ITEM: For cellcos, delivering the best mobile video experience for consumers doesn’t necessarily require offering the fastest data speeds. In fact, according to a new report from OpenSignal, faster isn’t always better when it comes to video quality.
OpenSignal’s latest State of Mobile Video Report [PDF] measures the video experience on over 8 million devices in 69 markets using metrics such as picture quality, video loading time and stall rate, with scores assigned from 0 (poor) to 100 (excellent). OpenSignal also measured average bandwidth speeds for each market.
One interesting finding is that while South Korea boasts the fastest average mobile broadband speeds by far (well over 45 Mbps), it ranks 16th on the video experience scale. Granted, its score is still in the “good” bracket (between 55 and 65). Even so, the report says, having the fastest pipes clearly doesn’t guarantee a great mobile video experience.
According to the report, the best video experience can be found in the Czech Republic, one of 11 markets to score in the “very good” range (65-75), even though it ranks 11th on the speed chart with data speeds falling shy of 30 Mbps.
A more extreme example is Kuwait, whose video experience score was just below South Korea’s despite sporting far lower average download speeds at 14.7 Mbps.
That’s not to say that speed doesn’t matter – OpenSignal points out that when you map out the results on a full spectrum chart (see below), there is a general correlation between average speeds and video quality. Simply put, the faster speeds get, the more video scores generally improve.
But as the South Korea/Czech Republic example shows, it’s not an exact overlay. In fact, once data speeds rise past the 20-Mbps threshold, the link between data speed and video experience weakens considerably.
It’s not just the speed
According to OpenSignal, the explanation lies in the fact that raw speed isn’t the only factor in video quality – two other factors in play here are latency and the consistency of connection speed:
A super-fast connection isn’t necessary to stream video over mobile networks, but a video needs relatively consistent throughput to avoid stalling. Thus a network that delivers a 50-Mbps connection one second and a 2 Mbps connection the following second is likely to provide an inferior overall video experience than a network that can maintain a constant 20 Mbps connection over a long duration of time.
Connection consistency is especially key because, as the report also points out, it’s a very hard metric to deliver on cellular networks. It’s the nature of the beast – users move from cell to cell, which means capacity requirements and data demand shift all the time. Most cellular networks are also multi-layered, which means users move up and down between 4G, 3G and even EDGE in markets where 2G still exists, and between the different bands supporting each service. Obviously it’s not impossible to deliver a consistent data connection under such conditions – but it’s hard to do it at very high data speeds.
Another factor impacting the video experience, says OpenSignal, is operator policy:
Many operators globally use video optimization technologies to restrict the level of video resolution their customers can access on their phones. As our tests sample video at different resolutions, any downgrading of video quality — say from HD to SD — would have an impact on our scores.
OpenSignal cites the US is a prime example of this – average speeds are 16.5 Mbps, but its video score was only in the “fair” range at 46.8, while markets with similar data speeds scored much higher. One reason: US cellcos currently compete on unlimited data plans, which can overload the network if users watch too much video at once. US cellcos mitigate that with streaming restrictions on different plan tiers, which is why many users can only stream video at 480p resolution.
Ironically, the report says, lifting those restrictions could make the US mobile video experience even worse, as higher resolutions would create traffic congestion that would impact both latency and connection consistency.
In any case, with video now dominating mobile data traffic and primed for even more growth in the near future, OpenSignal recommends that operators who want to deliver a great video experience focus less on raw speed and more on metrics like latency, consistency and policies.
That said, with no market having yet achieved a score in the “excellent” bracket, OpenSignal also allowed for the possibility that 4G – even in its LTE-A Pro incarnation – can only deliver so much video quality. Which is to say, mobile video may never realize its true potential until 5G arrives.
That may be – on the other hand, while 5G is designed to handle the latency issue, operators who deploy 5G will also face the same speed consistency challenge, as 5G will essentially be another overlay on top of 4G, 3G and (where applicable) 2G, and the most optimistic forecasts right now expect 4G subscribers to remain the largest group of mobile users globally until at least 2025. That’s something that cellcos may like to keep in mind as they make plans for 5G with visions of 8K virtual reality video holograms dancing in their heads.