Wireless Internet Handbook: Technologies, Standards, and Applications (Internet and Communications)
V
Variable length coding (VLC) techniques, 106
VAX computer, barcode files from, 452
VBScript, 21
Vector
graphics, 97, 98
-sum excited linear predictive coding (VSELP), 155
Venture capital, 430
VeriSign wireless trust services, 506
Verizon, 190, 438
CDMA used by, 57
Wireless, 436, 439, 442
Vertical handoff(s)
intelligent management of, 416
translation of mobility profiles during, 422
Video
calling, face-to-face, 28
camera, 25
compression
algorithms, 78
standards, 106, 107, 109, 110
technology, 78
data
end-to-end delivery of compressed, 111
MPEG, 111
decoded, 120
encoding
delay, 487
techniques, scalable, 107
over IP, 470
QoS metrics, 485
real-time, 78
Redundancy Coding Header, 111
server, 273
streaming architecture, cross layer design, 118
Videoconferencing, use of H.263 in, 108
Videophone, 471
Video telephony, mobile, 469–495
end-to-end system architecture, 470–473
mobile networks for video telephony, 473–474
performance issues in, 484–493
error resilience and QoS, 484–485
RTCP performance, 491–493
SIP signaling delay, 488–491
video QoS metrics, 485–487
video quality results for 3G-324M, 487–488
standards for, 474–483
circuit-switched, 475–479
packet-switched, 479–483
Virtual Bottleneck Cell, 218
Virtual circuits, 292
Virtual connection tree, 271, 277
Virtual tree
-based rerouting, 270
number of nodes in, 279
setup time, 279
teardown time, 279
Viruses, 65
Visa card holders, WAP location service for, 191
Visitor location register (VLR), 353, 368, 410
VLC techniques, see Variable length coding techniques
VLR, see Visitor location register
Vodaphone, 439
Voice
coding, 151, 154
communication, QoS management for, 150
decoding, rate of, 177
information
high-quality, 318
synchronous, 319
packets
digitized, 153
RLP function and, 163
RTP, 167
payload design, GPRS VoIP, 176
portals, 19
quality
inferior, 181
network, 156
services, success of wireless, 149
signal coding, 156
traffic bursts, 179
Voice over IP (VoIP), 150, 470, 479, see also VoIP services
call(s)
seamless switched, 373
setup, performance of, 166
designer, 177
gateways, 222
implementation, high-level view of, 165
SIP signaling for, 162
traffic blocking, 178
Voicestream, 57
VoIP, see Voice over IP
VoIP services, 149–183, see also Voice over IP
basis of voice coding, 154–155
H.323 implementation architecture, 165–175
analysis of RTCP:CNAME packet delay, 169–170
average H.323 call setup delay, 172
average TCP packet transmission delay, 171–172
delay analysis of H.323 control signaling over wireless, 168–169
experimental verification, 172–175
H.323 call setup message delay analysis, 170–171
media packet-blocking analysis in GPRS, 175–180
network quality requirements, 155–158
overview of H.323 protocol, 158–161
overview of SIP, 161–163
RLP, 163–165
wireless networks, 151–154
VSELP, see Vector-sum excited linear predictive coding
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