Wi-Fi's Fast-Changing Future
Almost any mobile device you buy today either has a Wi-Fi radio chip in it, or can be fitted with one. But the still annoying and baffling part of Wi-Fi is that while it lets you move around, you still have to move around from one place to another, each having a Wi-Fi hotspot or network.
The feverish vision of Wi-Fi networks blanketing entire cities has pretty much shriveled, (though some observers think federal stimulus dollars may re-energize it) even as mobile carriers now race to deploy Wi-MAX or, as even Clearwire now is hinting, WiMAX-like Long Term Evolution (LTE) networks as the foundation for pervasive wireless connectivity.
Yet LTE will remain a relatively expensive service. Wi-Fi is becoming a comparatively low-cost, high-bandwidth wireless technology that's being embedded in a growing number of devices as well as a growing number of locations, including vehicles and carrier hotspots, like proliferating lilypads of connectivity.
Many of the most immediate changes ahead for Wi-Fi are those that will strengthen wireless connectivity as an increasingly pervasive "utility."
This week, for example, the WiGig Alliance is announcing the next moves in bringing the Wi-Fi to a new frequency band: 60 GHz. The new band will make it possible to deliver up to 7Gbps over relatively short distances, say the size of a living room or den.
That's a huge increase compared with what is now becoming the Wi-Fi standard for access points and a growing number of client adapters: 802.11n. The 802.11n radios use two or three simultaneous data streams, and can merge two 20MHz channels together. The results are data rates that can start at over 100Mbps and reach 300Mbps, though useable throughput is much less. By comparison 802.11g and 802.11a have a maximum data rate of 54Mbps and throughput in the 20M to 24Mbps range in ideal conditions.
The WGA's plan is to support a rapid industry deployment of its specification into products that will support existing Wi-Fi standards, notably 802.11n, while adding the 60GHz frequency to support very high data transfers over short distances. Applications include wireless I/O, uncompressed video streaming, high-speed data networking and the like.
This week, WGA makes its 1.0 specification available to a much larger group of vendors. Vendors that agree to the royalty-free licensing terms can take the spec and begin developing products based on it. The WGA is also partnering with the Wi-Fi Alliance to create an interoperability testing and certification program, modeled on the one the WFA has developed in the past for proving compatibility among Wi-Fi equipment.
Later this month, WGA will submit to the IEEE standards group a unified proposal to use the WGA specification as the foundation for a new 802.11 standard supporting multi-gigabyte data rates in 60GHz. Last year, the IEEE created two new 802.11 groups, 11ad for the 60GHz band, the other, 11ac, in the bands below 6GHz.
The WGA plans to fully support the IEEE's 60GHz work, but if that work bogs down, WGA plans to push ahead, according to Mark Grodzinsky, marketing work group chair for the WiGig Alliance. "We'll participate actively in the IEEE process," he says. "But we're not going to wait for another seven-year-long [standards] process [a reference to the 11n approval cycle]."
Chips implementing the WiGig spec would be able to support all three frequencies: so the same radio could use 60GHz for blazingly fast downloads or uploads of data or video, and then 2.4 or 5GHz for, say, Internet or private cloud connectivity.
Sometime in the next 12 to 18 months there will be other Wi-Fi changes also:
* Simple, direct connections between Wi-Fi client devices, bypassing an access point or wireless router.
The Wi-Fi Alliance is crafting a specification called Wi-Fi Direct. Like Bluetooth, the spec will include protocols to let Wi-Fi devices discover each other and securely create a direct connection with each other. The spec will support 802.11n and enterprise-grade Wi-Fi Protected Access 2 (WPA2) security. The WFA will begin certification testing for "Direct" in Q3.
The current 802.11 standard supports a peer-to-peer connection but it lacks the smarts that Wi-Fi Direct will add, and has performance and security trade-offs, says Edgar Figueroa, Alliance CEO.
* Improved VoIP support, with a new set of WFA-authored protocols to let Wi-Fi networks support many high-quality, concurrent voice calls.
* Wi-Fi mesh networks. Mesh connections, which let access points connect directly to each other and transmission hop from one to another, are currently offered based on non-standard, often proprietary protocols. An IEEE standard, 802.11s, which is due out by mid 2011, will make Wi-Fi mesh networks simpler to create and use. More widespread use of a standard mesh will increase the footprint of Wi-Fi networks, and by offering alternate routes, will improve reliability.
* Improvements in Wi-Fi signal quality and reliability as chipmakers and equipment vendors implement more of the features in 802.11n. Adding such arcane capabilities as low-density parity check coding, to improve error correction, and transmit beam forming, which uses feedback from a Wi-Fi client to focus an access point's RF transmission, will lead to more robust Wi-Fi networks.
* Smarter Wi-Fi clients, cooperating with access points or hotspots to improve performance and security. The 802.11v standard, due for completion this summer, is aimed at providing more client data, and power management, to incorporate and control client radios in network management. Accelerating implementation of 802.11k, for radio resource management, will let Wi-Fi networks "see" the client's RF environment, identify weak signals or poor coverage, and optimize the connection.
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