Motorola Enterprise WLAN Controller Buyer's Guide

By Lisa Phifer | Feb 25, 2011 | Print this Page
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In this installment of our WLAN Controller Buyer's Guide, we consider controller products offered by Motorola Solutions and how they fit into Motorola's wireless LAN (WLAN) portfolio. According to Senior Marketing Manager Alan Lopez, Motorola's line of WLAN access points (APs) and controllers are designed to meet diverse needs at low total cost of ownership.

"The WiNG5 architecture is Motorola's secret sauce," he said. "With key advantages like built-in SMART RF management, remote troubleshooting, and a deployment approach that doesn't require VLAN re-architecting, we believe the efficiency of our solution is second to none."

Simply put, WiNG5 is a descendant of the original "thin access port" architecture patented by Symbol, acquired by Motorola in 2006. "Symbol founded the controller-based WLAN architecture," explained Sunalini Sankhavaram, Motorola Enterprise Mobility Director of Product Management. "But with 802.11n, WLANs have six times the speeds and feeds, which can turn the controller into a choke point"

"That lead to the WiNG5 architecture, where we can now offer all mobility services at the edge of the network, without adding choke points or requiring redundant hops. With WiNG5, all control and data plane functions are now available at the access point. Essentially, our adaptive APs can become virtual controllers," she said.

Flexible network design

Of course, this evolution does not mean that Motorola no longer offers dedicated WLAN controllers. Rather, customers now have a broader set of devices from which to choose to perform control functions.

"We offer flexible deployment architecture so that customers can fit wireless into their current network design," said Sankhavaram. Some customers want to deploy only APs at the network edge, managed by a central WLAN controller at the NOC. As before, those customers can forward all traffic back through the NOC controller if they wish.

However, customers can now opt to deploy adaptive APs in every remote office, using at least one AP at each site as a virtual controller. The NOC controller manages configurations for the entire WLAN, while adaptive APs provide local control functions, and all APs perform data forwarding. "This gives customers one point of configuration, but many points of enforcement," said Sankhavaram.

The line-up

To see how components fit together, let's take a quick tour of Motorola's WLAN portfolio, starting with its AP line-up.

  • The AP 300 is a traditional thin 802.11a/b/g AP used in venues with reliable uplink to a controller, such as a large office building or campus. AP 300's can be uplinked at layer two or three, but are not operational until "adopted" by a controller. Customers seeking a thin 802.11n AP should consider the dual-radio, dual-band concurrent AP 650.
  • In contrast, adaptive APs like the AP 5131 (802.11a/b/g) and AP 7131 (802.11a/b/g/n) can operate in two modes: stand-alone or controller-adopted. This can change over time, such as when a previously-adopted AP must survive loss of controller contact to deliver stand-alone services. The AP 5181 and AP 7181 are siblings for outdoor/mesh rather than indoor deployment.

In Motorola's lingo, dedicated controllers are referred to as wireless services controllers or RF switches (RFS). Uses range from campus/warehouse to branch office as follows:

  • The RFS 7000 can control up to 1024 adaptive APs or 256 thin APs. Up to 12 RFS 7000's can be clustered for capacity or redundancy. For example, an RFS 7000 cluster might support as many as 96,000 users in a heavily centralized WLAN.
  • Each RFS 6000 can control up to 256 adaptive APs or 48 thin APs, in clusters up to 12. The RFS 6000 is slated for medium-to-large enterprise WLANs, including sites that require broadband WAN fail-over.
  • The RFS 4000 can control up to 6 adaptive or thin APs, with similar clustering. This model can even include an on-board dual-band 802.11n AP for customers seeking a self-contained small business or "branch in a box" solution.

Mix-n-match

All three controllers can supervise any of the adaptive or thin APs listed above. Customers can therefore combine these based on geography and workload. For example, a typical enterprise might need to cover a data center, two or three large corporate offices, and many field offices.

"From a WiNG5 perspective, field offices with less than 50 users can deploy an adaptive AP to handle all traffic locally. Corporate offices with hundreds of users might deploy WLAN controllers and thin APs. But you don't have different policies for each location; you just push all policies out from the data center to every [site]," said Sankhavaram.

"So why do I deploy adaptive APs in some locations and controllers elsewhere? A single 7131 adaptive AP can manage up to 24 other adaptive APs. Beyond that, you'd want a controller. It's a function of scale--there is no compromise on mobility or security," she said. RFS 6000 or 7000 controllers are recommended for large installations, no matter which kind of APs are deployed.

However, an RFS is probably not the only product back at the data center. There, Motorola offers modular network, security, and assurance management solutions that run on an AirDefense Services Platform:

"We build our APs to be leveraged by AirDefense in order to reduce TCO," said Lopez. Cost analysis data and comparisons are posted on Motorola's website.

Pushing control to the edge

According to Sankhavaram, policies relating to network services, quality of service, security, and availability are managed by controllers, pushed from controllers to APs, and enforced by APs. During loss of communication, adaptive APs become a virtual controller for their site by performing all control plane functions, using local copies of policies.

For example, Motorola controllers include network services such as DHCP, DNS, and RADIUS servers. Every adaptive AP maintains a synchronized copy of the centrally-defined RADIUS user database. In case of WAN outage, an adaptive AP can automatically turn into a virtual controller, using its copy of the user database to authenticate new sessions without disruption.

A similar split exists for dynamic radio resource management. "SMART RF is available on all controller models," said Sankhavaram. "If an adaptive AP loses communication with a controller, APs still coordinate among themselves. If one AP fails, others increase power to cover dead spots or can change channels to mitigate interference."

However, there are some advanced application services that adaptive APs cannot perform. "One example would be geo-fencing. Both controllers and adaptive APs can deny or limit WLAN access based on user location. But advanced application services are available only on [dedicated] controllers, such as Ekahau location based services and RFID management," she said.

Finally, Motorola argues that its controller portfolio delivers cost-effective scalability. "Up to 12 controllers can be clustered for a single point of policy enforcement, and cluster members can talk to each other to load-balance APs across the entire WLAN," said Sankhavaram. "For redundancy, you can add a zero-AP-license controller. If another controller fails, it can adopt not only those APs, but also its AP licenses."

Bottom line

Ultimately, Motorola believes that its WiNG5 architecture, mix and match deployment model, integrated network services, and support for clustering create a cost effective, scalable solution. To learn more, visit Motorola's WLAN products page or download this portfolio overview [PDF].


Lisa Phifer owns Core Competence, a consulting firm focused on business use of emerging network and security technologies. An avid fan of all things wireless and frequent contributor to Wi-Fi Planet, Lisa has reviewed, deployed, and tested 802.11 products for nearly a decade.