New Wi-Fi Spec Simplifies Connectivity
The Wi-Fi alliance has begun certifying devices that support Wi-Fi Direct, a new mode of communication that eliminates the need for a wireless router. The technology promises to simplify connectivity to peripherals and between computers via a peer-to-peer network. Atheros, Broadcom, Intel, Ralink, and Realtek have all demonstrated Wi-Fi Direct devices.
The new protocol runs on existing Wi-Fi equipment and can be implemented as a software-only driver update, said Vijay Nagarajan, product line manager for Broadcom's WLAN business unit. The first applications will be for simplifying connectivity with peripherals. But Nagarajan said they're working on APIs and development tools to make it easier to implement Wi-Fi connect functionality in novel ways. For example, collaborative document editing and presentation applications could let people collaborate without a dedicated LAN. A mesh-networking application could use the protocol to create ad hoc links to form larger networks.
More than 1 billion Wi-Fi devices are in use today, and another 1 billion are expected to ship in 2011, according to market research firm ABI Research. Although these devices won't necessarily be upgraded to support Wi-Fi Direct, all of them will be capable of connecting directly to Wi-Fi Direct devices.
Simplifying the Link
Wi-Fi has become very popular as a short-range technology used for Internet access and for connecting smart phones, peripherals, and laptops within a home or office. However, Wi-Fi access typically requires users to access a wireless network access point, which poses a variety of limitations and challenges relating to availability and configuration.
Many existing Wi-Fi devices support an ad hoc mode, but these connections are slow (11 Mbps) and difficult to set up. Wi-Fi Direct networks will be easier to set up and will scale to support up to 250 Mbps. Devices with Wi-Fi Direct can be automatically paired using hardware-activated switches for security, in much the same way Bluetooth pairing is done today. For example, someone could press a button on the printer and wait for a menu icon to pop up on the computer to complete the pairing. The new mode also features built-in Wi-Fi protected access (WPA) security, which makes it easier to establish secure connections between devices.
Wi-Fi Direct certification requires support for 802.11 g, WPA2-Personal, Wi-Fi Multimedia, and Wi-Fi Protected Setup. All Wi-Fi Direct devices will be able to support one-to-one connectivity, and some will support one-to-many connectivity, such as a laptop connecting to peripherals. Optional support for concurrent connections could let a PC provide Internet access for TVs, cameras, and legacy printers. New management features will help prevent cross-connections that jeopardize security.
A Wi-Fi Direct device will be able to simulate an access point to legacy devices and so provide backward compatibility. But these types of connections will require more technical skill to set up than it does when both devices support Wi-Fi Direct.
Many Wireless Challengers
The development of Wi-Fi Direct pushes Wi-Fi technology into a whole new class of applications that let it compete with other protocols for media transfers and peripheral links, such as Bluetooth, said Craig Mathias, president of the Farpoint Group wireless consultancy. "This positions Wi-Fi into the personal area networking space that has traditionally been Bluetooth territory. But before that there was IrDA."
Many expect the technologies to co-evolve to solve different networking challenges. "Wi-Fi Direct and Bluetooth are extremely complementary to each other," Nagarajan said. "You can think of use cases where you could use Bluetooth or Wi-Fi depending on the applications." For example, Bluetooth is extremely power efficient, but only goes up to 25 Mbps over short ranges. In contrast, Wi-Fi Direct will be able to carry up to 250 Mbps over hundreds of feet.
In the long run, this new mode could find itself in more demanding applications, such as video distribution, replacing alternatives such as WirelessHD, said Phil Solis, research director at ABI. He expects the technology to eventually support the higher speed Wi-Fi running on top of 802.11ad at 60 GHz.
Building the Wi-Fi Direct Ecosystem
The successful certification of the first devices marks a major milestone, as vendors now have a process to quickly test new drivers for compliance. Nagarajan said that all the major vendors are working on adding drivers for legacy devices. This will make it easy to upgrade computers, smart phones, and other configurable devices to Wi-Fi Direct.
But to get the most use from Wi-Fi Direct, software developers will have to develop new applications. Toward that end, Broadcom has release a suite of APIs for simplifying Wi-Fi Direct across all devices. It has also released a more sophisticated suite of tools called InConcert Maestro that makes it easy to seamlessly manage both Wi-Fi and Bluetooth connectivity.
"Wi-Fi Direct can connect to legacy devices, so it has the potential for amazing uptake," said Sarah Morris, senior marketing manager at the Wi-Fi Alliance. "Then, as more Wi-Fi Direct devices get out there, we'll get richer device discovery right out of the box. The next generation of applications will be very exciting with the opportunity to innovate on top of that with gaming and social applications."
For more information, visit the Wi-Fi direct home page at www.wi-fi.org/wi-fi_direct.php.
George Lawton is a freelance journalist based in Guerneville, CA. You can contact him via his website at http://glawton.com.