by Steven J. Vaughan-Nichols

Five Reasons — Wait, Six! — to Start Considering WiMax Today

May 15, 20087 mins
MobileNetworkingSmall and Medium Business

WiMax just may turn out to be exactly what IT managers need for their corporate wireless needs, particularly if more users are going mobile. (And aren't they all?) Because these mobile hotspots are the size of a city.

It’s a Wi-Fi world, but Wi-Fi has its own set of problems. Now, mobile WiMax may provide corporations with another, better way of networking the mobile workforce.

Today, everyone in the user community swears by IEEE 802.11–based wireless networks. But IT people all swear at it. The high-speed, 100Mbps-plus, 802.11n standard still hasn’t been finalized; covering space adequately with PoE (power over Ethernet) 802.11g access points (APs) continues to be difficult; and it’s all too easy to overrun a single AP with too many clients.

So, while Wi-Fi is far too useful to consider getting rid of, it also continues to be an IT deployment and management headache. This is why mobile WiMax, IEEE 802.16e, is beginning to catch the attention of CIOs and CTOs.

Here are several good reasons to consider WiMax for your future wireless network needs.

1. Lower acquisition costs. Instead of worrying over dozens of 802.11 access points, their wiring and their power needs, you may need to install only a single Mobile WiMax AP.

One problem that the Sprint, Clearwire and the other major mobile WiMax companies are facing with their deployments is that they need gigantic Internet pipes to supply their bandwidth needs. A few T1s with their 1.554Mbps throughput don’t come close to meeting their needs. A corporate WiMax network shouldn’t require any more bandwidth than you’re currently using.

2. Interoperability with the public WiMax networks. Sprint, Clearwire, Intel, Google, Comcast, Time Warner Cable and Brightcove Network have joined forces to create a nationwide mobile WiMax network. Your mobile users will be able to use this network, just as they now use Wi-Fi hot spots to connect with the office. But the key difference, as Xohm President and Sprint Chief Technology Officer Barry West puts it, is that the hotspots will now be the “size of a city.”

3. No vendor lock-in. As Motorola’s WiMax solutions marketing manager, Ben Ansell, said, “For mobile WiMax to be seen as a truly open standard, products need to be interoperable.” The WiMax Forum won’t certify equipment unless it interoperates, so you can be sure that equipment you buy from one vendor will work with devices you get from another company. The bottom line: You can shop on the basis of price and quality without worrying over incompatibilities.

4. Broad vendor support. Mobile WiMax is a new technology, but there’s nothing so cutting edge about it that it will make you bleed IT money as you install it. This wireless technology has support from the big boys of computing: Intel, Cisco, Microsoft, Nokia and more than a hundred other major vendors.

This isn’t just lip-service support. Intel is incorporating WiMax into its next generation of laptop Wi-Fi chips, the Montevina/Centrino 2. These chips will start shipping in June. Nokia has already announced that it will incorporate this chip family into its next-generation Internet tablet, the N810. By year’s end, any new Intel-powered laptop you buy will have mobile WiMax baked in.

5. Lower management costs. The math here is easy. Would you rather maintain and monitor dozens of Wi-Fi APs per building or a single WiMax ground station? Would you prefer to support hundreds to thousands of 802.11 APs on a campus, or two to three WiMax stations? I think the answer’s pretty darned easy.

And here’s a bonus sixth reason. Newcomer Grid-Net has allied with General Electric and Intel to bring a new generation of electrical power meters to homes and businesses. These meters come with mobile WiMax built in. The resulting Smart Grid communications and networking platform promises to allow both the utility company and customers to be able to actively manage and control their electrical use and costs, and to make WiMax as ubiquitous as electrical power. American Electric Power and EnergyAustralia are already deploying these smart power meters.

The Techie Details

Mobile WiMax is quite new. Its IEEE standard 802.16e was only ratified in December 2005 as a set of amendments to 802.16-2004, the WiMax standard. These two standards work together in lockstep; without 802.16, there can be no 802.16e. The critical difference between the older foundation technology and mobile WiMax is that 802.16e can support mobile clients moving at up to 100Kmph.

WiMax has a maximum transmission range of 35 miles. However, distance quickly lowers the available bandwidth. For practical purposes, 10 miles is a more realistic limit in rural areas. According to Roger Marks, chairman of the IEEE 802.16 Working Group, one mile is a reasonable range to expect from mobile WiMax deployments in urban environments. In comparison, Wi-Fi has a range of several hundred feet, and two to three miles for 3G.

In theory, mobile WiMax can deliver 70Mbps on a single channel. In practice, range quickly attenuates its maximum throughput. Today’s WiMax modems can support a sustained bandwidth of 6Mbps.

Mobile WiMax can operate on any range from 700MHz to 66GHz, but in the Americas, it will operate at 2.5GHz. This lower bandwidth gives mobile WiMax better building and obstacle penetration. You could cover an entire office building with a single WiMax ground station/access point.

Unlike 802.11 Wi-Fi, WiMax incorporates QoS (quality of service) by assigning each device using its service an access slot. Depending on the overall use of the WiMax network and the kind of traffic the device requires, this slot may expand or shrink, but a device is also guaranteed a minimum amount of access to the network. In contrast, it’s all too possible for a Wi-Fi AP to be overwhelmed by multiple clients demanding simultaneous access.

It also delivers mobility to its clients by enabling ground stations to switch data transmissions as a mobile client moves between them. For practical purposes, 802.16e uses two different approaches. In the first approach, soft handoffs require a mobile station to make a connection to the next base station before switching off from the old base station. This works well for voice, multimedia, gaming and other latency-sensitive applications. It’s inefficient, however, for delivering normal Internet traffic such as Web browsing or e-mail, which tend to come in data bursts.

For this kind of traffic, a hard handoff, or break-before-make, works better. As the name implies, when Internet IP traffic is detected, the mobile WiMax devices first disconnect from one base station, for a delay of up to 50 milliseconds, before connecting to the next base station.

In addition, 802.16e added other features to improve its utility. Like 802.11n, mobile WiMax incorporates multiple input/multiple output (MIMO). MIMO enables networks to work efficiently with multipath distortion, which occurs when broadcast signals not following a line of sight bounce off large objects and end up out of sync, thereby scrambling the received transmission. MIMO turns this commonplace problem into an advantage by descrambling the distorted signals.

Unlike 802.11n, 802.16e is an established standard with broad vendor support. The WiMax Forum has two certification labs: one in Malaga, Spain, and the other, which just opened, at the University of Maryland in College Park, Maryland. For a device to pass certification, it must show that it interoperates with other vendors’ 802.16e equipment.

Do keep in mind that mobile WiMax is still in the process of being certified and deployed. That said, all the signs indicate that within the next year, mobile WiMax will become a serious contender for your networking budget dollars. You won’t want to deploy mobile WiMax in the next quarter, but you should start considering whether it’s a choice for your company in 2009. It really is coming in that fast.

Steven J. Vaughan-Nichols has been writing about technology and the business of technology since CP/M-80 was cutting edge, 300bps was a fast modem, WordStar was the state-of-the-art word processor, and we liked it that way. In addition, Vaughan-Nichols has been working with wireless technologies since aiming a microwave-carried T1 across the Goddard Space Flight Center campus.