Understanding Miracast as a wireless display technology

Copperpod IP
6 min readJan 14, 2021

Miracast is a standard for wireless connections that defines a protocol to connect external monitors via Wi-Fi to your device. It can be described as “HDMI over Wi-Fi”, replacing the cable from the device to the display. Miracast devices make use of a Wi-Fi connection to deliver audio and video content from one device to another. These devices connect directly, so you can do things like watch videos from a smartphone on a big screen television or share a laptop screen with the conference room projector to collaborate in real-time.

Miracast technology was first introduced in 2012 by the Wi-Fi Alliance. Wi-Fi Alliance is a non-profit organization that promotes Wi-Fi technology and certifies Wi-Fi products.

Miracast employs the peer-to-peer Wi-Fi Direct standard. This technology is based on IEEE WLAN standards i.e. 802.11. IEEE 802.11 is part of the IEEE 802 set of LAN protocols, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) Wi-Fi computer communication in various frequencies. Miracast devices do not require any home network to exist for making paired connection. This is as simple as Bluetooth or Wi-Fi as far as connection establishment is concerned. Miracast support H.264 and hence 1080p video and 5.1 surround audio.

Following are the features of Miracast technology:

  • Standards: Wi-Fi P2P, Wi-Fi Direct
  • Application: Screen Mirroring
  • Frequency allocation: 2.4GHz, 5 GHz
  • Encryption: WPA2
  • Network type: P2P
  • Power: same as WLAN standards (11a/11b/11g/11n/11ac/11ax)
  • Range: same as WLAN standards
  • Data Rate: same as WLAN standards

What do you need to use Miracast?

The foremost requirement is that both the devices must support Miracast. For the device whose screen you want to mirror, support for Miracast requires three things: wireless chipset support, operating system support, and driver support. Even if your device doesn’t meet all the three requirements you can buy a Miracast adapter and upgrade your operating system. Miracast source adapters are often bundled with Miracast receivers like Actiontec’s ScreenBeam kit.

On the software side, Miracast is supported in Windows 8.1 and Windows 10. Older Windows versions can be made to support Miracast through third-party apps. Linux distros have access to wireless display support through Intel’s open-source Wireless Display Software for Linux OS.

Android supported Miracast in Android 4.2 (KitKat) and Android 5 (Lollipop). However, Google dropped native Miracast support in Android 6 (Marshmallow) and later. If you want to mirror the display from a newer Android phone or tablet, you’ll need to do so via Chromecast.

Neither Apple’s OS X nor iOS support Miracast. Instead, Apple has opted for its own AirPlay technology, which requires an Apple TV to mirror the display wirelessly on a television screen.

Among Windows hardware, laptops and tablets starting with Intel’s fourth- and fifth-generation Core processors and Intel’s own 7260 wireless chip supported Miracast, but the Intel technology underlying that support, WiDi, has been discontinued in favour of the Windows 8.1/10 support mentioned above.

Does this technology have an alternative? The similar technology is developed by some major companies like Apple, Google and Intel. Unlike protocols like Apple’s AirPlay and Google’s Chromecast, Miracast is designed to be a cross-platform standard. Miracast functions exclusively as a “screen mirroring” protocol. So, if you wanted to start a Netflix video on your phone and play it via Miracast, you’d have to leave your phone’s screen on the whole time. Everything on your phone’s screen would be mirrored on the TV.

Let’s now discuss the Miracast alternatives (AirPlay, WiDi, and Chromecast) to understand the differences between all these different protocols.

Apple AirPlay AirPlay is Apple’s wireless display standard. It allows you to stream video from an iPhone, iPad, or Mac to an Apple TV. Airplay 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. Even though AirPlay is smart, but it comes with a big limitation — it only works with Apple devices.

Intel 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. But 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.

Google Chromecast Chromecast is Google’s 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.

Even though Miracast has an advantage to connect devices even if they are from different manufacturers it does come with some problems too.

Problem 1: It’s Only Screen Mirroring As Miracast is all about screen mirroring and doesn’t have the “smarts” you see in protocols like AirPlay and Chromecast, which can hand-off streaming to another device and display a different interface on one device’s screen. Miracast can best be thought of like a wireless HDMI cable. For instance, you could open the Netflix app on your phone, locate a movie you want to watch. With Miracast, your phone’s screen would have to stay powered-on and streaming the video for the entire length of the Netflix movie, draining its battery. Unlike AirPlay and Chromecast, it lacks smart protocols which could help in better viewing experience. For instance, you could watch a Netflix video and view the playback controls only on your phone, so they wouldn’t get in the way on the TV or you could play a video game and view only the game world on the screen, with a separate set of controls on your phone.

Problem 2: It’s Unreliable and Often Doesn’t Work This is the biggest problem with Miracast. It’s an open standard and Miracast-certified devices are supposed to communicate just fine with other Miracast-certified devices. However, they often don’t. There have been constant reports of problems from many users around the globe. Therefore, in terms reliability it doesn’t score good.

Who are the Big Players of the Miracast? Almost every Android phone and Windows 10 PC has Miracast technology built-in, as do major streaming devices, like the Roku players and the Amazon Fire TV.

Some prominent players in the Miracast Technology are listed below: • Google, Inc. • Amazon.com, Inc. • Microsoft Corporation • Roku, Inc. • Sony • LG • Samsung • Nvidia • Rockchip • Lattice Semiconductor • NETGEAR, Inc. • Cavium, Inc. • Toshiba • Panasonic • Actiontec Electronics, Inc. • Belkin International, Inc.

The global wireless display market size was valued at USD 3.0 billion in 2018. It is expected to reach USD 6.3 billion by 2025. It is anticipated to expand at a CAGR of 11.2% from 2019 to 2025. Several organizations across the globe are using various wireless streaming devices to effectively communicate and collaborate with their stakeholders, including employees, customers, and investors.

Increasing adoption of wireless display technologies in residential applications for streaming online content or mirroring content from external sources is projected to continue to stoke the growth of the market.

This story was first published here.



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