to the maximum

The transmission quality of radio is easily affected by environments The transmission quality of radio is easily affected by environments such as buildings, moving objects, and atmosphere, etc. Moreover, such as buildings, moving objects, and atmosphere, etc. Moreover, because of the mobile nature of the users, the access point of a mobile because of the mobile nature of the users, the access point of a mobile user changes continuously. All these factors in wireless networks give user changes continuously. All these factors in wireless networks give rise to issues such as effective bandwidth allocation, high channel bit rise to issues such as effective bandwidth allocation, high channel bit error rate, and user handover error rate, and user handover

Integrated Network (Broadband + Mobile) Integrated Network (Broadband + Mobile)

Methodology explaining end-to-end Transmission Methodology explaining end-to-end Transmission over wireless network:over wireless network:

To provide efficient communication and quality of media content sentTo provide efficient communication and quality of media content sent

over, the system consists of three major components:over, the system consists of three major components:

1.anyDevice1.anyDevice

2.Center Server2.Center Server

3.Agent Server3.Agent Server

Network architecture Diagram:Network architecture Diagram:

1. anyDevice is a client-side protocol stack working on terminals and it 1. anyDevice is a client-side protocol stack working on terminals and it helps terminals to communicate with servers. It is also responsible for helps terminals to communicate with servers. It is also responsible for communication control, data transmission between terminals and communication control, data transmission between terminals and servers, and user profile management.servers, and user profile management.

2. Center Server provides indexing and database services and is 2. Center Server provides indexing and database services and is responsible for session management. It helps terminals to quickly restart responsible for session management. It helps terminals to quickly restart data transmissiondata transmission

3. Agent Server provides data buffering and multimedia transcoding 3. Agent Server provides data buffering and multimedia transcoding services. The former prevents transmitters retransfer lost data during services. The former prevents transmitters retransfer lost data during network congestion or disconnection. The latter helps heterogeneous network congestion or disconnection. The latter helps heterogeneous terminals communicate with each other seamlessly and efficiently.terminals communicate with each other seamlessly and efficiently.

Communication between terminals and agent ServerCommunication between terminals and agent Server::

Performance of Wireless in comparison to othersPerformance of Wireless in comparison to others

Advantages:Advantages:

Dramatically lower in cost Always on Anytime, anywhere and in any form Voice and multimedia Self service, intuitive Simpler for the end user

Enhancements to the networkEnhancements to the network

Problems accessing Multimedia :Problems accessing Multimedia :

1.1. Limited bandwidth of wireless networks. Limited bandwidth of wireless networks.

2.2. Limited capabilities and limited Resources of wireless terminals.Limited capabilities and limited Resources of wireless terminals.

3.3. Diversity of wireless terminals.Diversity of wireless terminals.

4.4. Fluctuated Bandwidth and Blackouts of wireless connections.Fluctuated Bandwidth and Blackouts of wireless connections.

These are major problems for the efficient transmission of multimedia These are major problems for the efficient transmission of multimedia flows.flows.

To run multimedia over broadband network, several issues are to be To run multimedia over broadband network, several issues are to be addressed:addressed:

1.1. Transmission must be real-time and maintain good quality of Transmission must be real-time and maintain good quality of service for the real time traffic which is extremely dense and heavy.service for the real time traffic which is extremely dense and heavy.

2.2. Storage compression and decompression must be efficient to utilize Storage compression and decompression must be efficient to utilize limited bandwidth efficiently.limited bandwidth efficiently.

RTP is used to transmit real time data over IP and MPEG video coding is RTP is used to transmit real time data over IP and MPEG video coding is used to obtain high video quality which is accepted even when used to obtain high video quality which is accepted even when bandwidth decreases to 56kbps.bandwidth decreases to 56kbps.

Real time transmission:Real time transmission:

To transmit real time data on network, a protocol must provide end to To transmit real time data on network, a protocol must provide end to end real time data delivery and satisfy the following constraints.end real time data delivery and satisfy the following constraints.

1.Regulation between server and client.1.Regulation between server and client.

2.Capacity to solve asynchrony caused by the network2.Capacity to solve asynchrony caused by the network

3.Capacity to synchronize between data streams.3.Capacity to synchronize between data streams.

4.Ability to give priority to one type of media over the other4.Ability to give priority to one type of media over the other

5.Informs sub-layer about the type of information contained in the 5.Informs sub-layer about the type of information contained in the packets.packets.

6.Allows multiplexing and demultiplexing different types of information 6.Allows multiplexing and demultiplexing different types of information along with synchronization.along with synchronization.

RTP:RTP:

To ensure end to end real time data delivery we use RTP. The To ensure end to end real time data delivery we use RTP. The services provided by RTP include services provided by RTP include

1.Packet loss detection1.Packet loss detection

2.Security and Content identification.2.Security and Content identification.

3.Sequence numbering3.Sequence numbering

4.Timestamping4.Timestamping

Sequence numbers are used to order incoming packets and to detect Sequence numbers are used to order incoming packets and to detect packet losses.packet losses.

Time stamping is a very important information for real time Time stamping is a very important information for real time applications.applications.

A payload type identifier specifies the payload format as well as the A payload type identifier specifies the payload format as well as the encoding/compression schemes.encoding/compression schemes.

RTCP:RTCP:

RTCP is a second protocol of RTP which transfer the control traffic.RTCP is a second protocol of RTP which transfer the control traffic.

It sends the transmitter about the quality of transmission.It sends the transmitter about the quality of transmission.

RTCP which provides control information to transmitter provides RTCP which provides control information to transmitter provides following services.following services.

1.QoS monitoring and congestion control1.QoS monitoring and congestion control

2.Source identification.2.Source identification.

3.inter-media synchronization3.inter-media synchronization

4.Control information scaling4.Control information scaling

Architecture used for data compression:Architecture used for data compression:

The diagram explains layered architecture of MPEG terminals.The diagram explains layered architecture of MPEG terminals.

1. Compression layer processes individual audio-visual media streams.1. Compression layer processes individual audio-visual media streams.The compressed content is organized into Elementary Streams (ES).The compressed content is organized into Elementary Streams (ES).

An interface is used to transmit data from one layer to the other and it is An interface is used to transmit data from one layer to the other and it is called as Elementary Stream Interface (ESI).called as Elementary Stream Interface (ESI). 2. A homogeneous encapsulation of ES carrying media or control 2. A homogeneous encapsulation of ES carrying media or control information is defined by the sync layer (SL). This layer provides information is defined by the sync layer (SL). This layer provides synchronization between streams. synchronization between streams.

An interface used to establish sessions and access transport channels is An interface used to establish sessions and access transport channels is called DMIF application interface (DAI)called DMIF application interface (DAI)

3. Delivery layer provides transparent access and delivery of content 3. Delivery layer provides transparent access and delivery of content irrespective or technologies used.irrespective or technologies used.

Issues with wireless architecture:Issues with wireless architecture:

A wireless access point may open the internal, non-protected network up to unknown and non-trusted users who are simply within communication range.

Damages can include leaking secret information, message contamination, and node impersonation

network monitoring in wireless ad hoc networks is performed at every network node. This approach is inefficient due to network bandwidth consumption and increased computations resources that are highly limited in a WLAN.

Structural and behavioral differences between wired and wireless mobile networks make existing designs inapplicable to the wireless networks.

Issues when Security is not maintained:Issues when Security is not maintained:

Maintaining Security :Maintaining Security :

Security in a system can be maintained from outsiders or internal Security in a system can be maintained from outsiders or internal factors using Intruder Detection System (IDS).factors using Intruder Detection System (IDS).

These wireless IDS can monitor and analyze user and system

activities, recognize patterns of known attacks, identify abnormal

network activity, and detect policy violations for WLANs. Wireless IDS gather all local wireless transmissions and generate alerts based

either on predefined signatures or on anomalies in the traffic.

IDS maintaining a secure system:IDS maintaining a secure system:

Conclusions:Conclusions:

Quality of video transmitted is very highQuality of video transmitted is very high Real time transport of data is ensured.Real time transport of data is ensured. Asynchrony problems like jitter are removed.Asynchrony problems like jitter are removed.

QuestionsQuestions

Necessity of using Broadband wireless networksNecessity of using Broadband wireless networks

How security can be maintained over the networkHow security can be maintained over the network

How the available bandwidth is utilized efficiently in wireless How the available bandwidth is utilized efficiently in wireless networknetwork