How is Miracast related to Wi-Fi Direct?

How is Miracast related to Wi-Fi Direct?

Wi-Fi Direct allows devices to connect directly to each other, without the need for a Wi-Fi access point (AP). It simply requires the push of a button or the entry of a PIN. Wi-Fi Direct allows source and display devices to discover one another and provides the underlying device-to-device connectivity for Miracast. Miracast builds upon Wi-Fi Direct with mechanisms to negotiate video capabilities, setup content protection (if needed), stream content, and maintain the video session.

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Frequently Asked Questions

What has changed in Miracast since its original release?

New enhancements focus on high-definition (HD) content, increased performance, and better battery life for Miracast devices.

Is a Wi-Fi connection needed to stream a video from the internet?

Miracast is unique to other wireless display solutions in that a direct peer-to-peer connection between two devices may be formed to share content residing on the source device, without the need for a Wi-Fi network. If streaming content from the internet, a network connection is required.

Does Miracast support devices like wireless speakers? (audio only)

Audio-only devices are not part of the Miracast certification program.

How does Miracast protect premium content?

Miracast provides industry-standard protection of premium content through support of High-bandwidth Digital Content Protection (HDCP). HDCP is a wireless adaptation of the same trusted content protection mechanisms widely used for cabled interfaces, providing diversity in premium content options. This feature is designed to protect the digital rights of content owners and to encourage their efforts to make their content available.

What formats does Miracast support?

Miracast supports many commonly used audio/video format.  For a complete list, download the Miracast Technical Overview.

What features does Miracast certification test?

Miracast certification includes testing for audio/video (A/V) latency, quality, and synchronization offset. Testing ensures that devices operate across vendors, provide simplified discovery and setup, meet the minimum display resolution requirement, and implement content protection (when implemented). Miracast devices are also tested for implementation of WPA2™ security. Wi-Fi Alliance members may view details on certification testing in the Wi-Fi CERTIFIED Miracast Test Plan.

Must both the content source and display be Miracast devices?

Both the display and the source devices must be Miracast certified. Miracast may be used on devices without embedded Wi-Fi capability by using a Miracast-certified adapter that supports an interface such as High-Definition Multimedia Interface (HDMI) or Universal Serial Bus (USB).

What types of equipment are tested?

Miracast certification is available for video-capable devices such as TVs, handsets, tablets, laptops, set-top boxes, cameras, and projectors.

What is the difference between Miracast and Wi-Fi Display?

Miracast is the brand for the certification program operated by Wi-Fi Alliance. Devices that pass this certification testing can be referred to as “Wi-Fi CERTIFIED Miracast™ devices” or “Miracast® devices”. Miracast certification is based on the Wi-Fi Alliance Miracast Specification. This is the underlying specification developed by Wi-Fi Alliance members, and is copyrighted and owned by Wi-Fi Alliance. Wi-Fi Display is the original name for the Miracast technology.

How does Wi-Fi Alliance help ensure product compatibility and a good user experience for certified products?

Compatibility and quality are achieved through testing of Wi-Fi products. Consumers should always look for the Wi-Fi CERTIFIED logo to ensure the best user experience possible.

Can a network based on devices certified under the Wi-Fi Direct program cross connect to an infrastructure network for internet connectivity?

Yes. A single device in a Wi-Fi Direct-certified group network may share internet connectivity with other devices in the network by creating simultaneous infrastructure and Wi-Fi Direct connections. A network of devices certified under the Wi-Fi Direct program operates in a security domain separate from the infrastructure network, even when cross-connected.

Are Wi-Fi CERTIFIED products protected by security?

As of July 1, 2020, all new Wi-Fi CERTIFIED devices require WPA3. The only way to be sure that a product meets the latest security standards is to purchase only Wi-Fi CERTIFIED products.

Can all devices start a network based on the specification underlying the Wi-Fi Direct program?

All Wi-Fi Direct devices can start a group, based on the specification underlying the Wi-Fi Direct program, but it’s most likely that devices with more computing power (laptops, handsets, gaming devices) will more frequently manage the network than those with less power (digital cameras, printers, etc.).

How fast is Wi-Fi Direct?

Wi-Fi Direct supports Wi-Fi speeds up to 250 Mbps. Even at lower speeds, Wi-Fi provides plenty of throughput for transferring multimedia content with ease. The performance of a particular group of Wi-Fi Direct devices depends on whether the devices are 802.11a, g, or n, as well as the particular characteristics of the devices and the physical environment.

If I make a Wi-Fi Direct group with another person, can they see all of the contents of my device?

Not without your permission. The content available over a Wi-Fi Direct group connection is driven by the applications you are using. While there may be applications which allow an authorized use to “browse” the content on your device, most applications will have a specific focus, such as sharing a game application or transferring photos.

Does the specification underlying the Wi-Fi Direct certification program work on both 2.4 GHz and 5 GHz frequency bands?

Yes, the specification underlying the Wi-Fi Direct certification program supports operation in both 2.4 GHz and 5 GHz. Devices operating in the 2.4 GHz frequency band only and devices operating in both the 2.4 GHz and 5 GHz frequency bands can be certified under the Wi-Fi Direct program. Not all Wi-Fi Direct-certified devices support both frequency bands, however, so you should check which bands your devices support.

How does security work for Wi-Fi Direct products?

Group networks based on the specification underlying the Wi-Fi Direct program operate in a security domain that is independent from any infrastructure network. This means that they have protection of the security features certified under the WPA2 program, but are managed separately from the security system in the AP-based network (home, enterprise, hotspot). This means both the group networks based on the specification underlying the Wi-Fi Direct program and the infrastructure networks can be protected, but users don’t need credentials for the infrastructure network to connect to the network based on the specification underlying the Wi-Fi Direct program.

How many devices can connect?

A Wi-Fi Direct-certified network can be one-to-one, or one-to-many. Connection to multiple other devices is an optional feature that will not be supported in all Wi-Fi Direct devices; some devices will only make 1:1 connections.

How does the specification underlying the Wi-Fi Direct certification program work?

The underlying specification connects devices using an approach similar to the traditional AP-to-client connection used in Wi-Fi CERTIFIED infrastructure networks. One Wi-Fi Direct device provides the connection to other participants in a group of Wi-Fi Direct devices in lieu of an AP. A device certified under the Wi-Fi Direct program does not require special hardware compared to traditional Wi-Fi AP devices.

What about power management protocols? Are devices implementing the technology behind Wi-Fi Direct a power hog?

Most Wi-Fi Direct devices are power sensitive, and in many cases, battery powered. Wi-Fi Direct devices can support the Power Save feature certified under the WMM® program, and the specification underlying the Wi-Fi Direct program also defines power saving mechanisms.

Can a device simultaneously connect to a regular Wi-Fi network and a group of Wi-Fi Direct devices at the same time?

All devices certified under the Wi-Fi Direct program allow the user to connect to an infrastructure or a Wi-Fi Direct network. Some devices certified under the Wi-Fi Direct program support connections to both an infrastructure network and Wi-Fi Direct group at the same time (e.g. a laptop may support an infrastructure connection while also belonging to a Wi-Fi Direct-certified group). Simultaneous connection to a Wi-Fi Direct group and an infrastructure network is an optional feature.

Which Wi-Fi Direct device will create and manage the connection?

Devices conduct a negotiation to determine which device is most appropriate. This may be determined by considering a number of factors including but not limited to power management, number of connections supported, richness of user interface and services being offered. The Wi-Fi Direct device that offers the connection manages the creation, admission to, presence, and termination of that network implementing the specification underlying the Wi-Fi Direct program.

Do products certified under the Wi-Fi Direct program interoperate with my other Wi-Fi devices?

Yes. A Wi-Fi CERTIFIED Wi-Fi Direct device is able to make device group connections with existing Wi-Fi CERTIFIED™ gear.

How far does a Wi-Fi Direct connection travel?

Wi-Fi Direct devices work just like any Wi-Fi device, with ranges up to 200 meters. They can connect from just a few feet away, but also across a home. This means that making a Wi-Fi Direct group connection will be convenient, even when devices aren’t in immediate proximity to one another.