Multiple studies have found that the majority of Internet video views are now on mobile devices. In fact, the percentage of video viewed on mobile devices is directly related to smartphone penetration, with both growing beyond 50% at the end of 2016. And the GSMA predicts there will be a further 1 billion active smartphones added between 2015 and 2020.

Media agency Zenith Optimedia estimates that mobile devices are the only device platform increasing its share of time spent consuming media, while every other "device" type, including TVs, movie theaters, newspaper and desktops, is showing a decline.

While WiFi offload is common for video consumption, particularly in developed countries, mobile data usage is also growing rapidly. According to the ITU, there were more than 7 billion active mobile-cellular subscriptions worldwide at the end of 2015, and almost half of those had active mobile data subscriptions as well. By 2020, the GSMA expects 60% of the world's population will have mobile broadband; with smartphones the only access point for many in emerging markets.

These facts imply an explosion of video traffic on mobile networks in any case, resulting in predictions that 80% of mobile network traffic will be video. But there is a further challenge developing for mobile operators: Social media sites are increasingly shifting communication from text to video. Facebook CEO Mark Zuckerberg said last year that "most of Facebook would be video before 2020," following up that comment in a letter to shareholder last July, which said "video is at the heart of all our services."

Facebook Live was launched in April 2016, allowing Facebook users to essentially broadcast live videos using the platform. By this time rival Snapchat was already delivering 10 billion video views daily on its platform. Live streaming gained even more attention during a stand-off in the US Congress when Democrats staged a sit-in to protest gun legislation. When the house cameras were switched off, the protesters live-streamed the proceedings using Facebook Live and Twitter's Periscope.

These applications are directly targeted at smartphones. In some cases users may stream from their homes or offices (using WiFi networks), but increasingly mobile operators have to expect that these streams will be generated out-of-home. In particular, live streaming from a sports event, a political rally or inauguration, or music concerts and theatrical events could create sudden spikes in network traffic which would be difficult to cater to.

Both fixed-line and mobile operators have had to cope with videos that go "viral" on social media, but the duration of the spike could be considerably longer in the case of live streams. The impasse -- and consequent streaming -- from the US congress sit-in lasted more than 24 hours. So live streaming threatens to combine the volume and unpredictability of user-generated videos, with unprecedented session duration.

And it's not just downstream capacity operators need to be concerned about. The events described above will result in large numbers of users trying to live stream their point-of-view, which will hit upstream capacity. Most networks are better engineered to handle spikes in downstream capacity, but how many can handle huge, unpredictable bursts of traffic going the other way?

In fact, according to Huawei's Mobile Live Video Report, mobile video live streaming will create a "multiplier effect" on data traffic: 1GB of total upstream traffic will drive an average of 120GB total downstream traffic.

Today, most videos are being live streamed at low bandwidth, but with 4K cameras being offered in smartphones already, quality (and required bandwidth) is likely to ramp up rapidly. And that's without looking at virtual reality/360-degree video, with its unprecedented bandwidth requirements.

Operators will need to find ways to manage network capacity while ensuring an adequate quality of experience for mobile users. If social live streaming becomes as popular as the Zuckerbergs of the world anticipate, it could become the greatest challenge confronting mobile operators in coming years.

This blog is sponsored by Huawei.

— Aditya Kishore, Practice Leader, Video Transformation, Heavy Reading