Many mobile operators are expanding into Service Provider Wi-Fi to complement their 3G and LTE rollouts. Stephane Daeuble of Nokia Solutions and Networks outlines four key areas gained from their experience. He thinks HotSpot 2.0 won't be an "instant fix" for mobile operators , and explains how traffic steering between Wi-Fi and Cellular can be achieved today using other traffic steering mechanisms and early implementation of ANDSF and ANQP.
Nokia Solutions and Networks Wi-Fi heritage
NSN (which no longer has the Siemens association) have been quietly working on Service Provider Wi-Fi solutions for the past 4 years. They've concentrated on the core network and gateway products rather than the Wi-Fi access points, for which they partner with Ruckus Wireless. They claim to be the first to productise an integrated Cellular/Wi-Fi solution based on the 3GPP Release 8 standards.
Their approach is based around four key areas:
1. Carrier Grade Wi-Fi radios
Ruckus Wireless Access Points provide the wireless links, with service provider capabilities including robust, ruggedized casings, Power-over-Ethernet, adaptive beam-forming and high capacity (both in total number of connected devices as well as throughput).
2. Integration of Wi-Fi into the 3GPP core network
NSN's network and device management elements allow Wi-Fi radio networks (stand alone Wi-Fi Access Points or combined cellular/Wi-Fi small cells) to be integrated into an operator's existing 3GPP core network and other back end infrastructure. They have devised a way for smartphones to be provisioned with automatic access to Wi-Fi without the need to re-enter a username/password each time by using EAP-SIM authentication.
This system is already live in a number of commercial mobile networks and allows operators to enable public access Wi-Fi from any roaming partner access point with only a one-time acceptance of the Wi-Fi settings on their smartphone or tablet device. This would include, for example, Starbucks, Conference centres, foreign Wi-Fi networks and (for fixed/mobile operators) all their residential Wi-Fi access points.
This provides a seamless experience for end-users, where Wi-Fi "just works" and provisioned subscribers no longer need to re-enter passwords each time they want to connect in a new location. By having the Wi-Fi radio always turned on in the device, the subscriber can rely on the mobile operator providing a superior services by the most suitable radio link available, whether cellular or Wi-Fi.
This solution does require EAP-SIM capability within the smartphone/tablet device, which has been embedded in most devices shipped in recent times.
3. Personalise the Customer Experience
Customer Experience Management (CEM) tools can monitor and segment end-user behaviour patterns, providing insights into what different groups of users are doing.
Distinct groups of users can be identified and provisioned with appropriate parameters, such as prioritising those higher value customers on premium tariffs. Operators can develop a segment by segment Wi-Fi adoption campaign, either to increase revenues directly from the service or by bundling it with selected tariffs
4. Wi-Fi traffic steering
This is a key issue for operators and has seen the most recent. The goal is how to manage Wi-Fi like any other RAT (Radio Access Technology) to ensure that users get the best experience at all times using all available radio resources.
NSN have used three specific features towards that goal:
ANDSF (Automatic Network Discovery and Selection Function)
ANDSF is a 3GPP standard feature which operates using a set of static rules provisioned to each subscriber's device based on location, time and application usage, etc. When a pre-defined rule is met and a Wi-Fi network is available, the subscriber is then handed out to Wi-Fi. While this provides a nice way of handling predictable traffic patterns in a preventative manner, it does not handle more dynamic loading scenarios.
Also, ANDSF requires newer devices that are only now coming to market.
Like the one launched by NSN, one way to accelerate wider-use of ANDSF is a software client that runs on smartphones and enables ANDSF capabilities on existing recent smartphones and tablets meaning operators do not have to wait for increased ANDSF device penetration.
Dynamic Load Based Traffic Steering
NSN claim to be the first to launch this feature late 2012. It enables operators to set rules to automatically push different groups of users across to Wi-Fi in a controlled manner based on dynamic network loading information coming from Wi-Fi and the 3GPP cellular networks. For example, this allows Bronze and optionally Silver customers to be offloaded to Wi-Fi at peak times while retaining Gold users on 3G or LTE to provide a more consistent service level. At other times of day, everyone might be retained on the cellular network.
This ensures that when users are "pushed to" Wi-Fi they get a good experience while maintaining a balanced load across all available radio layers. Otherwise, without such a mechanism in place, subscribers may be forced onto a congested Wi-Fi network when the 3G/LTE network has plenty of spare capacity - significantly damaging customer satisfaction and leading to many LTE subscribers starting to disable Wi-Fi on their smartphones when outside of the home/office.
The additional benefit of NSN Dynamic Load Based Traffic Steering solution is the fact that it is compatible with almost all existing Wi-Fi capable smartphones, which is important in the short to medium term for operators to maximise their deployed Wi-Fi network.
ANQP (Automatic Network Query Protocol)
ANQP is another feature of HotSpot 2.0, complementing ANDSF and Dynamic load based traffic steering.
This feature is used by devices after they have switched to Wi-Fi, steering the device to the most suitable and better performing Wi-Fi access points.
Using ANQP, a mobile device can discover a range of information from each Wi-Fi access point, including details of which roaming partners are accessible and the level of congestion. The device can then make a more informed decision about which Wi-Fi network and/or access point to select and attach to next.
Our thanks to Stephane Daeuble, Senior Product Marketer for Small Cells Nokia Solutions and Networks, for help in preparing this article