Siemens released its line of 802.11n product line today, joining a growing number of wireless LAN vendors -- which includes Cisco Systems, Meru Networks, Aruba, Trapeze, Colubris and Ruckus Wireless -- that are designing high-capacity wireless LAN gear for the enterprise. There seems to be little doubt that 802.11n will eventually displace its a, b and g predecessors (IT research firm The Burton Group believes that 802.11n will even replace wired Ethernet LANs in the next two years). The question is whether the enterprises need them, or can even support them, today.

Keep in mind that 802.11n isn't a fully standardized technology just yet. The IEEE delayed a final approval of the standard until this year, but in order to prevent trigger-happy vendors from shooting hundreds of proprietary and non-interoperable products into the market, the Wi-Fi Alliance agreed to do certification based on the last draft of the IEEE. Any product out there is officially certified to the IEEE 802.11n draft 2.0 spec, which WLAN equipment vendors say contains 99% of the final standard. Of course, we hear this claim a lot about pre-standard equipment, but given that the Alliance was willing to stamp their Wi-Fi logo on it, there's probably some truth to it.

The standards debate may not be of much concern to the home user with a D-Link Draft n router and laptop card, but to an enterprise investing tens to hundreds of thousands of dollars in WLAN, it has to be worrisome. Vendors are promising that any differences between the current and final specifications can be addressed with a simple firmware upgrade, which may assuage some of those concerns. But there are some other reasons why they may not be so keen on fancy smancy network technology.

First off, they might not actually need it. Siemens vice president of enterprise mobility Luc Roy readily admits if an enterprise is just looking for fast network access, 802.11a/b/g will suit their needs just fine. There won't be much difference surfing the net at 802.11n's 140 Mb/s versus the 22 Mb/s. The demand for 802.11n is really being seen in the verticals, which are placing huge capacity demands on their current WLAN infrastructure. Hospitals in particular have already soaked up 802.11a/b/g's capacity, running their entire PBX networks over Wi-Fi phones and exchanging Wi-Fi tablets for paper patient files. Now demands to send MRI scans and X-rays via the wireless network are overtaxing what their networks can physically provide, Roy said. "There are 300-bed hospitals with only three wired phones," Roy said. "Everyone and everything is wireless."

Other industries like manufacturing have thousands of radios linked to machinery all communicating wirelessly in real time. And even is some service industries such as convention centers, the limits of 802.11a/b/g have clearly been reached when hundreds if not thousands of people in the same room try to log on to a few access points. In those verticals the demand for 802.11n is obvious, but most typical enterprises haven't hit that critical mass.

The second reason is expense. Upgrading to 802.11n doesn't just involve exchanging access points. It often involves a complete overhaul of the LAN infrastructure. It involves upgrading from 10/100 Ethernet to Gigabit Ethernet, to handle the huge uptake in capacity. It often involves snaking power lines to the access points themselves. Most enterprise wireless LANs run off Power Over Ethernet (POE), using the electricity transmitted over the Ethernet cord to power the access points. Because 802.11n's additional capacity and range it demands more power, which traditional POE can't deliver. The way around it is to reign in the capacity of the access point by limiting the number of antennas transmitting (which effectively eliminates the advatages 802.11n), provide direct power to the access point or upgrade the POE architecture. Roy said Siemens has managed to produce a low-power 802.11n, which will use standard POE to 100 meters--a development that explains, Roy said, why Siemens is much later to market than its competition.

So the bottom line is enterprises may be faced with the quandry of deploying a network that they don't yet need at a cost that would be much higher than a standard WLAN system. But that hasn't stopped customers from expressing interest in the technology. Roy predicted 50% of the HiPath equipment Siemens ships in 2008 will be 802.11n gear. The reason is one of simple future-proofing. Companies may not need the capacity now, but they will need it in the future as more and more applications shift to the wireless network. What started out as a way to connect your laptop in the break room has grown to encompass converged voice networks and even video. As more wireless appliances make their way out of the verticals and into the typical enterprise, the capacity demands of the hospital will be shared by the office building.