existing coaxial cable. Forty prod-
ucts certified.
continued from page 3
do IPTV over HFC,” Harmonic
VP Product Marketing Nimrod
Ben-Natan said.
ON THE HOMEFRONT
The architectural diagram on page 6 posits several options
for the delivery of IPTV services at the home.
MPEG:
Moving Pictures Experts Group.
Audio and video compression and
transport standard. MPEG- 4 AVC
provides highest available compression factors.
MULTICAST:
One of four forms of IP addressing (others being unicast,
broadcast and anycast.) Within
IPv6, multicast is expanded and
becomes default.
HYBRID HOME GATEWAY
The hybrid is a combination of video QAM tuners and
DOCSIS QAM tuners. CableCARDs help leverage the existing conditional access (CA) system. This option does not
require additional HFC spectrum—a significant advantage.
IPTV set-tops communicate with the home gateway over
MoCA (so as to leverage in-home wiring). These set-tops
can have a new CA/DRM system.
NGAA:
Next generation access architecture. A Comcast proposal for
a driving down cost per bits by
reducing the number of managed
devices while increasing their
capacity. RFI distributed in March
2009. Expect an RFP in Jan 2010.
EFFICIENCY GAINS
At the same time, Ben-Natan
believes that edgeQAM
manufacturers will stay a step
ahead of CMTS vendors, who
cannot focus exclusively on
new technologies, such as
Fast Digital to Analog (Fast
DAC), that are improving efficiencies of QAM modulators.
Harmonic is also seeing
interest is in its MediaPrism
suite, or family of products
that manage the workflow
of content-based operations.
“There’s a lot of activity
around TV Everywhere. Not
just in the context of authentication,” Ben-Natan said.
“More in the context of how
to deal, manage, and manipulate content and distribution in
the network, ” he said.
Cisco’s Brown also pointed
to the potential for efficiencies
in this area—and the cost of
the opposite. “How do you
avoid having to transcode all
of your content in two different formats? Or…avoid encoding everything twice?”
A final promising area for
increased network efficiency
is that of variable bit rate
(VBR) encoding. In a paper
presented at this year’s IBC
that built upon earlier research
supported by the European
Commission, ARRIS VP
Advanced Technology Mark
Bugajski drew some concluded that VBR reduces the
cost to deliver an equivalent
constant bit rate (CBR) stream
by 65 percent.
Or conversely, VBR enables
50 percent more streams
DOCSIS-BASED HOME GATEWAY
This gateways has multiple QAM tuners. This approach
requires additional HFC spectrum. In both hybrid and
DOCSIS-based options, tru2way middleware or a thin
browser-based middleware can be the basis of service application development.
ETHERNET-BASED HOME GATEWAY
This approach, available to some MSOs with fiber access
technologies, would linke to an optical network terminal
(ONT).
TRU2WAY:
Brand name for CableLabs
OpenCable Application Platform
(OCAP), a middleware developed
to support removable security and
Java-based apps.
WIRELESS
A fourth option for delivery of IPTV services to the home—
or wherever—is available to MSOs with wireless spectrum.
TV EVERYWHERE:
An initiative announced by Tim
Warner in February 2009 to
provide television programming
over the Internet to authenticated
subscribers of cable services. In
June, Time Warner and Comcast
endorsed a set of principles guiding the TV Everywhere model.
UDP:
User datagram protocol. A low-overhead transport layer protocol
used for delivering IPTV content
across a broadband network. Can
be used with real-time transport
protocol (RTP) to ensure reliability.
delivered by the same CMTS.
Bugajski documented similar
gains in operations of VOD
servers, CDNs, and the HFC
plant itself.
There are other potential
game changers. Properly
enhanced, IP Multicast—now a
fixture in IPv6—could positively
impact if not disintermediate
existing CND architectures.
For now, however, the focus
for MSOs remains on the
CMTS itself and the endpoints
leading within the home network. (For more on endpoints,
see above, and the architectural diagram on page 6.)
The intense, industry-wide
discussion around those two
points, which represent some
85 percent of capital spend,
suggest to one insider that
this is ”the biggest transition
since we went digital.”
Brown said these changes
represent “an evolution, not a
rip and replace.”
Likewise, he said the ques-
tion of business models is
best described in terms of a
spectrum of choices regarding
the managed or unmanaged
status of the network, devic-
es, content or even metadata.
“There are actually quite a
few degrees of freedom,” he
said.
