* First Industrial opts for 'cooperative' WLAN architecture
Despite the deafening 802.11n buzz in highly mobile and bandwidth-intensive university and healthcare environments, not all organizations are ready to buy into the pre-standard technology. First Industrial Realty Trust, for example, is currently building a 50-site 802.11a/g network. And it is doing so with a controller-less architecture.
The nationwide diversified industrial real estate company is in the process of covering its Chicago headquarters and 40 worldwide branch offices with distributed access points (AP) from start-up Aerohive. The Aerohive gear uses a so-called “cooperative control” architecture that functions conceptually much like a mesh router network: APs use special control protocols to discover one another and exchange state and best-path information. However, AP provisioning, configuration and policy setting are centralized at a special management console.
First Industrial will deploy 802.11a, which operates in the 5GHz band, in high-density areas such as its Chicago offices where the 2.4GHz frequency is cluttered with “thousands of Wi-Fi radios,” says Nick Colakovic, director of IT. He says he would rather have deployed 802.11n, but the final standard, not expected until spring 2009, has taken too long to materialize.
“There will be no pre-standard N here. We don’t believe in interoperability testing” of pre-standard products, which the Wi-Fi Alliance is currently conducting. “And you can’t really run all the [11n] radios you want off a standard power-over-Ethernet environment” because the aggregate power requirements are too great, he says.
Colakovic searched for a controller-less approach to save the capital and operational expenses associated with buying and operating many WLAN controllers.
“We have quite a few locations,” Colakovic explains. “To deploy a controller costing five figures in each location is extremely expensive, and many have disks that must be maintained and can fail. We’d need a full-time staff person to maintain that infrastructure.”
Having the control functions embedded in intercommunicating Aerohive APs eliminates the need for wireless LAN controllers that have gained prominence over the past five years. Colakovic estimates a 48% savings in capital costs using the controller-less architecture, a number that “would be much higher if we figured in the soft costs,” he says.
Many suppliers of controller-based WLANs do require or recommend at least a low-end controller in each branch site. However, most are also making available alternatives that can eliminate the local controller by using approaches such as local bridging and smart or adaptive remote APs.
