BBH Central IconBBH Report Home PageSandy and Dave
  CENTRAL home  |   REPORT home About/Contact Us  |   Subscribe  |   Index by Topic  
The October 18, 2009 Issue Provided by System Dynamics Inc.
Table of Contents Print this article Email this article to a friend

Wi-Fi Direct--A New Approach to WPAN

On October 14, the Wi-Fi Alliance announced that it was "nearing completion of a new specification to enable Wi-Fi devices to connect to one another without joining a traditional home, office, or hotspot network." The new specification, called Wi-Fi Direct, provides a standardized mechanism for Wi-Fi devices to talk to each other directly, without an access point. By bringing together similar mechanisms that have been developed by many companies, it should expand the market for Wi-Fi devices and simplify life for users of PCs and other Wi-Fi equipped devices.

Ozmo mouse and sound dock --> Click for larger pictureThe key to the new specification is to extend Wi-Fi firmware to support peer-to-peer networking simultaneously with connections through access points. We described this approach in an article about Ozmo Devices, which is developing low-power chips for devices like mice, keyboards, and wireless headsets. As Roel Peeters, Ozmo's VP of Marketing/Business Development, told us more than a year ago, the key concept is to leverage the existing Wi-Fi capability already present in many platforms. Special software in the host device "virtualizes" the Wi-Fi radio, sharing it between standard Wi-Fi WLAN devices and peer-to-peer WPAN devices including those equipped with Ozmo's single-chip IC. The existing host Wi-Fi radio plays both roles simultaneously, eliminating the need for an additional radio or a dongle.

We heard a similar idea at CES in January in a discussion with Mahesh Venkatraman, then Director of Marketing, Consumer and Retail Networking Products at Atheros. Mahesh described what Atheros calls "direct connect technology," which had already been implemented in Atheros 802.11n chips. Direct connect enables a Wi-Fi device to operate simultaneously as a Wi-Fi client and access point. Mahesh described many uses for direct connect, such as creating a simple connection between a digital camera and a PC. At the show, he took our picture with a digital camera equipped with a Wi-Fi radio and instantly transferred it to a Mac laptop.

Our article about CES mentioned that Intel had already announced and was promoting a similar idea called "Intel My Wi-Fi Technology."

The Wi-Fi Alliance has now stepped in to standardize this concept. The recent announcement says that it is "nearing completion" of the specification, "expects to begin certification .. in mid-2010," and will logo the certified products as "Wi-Fi CERTIFIED Wi-Fi Direct."

Ozmo, Atheros, Intel, Marvell and Apple all enthusiastically endorsed Wi-Fi Direct with press releases timed to accompany the Alliance announcement.


Simplifying Wireless Networking

Wi-Fi Direct should simplify wireless networking for consumers. Some immediate applications include:

  • Connecting simple wireless peripherals such as keyboards, mice and headsets: Most of these now use proprietary protocols. [Dave] I'm writing this using a wireless keyboard and mouse connected with a separate wireless dongle. I talk with Skype over a headset connected by a USB cable. New devices, such as those powered by Ozmo's chips, would use the Wi-Fi radio already in my PC.
  • Connecting cameras, smart phones, MP3 players, and other peripherals: These are now mostly connected by USB cables. The Wi-Fi Alliance says that any of these already equipped with Wi-Fi will be able to connect to PCs equipped with Wi-Fi Direct, and expects many more devices to come to market as new consumers' PCs come pre-equipped.
  • Connecting two PCs together in a peer-to-peer network to share an Internet connection.

The latter application really appeals to us. We always travel with two notebook PCs. Nearly all hotels now provide broadband Internet access, but most provide access to only a single PC per room -- either because there's only one Ethernet port in the room, or because the access mechanism assigns a password for each room and allows only one PC at a time to be logged on with that password. (In some hotels we've crashed the access mechanism when we tried to use two PCs with Wi-Fi.)

We have long used Windows Internet Connection Sharing (ICS) to get around this. If the hotel room has an Ethernet connection, we need to configure ICS on the PC connected by Ethernet; ICS then shares the connection through Wi-Fi. If the hotel room has Wi-Fi, we set up ICS and connect our PCs together with an Ethernet cable; the PC connected by Wi-Fi shares the connection through Ethernet (we can't share the connection through Wi-Fi since a Wi-Fi PC works either as a client or an access point, but not both).

ICS takes time to set up and is complex even for us, so we often don't bother to do it--and then one of us gets annoyed that the other is hogging the Internet connection. And then we have to remember to disable ICS when we're done--if we don't, we'll get into trouble the next time we try to connect to the Internet (Dave has lost sleep trying to reconnect when we get home from a trip).

Wi-Fi Direct promises to make life easier for us.


What about Wireless USB and High-Speed BlueTooth?

Readers of this report will recognize that we've written about many of these applications before. Wireless USB promised to support the higher-speed peripherals such as digital cameras, printers, and MP3 players. Bluetooth has long been promoted as a way to connect lower-speed peripherals, but most devices use proprietary wireless mechanisms. High-speed Bluetooth promises to support connecting fast peripherals.

Wireless USB requires another radio and antenna in the notebook PC--most notebook PCs don't have room for either, and notebook makers don't want to pay for the additional hardware and software. High-speed Bluetooth, even if it leverages the existing Wi-Fi radio, requires an additional protocol layer on top of Wi-Fi, and an added layer of complexity for the end user.

Wi-Fi Connect would appear to eliminate the need for additional radios and complex protocols and procedures. We expect it to become taken for granted as a standard part of Wi-Fi, and think it will open the door to even wider use of wireless networking by consumers.


For More Information

( www.wi-fi.org ) ( www.ozmodevices.com ) ( www.atheros.com ) ( www.intel.com ) ( www.marvell.com )