Information Technology Reference
In-Depth Information
We have presented an efficient implementation of control and data multi-
plexing protocols H.245 and H.223, targeted for multipoint video user in both
3G and Internet environments. With a serialization approach to the multiplex
descriptors, support for multiple media streams control function, our H.245 and
H.223 implementations make the set-up and performing of video transmission
much more convenient and efficient. With tests on the prototype system, the
performance of our protocol implementation is satisfactory and stable.
Currently, we are investigating the transcoding and compatibility between
3G-324M terminals through heterogeneous environment. We'll try to make our
protocol stack and video communication system compatible across 3G-324M,
Wi-Fi, and WSN [29]. Thus, the video communication system can be performed
over both 3G mobile and other networks, with the support of gateways.
3.3 Communication between Sensor and UMTS Network
Recent technological advances show us that a huge amount of low-power inex-
pensive video sensor devices could easily communicate with other networks
like UMTS network and worldwide interoperability for microwave access
(WiMAX) networks, merging them together in a hybrid network to bring the
sensor video streaming to the terminal anywhere. With the rapid develop-
ment of third generation telephony (Video Telephony), it is possible that dif-
ferent network domains that is, circuit switched networks (CSN) and packet
switched networks (PSN), could interconnect with each other. To achieve per-
vasive video communication, the UMTS network foreseen to be the enabling
technology for multimedia services with up to 64 kbps for a circuit switched
network and 2 Mbps for a PSN, makes it feasible for visual communication
over the wireless link. Compared with the UMTS infrastructure networks, the
sensor networks build up a self-organizing ad hoc network to forward data
packets to the sink nodes using multi-hop connections. Researchers at Berkeley
developed embedded wireless sensor networking devices called motes, which
were made publicly available commercially, along with TinyOS, an associ-
ated embedded operating system that facilitates the use of these devices. To
date, wireless multimedia study has focused on robust video transmission
over general PS wireless channels. Figure 3.1 shows an easily programmable,
fully functional, relatively inexpensive platform for experimentation, and real
deployment has played a significant role in the ongoing wireless sensor net-
works revolution. There is, however, a scarcity of work performed on deliver-
ing data from sensor wireless PSN or system to other CSN. The key issue for
data delivery over a 3G network, which consists of several layers, is that it is
not obvious how to achieve end-to-end optimality for data delivery although
a single-layer performance can reach optimum. M.Y.Aal Salem did some work
[31] about the interoperability framework for Sensor and UMTS networks;
