WI-FI: Wireless' New Frontier

A new wireless standard 802.11n is gradually gaining recognition as successor
to the currently prevalent 802.11a/g. Even though it is still at least a couple
of years before the specifications of the new standards are finalised, it is
already been seen as something that would revolutionise the scope of wireless
LAN and take it beyond it current appeal. That is largely because not only
802.11n promises a minimum throughput of 100 Mbps (which some vendors are trying
to take up to 500 Mbps to 630 Mbps), it is likely to target markets beyond
home/enterprise networking and consumer electronics, segments that 802.11a/g
serve. Some companies working on 802.11n are optimistic that 802.11n will serve
markets like cellular telephony, mobile radio, personal computing, public access
and VoIP besides consumer electronics and enterprise networking. Vendors believe
that "802.11n will be an especially important standard in the WLAN market
as it will build upon and extend the capabilities for the vast number of users
currently enjoying the benefits of Wi-Fi connectivity."

IEEE says that as enterprise networks in offices and campuses typically have
100 Mbps wired network connections, 802.11n standard will create parity between
wired and wireless systems, so enterprises can extend their use of wireless
networks to areas where the rate of existing wireless products has been
insufficient. "WLANs having throughputs of 100 Mbps were considered
impossible just a few years ago," said Stuart J. Kerry, IEEE 802.11 Working
Group Chair. "But the success of IEEE 802.11 WLANs and a number of
technology improvements have made far greater throughput feasible. These
improvements include higher-performing radio frequency and analogue chips based
on advanced CMOS technology and the integration of entire WLAN adapters onto a
single chip. "We expect the new standard to meet the current demand for
better WLAN service and allow a range of advanced uses. It might, for example,
let wireless systems replace data-hungry wired networks such as those serving
groups involved in computer-aided design," Kerry added

However, unlike 802.11a/g, 802.11n is facing a divided industry largely on
the issue of spectrum utilization. While on one side of the spectrum are a group
of companies called TGn Sync (which stands for Task Group n Synchronization),
one the other side is WwiSE (worldwide spectrum efficiency), another group of
companies. The leading companies in TGn Sync are Agere Systems, Atheros
Communications, Cisco Systems, Intel Corporation, Marvell Semiconductor, Nokia
Corporation, Nortel Networks Corporation, Panasonic (Matsushita Electric
Industrial Co. Ltd.), Royal Philips Electronics, Samsung Electronics, SANYO
Electric, Sony Corporation and Toshiba Corporation. WWiSE includes such
companies as Broadcom, Conexant, Texas Instruments, Airgo, STMicroelectronics,
Bermai and Realtek.    

While both the groups agree on the use of Multiple Input Multiple Output
antenna technology (MIMO) for taking 802.11n to its promised throughput, it is
on the use of channel bands that they disagree. TGn Sync is for using 40MHz
channels in the 5GHz spectrum (same as used by 802.11a). WWiSE companies support
20MHz channels in the 2.4GHz (used by 802.11b/g).

Amidst all these, some vendors have already begun shipping 802.11n products
or in the process of doing so. Vendors like Agere and Atheros have released
consumer-oriented HDTV and video products based on ultra-fast data transmission
based on the specifications that TGn Sync supports. Interestingly, the
availability of 802.11n products in the market before the finalization of
standards is not without precedent. 802.11g products were out in the market six
months before the Institute for Electrical and Electronics Engineers (IEEE)
ratified the 54Mbit specification. Perhaps, this is what that has inspired Agere
and Atheros. Industry observers have coined a new term for these pre-standard
products - they are called pre-802.11n. While these products have offer the
speed and other benefits that 802.11n ultimately promises to deliver and might
be backward compatible with 802.11b/g, they may not work with 802.11n products
that are based on the final standards. As such, the buyers of these products
would be in for a raw deal. And this is what the leading wireless networking
industry group Wi-Fi Alliance is worried about.

Wi-Fi Alliance feels that these vendors may be moving too fast. The Alliance
recently asked vendors not to move too fast on 802.11n. Arguing that the 802.11n
standards being developed by the IEEE are still not final, the Wi-Fi Alliance
recently said it would be difficult for it certify features based on the 802.11n
unless the standards are finally ratified. "No IEEE 802.11n products
currently exist, and none are expected to exist until the standard is completed
in approximately two years (November 2006). Due to the potential for customer
confusion, the Wi-Fi Alliance strongly discourages use of the term IEEE 802.11n
in association with any Wi-Fi CERTIFIED product,'' the Alliance said.
Pre-standard products always present an inherent risk for technology adopters,
and that is why we will not certify 802.11n products until the IEEE standard is
finalized, said Wi-Fi Alliance Managing Director, Frank Hanzlik.

The alliance is not expecting the standards to be final for the next two
years. Wi-Fi Alliance's main argument is that releasing products based on
802.11n (before the standards are final) would very much mean cheating
consumers. The Alliance said it would reserve the right to revoke the Wi-Fi
Certification of vendors' products if they move too fast to introduce such
features in a way that detracts from existing interoperability levels.

Ravi Shekhar Pandey

The 802.11n Promise