802.11n Is Here. Get Ready For A Wire-Free Enterprise

As the new 802.11n spec, with its increased speed, coverage, and reliability, intersects with a broader selection of vendor offerings, wireless is becoming a viable platform for mission-critical network connectivity.

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It's an oversimplification to say that 802.11n heralds the era of the wire-free office--though with top speeds of up to 300 Mbps, it's clearly a catalyst for cutting the cords that tether users to their desks. Yet there's no question that within a few years, Wi-Fi will become the new network edge for companies interested in saving money, attracting top talent, and increasing security.

Of course, pure-play wireless LAN vendors have been saying for a while now that wired Ethernet to the desktop is dead, despite lingering concerns about reliability, the suitability of WLANs for telephony, the complexity of managing mixed wireless and wired networks, branch office and teleworker support ... and, oh yeah, the fact that the legacy infrastructure is chugging along just fine.

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Business technology managers have long weighed these factors against the most touted benefit of Wi-Fi: increased productivity. The efficiency studies are many and the refrain generally the same: Wireless keeps information at employees' fingertips, enables quicker decision making, reduces downtime, and enables collaboration. But in today's tight economic environment, the savings picture is just as compelling. Intel estimates--and we agree--that moving to a largely wireless network can reduce capital costs 40% to 50% and operational costs 20% to 30%. Luc Roy, VP of enterprise mobility at Siemens Enterprise Communications, cites a Canadian government customer that's saving $500 per event for moves, additions, and changes.

With the rising price of all modes of travel, teleworking is looking mighty attractive as well, and IT can now extend wireless to remote sites. Aruba Networks recently announced an access point, developed with Avaya and called the Mobile Remote Access Point, that can use any broadband connection to provide secure access to business resources for both data and voice. All the employee needs is a single- or dual-mode phone, or a softphone on a wireless laptop. Remote and branch offices also are obvious places to take advantage of all-wireless access (see story, "Next-Gen IT: Building Better Branch-Office Wireless"), especially as management tools emerge for monitoring mixed-vendor WLANs (see story, "Rollout: AirWave's WLAN Management Suite Put To The Test").

Cisco Systems, Motorola, and others now offer 3G interfaces that can provide backups for branch offices and locations with minimal WAN connectivity, or for failover of critical applications. And WLAN security can beat that of most wired LANs--yes, you read that right. Sites looking into desktop virtualization should do fine on an all-Wi-Fi network as well, thanks to the small packet sizes inherent in virtual desktop infrastructures.


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Motorola sees 802.11n as an inflection point in the industry and has adopted the slogan "Wireless by default and wired by exception." It and other vendors are practicing what they preach, deploying ubiquitous WLANs in their own offices.

Should you follow suit?

Although wireless vendors such as Motorola are happy to promote the wire-free office concept, Ethernet switch sellers, including Cisco and Hewlett-Packard, approach the concept with caution. That's not surprising: Switch vendors stand to lose big money as we move away from Ethernet to the desktop. Even if companies pay the manufacturer's suggested retail price for enterprise-class 802.11n gear, it's still much less expensive per user than a new 10/100/1,000-Mbps switch deployment with $250-per-drop wiring costs.

But don't feel too bad for Cisco--no enterprise WLAN vendor is claiming to replace wire at the core or distribution layers, and besides its wire-side dominance, Cisco owns more than half of the enterprise WLAN market with its wireless gear set, originally from Aironet and later supplemented with its Airespace acquisition. Chris Kozup, manager for mobility solutions at Cisco, emphasizes that the company is making the most of its leadership in both wired and wireless with a "unified" network approach that blankets the office with Wi-Fi while keeping a few wired ports at every workstation. Nice if you can afford it. Cisco is clearly cautious in its pronouncements regarding the all-wireless office. Don't look to the WLAN gear leader to be in front of this charge.

No. 2 switch vendor HP, which mixes some of its own Wi-Fi gear with licensed technology, is also approaching the all-wireless office carefully. Andre Kindness, Americas security and mobility solution manager for ProCurve networking, says HP's customers are driving that stance. Companies are looking to reduce their operational costs through a consistent management system that covers both wireline and wireless and provides product longevity, Kindness says. However, such management doesn't yet exist. Cisco talks about a unified network, but it's not yet providing integrated management. HP openly discussed the problem of inconsistent management tools between wired and wireless networks, and we see it making the most credible progress of any of the "we do both wired and wireless" players. Other vendors looking to cover these bases include Nortel Networks, which says it's developing its own 802.11n gear--essentially shunning its OEM partner, Trapeze Networks--and Enterasys, Extreme Networks, Foundry Networks, and Juniper Networks, all of which are OEMs or resell wireless products.

Meanwhile, overlay vendors such as Aruba, Motorola, and Trapeze treat the wired network as more or less a dumb transport for their wireless traffic. It makes for easier sales to the wireless-oriented parties in IT organizations, but this stance leaves those who must manage both with a less-than-easy feeling.

Another angle enterprise switch vendors play is to suggest that all-wireless is a better fit for the remote or branch office, rather than main sites, appealing to interest in this architecture while protecting their wire-side revenue. Most also deliver some variation on the message that IT should be about "providing flexibility to the business"--in other words, preserving wired connectivity where it exists and delivering wireless where it's wanted. Tim Purves, CTO of the Henry Ford Health System in Detroit, says it's his department's aim to "align technology with business workflow processes." While that's a familiar mantra, if those processes are tied to immobile approaches that ignore the productivity increases and workflow improvements possible via a pervasive wireless network, IT must step up and champion a new way forward.

Fortunately, not all enterprise switch vendors are stonewalling. Trent Waterhouse, VP of marketing for Enterasys, says his company sees wireless as a strategic component of its business and is evaluating WLAN players with an eye toward an acquisition. Juniper is shopping around, too; it was spurned by Meru Networks, which also acts as an OEM for Foundry, on at least one occasion, say industry sources. No matter--Aerohive, Bluesocket, Colubris, and Xirrus stand out as attractive acquisition targets for enterprise switch vendors that lack their own wireless products. Trapeze might be a good fit for Nortel, if it decides to turn to its former OEM partner rather than build its own 802.11n gear.

Impact Assessment: 802.11n And The Wire-Free Office

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Truly transforming the workspace extends beyond installing access points and providing laptops, to physical reconfiguration. Take Capital One's Future of Work program. The financial services firm's 360-acre, eight-building campus almost doubled the number of employees it could house, from 650 to 1,100, by adopting the concept of hoteling. Rather than being assigned a specific location, employees who participate in this optional program have access to a generic cubicle, as well as conference rooms and open areas. Space is essentially overbooked. Each employee is assigned a telephone number that flows to a Cisco voice-over-IP phone and/or BlackBerry. The WLAN is the primary medium for network access.

"Today, work is what you do, not a place you go," says Rob Alexander, Capital One's CIO. "The wireless and mobile technologies we provide through our Future of Work environment provide our associates greater flexibility in how and where they work, which in turn improves collaboration and productivity." Employees are happy, and the company saves big on facilities.

Intel takes a similar approach at its Jones Farm, Ore., campus. This location serves almost 6,000 employees using Cisco wireless gear. Intel started with an overlay network for wireless access, but as Wi-Fi caught on, it's become the first choice for employees. In addition to Centrino-based laptops (of course), Intel also uses Cisco Wi-Fi phones for voice services, as well as softphones and dual-mode devices.

Cisco has its own initiative, called the Connected Workspace. In line with its preferred converged approach, wireless is deployed everywhere, but wired ports for high-bandwidth communications needs, such as backups and video streaming, also are available. Still, the company has cut its need for copper by 60%. "The Connected Workspace encourages collaboration and reduces real estate and infrastructure costs, while accommodating different work styles," Cisco's Kozup says.

Aruba and Motorola have been the most vocal vendor supporters of the wire-free office. With no wired revenue to lose, they can only gain by stealing away dollars that would normally be spent on their competitors' Ethernet switches. With 802.11n offering comparable performance to a wired network, but with added mobility, they have a strong argument.

Of course, the wireless office is like the paperless office--though electronic documents and e-mail have become the main forms of information storage and redistribution, there's still paper exchanged in the postal mail. In the same way, wireless will become the primary connection only at the access layer. "'All wireless' is a bit of a misnomer," says Kozup. There will still be cables, but they'll reside predominately in the distribution and core layers of the network, unseen by the average user.

The security breach at TJ Maxx parent TJX, where attackers took advantage of a wireless connection secured only with Wired Equivalent Privacy to capture credit card information on tens of millions of the retailer's customers, remains fresh in many CIOs' minds. The fact that the key element in that equation is "secured only with WEP" is a detail easily ignored by the security paranoid.

Done right, Wi-Fi can be deployed with greater security than wired networks, which often leave ports unprotected in cubicles and conference rooms. Because security concerns have long been a drag on WLAN adoption rates, it's now standard form to use 802.1X to ascertain a connection's user credentials and the Advanced Encryption Standard to encrypt traffic until it reaches a wireless controller in the data center or at the network edge. Those still using a VPN overlay on an open wireless network, take note: Unless you have specific application requirements or hardware limitations, now is the time to move to 802.1X with AES.

A wireless network's greatest vulnerability is in performance-degrading interference or denial-of-service techniques, some facilitated by options in the 802.11n standard. Your wireless infrastructure management system may be able to pinpoint the source of malicious traffic, or else a product from an overlay wireless intrusion-prevention system vendor like AirDefense, AirMagnet, or AirTight can do that and more. Work on the 802.11w standard is progressing to offer management frame protection, among other capabilities, to fill gaps.

If you have some sentimental attachment to the copper feeding your desktop, consider that your future workforce has spent the past four years in a wireless oasis. Most colleges and universities provide Wi-Fi in a substantial portion of their classrooms and public spaces, some in their dorms. Freshly minted graduates expect mobility when they step into the workforce, and that starts with Wi-Fi access in the office.

If businesses want to attract young talent, staying on the cutting edge isn't optional. To see how close we can come to going wire-free, we broke down wireless communication into three areas: data, voice, and video.

Conventional office applications account for the majority of data access. Whether e-mail, productivity suites, or line-of-business applications, data apps consume the largest amount of a knowledge worker's time and have been successfully mobilized, in and out of the office.

Wireless voice is often thought of in terms of cellular services, but voice over Wi-Fi, or Vo-Fi, increasingly is considered a key application for wireless networks. CIOs are generally cautious about running voice over their enterprise WLANs, for good reason: Unless the wireless network was engineered with voice in mind, whether it be first- or third-generation gear, poorly implemented quality-of-service functions and a weak signal will lead to disappointed users. All the major WLAN infrastructure vendors have spent considerable time working with enterprise-class Vo-Fi providers, such as Cisco, Polycom (formerly SpectraLink), and Vocera, developing deployment guides to assist VARs and IT groups with configuring the WLAN for QoS.

Wireless video, which generates much higher traffic volumes than voice, requires special consideration as well. Although we don't see enterprises deploying Cisco's TelePresence over Wi-Fi anytime soon, video-based corporate training and closed-circuit television for both inside cameras and those mounted in the parking lot are here now.

Not all apps can be neatly siloed into voice, video, and data. Environmental controls and security monitoring can also be performed wirelessly, eliminating time-consuming and expensive installations. Services such as location and presence increase productivity and security. We're in the midst of a Rolling Review covering location systems, and we like what we see; check out our findings on our Rolling Reviews page.

Throughput is the first consideration when it comes to network connectivity, and 802.11n delivers: Both vendor and independent tests have shown that peak rates upward of 130 Mbps are achievable in good conditions. Advanced antenna designs, spatial streams, and multiple input/multiple output (MIMO) technology mean 11n also offers better coverage and improved radio frequency reliability and consistency. Access points can be spaced farther apart, if desired, but the better signal may more effectively be used to achieve higher access rates. Multipath, which previously degraded signal quality, is now used to good effect by MIMO to reduce the effects of fading and interference.

There are other benefits of 802.11n. First, it's essentially the fourth generation of the 802.11 standard, yet despite the evolution, each revision is backward compatible on both clients and access points, albeit at lowest common denominator rates. Companies can upgrade gradually because 802.11n clients work with 802.11a/b/g APs, and vice versa.

Second, as the market developed, amendments have been added to address deficiencies in the original 802.11 specification. The most significant are 802.11i, which deals with security, and 802.11e, which introduced quality-of-service features. Architectural approaches also have broadened. First-generation access points were standalone, with little to assist IT in terms of scalability, RF management, and Layer 3 roaming. Startups generally swung to the opposite extreme and centralized everything, leading to what pundits called "thin" APs.

With development of 802.11n and its higher traffic rates, a more sensible distributed approach, first used by Colubris in 2005, has evolved. The management plane remains centralized, as is common in any enterprise service framework, but the control and data planes can be placed at the core, edge switch, or access point. Motorola calls this "adaptive AP," while Trapeze has taken the moniker "Smart Mobile." Even Aruba, with its emphasis on centralized data flows, provides flexibility as described earlier with its Mobile Remote Access Point. Even if the WAN link is interrupted, connections stay up and local traffic will continue to be switched locally.

With 802.11n just around the corner, early adopters whose 802.11b/g gear is nearing end of life face a conundrum: Pay top dollar for 802.11n, stick with b/g, or add 802.11a support to their access points by buying new gear or moving to a different vendor. While 802.11a buys some advantages, at this point we recommend sitting tight until prices, AP maturity, and/or standard adoption are such that you feel comfortable upgrading to 802.11n. In fact, Aruba has a new marketing pitch: Buy its 802.11a/b/g APs today, and buy a key later to activate 802.11n. This approach helps customers split their costs over time--and assures Aruba market share.

It doesn't help purchasing decisions that the 802.11n standard isn't complete. Working group approval is tentatively scheduled for March 2009, many months past predictions. Vendor adoption of the draft 2.0 spec, along with all the pre-standard chipsets already in use, make it highly unlikely that a final standard that's incompatible with existing products will be adopted. Nevertheless, we can't argue the logic of waiting. Second-generation standards-based 802.11n products, even if functionality equivalent, will have many of the bugs and kinks--for example, 802.3af Power over Ethernet support--worked out. Prices will drop, and processes regarding site planning, installation, and maintenance will be better defined.

Enterprise network administrators also are concerned about reliability. Will that unforgiving terminal session or enterprise application drop every time the microwave goes on in the cafeteria? There remain a plethora of wireless supplicants, and connectivity is still not as certain as with Ethernet. With proper device selection and configuration, connectivity bugs can be minimized, but there's still room for improvement. Most users will trade a few connectivity blips for mobility. Some won't.

Voice Options For The Wire-Free Office




Works anywhere with wired on laptopor wireless connection; wide PBX support

Laptop must be on to take a call; requires headset or earpiece

Mobile cellular phone

Form factor and experience well-understood by users; variety of providers and pricing plans

Indoor coverage typically challenging; no PBX integration; may not be acceptable for regulated industries

Voice-over-Wi-Fi handset

Truly portable voice option; coverage wherever your WLAN reaches

Few PBX vendors offer Vo-Fi systems; requires strict attention to RF design

e-FMC phone

Best of both worlds that supports cellular and Wi-Fi

Usually requires integration and sophisticated handsets; nascent market

Despite all the performance and other benefits of 802.11n, there are still questions about reliability, performance, legacy devices, integration into the existing wire-centric infrastructure, and market dynamics.

RF remains a black art, and although MIMO makes Wi-Fi more reliable, it's still no guarantee that interference won't interrupt. For starters, good planning is required, perhaps using a tool such as Cisco's Spectrum Expert (formerly Cognio), which identifies possible sources of interference. There are also architectural approaches to address the reliability problem. Meru's newest 802.11n access point, the AP400, was designed for robustness. Its four built-in radios can operate simultaneously, on different channels; interference on one channel or band doesn't prevent a client from roaming to another radio. Another approach, used by Ruckus Wireless and Xirrus, is to employ directional antennas. These approaches are still considered a bit unconventional, but they're worth watching.

If aggregate performance is a key issue, legacy clients that operate only in 802.11b mode may need to be replaced or upgraded. That's not always possible with older Vo-Fi handsets, portable scanners, and other application-specific devices. In these cases, moving nonlegacy clients to the 5-GHz band, where there's great channel selection and support for multiple 40-MHz channels, may be prudent. That way, the legacy clients won't impact the peak-performance capabilities of the 802.11n-capable gear.

The challenge of consistent network management between wired and wireless networks is also vexing. Even Cisco, which leads in market share in both segments, doesn't have a management interface between both platforms. As HP points out, enterprises aren't eager to layer on a different set of intrusion-detection and -prevention systems, security, and network-access control tools for the wireless environment. For now, you will need different sets of tools for managing wired and wireless networks, so for organizations that do both, back-end support costs will rise, not fall.

Illustration by Nick Rotondo

Continue to the sidebars:
Rollout: AirWave's WLAN Management Suite Put To The Test,
Copper Costs Lots Of Pretty Pennies
Voice Is A Bump On Road To Wireless
Continue to the story:
Building Better Branch-Office Wireless

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