MULTICAST ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
By: Vidya S Nath, Sr. Research Director Swetha R K, Sr. Research Analyst
INTRODUCTION Video viewing habits have changed over the last decade driven by proliferation of connected
mobile devices - especially smartphones and tablets. Most of these devices have strong
capabilities to support high quality video playback thereby making these screens-of-choice for several users.
One study found that 89% of US video viewers use their smartphones while watching content on TV1. In some instances, these viewers are engaged in television-content related activities
on their connected devices. At least 20% of viewers watch more than one program at the same
time using a second screen T while 19% engage in real time social media discussions about the content they are watching2. Sometimes, the second screen is a natural substitute or
alternative for the TV set. For instance, a viewer could start watching a video on the livingroom TV set and then continue watching it on their smartphone or tablet in bed. Regardless of the use case, multiscreen video is the new normal for consumers and they expect the same
or similar quality of experience (QoE) across all platforms.
For Pay TV operators worldwide, multiscreen distribution is a must-have strategy, and many leading operators, including SFR and Orange in France, PCCW in Hong Kong, Ziggo in
Netherlands, Verizon and Comcast in the US, among many others already enable it. But
several find it challenging, as it requires a simulcast of TV services to not just a television set
powered by a set top box (STB), but also to multiple connected devices that differ in brands, form factors, operating systems, and resolutions.
1 Smartphone use while watching TV - US, Statista, 2017 2 Ericsson Consumer Lab Survey, 2016
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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Content distributors deliver video content over broadband to multiscreen devices using HTTP
adaptive bit rate streaming; however HTTP was not built for video delivery, resulting in significant cost and operational hassle for many Pay TV providers. The most commonly used
streaming protocols include HLS and DASH, but live multiscreen delivery continues to be
plagued by latency issues. In order to address these challenges, operators, especially IPTV service providers and cable MSOs, are considering multicast adaptive bit rate (M-ABR) technology for multiscreen video delivery.
This whitepaper elaborates upon the challenges faced by Pay TV operators that can be addressed by M-ABR.
A PAY TV MULTISCREEN DILEMMA MANAGING TRAFFIC FROM MOBILE DEVICES The pay TV market worldwide has become highly mature and is universally threatened by a
gradually growing number of ‘cord shavers’ and ‘cord cutters’- subscribers who are either reducing the time and money on pay TV or canceling their subscription to switch to other alternatives (such as over-the-top video services). Frost & Sullivan estimates that the number of pay TV households will grow from nearly 900 million in 2017 to over 1.5 billion at a CAGR
of 6.2%T, and revenue could grow at a CAGR of 1.3% from $199 billion to $207 billion. Yet,
predictions are becoming increasingly fluid and are dependent on how viewership habits will trend. Almost 60%3 of video viewing today happens over mobile devices and has been
increasing at double digit growth rates over the last two years. It is forecast that the number
of smart phone users is expected to increase at a CAGR of 25% from 2 billion in 2017 to 3.9 billion by 2020.
Consequently, operators have no choice but to deliver content to where the audience is. Unfortunately, live streaming to mobile devices cannot be achieved with the same speed as TV. Linear TV provides for a one-to-many scenario, and there is little impact of ‘traffic’ on the headend. Bandwidth requirements for linear TV are driven by how many channels an operator
has to carry and not so much by how many viewers will access the channels.
3 Ooyala Global Video Index, Q4 2017
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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But with HTTP adaptive bitrate video delivery to mobile devices, connected TVs and Android
set-top boxes, the pressure of bandwidth usage has shifted towards the delivery network.
Higher the demand from individual viewers from connected devices for each channel, the higher the traffic, resulting in spikes in the network usage. Traffic is unpredictable and can fluctuate dramatically based on peak times for television viewing, such as prime time, or live events, especially sports.
Most operators handling HTTP video delivery are not prepared for this, thereby resulting in significant cost of content delivery through unicast streams to each and every connected
device. These costs are compounded for HD and 4K streams, not to mention the difficulty in keeping bandwidth constant with minimal packet loss.
Multicast ABR or M-ABR leverages the bandwidth efficiencies of IP multicast over the operator
network, and combines it with adaptive bit rate streaming to enable the operator to stream live
content only once in its network. The content is then deployed to the home network via a settop box or home gateway, which then unicasts the content to the connected devices.
M-ABR enables an operator to smoothen the traffic demands for any channel, thereby rationalizing network bandwidth usage, while improving the quality of service.
Exhibit 1: Unicast ABR Delivery versus Multicast ABR Delivery
Unicast peaks with Traffic
Unicast peaks with Traffic
Multicast ABR
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
Multicast ABR
Source: Broadpeak
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LIVE TV STREAMING – HOW CAN LATENCY BE REDUCED?
It is expected that consumption of live video would grow 15 times by 2021, constituting up to
13% of Internet video traffic4. One live TV genre that will drive this trend is sports. As more
premium sports content becomes available on a handset, it is expected that mobile video streaming could exceed 70%1 of all video viewing.
For Pay TV operators, it is extremely important to get sports streaming right as it guarantees
a large base of loyal subscribers. This means having to chase the highest benchmarks for quality of service and quality of experience, which once established can be replicated for all
other genres if needed. Popular live sports events intensify viewership traffic as well as viewer sensitivity towards latency and quality of video streaming (with little or no instances of
buffering, freezing, or other glitches). Subscribers want no or minimal difference between what is telecast on linear TV and what they get to view on mobile devices.
The key to non-latency lies in how to optimize the workflow tasks that make up the video Exhibit 2
delivery process- video encoding, packaging, transmission, decoding, encryption, and others. As seen in the illustrated Exhibit 3, unicast delivery can cause a 40-43 second delay compared
to a 2-5 second delay in IPTV. There is little buffering required in the latter as the networks are provisioned for content delivery to set top boxes.
Exhibit 2: IPTV Delivery versus ABR Unicast Delivery Total delay: 2 120 – 5 150 ms
IPTV delivery
3,6 s Video encoding 50 – 2 000 ms
Transmission 20 – 600 ms
Buffering 0 – 50 ms
Fast Channel Change buffer 2 000 ms
Decoding 50 – 500 ms
ABR delivery
41,6 s
Video encoding 50 – 2 000 ms
Packaging 10 000 ms
Transmission 20 – 600 ms
Buffering 30 000 ms
Decoding 50 – 500 ms
Total delay: 40 120 – 43 100 ms
Source: Broadpeak
On the other hand, unicast delivery is delayed significantly by 40-43 seconds because of packaging as well as buffering in the device to ensure video streaming continuously.
4 Cisco VNI, 2016 - 2021
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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A number of HTTP streaming protocols evolved over time to enable video delivery to
connected devices, however, many have been gradually replaced and the dominant ones in usage today are HLS and MPEG-DASH. The challenge is that not all devices are compatible
with both formats, and while over the last couple of years, CMAF emerged as unifying format, it is yet to become a universal standard. CMAF comes with a low latency profile that brings
latency improvement by allowing the segments of video to be processed on the fly at each step even if they are not completely received. Packaging is therefore a key step for HTTP video
delivery. The process takes the transcoded video and applies appropriate streaming format based on the device that requests for it.
After packaging, HTTP video delivery includes buffering- which is necessary to handle bursts of IP packets that in a standard unicast network are delivered in a best effort mode. If the buffer
size is too small for the type of network that is used for content delivery the playout will be
interrupted whenever the rebuffering will occur often causing service interruption. Hence the quality of video depends on the network speed, the number of concurrent viewers, quality of
the embedded device video player, and the resolution of the video to be streamed. With iOS
devices, each chunk can last 6-10 seconds and usually 3 chunks are buffered in the player,
causing up to 30 second delay from live transmission. Some Android video players require 5 chunks of 2s each.
Exhibit 3: IPTV delivery vs ABR Unicast Delivery vs M-ABR Delivery- Latency IPTV delivery 3,6 s
Video encoding 50 – 2000 ms
Transmission 20 – 600 ms
Buffering 0 – 50 ms
Decoding 50 – 500 ms
Fast Channel Change buffer 2 000 ms
Total delay: 2 120 – 5 150 ms
ABR delivery
41,6 s
Video encoding 50 – 2000 ms
Packaging 10 000 ms
Transmission 20 – 600 ms
Buffering 30 000 ms
Total delay: 40 120 – 43 100 ms
Decoding 50 – 500 ms
ABR delivery with multicast ABR 5,6 s
Video encoding 50 – 2000 ms
Packaging 2 000 ms
Transmission 20 – 600 ms
Buffering 2 000 ms
Decoding 50 – 500 ms
Total delay: 4 120 – 7 150 ms
CMAF low latency with chunk transfer encoding and multicast ABR delivery 2,6 s
Video encodingg 50 – 2000 ms
Packaging g g 40 ms
Transmission 20 – 600 ms
Bufferingg 1 000 ms
Decoding 50 – 500 ms
Total delay: dela 1 160 – 4 140 ms
Source: Broadpeak
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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M-ABR can alleviate these concerns. With M-ABR, an operator can bring the traffic from an
unmanaged network to a managed multicast network, reducing the size and number of chunks
to buffer for a smooth playout, and drive low latency packaging, bringing it down from 40 seconds to 6 seconds, thereby driving significant improvement in QoE metrics. With its low
latency flavor, CMAF with Chunk Transfer Encoding (CTE) allows to further reduce latency and brings it down to 2 to 3 seconds.
SAVING COSTS ON VIDEO DELIVERY ON MANAGED NETWORKS Unlike traditional unicast systems where cost to the operator goes up as the number of users
or the amount of peak traffic rises, a multicast system gives more savings in the same scenario. For instance, if one million concurrent viewers are watching a live event using an operator’s
network at 2 Mbps, the content has to be streamed to every user, making the load at the edge
2 Tbps. On the other hand, with multicast, the load at the edge would just be few Mbps since the content is carried only once over the entire network, thereby making it more efficient.
While there is an upfront additional infrastructure investment for an M-ABR server and software
license apart from the unicast infrastructure, the ROI is huge, especially when the service scales up. This gives clear cost savings in the range of 50% - 90%, compared to unicast, depending on the specific operator requirements.
The chart below compares the cost dynamics in unicast and multicast ABR systems based on the number of users across different scenarios.
Exhibit 4: Cost Benefit with M-ABR Delivery compared to Unicast ABR 18
70
16 60 14 Cost to Op perator (Million € €)
50 12
Number of userss (Millions)
Exhibit 4
40
10
8
30
6 20 4 10 2
0
1
2
3
4
5
Scenarios Number of users
Unicast
Multicast
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
Source: Frost & Sullivan analysis
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As can be seen in the chart, the cost of unicast ABR is correlated to the number of concurrent users, and eventually to the bandwidth consumption, stream bitrates, pixel quality of content,
and number of streaming formats (HLS/DASH). With the demand for bandwidth intensive 4K/UHD/8K content going up phenomenally, costs of premium live streaming will certainly go up, thus strengthening the case for M-ABR.
Another alternative explored by operators is to use CDNaaS (CDN as a service) and add
multiple Points of Presence (PoPs) with more servers to support more and more concurrent
users, but it is not economical. A single CDN can typically support up to one million concurrent users, beyond which QoE metrics drop. The total cost of ownership for an IPTV operator in using multicast ABR instead of CDN-as-a-Service (CDNaaS) can reduce costs significantly, especially when the service scales up.
While multicast ABR is a cost-effective solution for an operator to handle peaks in live multiscreen IPTV distribution, it should also be transparent and compatible with the consumer
device without requiring huge modifications. A solution such as that of Broadpeak’s
nanoCDN™ boosts the benefits of the operator’s home network by serving as a cost-effective extension to manage peak loads.
SOLUTION BRIEF: BROADPEAK’S NANOCDN Broadpeak’s nanoCDN™ technology empowers cable and telecom operators to deliver live OTT content in a scalable way to millions of users, leveraging their control over home network components – set-top-boxes or home gateways.
Origin Live Streams
On-the-go Unicast ABR
Non-Multicast Public network
Unicast ABR
Standard OTT players Low popularity
Multicast ABR
Operator’s IP network t k
High popularity
Home Gateway or STB
Unicast Agent
Transcaster
Multicast to Unicast
Unicast to Multicast
Home Network Video Delivery Mediator
Analyytics server
Popularity Live measure
Usage g feed dbacks aggregation gg g
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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The Video Delivery Mediator constantly measures the popularity of each channel and
automatically allocates to the nanoCDN the requests for the most popular ones. For these channels, a transcaster in the head-end converts the unicast streams into multicast, allowing
the operator to serve millions of viewers with a single stream. In addition, it creates the conditions for resolving typical quality of experience issues related to http streaming such as
high latency or recurrent buffering. An agent installed in the CPE receives the multicast stream and converts it back to unicast for delivery to individual devices across the residential environment. The compatibility with DRM and the Adaptive Bitrate policy remain unchanged.
At the end of each user’s session, the nanoCDN feeds back the system with information allowing the Video Delivery Mediator to update dynamically the channels popularity. The multicast resources can thus be reallocated accordingly. CASE STUDY The Problem: A major telecom operator in Europe was looking for solutions to reduce the cost of bandwidth usage for its newly launched TV DSL service—which included distributing
20 channels to 200,000 TV subscribers and 3 million mobile subscribers, across a large
network covering 7 different time zones. Having to scale up its service to a large and widely distributed subscriber base ended up in escalating costs of content delivery, while shrinking its bottom line.
The Solution: Broadpeak implemented the nanoCDN solution to make the service more scalable for the operator without significant overhead. Deploying the nanoCDN technology has helped the operator to maintain a fixed live video delivery cost, thereby saving 90% of
what it would have otherwise spent on content delivery for traditional http distribution. The
nanoCDN agent was embedded in two different Android based home gateways. This project
including the integration with the full ecosystem (service platform, middleware, and, headend) was executed in less than 6 months.
3,4 YouGov
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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THE BOTTOM LINE
Multiscreen video delivery is the new age reality, but still highly challenging for operators in several parts of the world. Legacy IPTV and cable networks are capable of only delivering
MPEG Transport Streams to television, and hence to distribute video to connected devices such as smartphones, tablets, PCs, connected TVs, and Android STBs, operators typically need to use http delivery. This not only adds to operational cost but also impairs QoE metrics
such as scalability and latency, especially during live streaming of events and sports. Multicast ABR offers a suitable fix by combining the benefits of adaptive bit rate delivery (in terms of functionality and device reach) with multicast delivery while keeping overall costs rational. CALL TO ACTION
Frost & Sullivan has put together a list of questions that can help an operator decide if M-ABR is important to be considered for its
multiscreen distribution strategy. If you answer "yes" to more than two of these, you need to evaluate your ROI for multiscreen delivery, your requirements to scale in the future, and how you could deploy M-ABR for your needs.
Are you an IPTV provider who is also distributing live content to mobile devices such as smart phones, tablets and laptops?
Are you a cable MSO with a DOCSIS enabled network, and are you distributing live content to mobile devices such as smart phones, tablets and laptops?
Are you seeing an increasing uptake of your television content by your subscribers on mobile devices?
Are your subscribers facing latency of more than 30s for your live streams across devices?
Are you incurring significant costs with your multiscreen strategy and are you looking to streamline it?
Do you experience difficulties in scaling up your service to multiple devices and still maintain an optimal QoE?
Multicast ABR: A Pay TV Operator’s Key to Multiscreen Live Streaming
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Frost & Sullivan, the Growth Partnership Company, works in collaboration with clients to leverage visionary innovation that ddresses the global challenges and related growth opportunities that will make orbreak today’s market participants. For more than 50 years, we have been developing growth strategies for the Global 1000, emerging businesses, the public sector and the investment community. Is your organization prepared for the next profound wave of industry convergence, disruptive technologies, increasingcompetitive intensity, Mega Trends, breakthrough best practices, changing customer dynamics and emerging economies? For information regarding Frost & Sullivan's whitepaper, please write to: Vidya S Nath Director, Digital Media, Frost & Sullivan P: +91 44 6681 4001 | M: +91 99401 94838 | E: vnath@frost.com
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