Once deeply mistrusted by carriers, Wi-Fi is now a key part of their strategy to deliver a decent quality of experience, especially for video, without breaking their 3G networks. Many specialist vendors, such as BelAir and Ruckus Wireless, have risen to the challenge, but Cisco is always the big gorilla when it comes to Wi-Fi. The firm sees data offload and video optimization as two essentials of the cellco’s new toolbox, and both are categories where it has established platforms which can help it extend its reach within the mobile operator community. Most of the headlines at last month’s Mobile World Congress went to its MOVE platform for video, which integrates its Videoscape content delivery network into its packet core, but the giant also unveiled its carrier grade Wi-Fi strategy, including support for the latest in the alphabet soup of 802.11 WLan standards, 802.11u, which addresses offload.
Like most Cisco platforms, Carrier Grade brings together existing and upgraded elements and glues them together. The centerpiece of the range is the latest in the Aironet family of access points, the 1550 Outdoor device. This incorporates Cisco’s Clean Air technology, which helps the network route around any interference to improve quality of delivery in unlicensed and sometimes congested spectrum. Clean Air first appeared last spring in enterprise wireless routers and is now being expanded to the outdoor public access market.
As well as promising fast speeds, using 802.11n, and better QoS, Cisco is also addressing the walls that still exist between the cellco’s 3G and Wi-Fi networks. When a customer moves onto the WLan, he or she becomes invisible to the carrier, and the user has to choose to switch to a hotspot when it is in range, which can be an awkward experience. Cisco is addressing this with its Next Generation Hotspot system for the Aironet 1550, a platform for authentication and roaming. “We are positioning this as a peaceful coexistence with 4G. Both have a role,” Jaishree Subramania, product marketing manager for mobility, said in an interview at MWC. “The very foundation of our approach is a carrier-grade system across the entire network architecture. The key is the unification for architecture. It’s all about delivering consistent Wi-Fi experience across a variety of environments, and all of this can be managed and controlled from a single point in a carrier network.”
Also helping to achieve seamless roaming and offload is 802.11u, which Cisco will support in the new architecture. This allows Wi-Fi access points to advertise themselves and devices can then connect to them using SIM-based authentication, without the user having to select an SSID number. The new standard extension goes beyond the previous technology for 3G/Wi-Fi interoperability, the 3GPP’s UMA (Unlicensed Mobile Access), which is used by carriers like T-Mobile for fixed/mobile convergence, mainly in the home. Approved last month, 11u allows the WLan to detect a user and advertise its services (provided the device supports the standard). The device sends a query to the access point asking for an NAI (network access identifier) realm list, which includes all the cellcos that are allowed to move a subscriber automatically onto a hotspot. If the carrier in question is on that list, the device can be automatically authenticated and offloaded without user intervention.
This will not happen overnight ‘ not only do device makers need to support the standard in their upcoming dual-mode handsets and tablets, but roaming deals need to be struck to get the cellcos onto the NAI lists. Cisco is already working with Orange on 802.11u roaming and with Samsung in complaint smartphones.
Chris Kozup, Cisco’s director of borderless networks, says offload is just the start and 11u can also ‘pave the way for new service delivery’, such as retailers offering instant coupons to people coming into their stores.
Such applications would harness not just 11u but the Mobility Services Advertisement Protocol (MSAP), which allows 11u devices to obtain local information as they authenticate. “802.11u might be able to advertise that there are services available, while MSAP is the protocol that get the service into an app to be delivered down to a device,” Kozup said. “We about the delivery of transient application, so when the device is in the proximity of the hotspot it has the ability consume the app and when the device is outside hotspot, we don’t necessarily want the application to remain on the device.”