Cisco’s partner Agito Networks will be making use of this particular function and providing the mobility controller. According to Pejman Roshan, Agito’s co-founder and VP of Marketing, the key to providing an effective handoff between the WLAN and the cellular network is to have a clear view of the status of both networks as well as the device itself. He notes that the client software allows the handset to monitor the quality of the cellular coverage based on signal strength, but it needs a better view of what’s going on in the WLAN to determine which network would support the call best. The MSE provides Agito’s Mobility Router with a composite metric of user location and WLAN availability so they can make an intelligent choice as to whether a call should be handed off. For example, the MSE might signal that they should hand off the call to cellular, but if the client signals that the cellular service is poor or non-existent, they might choose to leave the call on the wireless LAN. Along with the network metrics, the Mobility Router can also consider factors such as battery state (cellular is more battery-efficient than Wi-Fi), session quality, or user defined policies.

THE ARCHITECTURE

The bigger part of the announcement is the architecture (Figure 2), which describes a framework in which developers can build applications that link to the wireless network. The definition of the “wireless network” can now extend beyond Wi-Fi.

The applications access the mobility services layer over a set of SOAP/XML-based open APIs allowing applications providers defined service links to the wireless network. At the network layer, the wireless controllers use CAPWAP (the Control And Provisioning of Wireless Access Points protocol) to communicate with the thin access points that compose a WLAN switch implementation. The CAPWAP working group is now splitting the specification, a move that will allow it to address other technologies including wired Ethernet, cellular, WiMAX, ZigBee, and Ultra Wide-Band (UWB).

FIGURE 2

Cisco argues that their architecture will provide for better scalability, as the network controllers are configured with a high capacity data path while the MSE will feature a high capacity CPU. In centralized WLAN switch architectures like Cisco’s, all of the traffic on and off the wireless LAN is passed through the wireless controller, and controller capacity is becoming a concern with the higher-capacity 802.11n radio link.

THE STRATEGY

Cisco is clearly looking to change the rules of the wireless LAN game. They now enjoy a dominant market share in wired and wireless local area networks, and their share of the IP PBX market is growing. The only other vendor with a product line nearly this wide is Siemens, which has an IP PBX, a wireless LAN solution (through their Chantry group), and what may be a superior unified communications solution in their OpenScape platform.

Cisco can now describe a more comprehensive picture of enterprise mobility with the Mobility Services Engine, and by enhancing CAPWAP, they can expand the definition of the “wireless network” beyond Wi-Fi. Open interfaces will allow them to attract partners to develop application solutions that depend on functions that are unique to their wireless products. The key element in this strategy is that Cisco products are at the core of the infrastructure.

CONCLUSION

Mobility is becoming one of the key drivers for enterprise communications, and that vision encompasses voice, data, and applications services. This emphasis on mobility is taking Wireless LAN technology from being a convenience to an essential part of the business environment. Cisco is describing a vision that combines WLAN voice, fixed mobile convergence, and mobile unified communications to provide the core elements for developing wireless communications-enabled business processes.

It will be interesting to see how the other WLAN, IP PBX, and unified communications vendors respond to Cisco Motion. The big question is whether the IP PBX and UC vendors build interfaces that tie into the architecture. In the WLAN area, the announcement has certainly added a new angle to the debate over centralized versus distributed WLAN switch architectures. The other WLAN vendors will have to start working on ecosystems of their own or risk losing market share to the Cisco juggernaut.

Cisco Motion Delivery Schedule
May 2008: Wireless Network Software Release 5.1
June 2008: Mobility Services Engine (MSE); Context-Aware Location Software
2nd Half 2008: Mobile Intelligent Roaming Software; Adaptive Wireless Intrusion Protection System
1st Half 2009: Secure Client Manager Software