Wi-Fi Direct™, formerly Wi-Fi™ Peer-To-Peer, is a Wi-Fi™ Alliance technology that joins Wi-Fi™ CERTIFIED devices together without need of a hotspot or router. Similar to Bluetooth® but more robust, this technology allows devices to automatically find each other and connect with the click of a button, to share files, synch, play video games, exchange text messages, or to use resources such as printing.
According to the Wi-Fi™ Alliance, Wi-Fi Direct™ can operate at distances of up to 656 feet (200 m) and can join devices 1:1 or one to many, depending on the equipment and its certification(s). It operates in the 2.4 GHz band, but can also operate in the 5 GHz band, though not all certified devices operate in both bands.
This technology is not intended to replace WLANs, but to make sharing easier among Wi-Fi™ CERTIFIED devices. Only one device in a group needs to be compliant to connect them together. The certification calls for all devices in range to be scanned for basic information, such as power management and the type of services that might be offered by the device. An invitation appears, which a user can decline or accept, and upon acceptance, a secure link via second generation Wi-Fi™ Protected Access (WPA2) is established.
This type of network might optionally join a traditional wireless local area network (WLAN) to provide a shared Internet connection, compatible with 802.11/a/g/n Wi-Fi™ CERTIFIED equipment. The ability to maintain a Wi-Fi Direct™ network simultaneously with a traditional WLAN is an optional capability that might not be offered in every product.
The specification calls for management of the network by the most optimal device in the group. Power capabilities, software, and other considerations play a part in self-determining which device becomes the soft access point (AP) for the network, though all Wi-Fi Direct™ devices have AP capability.
In practical terms, a Wi-Fi Direct™ digital camera can stream home videos to a Wi-Fi™ CERTIFIED high-definition television or Blu-ray™ player, a cell phone can share pictures with another phone or computer, or two people traveling on a train can play a video game against one another. Remote printing and text messaging are additional uses. Kiosks that are enabled could open the door to more convenient printing on-the-go, offloading of data to flash media or other transit services.
This technology is backward compatible with Wi-Fi™ CERTIFIED devices, and depending on the equipment, can reach data transfer speeds of up to 250 megabits per second, according to the Wi-Fi™ Alliance. In most cases, applications on the connected devices will limit the content available to the network, prohibiting free-range browsing. Power saving features are also built into the specification. Marketed since October 2010, these products are Wi-Fi™ CERTIFIED and carry the Wi-Fi Direct™ logo.