First 4G Apps Are Visual, Real-Time

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The Year of 4G
Now that wireless carriers are rolling out faster, next-generation wireless networks, we will gradually start seeing connection speeds that are far faster and steadier than those of older 3G networks. The carriers say that 4G LTE and WiMax networks produce data throughput that is ten times faster than 3G.

Although that 10X speed increase is not yet a reality in most of the United States, by the middle of 2012 the higher speeds will have reached enough markets and enough consumers to establish a new baseline for U.S. wireless broadband speed. Users will no longer expect Web pages to load slowly on their smartphones, and consumers will demand that video play smoothly and at high quality.

With network performance kicked up a few notches, we'll naturally want to do some new things with our devices. The wireless carriers, meanwhile, will want very much to get as many customers connected to their new 4G networks, and to lure us in they’ll tempt us with amazing apps that fully utilize the speeds of 4G. Consumers might begin to see these fast new apps as must-haves--just as mapping apps have become essential in the 3G world.

The first-wave 4G apps that the carriers are demonstrating are not entirely new things--they're simply apps that we traditionally use at home, but they're now making their debut on mobile devices. During press conferences and private demos, as well as in Web and TV ads, the wireless carriers are emphasizing three categories of apps in particular: HD video streaming, videoconferencing, and online gaming. Here's a look at each category.

HD Video Streaming

Watching video on a smartphone with 3G service often means tolerating pixelation, jerky movement, and even screen freezes. The video lacks the look and feel of what we recognize as high definition on our TVs at home. That's because 3G service cannot establish a large enough data pipe to the end device to deliver a high number of video data packets fast enough (not to mention with minimum packet loss) to create genuine high definition on the small screen.

HTC EVO 4G smartphone
Another crucial issue is packet latency, or the time in milliseconds that a packet of video data (in this case) takes to move from a server up in the network down to the end device. With 3G service, the latency time can be around 150 milliseconds, which is too much drag time for high-definition streaming video. Mobile HD video requires a fast and steady stream of packets moving to the end device in order to remain “HD.”

In 4G networks, the latency time is much less; for instance, Verizon’s new 4G LTE service is showing latency numbers of around 40 milliseconds. That near-instantaneous send-and-receive connection between the end device and the server--combined with much higher raw data speeds--creates a video image that looks rich in color, has obvious dimension, and handles movement in a smooth and fluid way. In short, it looks like what we know as HD video.


You might notice that many (if not the majority) of the new 4G handsets being announced these days have front-facing cameras in addition to the camera on the back. We’re even beginning to see a move from 1-megapixel front-facing cameras to 2-megapixel cameras, which increase the quality of the video of the caller being sent upstream through the network.

Videoconferencing is a bit different from HD video streaming in that it is a real-time, bidirectional application. Like HD video streaming, videoconferencing requires a certain threshold of download speed--preferably around 1 megabit per second--to pull down the moving image of the person on the other end from a server on the network. The real challenge, however, is the upload speed. Because today’s networks are configured to serve up far faster download speeds than upload speeds, and because videoconferencing requires adequate downlink and uplink speeds, poky upload speeds are often the bottleneck in substandard videoconferencing sessions.

iPhone videoconferencing
Thankfully, 4G networks not only offer higher download speeds but also higher upload speeds. Sprint’s and Verizon’s respective 4G networks, for example, can consistently deliver upload speeds of more than 1 mbps--enough to accommodate the uplink requirement of mobile videoconferencing.

Low latency is even more important to videoconferencing than it is to HD video streaming. In-person communications involve very little gap between one person’s talking and the other person’s responding; we rely on quick verbal and visual clues to know when to speak and when to listen. When the conversation is taking place over a network, even the slightest delay in communicating those cues can cause the callers to begin talking over each other.

But again, the 4G networks of today reduce the latency of 3G networks by about two-thirds. Even at 4G speeds, mobile videoconferencing may not be perfect, but it’s likely to be good enough for effective communication--and it will probably only get better as network speeds increase and handset cameras improve.

Mobile Gaming

Gamers have long imagined a day when they can play high-definition games with their friends using their mobile devices. That time has come. The advent of 4G will likely spur the first generation of real-time mobile games that operate on cellular networks.

The limitations of 3G networks have confined gaming to an asynchronous model. In a Scrabble game, for instance, one player takes a turn placing a word on the board, and then the other player receives a notification when the network is ready for the next move. Such games don’t require fast network connections or low latency rates.

But because 4G networks can deliver more data packets (upstream and downstream) at a more predictable rate and with less latency, a whole new class of games is becoming possible on mobile devices. The games we’re used to playing on a home PC with a wired broadband connection will become possible on devices connected on a cellular network.

Mobile gaming

The 4G networks will be able to accommodate synchronous gaming--games in which players make quick moves in reaction to the moves of other players, or to the moves of a virtual opponent that the game creates at the server. In a shooter game, for example, Player A might be dodging the shots that Player B fired in real time, while reacting to his opponent's evasive moves to decide where to fire his own shots. For that kind of quick interplay to work, players must be able to see and hear these events almost immediately when they happen.

Another (more peaceful) example is Rock Band, which Verizon featured in a 4G demonstration at the Consumer Electronics Show in Las Vegas. In the game, a group of mobile players must play in unison with the music the game generates, following visual cues on the screen. Meanwhile, they must play in unison with other (mobile) band members in real time.

Such synchronous games rely on very fast download speeds to convey a high-definition gaming environment to the mobile device, as well as to communicate the movement of the game to all players quickly. Very low latency is necessary to communicate the moves of the players almost instantaneously to the server and to one another. Such games also depend greatly on the reliability of the network connection; the network can compensate for a certain number of lost packets, but if too many are lost, the fluidity of the game breaks down. And finally, the network must allow for very little jitter, meaning that the rate at which the packets flow back and forth between the players and the server should remain relatively constant and not slow down or speed up drastically.

That’s a lot to ask of a radio network with no wires.

Today 4G networks are far from ubiquitous in the United States, and the network technology the mobile carriers are currently building out represents only the earliest stages of 4G's evolution. It will be the mass appeal of mobile apps such as HD video streaming, videoconferencing, and gaming that will accelerate the arrival and improvement of 4G service. Don’t be too surprised if these apps have become mainstream by the end of 2013.

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