Information Technology Reference
In-Depth Information
compile-store-reuse model for speeding up the process of encoding the
ITU-T H.245 ASN.1 formatted messages in a binary stream. In this method,
H.245 sets of messages are compiled, used, and stored in a table. For encod-
ing further incoming messages, the table is queried and the matching result
is used instead of recompiling the messages again and again. Experimental
results show that our algorithm greatly improves call handling efficiency of
a 3G gateway. Thus, we have proved that our lookup table-based message
encoding algorithm can provide stable performance and a satisfactory QoS
assurance even under high traffic conditions. Also our method is tested to be
fully compatible with existing 3G protocols.
3.6.4 Communication between Sensor and uMTS Network
UMTS users could conveniently and quickly access sensor network. We
have proposed architecture for video transmission from WSN to UMTS
networks, which allow an ad hoc PSN communicating with a CSN.
However few researchers consider integration of the mobile network infra-
structure a sensor network. Our new approach, use the characteristics of
sensor networks and mobile network infrastructure to deliver sensor net-
work signals. Furthermore, we build up the platform and implement the
video gateway. The advantages are that communicating between these two
systems dynamically and intelligently can reduce the cost and increase the
lifetime of sensor networks. It was also shown that this approach is suitable
for all organizations and for gathering data on demand. The feasibility and
viability of the proposed method has been proven through initial experi-
mental work.
3.6.5 Mobile Video Quality Measurements and Predictions
We present how these results can be further exploited toward developing a
video quality prediction method base on network status and original frame
lost rate. Hence, consider an unknown video clip in a specific network envi-
ronment and predict its PEVQ that better describes its quality after transmis-
sion and encode, decode. Thus the algorithm can successfully predict the
video quality. Consequently, the service provider can analytically predict
video service quality that satisfy specific quality levels at a pre-encoding
state.
We'll try to make our protocol stack and video communication system
compatible across 3G-324M, Wi-Fi, and H.323. Thus, the video communica-
tion system can be performed over both 3G mobile and internet networks,
with the support of gateways. In order to support more users and improve
the call quality, the 3G gateway should be composed by the following unit:
call setup server for connecting the 3G network to IP network, transcoding
server for transcoding the multimedia in different network, register server
for VoIP user, and AAA server for billing.
