There are several issues to be considered to develop a wireless video transmission system successfully.Problems such as the lack of bandwidth in wireless channel, and the dense nature of video data etc. The wireless video transmission system that is mentioned in this paper uses a few approaches to tackle these problems. The 3D set partitioning in hierarchical trees (SPIHT) coder is employed in our system. This coder is very efficient and proves to have real-time capability in compressing video. A grey scale image with size 72x88 needs to be represented with 50.7kbits. If we want to transmit 16 frames/s video, the system needs to have a transmission rate of 811.2kbits/s. It is well known that wireless technology has limited bandwidth. For example, bluetooth has a maximum transmission rate of 721kbits/s. The coder can achieve 40:1 compression ratio introducing minor distortion on the video. We investigated a few ways to improve the processing time of the 3D-SPIHT and its error resilience. Then we try to classify different objects in the video with different priorities. This allows us to minimise the maximum bits that are needed to encode the video sequence. The feedback from the channel is used to control the maximum bits used.

Still some development is made in the 3G technology in mobile communication.In 3G we prompt to use the B-ISDN (Broadband ISDN) which is used to transmit the data at the ultra high speed even in several Mbps towards the receiver.But the compressed data enhance the possibility of introduction of error n loss in the data received. So there some advancement is still required to improve the quality of data received.IEEE standard still working on this issue.


Posted by Bhavin | 12:56 AM

"Claytronics" is an emerging field of engineering concerning reconfigurable nanoscale robots ('claytronic atoms', or catoms) designed to form much larger scale machines or mechanisms. Also known as "programmable matter", the catoms will be sub-millimeter computers that will eventually have the ability to move around, communicate with other computers, change color, and electrostatically connect to other catoms to form different shapes. The forms made up of catoms could morph into nearly any object, even replicas of human beings for virtual meetings.

Claytronics technology is currently being researched by Professor Seth Goldstein and Professor Todd C. Mowry at Carnegie Mellon University, which is where the term was coined. According to Carnegie Mellon's Synthetic Reality Project personnel, claytronics are described as "An ensemble of material that contains sufficient local computation, actuation, storage, energy, sensing, and communication" which can be programmed to form interesting dynamic shapes and configurations.

Properties of Claytronics Atoms (Catoms):
• real, physical objects; analogous to “physical voxels”
• include processing, networking, energy storage, etc.
• also include a means of actuation (locomotion and adhesion)
– move in 3D relative to other catoms, using magnetic or electrostatic forces
– communicate & coordinate with other catoms to control their motion
– a catom itself contains no moving parts (“ensemble principle”)
• outer surface of each catom is a video display
– renders visual details at a higher resolution than physical catom size

for more information about its application refer the link beow: