Miroshnikov
G.G.
Astrakhan
State University
Prospects
of the use of wireless access networks for IPTV services
The increasing popularity of Internet Protocol Television
(IPTV) services may reside on its versatility at providing multimedia services.
The next logical step should be to provide those services right where
subscribers are. As traditional wired networks can only deliver data to fixated
points, wireless broadband technology could be an alternative for achieving so.
That is, however, considering that streaming IP-video imposes special
requirements on the network and video traffic do require a stable high speed
bandwidth.
VoIP and general traffic over the Internet is always
characterized by constant fluctuations of speed and more prone to delays. Table
1 shows the requirements of data rate for different parameters of video stream.
As streams grow in definition and quality they require increments of bandwidth
per channel with subsequent investments in equipment and technology.
Table 1: Video type characteristics comparison
|
Video Type |
Format |
fps |
Dimension (Mega
pixels) |
Streamed
Mbps |
|
|
MPEG-2 |
MPEG-4 |
||||
|
Analogue |
NTSC |
30 |
0.2 |
6 MHZ |
6 MHz |
|
Standard Definition |
480i |
30 |
0.5 |
7 |
2 |
|
High Definition (HDTV) |
1080i or 720p |
30 |
2 |
20 |
8 |
|
Super HD (SHDTV) |
2160i |
30 |
8 |
60 |
32 |
|
Ultra HD (UHDTV) |
4320i |
60 |
32 |
480 |
256 |
Now we shall consider the characteristics of an IPTV system
should be deployed on a broadband wireless access network. Features of
multimedia broadcasting services for technology HSPA, LTE and WiMAX are
described on Table 2 (functioning parameters of these technologies are shown in
tabular form that may facilitate a comparison).
Table. 2: Comparison of technical parameters of
wireless broadband data
|
Technology |
WiMAX |
HSDPA |
LTE Rel.8 |
|
Band, GHz |
802.16d - 1,5-11, 802.16e - 2,3-13,6 |
1,9-2,2 |
1,4-20 |
|
The maximum downlink rate, Mbit/s |
802.16d - 75, 802.16e - 40 |
21 (HSPA+) |
58 |
|
Channel width, MHz |
FDD - 2×5, TDD - 10 |
2×5 |
äî 20 |
|
Access Method DL |
OFDMA |
OFDMA |
OFDMA |
|
Access Method UL |
OFDMA |
SC-FDMA |
SC-FDMA |
|
Duplex method |
FDD/TDD |
FDD |
FDD |
|
Frame, ms |
5 |
2 |
1 |
|
QoS |
Yes |
Yes |
Yes |
|
MIMO |
Yes |
Yes |
Yes |
|
HARQ (Hybrid automatic repeat request) |
Yes (802.16e) |
Yes |
Yes |
|
Handover |
Yes (802.16e) |
Yes |
Yes |
|
Multicast |
Yes |
Yes |
Yes |
The 3GPP LTE - 3GPP consortium project aimed to develop
standard technologies to improve mobile data on CDMA and UMTS. More
importantly, this technology was primarily designed for mobile operators
allowing a better integration of new LTE equipment with existing equipment
making this widely welcome. Benefiting from the strong competition between
television and cable, it seems possible that IPTV over wireless broadband could
become soon part of the services provided by mobile operators as well as other
Internet providers. The defining property being its more interactive nature, a
feature not truly available on regular TV broadcasting.
From a technical point of view, implementation and
deployment of IPTV services on the existing operator's network should account
for bandwidth requirements together with low latency parameters. This certainly
would involve an update of QoS mechanisms as well as a competent marketing
policy for subscribers to prevent network over loadings.
References:
1.
3GPP TS 29.214, “Technical Specification Group Core Network
and Terminals: Policy and charging control over Rx reference point”Rel.10 March
2011.
2.
Al-Jobouri, L., Fleury, M. and Ghanbari,
M., "Robust IPTV delivery with adaptive rateless coding over a mobile
WiMAX channel", ISRN Communications and Networking , Vol. 2011, No.,
(2011), 24
3.
Hoymann C. et al. Relaying operation in 3GPP LTE: challenges
and solutions //Communications Magazine, IEEE. – 2012. – vol. 50. – ¹. 2. – pp.
156-162.
4.
Raut, S., "WiMAX or LTE: Which Technology to Adopt? A
comprehensive Comparative Study''", Communications of the IBIMA, Vol. 9,
(2009).