page twenty four www.csimagazine.com Cable & Satellite International july-august 2009

VoD

As video-on-demand becomes

part of mainstream cable,

satellite and IPTV product

offerings, the volume of content is

increasing markedly. By 2012, 909 million

homes will have access to VoD, equivalent

to 78% of the world's TV households,

according to Informa. Add to that the

growth of time-shift services, a complex

variety of ingest formats and multi-screen

delivery and you're left with a huge

management headache.

The dilemma VoD operators will face is

one of scalability. They will be asked to

aggregate content from an ever-increasing

number of owners. “They will need to

create business-to-business transactions

which require that they establish procedural

hand-off for content in terms of how they

receive it, how it is processed, distributed or

sent on to the next process serviced by

another company,” says Tom Ohanian, chief

strategy officer at Signiant.

Even one variable such as content size

has a substantial impact on VoD operation.

As the industry moves to serving high

definition (HD) content then all areas from

storage and servers to the networks

themselves must be re-examined. “Most

obviously, as content volumes rise, and

catch-up services expand, VoD operators

have to deal with increasing storage costs,”

observes Jacques Le Mancq, Thomson's

product marketing manager for video

servers and service platforms.

Monetising the long-tail

Rather than addressing the issue by

throwing more racks of servers at it,

suppliers are working to increase the

intelligence of their customer's VoD

networks, ensuring that they're

propagating content across their

systems and streaming content as

efficiently as possible. The solutions pivot

around balancing the value of each asset

against the cost of storage.

“The main problem is not the amount of

content it's the amount of content which

has limited viewing,” notes Joachim Roos,

CEO of server specialist Edgeware. “It's far

more important to have premium quality

content since it's viewing that generates

revenue while assets sitting in a library

drain costs.”

James Brickmeier, Concurrent's

VP/general manager of converged video

solutions, agrees that the chief concern is

monetising the long tail. “Given that

it doesn't generate much in the way of

revenue it is always a balance between the

cost of storage, the population of content

on a network and the likelihood of making

revenue from that.

“The way that most operators have

looked at this is to try and build a tiered

storage model where higher performance

storage is used for the highest demand

content. As you move to the library

content there's a migration to lower

performance and lower cost disk drive

technology,” he says.

SeaChange is accomplishing this through

its back-office software platform that is

driving an appropriate mix of flash- and

disk-based storage systems. “While the

software and servers can be deployed

either centrally or as a distributed platform,

there's an increasing trend toward

centralised software and disk-based libraries

that complement flash memory storage

servers on the network edge,”

says Alan Hoff, VP of product marketing.

Harmonic sees the fundamental

conundrum, as one of centralised storage

versus transport costs: the more assets are

centralised (cheaper) the bigger the load

on the transport network (more expensive).

Scaling VoD contentVideo-on-demand growth can leave operators with a hugemanagement headache, but system intelligence can be athand to help, says Adrian Pennington

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Cable & Satellite International july-august 2009 www.csimagazine.com page twenty five

VoD

“One innovative approach being adopted by

operators is to cache the most popular

programme at the edge which will

immediately reduce the cost of transport by

reducing the load on the network,” says Gil

Katz, senior director of cable solutions at

Harmonic. “Our research shows that by

keeping the 100 most popular assets an

operator can save up to 50% of their

transport costs.”

Intelligent management

Since the most popular assets in any

network change every minute the operator

needs to invest in an intelligent asset

management system to manage and push

the assets to the edge of the network

dynamically. Harmonic's Armada, Katz says,

is designed to do just that.

Hierarchical content storage architecture

involves partitioning and/or copying

portions of the content library across

multiple storage tiers.

These tiers are often split across

geographical regions - for example national

or regional centralised libraries that are

shared by many edge servers, explains Arris

marketing chief Riki Rau. “The optimum

implementation places only the most

popular content closest to the subscriber. In

this way content storage/streaming and the

CDN are utilised more efficiently.”

Intelligent algorithms measure the assets

'churn popularity' and migrate each to the

appropriate delivery tier. “This conserves

transport bandwidth, simplifies management

and improves user experience,” says Rau.

“Ideally this is done proactively and in

anticipation that a given title is popular at

some point that day. Hundreds, even

thousands of assets are added and/or

deleted from various content tiers as

required, everyday. Optimising these

procedures is a critical part

of the operation.”

Telco and cable services can be

considered together, in the sense that they

rely on VoD server farms which deliver

content - often differentiated into more and

less popular content - as MPEG transport

streams on a managed network.

“In both cases we are talking about the

same catalogue volumes, the same video

resolution and the same streaming

technology,” says Thomson's Le Mancq.

“For both network types, it is critical to

make hot content available on fast (but

expensive) storage like RAM or flash disks,

while long tail content can remain on

slower (and cheaper) storage like SATA

disk arrays.”

Satellite and terrestrial broadcasters who

use hybrid networks for VoD typically

deliver content over unmanaged networks.

The technology of choice here tends

towards HTTP progressive downloads over

the internet. “This requires a content

delivery network (CDN) capable of

managing the storage and a service based

on popularity to ensure a suitable quality of

service,” says Le Mancq. “As an alternative

to developing their own CDN, satellite or

terrestrial operators could outsource to a

hosted CDN specialist, establishing QoS

standards as part of the contract and

leaving it to the host to establish a

popularity management regime.”

Le Mancq advises operators to

select a CDN vendor which can scale

independently as the number of streams

and the number of titles grows. “This must

be done by dynamically allocating streaming

capacity to hot content, based on real-time

usage statistics,” he says. “Delivery capacity

is managed by moving titles around the

storage network, allocating content to more

and/or faster servers as its popularity rises.

When the CDN is not fully automated to

balance demand, a growing catalogue will

translate into increasing operational costs

for the VoD platform. “All operators have to

maximise the content value,” says Remi

Beaudouin, product marketing manager for

content and streaming solutions at video

compression technologists ATEME. “They

face the pressure of not having to address

just one market but to deliver content to

multi-screens and to do so rapidly to meet

consumer demand.”

Beaudouin says ATEME's focus is on

preserving video quality at much lower

bitrates (based on H.264) so operators

can ensure their VoD service is as reliable

and robust as possible, as well as extend

their service to a wider subscriber base.

Regardless of platform, operators

are faced with a myriad of decisions

regarding managing their content.

For example, where is the content?

Under what rules is the content to be

distributed? Where do the rules of usage,

billing, and payment reside? Where is

content held in active storage, when is it

backed up?

“Certainly some combination of asset

management and content management

systems must be put in place in order

to facilitate these functions - for instance

content aggregation, transformation, and

distribution processes can all be centrally

managed and automated,” suggests

Signiant's Ohanian. “Content should be

moved the fewest amount of times through

the content aggregation, transformation,

and distribution cycle.”

Dr Dan Yuval, VP and founder of

broadcast management system developer

SintecMedia, says: “Ideally there should be

a single system that manages all types of

content - linear and non-linear. Are

operators going to manage different

contracts for rights to show a movie on

their pay-per-vide (PPV) linear channels

and VoD? Are they going to manage two

different airtime sales campaigns? It only

makes senses to have a single environment

that captures everything.”

Equally important is giving viewers the

ability to actually find the content they want

to watch. As the amount of available VoD

content increases, so too does the inherent

challenge that viewers face in navigating

through vast collections of titles.

“We're helping operators with

technology where viewers can search for

titles through keywords, genres, 'most

“Our research shows that by keepingthe 100 most popular assets anoperator can save up to 50% oftheir transport costs.”

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page twenty six www.csimagazine.com Cable & Satellite International july-august 2009

VoD

popular' lists, and social networking-style

recommendations from friends and family,”

says Hoff.

V2.0 ADI to the rescue

At the heart of this is effective metadata

tagging which the V2.0 ADI (Asset

Distribution Interface) specification from

Cablelabs goes some way to address.

Unlike older versions of the spec, 2.0

offers support for multiple client

platforms and applications including IP-

based distribution, VoD playlists, and

advanced advertising. Its primary purpose

is to assist operators as they extend their

VoD architectures to cover 'anywhere,

anytime, any device.' It also simplifies the

search feature and enables subscribers to

find what they want to watch - much as

they can do already today on the web.

“Much anticipated is a new feature that

creates asset distribution specifications

that reduce content churn,” says Arris'

Rau. “For example, if the content provider

had a better sense of an asset's status,

content delivery can be more 'intelligent'

and presumably result in less churn at

the operator. Previous versions of ADI did

not define an extended messaging

protocol between a provider and operator

and this presents two problems: once an

asset leaves the system, the provider has

almost no visibility of its status; and

operations on that asset become

'monolithic' - ie, replacing, modifying,

updating or anything else requires re-

pitching. ADI 2.0 introduces new

capabilities to allow providers to address

these issues.”

In summary, emerging VoD system

architectures take advantage of how

subscribers use them. Whether classic

VoD to TV set-top boxes or across the

web to PC and mobile devices, getting

popular content close to subscriber is

critical to reduce CapEx and OpEx. These

advanced architectures employ

hierarchical storage and tier-based system

architectures managed by intelligent

algorithms which measure the asset's

'churn popularity' and migrate each to the

appropriate delivery tier. CSI

Mobile VoD

Mobile VoD presents a peculiar set of

challenges. Storage may be reduced

because video resolution will be

significantly lower, but recent moves by

operators to offer all-you-can-eat data

plans combined with an exponential

increase in sales of smart phones, has

created significant capacity issues.

“Mobile is a compelling device that

content owners would like to utilise yet

the method by which mobile consumers

want to obtain and interact with their

content has yet to be successfully

addressed,” says Signiant's Ohanian.

“Pause, rewind and even PVR/DVR

capabilities are important to this

experience. Providing them in a mobile

VoD platform is an expense that is

greater than other platforms and even

requires more developmental work,”

he says.

One of the few companies to offer

things such as 'bookmarking' and ad

insertion is communications service

provider WIN, which says it's invested

heavily in technology so that VoD

services are compatible with a wide

range of mobile phones and data

networks.

“Mobile is a tough place to be,”

admits CEO Graham Rivers. “It's a

problem the industry has caused itself.

Devices capable of handling video

were available long before a suitable

infrastructure and when finally the

infrastructure is in place they do

something irrational and sell millions

of dongles to connect laptops. That's

a lot of capacity consumed by traffic

that is essentially email driven.”

Because of market saturation

operators are fighting on price, so they

are forever decreasing tariff and putting

immense pressure on CapEx and OpEx.

Rivers advocates moving to an

outsourcing model - coincidentally

something WIN provides. “Operators

and content owners have no choice -

that's where they will get pushed to,”

he claims. Outsourced data

management centres can leverage the

economies of scale and take the

headache of a non-core activity away

from the operator.

“We have the technology and

platform to deliver content,” he adds,

citing the streaming video service

it provides T-Mobile Germany's 38

million subscribers.

VOD Profile - 5300-hour library

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Content hours (sorted by popularity)

% o

f st

ream

s

0 500 1000 1500 2000 2500 3000 3500 4000

Source: Arris

CSI

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