The Wi-Fi Alliance announced this week its Wi-Fi Direct specification, which will enable Wi-Fi devices to talk to one other directly without going through an access point. The new extension to 802.11 will appear in hardware in mid-2010. It automatically scans the vicinity for hotspots and Wi-Fi equipped devices .
The current peer-to-peer WiFi ad hoc spec, which has not been implemented widely, and the new spec will deliver greater throughput and range than Bluetooth. It combines traditional functionality of WiFi with Bluetooth’s ability to connect devices directly, said alliance executive director Edgar Figueroa. It’s designed to enable wireless printing and file sharing.
Wi-Fi Direct works with cellphones, wireless mice, keyboards, digital cameras, printers, notebook computers, TVs and remote controls within a radius of about 300 feet. It enables faster speeds and longer range than Bluetooth. Intel claims its technology can connect up to eight Wi-Fi devices to a notebook at the same time that laptop is connected to a Wi-Fi access point, cellular or WiMAX connection. Intel’s My WiFi technology (below), explains the concept.
Atheros Direct Connect, the company’s own version, was first unveiled at CES 2008, and will be fully future-compatible with the new Wi-Fi Direct specification as is Marvell’s own Direct Connect version. The alliance expects to begin certifying Wi-Fi Direct devices as interoperable beginning mid-2010, with products available around the same time.
The spec, still under development, will ride on top of the current 802.11a/b/g/n WLAN standards, and deliver the same data rates and ranges as those standards. It also incorporates WPA2 security and Wi-Fi Protected Setup to simplify security setup.
Another advantage is more efficient bandwidth use. Wi-Fi Direct will use half the bandwidth of a traditional WLAN to transmit the same amount of data because data is sent directly from one device to another. In contrast, in a traditional WLAN incorporating a wireless access point, bandwidth is consumed when transmitting from one device to an access point and again when the data is retransmitted from the access point to the intended target device.
ABI Research indicates that wireless connections will remain the dominant technology, with Wi-Fi connections expected to rise from 113 million in 2008 to more than 285 million by 2012. Ethernet will remain a strong second place.
What about ad-hoc mode, already part of the 802.11 standard from the beginning?
A number of projects played with multi-hop routing across wifi nodes in ad-hoc mode (eg. LUNAR 2002).
Ad-hoc mode is missing discovery so perhaps wifi direct includes some sort of beaconing.
Then again, bluetooth was designed to do all of this from the start. Peer to peer connectivity including routing between peer groups – also at lower power than wifi and more resilient to interference due to channel-hopping. I think the BT spec was so over -designed noone ended up implementing most of it.
The BT hype has been around since 1999 – every electronic device would have BT and would be continually chatting each other up swapping data about refrigerator inventory and cell phone multiplayer gaming. I think there is still a huge opportunity to provide this in some form. Probably a radio much simpler than bluetooth – I’m not sure how complex zigbee is.
Left by Don Park on October 14th, 2009