Cisco presented a case in the last newsletter for implementing pre-standard 802.11n networks today. This time, Joanne Lennon from Nortel's WLAN marketing group points out some of the benefits of waiting for standards and product/technology maturity. Writes Joanne:

There’s no trivializing 802.11n’s inevitable impact on the marketplace. It affords significant enough bandwidth and range to be a key enabler of the future “unwired enterprise.” But, is 2008 the time for deployment? Nortel urges waiting. Here’s why:

* Ratification of 802.11n isn’t expected until mid-2009, giving many enterprises reason to pause. A 2007 Nortel/Kubernan survey found only 16% of respondents willing to deploy pre-standard products, and 15% of those were limited to controlled pilots.
* First-generation solutions hitting the market this year will have a maximum bandwidth of 150Mbps to 300Mbps. Full 802.11n capabilities utilizing more than the two spatial streams supported in today’s draft-gen of silicon won’t be here until 2009 or 2010. Should draft-gen APs not meet requirements, enterprises might have to later upgrade from 802.11n to a “better” 802.11n.
* Current 802.11n radios can be more than double the cost of 802.11 a/b/g access points. While AP prices will drop as demand increases, early adopters will initially pay a premium.
* Draft-n may necessitate reverting back to network interface cards, bringing added complexity and cost over currently embedded 802.11 clients.
* Maximum capacity and consistent coverage requires overlapping cells using 40MHz channel widths in 5GHz spectrum. Most consumer-oriented clients support “draft-n” only in the 2.4GHz band.

In addition to the above, there are infrastructure concerns. If the throughput benefits of 802.11n are to be realized, the WLAN architecture must be able to support higher traffic volumes. Edge switching capacity and switching power also need to withstand increasing requirements. Without GigE, APs generating around 100Mbps will be artificially constrained. And, today’s 802.3af PoE can’t supply enough juice for maximum data rates with MIMO. The better fit will be with the coming 802.3at [IEEE PoE Plus standard].

To be sure, 802.11n will be transformational at the right time, but there should be compelling reasons to adopt early, as much greater capabilities are around the corner. In the interim, enterprises need to consider how mobility and wireless access can transform their business, identify the high-value applications they want to support and build a plan spanning clients, network and applications to ensure successful implementation. Most enterprises, however, would be best served by waiting until the standard is ratified and the full ecosystem is in place prior to adoption.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.