Chargeable User Identity - Billing and analytics with privacy

As mobile and wireless networks have evolved, the ability for users to move between different networks while maintaining service, known as roaming, has become essential. WiFi roaming, while convenient for users, introduces several complexities for service providers, particularly in managing billing and user identity securely across network boundaries.

The Chargeable User Identity (CUI) parameter was introduced to address these challenges. While the specification RFC 4372 for CUI has existed for quite awhile, the implementations are now popularising as commercial Wi-Fi is becoming more sought after.

Chargeable User Identity uses and benefits

Chargeable user identity is a parameter used mostly by service providers to identify users for accounting in roaming networks, while ensuring their privacy is not compromised with trackable credentials. The CUI allows service providers to charge users based on their usage, even when users roam across different networks. It is primarily intended for billing purposes, but also provides other benefits to both public and commercial networks.

The main benefit of using Chargeable User Identity parameter is that it solves the business problem of anonymity in commercial networks, while not making any compromises in privacy and security. It provides a robust mechanism for calculating usage, which can be used not only for billing but also analytics purposes. For example, with CUI, roaming network providers can track whether their 100 sessions come from 10 users with 10 sessions each or by 2 users with 50 sessions each. This allows for more accurate analytics, but does not allow the networks to identify the users. This is possible in deployments where the CUI is the same across all of the user’s devices.

The use of Chargeable User Identity also allows public institutions to restrict and ban roaming users who violate their terms. Previously, when administrators decided to take action against users who violate their visiting terms, the user can simply log on with another device. With a CUI parameter that is mutual across user’s all devices, this is not possible.

Chargeable User Identity deployment

Chargeable User Identity is transmitted in RADIUS packets using dedicated RADIUS attribute 89: Chargeable-User-Identity. The implementation is specified in RFC 4372.

Upon sending the authentication Access-Request to the home organisation for a roaming user’s authentication, the visiting organisation should add the Chargeable-User-Identity parameter into the request with a null value. This signals the home organisation that a CUI is requested. The home organisation check’s for an existing valid CUI and sends either a new or existing valid CUI included in the Access-Accept.

The Chargeable-User-Identity parameter will remain the same for the duration of the roaming user’s session and is included in the accounting packets and responses.

Want to know more?

Are you looking to deploy Wi-Fi offloading or other Wi-Fi roaming functionality for your customers or members of your organisation? Or are you setting up a commercial Wi-Fi infrastructure to provide roaming services for operators? For both cases, Radiator AAA is the product for you.

Radiator AAA provides functionality for Wi-Fi roaming host organisations, with dozens of completed deployments for the biggest Wi-Fi roaming networks (eduroam, govroam, OpenRoaming). Combined with the Radiator SIM Pack, Radiator provides seamless authentication for Wi-Fi offloading, roaming between mobile networks and Wi-Fi. Both products and use cases include Chargeable User Identity function for Radiator.

For more information about CUI deployments, please contact our sales team at sales@radiatorsoftware.com

Cutting roaming costs and expanding coverage with Radiator SIM-based authentication.

Modern SIM-based devices, like smartphones and tablets, are able to join and switch between different networks automatically. This is especially valuable to mobile operators who want to offload data from their mobile network to a nearby Wi-Fi network, because Wi-Fi connections are significantly cheaper to operate. It also enables Wi-Fi providers to monetize their Wi-Fi net- works and provide services in partnership with mobile operators. In addition, with use of OpenRoaming or other Wi-Fi roaming services, it also provides a way to expand the coverage of carrier Wi-Fi.

Use cases for the SIM authentication include:

Wi-Fi Offloading:

In busy locations with high volumes of mobile traffic like sports stadiums, shopping malls, public transport hubs and underground metros, SIM-based devices can automatically switch from mobile data connections to local Wi-Fi networks. Transferring the data traffic to Wi-Fi networks reduces the load on the mobile network, which improves the coverage and the user experience. In addition, using Wi-Fi roaming services, such as Orion Wi-Fi or OpenRoaming, can further reduce costs when carriers can use these additional services for Wi-Fi offloading.

Voice over Wi-Fi

SIM-based devices can also switch voice calls from mobile networks to Wi-Fi networks, and this kind of call is known as Voice over Wi-Fi. As with data traffic, switching traffic from regular calls to Wi-Fi networks can help carriers and operators to reduce the load on the mobile network, enabling better call quality and continuity.

Wi-Fi Roaming

When a SIM-based device automatically joins a Wi-Fi network or switches to another one, this is called Wi-Fi roaming. Wi-Fi roaming is used to maintain an uninterrupted data connection when the user moves from location to location, or when the current Wi-Fi connection is overloaded or when the signal is weak. In these situations as well, using OpenRoaming and other Wi-Fi roaming services can expand the coverage for mobile carrier.

Wi-Fi SIM-based authentication is essential to making these capabilities work. Before a device is allowed to join a new Wi-Fi network, it must be authenticated using the IMSI*. For this reason, Wi-Fi SIM-based authentication is supported by the latest Android and iOS mobile devices. However, there are still some security issues with this type of authentication. As a result, mobile OS manufacturers are now pushing for even better security on Wi-Fi networks and they require IMSI Privacy Protection with all new OS versions.

How can Radiator help you in this?

The Radiator SIM Pack for Radiator AAA Server Software makes it easy for operators to enable IMSI Privacy Protection. It is the key component needed for secure and seamless switching between mobile and Wi-Fi networks using SIM-based authentication. The Radiator SIM Pack also provides all the functions required for a 3GPP AAA Server.

IMSI privacy is a key feature of the Radiator SIM Pack, and it provides server-side support for permanent identity protection during Wi-Fi SIM-based authentication, Wi-Fi offloading and VoWiFi, resulting in a higher quality user experience. You can read more about Radiator SIM Pack and IMSI Privacy protection from our IMSI Privacy whitepaper.

In addition to this, Radiator provides also all the services and products needed when joining to  Wi-Fi roaming services, such as OpenRoaming, or when connecting to mobile carrier infrastructure by using Diameter interfaces.

Would you like to know more?

If you would like to know more about Radiator, SIM authentication, IMSI Privacy, joining OpenRoaming etc., and how we can help you in your use case, you can always contact our team at info(a)radiatorsoftware.com. Looking forward to hearing from you!

*) In SIM-based mobile devices, like smart phones and tablets, the user’s unique identifier is stored on the SIM card in a standard format known as the International Mobile Subscriber Identifier, or IMSI for short.

Connect to OpenRoaming™ with Radiator

Wireless Broadband Alliance (WBA), provides OpenRoaming™, a roaming federation service enabling an automatic and secure Wi-Fi experience globally. It creates a federation of networks and identity providers to enable automatic roaming and user onboarding on Wi-Fi. More information can be found from WBA OpenRoaming™ pages or from the video below.

 

Recently, we have seen developments where carriers and other organisations, such as universities, are embracing OpenRoaming™ for their guest Wi-Fi access. This industry backig and focus on end user experience is one of the key benefits of OpenRoaming™.

As OpenRoaming™ becomes more integrated in the Android and Apple devices, the host organisations do not need to worry about how they will provide guest user credentials for guests. The guests will already authenticate with Apple, Google, participating operators and even in the future with Facebook credentials to guest networks without requiring host organisations to instruct them or provide configuration to their devices. For users, this development would bring significant benefits: secure and easy access to the Wi-Fi network wherever they go.

Radiator Software, being a WBA member and solution provider, can provide your organisation the products and services you need in order to join OpenRoaming™.

Radiator supports OpenRoaming™ requirements

For OpenRoaming™, support both for RadSec and DNSRoaming protocol is needed in order to implement the roaming securely and without extra effort to the end user. Radiator AAA Server supports both these protocols as can be seen from our product page. With RadSec, we are proud to tell that Radiator was the first commercial AAA Server where the protocol was implemented.

At the same time, we have 20 years of experience for providing roaming solutions to our Radiator customers - especially for international roaming federations suchs as eduroam and govroam. For these customers, we can of course provide assistance when joining OpenRoaming™.

Interested in joining OpenRoaming™ using Radiator?

For OpenRoaming™, our team can offer you a complete package: providing the software and the installation and the configuration assistance in order to join OpenRoaming™. After this, with Radiator support, you can ask for any later on assistance needed if for example configuration changes are needed.

Please contact our sales team at sales@radiatorsoftware.com