Video Over Cellular: the long-lasting status quo and great expectations
September 6, 2019
Have you seen anything genuinely new happening in mobile video industry in the last five years? Probably not.
Market trends and usage patterns have been following a smooth and steady evolution, toward ever-increasing data traffic and share of video, increased viewing on the go, growingly sophisticated mobile devices and displays, ever more generous data plans, plus the growing prevalence of OTT video traffic, the limited success of operators’ mobile TV services and the continuous erosion of their average revenue per user (ARPU).
The trends, quality of experience, technology and challenges in the video-over-cellular domain have not much changed during the 4.5G (LTE-Advanced) era.
Network Monetization: The Biggest Remaining Challenge
If monetization of data traffic has been a recurring issue for operators since the 2000s, it has become even more significant in the last 10 years with the growing predominance of video generating data traffic.
There are two main reasons for that:
- Video traffic is bandwidth-intensive and rapidly consumes network resources,
- Subscribers value the content of video, not its delivery; and they will often blame their service provider if their experience of video over cellular is poor.
Today, Communication Service Providers (CSPs) are facing a twofold challenge with regards to mobile video, directly related to OTT players and the traffic they generate:
- OTT mobile video traffic is dominant, out of CSPs’ control, sometimes undesirable in such proportions, bringing no positive monetary value to CSPs; and there is not much they can do about it except maintaining a scalable — and sometimes sophisticated — transport and interconnection infrastructure to the global CDN service providers in order to deliver this traffic with an acceptable QoE.
- OTT video streaming services (e.g., Netflix, DAZN, HBO, YouTube, myCanal) and video auto-playing on social networks like Facebook are in direct competition with operators’ own managed mobile TV services.
So CSPs are losing out both from infrastructure costs and service revenue standpoint. However, pay TV is still a key opportunity for them, and they should continue to explore new strategies (like commercial bundling), new business models (e.g., value-added video content aggregation on a growingly fragmented video content provider market) and new ways to save on video delivery costs.
Network Congestion: A Challenge to be Put in Perspective
While video-over-cellular traffic has never stopped growing, the magnitude of the problem it raises on operators’ networks is very variable.
In mature markets, the biggest issue is the large peaks of traffic, mainly caused by live sports events, unpredicted news, viral social network videos or eagerly awaited TV series episodes. Congestion hinders latency-sensitive video applications (they are not yet very widespread on-the-go though) and deteriorates throughput, impacting viewers’ Quality of Experience (QoE) at different levels (pixelization, stalling effects, rebuffering, start-up and live lag times).
Congestion mainly occurs on the radio cell side, sometimes on access backhaul and very rarely on aggregation and metro/core transport layers, unless mobile transport network has not been merged yet with the fixed one. On the backhaul side, most operators in mature markets have started to deploy vast campaigns of backhaul capacity upgrades, in anticipation of 5G.
The rest of the time, video-over-cellular traffic does not yet compete with the fixed traffic and is not a real problem for operators, at least from a transport network load point of view. Of course, the on-net operator-owned CDN infrastructure is also stressed in peak hours but this can be anticipated and mitigated with more capacity, usually deployed both for the mobile and fixed service.
In emerging markets, where fixed access, transport and backbone infrastructures are usually not established enough, the situation is different. Mobile networks are the main or only source of broadband connectivity, and the traffic they carry is comparable or even higher than the fixed ones.
In these countries and territories, the continuous increase of video consumption is becoming a challenge for the backhaul, at all levels.
The steady increase of video-over-cellular traffic is sometimes an issue for Mobile Virtual Network Operators (MVNOs) and CSPs leasing their transmission links, because they see their data bill exploding and their business model challenged.
Ubiquity of Service: The Forgotten Challenge
It is always a bit paradoxical to talk about 5G, to marvel at its ultra-high performance, while many countries, regions and locations (i.e., indoor) are not even yet properly covered with 4G or 3G. This is definitely an issue for the video-over-cellular services and their users.
Poor cellular coverage reduces cell capacity, leads to lower throughputs and instable connections, which most of the time translates to unacceptable video quality for mobile viewers (when they don’t experience loss of service or interruptions).
Many mobile subscribers worldwide still suffer from this lack of coverage, mainly due to a challenging business case for operators. Consumers would probably settle for lower bitrates in return for a more consistent service where they live, work and travel.
The great expectations
In light of the above, what is changing today in the mobile network industry that could help operators address these challenges? What are the most promising and eagerly awaited evolutions and innovations?
5G Leap Forward in Radio Capacity
In video-over-cellular, the limited radio cell capacity crystallizes most of the congestion challenges, as we said. Therefore, it is obvious that the huge radio capacity offered by 5G — up to 1000 times more, according to the amount of aggregated bandwidth — will de facto bring a big breath of fresh air to the average mobile user video experience.
However, as video applications and content will continue to be ever more sophisticated and bandwidth-intensive (i.e., 4K, stereoscopic video 360, holographic streaming) and improved video experience will boost usage, there is little doubt that we will again run out of capacity sooner or later in some regions and locations. It’s likely to start with the most densely populated areas.
Therefore operators will likely continue to optimize video delivery at radio cell and access backhaul levels.
As we said, many subscribers complain that they don’t have an acceptable throughput to enjoy video-over-cellular services wherever they live, work and travel; in some rural and hard-to-reach territories, many subscribers are even desperate to have one day a minimum service. At first sight they most likely will be disappointed with 5G, since its primary objective is definitely not coverage.
However, there might be some good surprises.
First of all because 5G should make more extensive use of lower frequencies, essential to the 5G uplink coverage: 700 MHz, 800 MHz and 900 MHz refarmed resp. from LTE and WCDMA/GSM, 1.5 GHz (not yet used for telecom services).
Secondly, because 5G will probably have a positive knock-on effect on 4.5G/4.9G (LTE-Advanced) deployments, similar to what happened with 3G enhancements when 4G was launched). This is due to the fact that operators will want to reduce the gap and ensure continuity of QoE when users move out of 5G coverage. 4G will become a very important underlying layer, and we expect 4G enhancements like MIMO4x4 to be more widely used (on top of multiple component carrier aggregation and higher modulations), with positive effects on both capacity and coverage in urban and suburban areas.
Also, small cells are expected to flourish at a larger scale in 5G, primarily for capacity, but also with deployments meant to improve the indoor and deep-indoor coverage.
Finally, in very low-densely populated areas, satellite communications will continue to play a key role, mainly in 5G backhaul, bringing affordable connectivity to 5G base stations located in low-density, remote and hard-to-reach areas, and contributing to the digital opening up of these regions. The satellite and telecom industries are conducting various common initiatives to achieve a stronger integration of their systems (e.g., via the Sat5G EU founded project, which Broadpeak is member of).
The Edge Layer
The risk with this huge capacity made available at the activation of 5G is that it will create a “pull factor” and stress those parts of the transport network where recent capacity upgrades have not yet been deployed, and put pressure on CDN capacity.
That is why it is important for operators to start distributing the core network and caching functions at the edge of the network, in order to offload the backhaul and distribute the streaming load over a number of cache servers.
Besides, the inconsistency and unpredictability of the radio medium will not vanish with 5G. A shorter physical distance between the mobile user and the base station — what the edge essentially brings — will always be beneficial to the QoE.
Given these benefits, the edge of the mobile network is expected to become a real strategic asset for the operators, and they are the only ones in hold of it.
The evolution of mobile network architectures is shifting toward radio and core functions at the edge (in reverse directions). Also, caching and additional computing capacity will be deployed at the edge, in order to meet the requirements of latency-sensitive and bandwidth-intensive applications promised with 5G.
Operators have a superb opportunity to harness this edge infrastructure by offering it to application and content providers that would otherwise never have been able to get so close to the mobile users, their end customers.
Multimedia Broadcast Multicast Service (MBMS)
When we speak about video and TV delivery, it is impossible to avoid the MBMS topic. This technology, initially introduced in Rel. 6 3GPP specifications, was mainly designed for such applications. But is MBMS — and its multiple evolutions — a “false good idea” or just a matter of time? And is 5G the genuine opportunity for MBMS to succeed?
It is hard to predict. First, it is troubling to see that the same arguments already predicting the success of MBMS in 4G (eMBMS, also called LTE-B) are now used in 5G, with the very relative success that we know.
In fact some tier-1 operators have deployed eMBMS and have found benefits, so Broadpeak continues monitoring the adoption of the technology by handset manufacturers and network providers.
Having said that, many challenges of eMBMS in 4G are going to remain in 5G:
- There are still a low number of supporting and enabled terminals (as an example, less than 1% of LTE devices are eMBMS capable),
- Engineering complexity (enablement on core, new broadcast radio channels),
- New network elements/functions are required, including broadcast/multicast service center (BM-SC), MBMS gateway, MBMS coordination entity (MCE).
Also, MBMS is not yet standardized for 5G in 3GPP, and it will not be before Rel.17. Despite the contribution proposals and expected technical improvements, a lot of architecture and protocol questions are open, which does not help provide reassurance on this technology.
Finally, and maybe decisively, the huge radio resources brought by 5G could nip MBMS in the bud, as the primary purpose of this technology is precisely to save radio resources.
Video Delivery System and Mobile Network Collaboration
So far, the possibilities offered by the standards and the incentives to connect the mobile network to the “applications world,” like the video content delivery system, for instance, have not been followed by action. The complexity of implementation has always prevailed over the needs and benefits, and the various initiatives have rarely gone further than the proof of concept phase.
As mobile video services and applications get more sophisticated, usage more important and traffic still concentrated in few areas with risk of congestion never very far away, the need for a closer interworking between the applicative level and mobile network functions, for more network-aware applications, is surfacing again.
This collaboration is expected to be especially relevant at the edge of the mobile network, in a multi-access edge computing (MEC) environment, for instance. Examples of useful collaboration for the video domain are:
- feedback loop on cell load and congestion for bitrate adaptation,
- user location-based ad insertion,
- video content-aware QoS traffic policy enforcement.
End-to-End Network Slicing
Despite the popularity and buzz around the concept, 5G end-to-end network slicing is still in a very early phase for most network operators. It is not yet fully standardized (radio part still missing); it requires significant changes in operators’ processes and organizations; it necessitates advanced automation to be cost-effective; it implies to invent and implement new business models.
However, it is expected to be very relevant for many applications, including video content delivery.
From a technical point of view, slicing will allow operators to meet and secure throughput, jitter and latency video delivery requirements, and improve QoE for mobile users.
From a business point of view, slicing will allow network operators to become video delivery-optimized slice providers to content providers and CDN service providers, opening up a very powerful way to monetize video. It should be the huge traffic that their networks carry, eventually.
Broadpeak is deeply involved in all these evolutions, providing and exploring a number of solutions designed to help mobile operators address the challenges and seize the opportunities of 4G and 5G.
Most of these solutions have been trialed with operators and/or experimented in the framework of European projects. Broadpeak has recently been an active member of 2 EU-founded projects, 5G-Xcast and SaT5G, aiming at developing 5G standards and testing new 5G architectures in the field of multicast/broadcast communications and satellite integration, mainly for the video and broadcast industry.
Broadpeak is proposing solutions to support various — non-exclusive — operators’ strategies.
Solutions to optimize operators’ video content delivery networks and improve QoE:
- cloud-native edge CDN components
- multicast ABR transmission (an area where Broadpeak was a pioneer)
- satellite contribution
- delivery path selection
- server-controlled functions
Solutions to improve video-over-cellular monetization and viewers’ personalization:
- mobile ad insertion
- premium customer and high-value content prioritization
- feedback loop from mobile network
- mobile device capability considerations
Solutions to support new business models between operators and content providers and provide to the latter an alternative to global CDN service providers, leveraging 5G architectures and technologies:
- either as cloud edge CDN infrastructure provider
- or as a video-optimized network slices provider
We believe the video-over-cellular status quo is likely to be challenged with 5G, and it’s time to turn the great expectations into reality with Broadpeak solutions and partnerships. Whether you are deploying 5G networks, planning to deliver your content over 5G or simply wondering what 5G means for your video business, contact us today to explore how Broadpeak can help you.