Wireless Display Standards Explained: AirPlay, Miracast, WiDi, Chromecast, and DLNA

Ref: http://www.howtogeek.com/177145/wireless-display-standards-explained-airplay-miracast-widi-chromecast-and-dlna/

HDMI allows you to connect almost any device to a TV or another external display, but HDMI requires a wired connection. You might assume there’d be a well-supported standard for wireless displays, but you’d be wrong.

When it comes to mirroring a device’s screen wirelessly or using it as a remote-control for media displayed on another screen, there is still a wide variety of competing standards fighting it out in the market.

AirPlay

AirPlay is Apple’s wireless display standard. It allows you to stream video from an iPhone, iPad, or Mac to an Apple TV. Using AirPlay, you can display the contents of your Mac’s desktop, start a video in an app on your iPhone and “push” it to your TV, or play a game on your iPad and mirror your display on your TV.

Apple’s AirPlay standard is flexible enough to work in two different ways. It can use display mirroring to mirror the contents of a device’s display, or use a streaming mode that’s smarter. For example, you could play a video in an app on an iPhone and use the playback controls on your iPhone to control the video on your TV. Even while fiddling with the playback controls on your iPhone’s screen, they wouldn’t appear on your TV — AirPlay is smart enough to stream only the content you want to see on the display.

AirPlay works very well, but it has a big limitation — it only works with Apple devices. If you have a Mac, iPhone, iPad, and Apple TV, you’ll be happy with it. If you want to stream from a Windows laptop or to a device that isn’t an Apple TV, you’re out of luck.

Miracast

Miracast is an industry-wide standard that’s essentially a response to Apple’s AirPlay. Miracast support is build into Android 4.2+ and Windows 8.1, allowing Android smartphones, Windows tablets and laptops, and other devices to wirelessly stream to Miracast-compliant receivers.

In theory, Miracast is great. In practice, Miracast hasn’t worked out so well. While Miracast is theoretically a standard, there are only a handful of Miracast receivers out there that actually work well in practice. While devices are supposed to interface with other devices that support the standard, many Miracast-certified devices just don’t work (or don’t work well) with Miracast-certified receivers. The standard seems to have collapsed in practice — it’s not really a standard. Check out this table of test results to see just how much of an incompatible mess Miracast seems to be.

Another problem is that the standard doesn’t mandate devices be branded with the “Miracast” brand. Manufacturers have taken to calling their Miracast implementations other things. For example, LG calls their Miracast support “SmartShare,” Samsung calls it “AllShare Cast,” Sony calls it “screen mirroring, ” and Panasonic calls it “display mirroring.” You might pick up a new Samsung TV, see the “AllShare Cast” logo on the box, and not be aware that this is theoretically a Miracast-compatible TV. You’d probably assume that it only worked with other Samsung devices supporting AllShare Cast — and you might not be wrong, considering how many theoretically compatible Miracast devices are incompatible with each other!

You might assume that, since Microsoft added built-in Miracast support to Windows 8.1, their Xbox One console would function as a Miracast receiver. This would make streaming from a Windows 8.1 tablet to your TV via your Xbox One possible and easy. You’d be wrong — the Xbox One can’t function as a Miracast receiver.

In other words, Miracast isn’t doing too well. Even if it were, there’s another problem: Miracast only offers display mirroring. You wouldn’t be able to stream a video from your phone on your TV without the playback controls appearing on your TV while you used them, for example.

WiDi

WiDi is short for Intel Wireless Display, a feature associated with Intel’s Wi-Fi Direct standard. This is Intel’s attempt at offering a wireless video and audio streaming system that could compete with Apple’s AirPlay. WiDi never saw much uptake.

Intel Wireless Display 3.5 makes WiDi Miracast-compatible, essentially turning WiDi into another branded Miracast-compatible standard. Intel has basically folded WiDi into Miracast.

Chromecast

When Google launched the Nexus 4 with Android 4.2 in 2012, they talked up its support of Miracast. Soon, they said, you’d be able to buy cheap Miracast-compatible receivers that you could plug into your TV’s HDMI port. The wireless display problem would be solved, enabling easy display-mirroring from Android and Windows devices.

These cheap, compatible receivers failed to materialize. Instead, a year later, Google launchedthe Chromecast. A Chromecast is a cheap receiver that plugs into your TV’s HDMI port, but it uses something called the DIAL (DIscover And Launch) protocol. To use the Chromecast, you open an app on your Android phone — Netflix, for example. You tell Netflix to play a video to your Chromecast. The Chromecast then connects to the Internet and plays the video, allowing you to control its playback via the app on your smartphone.

In this way, your smartphone allows you to discover videos, launch them on the Chromecast, and control their playback. The Chromecast doesn’t simply display the contents of your device’s screen. However, Chromecast also offers a feature that lets you stream your entire desktop or the contents of a Chrome tab to your TV via the Chromecast — just like AirPlay.

Like Microsoft’s Xbox One, Google’s Chromecast doesn’t support Miracast at all. The Chromecast is clearly an example of Google throwing their hands up in the air and giving up on Miracast, at least in the short term. Considering all the problems with Miracast and how well Chromecast works, Google appears to have made the right decision.

Play To, DLNA, UPnP

DLNA stands for “Digital Living Network Alliance.” DLNA uses Universal Plug and Play (UPnP) — but not the type of UPnP that allows you to automatically forward ports on your router.

Confused yet? Try not to be — this standard is a mess of different terms, but DLNA-enabled devices appear as “Play To” targets. That’s generally how you’ll see them.

DLNA isn’t really a wireless display solution. Instead, it’s simply a way to take content on one device and play it on another. For example, you might open Windows Media Player on your PC and use the Play To feature to play a video file from your computer’s hard drive to an audio/video receiver connected to your TV, such as a game console. Compatible devices automatically advertise themselves on the network so they’d appear in the Play To menu without any further configuration needed. The device would then connect to your computer over the network and stream the media you selected.

You can still use DLNA to stream media from a Windows 8.1 PC to an Xbox One. However, the standard was clearly designed years ago — it assumes you have local media. Play To only allows you to play local media files like pictures, videos, and music on your hard drive. There’s no way to play videos from Netflix or YouTube, stream music from an online service, display a presentation and control it on your screen, or just display the contents of your desktop.

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AirPlay arrived in 2010 and other companies are still struggling to match it. If you’re one of the many people who would like to see an open standard that allows non-Apple devices to wirelessly share their displays, the Miracast mess has been tough to watch.

LTE-Advance is the real 4G

Ref: http://spectrum.ieee.org/telecom/standards/lte-advanced-is-the-real-4g

TelecomStandardsFeature
LTE-Advanced Is the Real 4G
More network capacity, faster data speeds, and better coverage will come from LTE-Advanced mobile technologies

By Ariel Bleicher
Posted 31 Dec 2013 | 18:00 GMT

Illustration: Eddie Guy
This article is part of the “2014 Top Tech to Watch” series, IEEE Spectrum’s annual prediction of technologies that will make headlines in the coming year.

Have you ever called your cellphone carrier to report poor signal strength? Sure you have. And did that carrier do anything significant to fix the problem? Of course it didn’t—unless you live in South Korea.

“I guarantee you—if I call my carrier tonight and complain about not getting a good signal in my bathroom, they will send someone to install a repeater first thing tomorrow morning,” said Wonil Roh during an interview in Suwon last October.

Full disclosure: Roh heads the Advanced Communications Laboratory at Samsung Electronics Co. But he doesn’t need the lofty title to get that kind of attention in South Korea’s intensely competitive wireless arena. Home to Samsung and LG Corp., the world’s first- and fourth-largest smartphone makers, the country boasts some of the most advanced wireless networks on earth. Last June, for instance, SK Telecom Co. launched what it called the “world’s first publicly available LTE-Advanced network.” Short for Long Term Evolution, LTE is the globally embraced standard behind today’s top-of-the-line 4G smartphones and tablets. For the same price as an LTE plan, LTE-Advanced subscribers could now get twice the data rates, SK claimed. Not to be outdone, its competitors LG Uplus Corp. and KT Corp. began offering their own LTE-Advanced services in July. By October, a million people had signed up for SK’s service alone.

What’s happening in South Korea will soon come to pass in other parts of the world. Operators everywhere face a universal and unremitting predicament: Customers want more data at faster speeds to run ever more sophisticated applications. Today it’s video calls and sports broadcasts; tomorrow it’ll be telemedicine and virtual shopping sprees. Each year, according to Cisco Systems, global mobile traffic more than doubles. And that exponential growth is showing no signs of waning.

Fun Fact: In South Korea, LTE-Advanced subscribers can download an 800-megabit movie in as little as 43 seconds.
So now, four years after the first networks using LTE went live, operators are looking to its successor. Already, more than a dozen carriers outside of South Korea, including AT&T, Australia’s Telstra, Japan’s NTT DoCoMo, and Telenor Sweden have reported that they are testing LTE-Advanced technologies, and analysts expect commercial rollouts to start this year. By 2018, according to ABI Research, global LTE-Advanced connections will approach 500 million—about five times as many as LTE can claim today.

“There’s no way around it—LTE has to evolve,” says Lingjia Liu, a wireless expert at the University of Kansas. “LTE-Advanced will become the dominant standard.”

Wireless specialists are calling LTE-Advanced “true 4G” because unlike ordinary 4G LTE, it actually meets the International Telecommunication Union’s specifications for fourth-generation wireless systems.

One of these criteria is speed. LTE-Advanced can theoretically achieve data download rates as high as 3 gigabits per second and upload rates as high as 1.5 Gb/s. By comparison, LTE tops out around 300 Mb/s for downloads and 75 Mb/s for uploads. And LTE-Advanced isn’t just about faster rates. It also includes new transmission protocols and multiple-antenna schemes that enable smoother handoffs between cells, increase throughput at cell edges, and stuff more bits per second into each hertz of spectrum. The result will be higher network capacity, more consistent connections, and cheaper data.