According to Cisco's annual report, mobile video is exploding. In fact, according to the company, by 2019 over 80% of mobile data traffic will be video.
If you've been watching video over a cellular network, you know that the experience is less than ideal -- shifting network speeds, changing bitrates, and lots of buffering. Most of this is caused by increased network congestion as a result of more people watching video on their phones. It's a vicious circle that ultimately undermines the user experience and probably has some impact on customer churn.
But it's not all the operator's fault. Let's face it, the public Internet is becoming more congested as backhauling video competes against big video game downloads, operating system upgrades, and, you guessed it, online video consumption.
Thankfully, though, the mobile operators aren't sitting idly by. They are using a host of approaches (mostly within the network) to support the growth of video by mitigating both internal network congestion and public Internet problems. These solutions can include implementing content delivery networks (CDNs) and transparent caching; leveraging handset storage; implementing newer delivery protocols like LTE-B; architecting heterogeneous networks (HetNet); and optimizing network traffic management.
Let's take a look at each of these in a little more detail.
Content delivery networks: A CDN provides storage resources (caches) close to the end user. When requests are made for web-based resources, like a video, they are handled by the CDN rather than going back to the origin server. If the content is popular, it's more likely to be pulled from the cache. This means the delivery time for retrieving that resource is significantly reduced. Some operators are building out their own CDNs while others employ commercial providers such as Limelight Networks Inc. (Nasdaq: LLNW), Level 3 Communications Inc. (NYSE: LVLT) and Akamai Technologies Inc. (Nasdaq: AKAM).
Transparent caching: The problem with using commercial CDNs is that they usually terminate traffic on the operator's network. They don't exist within the operator's topology. That's where transparent caching comes in. This technology enables operators to automatically cache popular content in localized storage and deliver it from much closer to the end user than even a commercial CDN. Once again, this can cut down significantly on delivery time to end users since the request for video doesn't have to return all the way to the origin server.
Handset storage: Modern smartphones and other mobile devices can have significant storage already built in. Mobile operators are eyeing that storage as a way to deliver video assets that can be played back later. Imagine the most valued content (matching a user's consumption behavior) downloading to their device overnight so that it's available to watch in the highest quality whenever they want. Akamai, a commercial CDN, offers a SDK that enables app developers to embed this functionality into their software.
LTE-B: The problem with network congestion really stems from one fundamental issue: the delivery protocol. Right now, online video is delivered over unicast on operator networks. This means that each user is provided their own stream. So if you have ten users watching a 1Mbit/s stream, that's 10 Mbit/s of traffic on the network. The solution might be LTE-B (or LTE Broadcast), which employs a multicast protocol to deliver one stream to all users simultaneously. This is very similar to the way that broadcast television works. When you tune into a TV channel, the program doesn't start from the beginning. You join the programming in progress. That's how LTE-B works. It would significantly reduce the amount of congestion on operator networks for live, linear programming, like sports or television shows.
Heterogeneous networks (HetNets): A HetNet is a combination of macro, pico and other wireless cells all working together to provide more comprehensive coverage (especially indoors). Besides congestion, one of the main issues with streaming video over mobile networks is signal strength. So how are operators employing HetNets? First, they are improving the efficiency and capacity of their existing "macro" cell networks. By enhancing macro cells with more spectrum, advanced antennae, increased order of diversity on the receiver and/or the transmitter, and baseband processing capacity within and between nodes, the efficiency and effectiveness of the macro cell can be significantly increased. Secondly, operators are increasing the density of their macro cells, providing the ability to handle more simultaneous requests at higher bandwidth, which is especially relevant for serving video at a high bitrate. Finally, they are deploying smaller cells in harder-to-reach areas, particularly inside buildings. By complementing the macro network with small cells such as pico cells, low-power remote radio units (RRUs), or even WiFi, the operator can deliver high per-user capacity.
Traffic optimization: The final area that operators are working on to improve the mobile video experience is better management of their network traffic. It's no longer okay just to see one aspect of traffic flow. Operators are looking for solutions that enable them to see both server-side and client-side so that they understand what's happening at each end point. But video can't be treated just like normal traffic. Because of adaptive bitrate delivery, video chunks can exceed planned capacity if, for example, more users are being delivered a higher bitrate and capacity calculations are based on average traffic flows. This requires that network operators manage and shape video traffic specifically. Although the result may not mitigate congestion, optimizing video traffic across the network can prevent other poor experiences, such as multiple buffering events.
It's clear that mobile video consumption is only going to grow. But it's also clear that operators are expanding, tuning and improving their network using a variety of techniques, strategies and technologies to perform better and consequently provide the best possible end-user video experience. (See EE Mobile Video Chief Dissects Big Video).
So the next time the bitrate drops or a buffering event occurs when you are watching video on your smartphone, don't freak out. There's a good chance your mobile operator is aware of the problem and working hard to fix it.
— Jason Thibeault, Executive Director, Streaming Video Alliance