It’s a Digital World
CCTA 2008
1 | RGB Company Confidential
1 | RGB Company Confidential
Transitioning to an All Digital Network
As most Operators know, a number of FCC rulings are forcing all Cable Operators to look
at a transition to an All-Digital Network.
–
In 2009, Analog TV Stations across the U.S. and U.S. territories will shutting down in favor of
new dedicated channel assignments broadcasting All-Digital programs using a modulation
scheme called 8-VSB.
–
All new Set Tops coming from Vendors, as well as QAM TVs are to have separable
Conditional Access in the form of Cable Cards.
–
Most new Set Top offerings from Vendors no longer have Analog Tuners, hastening the push
towards an All-Digital Lineup.
This discussion focuses on the key Headend components that will need to be added to
allow for an easy, cost effective move toward an All-Digital Lineup.
2 | RGB Company Confidential
2 | RGB Company Confidential
Cable: The Analog Days
– Over the years, the FCC and other Government agencies around the world have created
frequency allocation maps which assign specific RF frequencies to all VHF and UHF
channels. This map is non-negotiable and all broadcasters and manufacturers must follow it
to ensure compatibility (and to avoid interference from channel to channel) on all equipment.
– At different points throughout the years, these agencies have also allocated frequency maps
to cable operators. Because these maps were implemented throughout different periods
and because lower frequencies carry better on coaxial cable, cable maps do not match the
off-air map for all channels and the cable channel frequencies are not always in order.
– A channel is defined as 6 Mhz of space and it takes a full 6 Mhz to broadcast 1 analog video
(AM modulation) with synchronized audio (FM modulation).
ExampleChannel number
Off-Air Freq
Cable Freq
2
55.25
55.25
3
61.25
61.25
22
519.25
169.25
23
525.25
217.25
3 | RGB Company Confidential
3 | RGB Company Confidential
Analog combining
4 | RGB Company Confidential
4 | RGB Company Confidential
Digital Cable

In the mid to late 90s, Cable Operators around the world began to deploy a digital tier
of cable. This was necessary to compete with satellite competition and to free up
precious space.

Digital is defined as an on or an off…also known as a 0 or a 1.

A Stream of meaningful zeroes and ones can be sent to a destination computer (or in
this case, a decoder/set-top) where the destination device is able to read the
language of zeros and ones and do what is requested in the transmission.

The language used by Cable Operators is known as MPEG-II (or in some cases DVB,
an MPEG-II based format with additional Tables in the stream), which allows analog
video and audio to be digitized, sent as a Transport Stream, and decoded back into
analog video and audio at the other end.

In the analog world, only one video can be sent in a 6 Mhz channel. But if the video is
digitized and compressed with MPEG-II, 10 or more services can be sent using the
same 6 Mhz channel using 256 QAM modulation.
5 | RGB Company Confidential
5 | RGB Company Confidential
MPEG Compression
MPEG offers superior video/audio quality at significant bandwidth savings. Digitizing a
standard U.S. movie without means of compression will produce a transport stream of
about 168 Mbps. Using 256 QAM modulation, it would take 5 separate 6 MHz channels
to transmit one movie.
Using an MPEG-II transport stream, this bit rate can be reduced to a 3-4 Mbps
elementary stream (a 50:1 reduction) without significantly effecting perceived video
quality.
This allows an MSO to transmit this movie plus 9 or more movies in just one 256-QAM 6
MHz channel.
6 | RGB Company Confidential
6 | RGB Company Confidential
Set Top Basics

A channel map will contain virtual channels (the channel displayed on the cable set top box) and
the real FCC defined channel. The frequency is fixed by the FCC, based on tuned channel.
Analog Set Top Channel Map

Cable box channel
Service
Tuned channel
2
FOX
2 (55.25 Mhz)
3
Sci-Fi Channel
3 (61.25 Mhz)
4
ABC
32 (271.26 Mhz)
5
CBS
5 (77.25 Mhz)
When multiple video services are combined into a single transport stream for transport on a 6 MHz
channel, each service is assigned an MPEG (also called Program or Service) number.
Digital Set Top Channel Map
Cable box channel
Service
MPEG service #
Tuned channel
2
FOX
1
2 (55.25 Mhz)
3
Sci-Fi Channel
2
2 (55.25 Mhz)
4
ABC
3
2 (55.25 Mhz)
5
CBS
4
2 (55.25 Mhz)
7 | RGB Company Confidential
7 | RGB Company Confidential
Digital modulation
Using a 6 Mhz channel for transmission, the data rate depends on modulation
Using 64 QAM, the maximum transmission rate is 27 Mbps.
Using 256 QAM, the maximum transmission rate is 38.8 Mbps.
IMPORTANT- If the accumulative data rate of all services exceed the total max allowed,
all pictures break up!!!

8 | RGB Company Confidential
8 | RGB Company Confidential
Typical Program Data Rates
A service can be encoded as a CBR or a VBR service.
CBR- Constant Bit Rate. The bit rate is constant regardless of scene complexity,
resulting in either wasted bandwidth or a low quality service.
VBR- Variable Bit Rate. The bit rate constantly changes based on the complexity of each
scene. Quality remains constant.
Typical bit rates Locally Encoded Services- 3-6 Mbps CBR (depending on settings)
 Most satellite delivered services- Approx 3 - 4.5 Mbps average
 Sports programming- 4 - 6 Mbps average
 HDTV Services will vary greatly depending on the Broadcaster. For DTV services, the
bit rate is typically around 5 Mbps. HDTV rates are usually between 11 – 19 Mbps.
This means that a 256 QAM 6Mhz channel (38.8 Mbps) can comfortably carry
about 9-10 services before risk of exceeding 38.8 Mbps.
9 | RGB Company Confidential
9 | RGB Company Confidential
Optimizing your Programming…
Original
Transports
Selected
Programs
Statistical Remultiplexer
New Transport
Stream
Statistical Remultiplexing involves the use of two important functions:

Statistical Remultiplexing (also called Rate Shaping or Transrating) allows an Operator to choose only
the services he desires from multiple Transport Streams (TS) and create a new TS with the new
services chosen.

Since most services are VBR (variable bit rate), the bit rate is always changing. However, the TS total
Bit Rate cannot exceed 38.8 Mbps, so a Transrater must “manage” the Bit Rate of each service to
avoid exceeding the TS bandwidth.
Additional Advantages of Advanced Next Generation Statistical Remultiplexers

DPI (Digital Program Insertion). Most Transraters can perform Digital Ad Insertions into Output
Program Streams.

Graphical Overlays and Logo Insertion. Some Next Generation devices are beginning to offer the
capability to inject Ad Content via Graphic Overlays on existing programming.

Next-Gen Products which offer Graphical Overlays can usually offer Text Crawls, too.

Most Next-Gen products can Transrate hundreds of services simultaneously.
10 | RGB Company Confidential
10 | RGB Company Confidential
Encoders vs. Statistical Remultiplexers
Going Digital begs the question of how to manage all existing services:
–
All Off-Air HDTV Services are already Digital. However, they are not efficiently muxed for
Cable System Transport. Most Off-air DTV Services can range from 5 Mbps to as high as 19
Mbps. However, the digital modulation used (8-VSB) restricts the maximum bandwidth to
19.39 Mbps. 256 QAM has a Transport Stream Bandwidth of 38.77Mbps. Decoding and reencoding using encoders involves multiple devices and forces a high quality signal back to a
semi-analog state. It is also costly. A Statistical Remultiplexer, also known as a Transrater
can multiplex 3 or more HDTV services at 15-19 Mbps or combine 1-2 HD Services with
multiple SD services easily as part of a 256 QAM destined Transport Stream without ever reencoding.
–
Most Satellite services will be digital directly from Satellite. The question becomes, should
you decode and re-encode or send these through a Transrater as well. Most Transraters can
reduce the aggregate bit rates of incoming services by up to 25% without ever causing
serious degradation of quality. This means 12-13 services can comfortably be remultiplexed
without issue. In rare circumstances where extreme bandwidth savings are required and an
Operator needs to reduce bandwidth on a Transport Stream by more than 40%, decoding and
re-encoding using a Real Time Encoder will always be the better choice.
–
In some circumstances, certain services from satellite may still be analog, even after 2009. In
this case, a Real Time Encoder will always be required.
11 | RGB Company Confidential
11 | RGB Company Confidential
How Transraters work…
Transport Stream
Managing service bit Rates (transrating) is done through several methods:

Stripping out null padding from encoder generated Constant Bit Rate (CBR) streams. This method
does not affect picture quality.

Time shifting. Because the transport streams are being buffered, recreating a mux allows the
opportunity to manage the buffers to ensure no two services peak at the same moment in Bit Rate.
This method does not affect picture quality.

Re-quantizing the video as required. This is usually achieved through proprietary algorithms. These
methods above can often achieve a 25-40% reduction of Bit Rate without significant loss in quality,
depending on the original content.
12 | RGB Company Confidential
12 | RGB Company Confidential
Digital Program Insertion (DPI)
Since 1997, the Digital Video Subcommittee of the SCTE has been developing standards, now known
as SCTE 30 and SCTE 35. The specification makes Digital Ad Insertion functionally equivalent to
analog Ad Insertion
SCTE 30, Digital Program Insertion Splicing API:
This Application Program Interface (API) creates a standardized method for communication between
Servers and Splicers for the insertion of content into any MPEG-2 Output Multiplex in the Splicer. This API is
flexible enough to support one or more Servers attached to one or more Splicers. Digital Program Insertion
includes content such as spot advertisements of various lengths, program substitution, public service
announcements or program material created by splicing portions of the program from a Server:
- cue tone detection.
- which ad streams require insertion into which source stream.
- general status information.
SCTE 35, Digital Program Insertion Cueing Message for Cable:
This standard supports the splicing of MPEG-2 streams for the purpose of Digital Program Insertion, which
includes advertisement insertion and insertion of other content types. An in-stream messaging mechanism is
defined to signal splicing and insertion opportunities:
- Provides for a digital equivalent to analog cue tones.
- Encoders will insert the message packet in the MPEG transport stream (as an elementary
stream) which will be detectable by the Headend splicing device.
13 | RGB Company Confidential
13 | RGB Company Confidential
Graphic and Video Overlays:
Targeted and Addressable Applications
Adding overlays on multiple streams simultaneously
creates new Ad Insertion possibilities
Want to buy PGA tickets? (Y / N)
– Embedded in picture
– Not a separate video stream
Type of overlays
See the latest shoe
– Motion Text Crawls– example: EAS/promotions
– Graphic/Bugs – example: logos/branding
– Motion graphics – example: iTV/ads
This is a test of the Emergency Alert System
14 | RGB Company Confidential
14 | RGB Company Confidential
Ad Campaign Communications
Operator
Messaging
Server
Ad Campaign Server
DVS/629
Digital Overlay Graphic Video
and text can be stored on the
Transrater or externally.
One national video production customized for targeted advertising
15 | RGB Company Confidential
15 | RGB Company Confidential
Getting ready for an All-Digital System
Recently, every major operator has begun a process of “Simulcasting” all analog
lineup services as digital services as a first step towards All-Digital.

In essence, every analog service is MPEG encoded (if necessary) and stat-muxed together for
transport to remote Headends.

These transport streams are typically transported as GigE MPEG video through switches and
routers to remote Headends and Hubs.

At each site, the Transport Stream is fed into QAMs and mapped in place of existing analog
services at the digital set-top.

The transport stream is also typically fed into decoders, BTSC encoders, SAP generators and
NTSC modulators to supply the analog line-up for “cable ready TV” customers and lifeline
customers.
16 | RGB Company Confidential
16 | RGB Company Confidential
Advantages of a simulcast environment
Simulcast Advantages in the Digital Line-up:

An all-digital lineup for customers (as opposed to existing digital tiers) with digital set-tops (and
QAM TVs) eliminates the sole advantage of a satellite operator...a fully digital lineup.

Broadcasting services in digital will improve picture quality by providing the same picture at the
Set-top which is found at the Headend. In essence, degradations like CNR, color distortions and
ingress/egress are virtually eliminated as services are sent through a cable system.

One lower cost ad insertion system can be managed, instead of an analog, as well as a digital ad
insertion system.

Additional Ad zones can more easily be added at a lower cost, increasing revenue.

Lineup changes no longer require rewiring existing Headends.
17 | RGB Company Confidential
17 | RGB Company Confidential
Digital Over Analog for the basic tier
Digital will always have an end of run advantage over analog. Low signal, low CNR,
Cross-mod and other common artifacts will always be noticeable on an analog
service. Provided the tiling threshold of a digital signal has not been crossed, the
digital equivalent will still reproduce the same picture that is found at the Headend.
Digital
18 | RGB Company Confidential
18 | RGB Company Confidential
Analog
Analog Advantages of Simulcast
Simulcast Advantages in the Analog Line-up:

Complete Headends can be collapsed into simple Hubs using decoders with RF outputs, making
maintenance and repairs easier at each site.

A decoder/RF Upconverter product purchase would also allow easy replacement of old failing
modulators at a reasonable cost.

Headend reliability goes up significantly with the reduction of racks of satellite receivers and single
channel analog fiber transport systems (if applicable) plus the new found ability to purchase full
Headend redundancy at an affordable price.

Better remote monitoring becomes available with the GUIs available from new decoders.

A single lower cost ad insertion system can be managed, instead of an analog, as well as a digital
ad insertion system.

Additional Ad Zones can more easily be added at a lower cost, increasing revenue.

The reduction of so much older equipment can save 10s of thousands of dollars a year in
Electricity and Cooling costs.
19 | RGB Company Confidential
19 | RGB Company Confidential
All-Digital Transition Diagram
20 | RGB Company Confidential
20 | RGB Company Confidential
VOD (Video on Demand)




With Video on Demand, one or more QAMs are dedicated to specific nodes or groups of people (often known
as a service group).
The QAMs will not broadcast any video until requested to by the VOD Server.
Once a request is received from a Set Top, the VOD will play a movie or other content from local hard drives
out to a specific QAM.
As more users watch movies and other content simultaneously, additional QAMs can be added.
3. The VOD Server will stream
the movie over a GigE Network
to a destination QAM.
2. Software in the digital set top sends
the request for the movie to the VOD
Server at the Headend.
1. A Customer selects a
movie through an
Interactive VOD
Guide
GigE Switch
QAM
21 | RGB Company Confidential
21 | RGB Company Confidential
A VOD QAM Environment
22 | RGB Company Confidential
22 | RGB Company Confidential
VOD Bandwidth…is there a solution?
In the world of Video On Demand, all streams are CBR and typically 3.75Mbps. HD
VOD has a considerably higher data rate. This means that no more than 10
services can ever be joined per QAM.
–
As VOD becomes more popular, some Cable Operators have reported double digit
increases in VOD subscription rates month to month.
–
As network usage increases, additional QAMs must be added to each zone.
–
Every QAM added requires another 6 MHz of valuable bandwidth.
–
Once channel capacity is reached, more costly and time consuming node splits must
be implemented to free up QAM space for each customer.
–
If an area has a sudden reduction in VOD buys due to special promotions, the money
spent above can be wasted, making today’s architecture less scalable than desired.
Is there a better way???
23 | RGB Company Confidential
23 | RGB Company Confidential
Why not Rate Shape at the QAM???
3.75Mbps
VOD
Programs
Statistical Remultiplexer
More efficient VBR
Transport Stream
Ideally, putting a Statistical Remultiplexer in front of the VOD QAMs would easily create
more efficient QAMs packing as many as 14 services into the same QAM. However,
there are several reasons why this has not been possible in the past.
24 | RGB Company Confidential
24 | RGB Company Confidential
Issues with Rate Shaping- COST
The cost per stream with today’s Transraters has been cost prohibitive for a VOD
environment, where thousands of streams must be Transrated simultaneously.
 The average per QAM cost for Rate Shaping is between $6,000 - $10,000
(U.S. Currency), depending on the Vendor chosen, special Operator pricing,
volume of purchase, etc.
 A typical VOD deployment in a medium to large sized city can involve more
than 1000 QAMs.
 This would mean an initial cost of up to $10 Million!!!
25 | RGB Company Confidential
25 | RGB Company Confidential
Issues with Rate Shaping- SPACE
Space would be a huge issue. With thousands of streams, today’s solutions would require
racks of equipment in Headends where space is at a premium.
 At 160 Mbps of output processing (4 QAMs) in a single RU, you would need to buy 250
Motorola CherryPicker DM-6400s, filling 14 7 Ft racks with DM-6400s!!!
 At 640 Mbps of output processing (16 QAMs) in 12 RU, you would need to buy 63
BigBand BMRs, filling 21 7 Ft racks with DM-6400s!!!
 Even with the extreme density of the RGB BNP, at 1280 Mbps of output processing (32
QAMs) in 1 RU, you would need to buy 32 RGB BNPs, filling 2 7 Ft racks with DM6400s!!!
26 | RGB Company Confidential
26 | RGB Company Confidential
Issues with Rate Shaping- Video Delay
Statistical Remultiplexers induce delays of 1.5 – 2.1 seconds (depending on the
Vendor) from input to output. This would not scale in a VOD environment where
channel changes must feel near instantaneous (less than 1 second).
 The Motorola DM-6400 has about a 2 second delay from input to output.
 The BigBand BMR has about a 1.8 second delay from input to output.
 The RGB BNP has about a 1.4 second delay from input to output.
27 | RGB Company Confidential
27 | RGB Company Confidential
New Products address this need…
–
New products just coming to market can Transrate 1200 services simultaneously, which
equates to 80 256QAM Transport Streams. Since less hardware is required, cost is decreased
dramatically, solving the issue of cost. Per QAM costs can now be in the low hundreds instead
of near $10,000.
–
Since a single rack unit SDV/VOD Transrater can manage 80 256QAM Transport Streams, the
space issue has also been solved.
–
Special SDV/VOD Transraters can Transrate at delays of less than 400ms, which makes delay
imperceptible to end users.
–
More Vendors are expected to compete in this area moving forward, allowing for choice and
competition.
28 | RGB Company Confidential
28 | RGB Company Confidential
BW Savings with VOD Transrating
Standard Definition Content
Percentage of Video Rate
reduction
Average Bit Rate per Service
Bandwidth required for
origional CBR services
Number of streams per
channel
Total number of 6 MHz
Channels needed
Number of channels
Saved/Freed with Transcoding
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
40.00%
3.75
3.58175
3.4135
3.24525
3.077
2.90875
2.7405
2.57225
2.404
37.5
35.8175
34.135
32.4525
30.77
29.0875
27.405
25.7225
24.04
10
10
11
11
12
13
14
15
16
100
100
91
91
83
77
71
67
63
0
0
9
9
17
23
29
33
37
Note – savings shown in a system with 25 Service Groups (4 x 6MHz channels per group)
High Definition Content
Percentage of Video Rate reduction
Average Bit Rate per Service
Bandwidth required for origional
CBR services
Number of streams per channel
29 | RGB Company Confidential
29 | RGB Company Confidential
0.00%
5.00%
10.00%
15.00%
15
14.26925
45
28.5385
27.077
25.6155
24.154
2
2
2
3
3
13.5385 12.80775
20.00%
25.00%
30.00%
35.00%
40.00%
12.077 11.34625
10.6155
9.88475
9.154
22.6925
21.231
19.7695
18.308
3
3
3
4
VOD Rate Shaping In Action
30 | RGB Company Confidential
30 | RGB Company Confidential
RGB Networks - Company Overview
Company Background
– 3 Founders: Pioneers in digital TV/video
– Founders also founded Imedia– (CherryPicker)
– 100 employees, based in San Mateo, CA
– Offices in Europe, Asia and Latin America
Sound Financial Backing
– Strong Board of Directors
– Fully funded by top tier venture capital
– Raised $37M total
Products
– First product shipment in August 2005
– 50+ Cable and Telco customers
– Products have been sold in 10 countries
 US, Canada, Mexico, Chile, Columbia,
Bahamas, Honduras, Jamaica, El
Salvador, Nicaragua, Guatemala, Trinidad
– 5-product family, 2000+ units shipped
Patented core technology
31 | RGB Company Confidential
31 | RGB Company Confidential
Muchas Gracias!!!
32 | RGB Company Confidential
32 | RGB Company Confidential