Guide to Enterprise Wireless LAN Systems
Top trends in the WLAN world
Changes in standards, convergence and product architectures drive the marketBy Craig Mathias, Network World, 10/1/07
Most observers of the wireless-LAN (WLAN) industry might have assumed that, more than 20 years into the evolution of the technology and the products based on it, we'd be, well, done at this point.
Let's see, we've got radios, protocols, a set of standards, lots of vendors, and lots of demand. We've got traditional office applications, a broad range of verticals, telemetry, voice, and more. We've got broad deployments across enterprises of all forms, and in public-space/metro and residential installations as well. In short, WLANs have seen phenomenal success, with more on the way.
But the idea of being "done" after a mere 20 years or so is rather abstract and theoretical in a field where the rate of innovation has never been greater – innovation driven by new technologies, market demand, and the fact that we still don't have a clear "best" way to build wireless LAN systems.
We started with the so-called "thick" access point (AP), the idea being that we would deploy these cellular-style and hand off client connections as they roamed within an area of coverage. It soon became pretty clear, though that a lot of the functions common to each AP could be centralized, and the switched WLAN was born. But I'm getting a little ahead of myself here.
It's difficult to pick the top five trends in a space where innovation influences every element, but I think there are in fact five key trends in enterprise-class wireless LANs today:
- 802.11n - .11n is the latest in a long line of standards produced by the IEEE 802.11 Working Group. 802.11, along with Wi-Fi, has been a key reason for the success of WLANs, just as 802.3 did for Ethernet. 802.11n is, however, perhaps the most important WLAN standard since the original of 1997. It's all about performance, moving throughput from today's 54 Mbps of 802.11a and .11g to as much as 300-600 Mbps, depending upon implementation. Sure, those are raw speeds, but we're seeing over 100 Mbps at Layer 7 today with early production products. More importantly, we're seeing better rate-vs.-range performance, corresponding to improved reliability. Capacity is the name of the game as WLANs become the primary and even default vehicle for almost all clients in the enterprise going forward. And, with the Wi-Fi Alliance now testing for interoperability, it's not too early to jump on the .11 train.
- Unified networks – The traditional model for WLAN installations has been the overlay – quite literally, overbuilding a WLAN on top of an area already provisioned with wire. We thus end up with two networks with common users but separate management, security, and operations. We're just now entering the era of unified networks, where the boundaries between wire and wireless won't be quite so defined. A common wired infrastructure with unified management is on the way, replacing today's separate networks with minimal points of intersection with, well, the LAN. Wireless will become the primary access for data, voice, and almost all client traffic, and wire will be used for stationary devices, interconnect of wireless components, and backhaul.
- VoFi – That's voice over IP over Wi-Fi. I've done enough experiments with VoFi to now be satisfied that a properly-provisioned WLAN infrastructure can in fact quite easily support a large number of high-quality voice connections. VoFi handsets are widely available, but the really exciting part is in trend #4.
- Convergence – There are already well over 100 cellular handsets on the market today that have built-in Wi-Fi. And many of those can be programmed to dynamically hand off voice and data traffic between these two radios. This is called mobile/mobile convergence, and it promises a future with a single subscriber unit that can quite literally do it all – voice and access to applications, in the office, in the home, and on the road.
- Architecture – Which brings me back to the point I started with, to wit: there is no trend in architecture. We still have traditional APs, and thin APs, as well as ultra-thin APs, "fit" APs, meshed APs, APs that can directly forward traffic without going through a central controller or switch, and APs that are ganged into Wi-Fi arrays designed to provide maximum capacity in a given area. The arguments over architecture won't be settled anytime soon, but it's a good bet that the tool needed for a particular job is going to be available, and often from multiple sources.
Innovation, like I said, is key to the future of WLANs as they race towards ubiquity. But even now we have excellent solutions meeting the needs of enterprise users today, and the trends noted above bode well for the future of enterprise wireless access.