Monday, November 16, 2009
What's next for Wi-Fi?
The recent formal approval of the IEEE 802.11n wireless standard marks not the end but the start of a wave of Wi-Fi innovation. In the next three to five years, the Wi-Fi experience will be very different from today.
The huge 11n performance jump -- to 300Mbps data rate and roughly 100M to 150Mbps throughput -- will become the basis for unwiring work and life to a much greater extent than ever before. You can picture it as a fast-growing archipelago of wireless connectivity, with access points becoming more prevalent, interlinked in meshed clusters, and able to cooperate far more closely with smarter Wi-Fi clients. Here we've focused on eight ways Wi-Fi will change for the better, enabling improved signal quality, more reliable connections, optimized bandwidth, increased battery life and stronger security.
1. Broader broadband
Although the IEEE has launched two projects intended to bring gigabit and multi-gigabit data rates to the 802.11 standard, neither has come up with a first draft.
But the 11n standard makes possible a range of high data rates, which can be adapted to different functions and devices. Today, all 11n radios support two spatial data streams that are sent and received using some combination of two or three antennas, and these radios are set to appear in mobile devices. Apple's newest Wi-Fi-only iPod touch, for instance, has a Broadcom radio chip that supports but doesn't yet use11n.
Soon, more Wi-Fi chips will support three and even four data streams, with respective data rates of 450Mbps and 600Mbps. Early in 2009, Quantenna Communications demonstrated its 4x4 chipset in action, streaming several high-def TV signals through a home-sized space.
"While there will not be a lot of client devices that support four spatial streams, properly designed access points will take advantage of the 600Mbps physical layer data rates to enable high-speed, wireless backbones," says William Kish, co-founder and CTO of Wi-Fi equipment vendor Ruckus Wireless.
You'll be able to mesh these high-end nodes via the 802.11s standard (due in September 2010), creating Internet-like Wi-Fi networks that are redundant and can route around failures.
2. Tougher radio frequency signals
More of 11n's optional performance features will appear in radio chips, and be used in wireless clients and access points to make RF signals more resilient, consistent and reliable. In other words, more like a wire.
"This new [11n] physical layer technology will make Wi-Fi more robust, with higher data rates at given ranges, and at longer ranges," says William McFarland, CTO for chipmaker Atheros Communications.
These performance features include: low-density parity check coding, which improves error correction; transmit beam forming, which uses feedback from a Wi-Fi client to let an access point focus the RF signal on the client; and space-time block coding (STBC), which exploits the multiple antennas more for improved signal reliability than for higher data rates.
"Today when you walk around a building with a [Wi-Fi] laptop, you'll find data rates drop or fade out," McFarland says. "But with STBC, the connection will still work."
3. The Wi-Fi-zation of things
Big innovations in power consumption and management are making it possible not only to extend battery life for Wi-Fi smartphones, but also to embed Wi-Fi into swarms of new devices and now even wireless sensors: medical monitoring devices, building control systems, real-time location tracking tags and consumer electronics. The result is the ability to continuously monitor and collect data, which can be personalized based on a user's identity and location.
"There's nothing that other contemporary limited-distance RF technologies can do that Wi-Fi can't," writes wireless consultant and Network World blogger Craig Mathias.
"With an enterprise wireless LAN, this infrastructure is already in place," says Atheros' McFarland. "Just add the low-power sensors."
Embedded Wi-Fi vendor Summit Data Communications recently announced 802.11a radios in various plug-in formats to let devices use the uncrowded 5GHz band. Start-up Gainspan offers 11bg Wi-Fi radios, with an IP software stack, that use so little power that wireless sensors can run for years on standard batteries. And Redpine Signals offers a single-stream embedded 11n radio.
4. Improved security
One of the most corrosive impacts of the Internet is the victimization of its users, via identify theft, denial-of-service attacks, privacy violations, spying and the corresponding lack of trust these abuses create. Mobility has the potential to make this even worse, if users become convinced that Wi-Fi connectivity opens them up to unacceptable risks.
The IEEE recently approved the 802.11w standard, which protects the wireless management frames used to make the radio link work better, says Matthew Gast, chief strategist at Trapeze Networks, now a Belden company. Today, a Wi-fi client can receive and obey a "get off the network" message that may have been generated by an attacker spoofing the MAC address of an access point. The 11w standard shuts down this line of attack.
More generally, says Michael Tennefoss, head of strategic marketing for Aruba Networks, Wi-Fi will increasingly liberate users through the use of identity-based security. In Wi-Fi networks, security policies are associated with a user, not with a switch port. A related benefit: Users can move between home, work, hotel, branch offices and public hotspots without compromising their security, Tennefoss says.
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Senior Marketing Manager