Bell Labs has global wireless roaming breakthrough

MURRAY HILL, N.J. --  Researchers at Bell Labs have announced a software breakthrough that will enable global roaming across all wireless network types, including third-generation (3G) technologies such as CDMA2000, Universal Mobile Telecommunications Services (UMTS) and other high-speed data access technologies such as 802.11.

The software architecture, called Common Operations (COPS), will allow mobile subscribers to access voice and data services, information, and messages when they are roaming outside of their home network, even in regions where different types of wireless networks predominate. It will also help mobile operators to upgrade and manage their networks more efficiently, improve operational performance, and reduce errors and expenses. 

COPS features a  "protocol gateway" capability that translates data from networks employing a variety of protocols into a single, common language. This makes it possible to maintain a single subscriber profile -- including authentication, authorization and location data -- that can be accessed from a variety of network types. Bell Labs is the research and development arm of Lucent Technologies.

"As next-generation high-speed mobile data networks emerge and new mobile Internet services are introduced, IP and cellular systems must be able to route calls and deliver services to one another efficiently," said Paul Mankiewich, chief technology officer of Lucent's Mobility Solutions Group. "This breakthrough from Bell Labs will, in the near future, help mobile operators to meet the demand for high-bandwidth services from increasingly mobile subscribers."

Problems with roaming

Global wireless roaming is not possible today because various wireless network types cannot work together to identify, electronically, the location of mobile subscribers. For example, a subscriber whose mobile operator uses Code Division Multiple Access (CDMA) technology is not currently able to access services when roaming on a Global System for Mobile Communications (GSM) network.

For a subscriber to initiate a mobile call or activate services such as voicemail, the wireless network must be able to identify the subscriber's location, obtain the subscriber's profile (listing the allowed services), validate the caller's right to the services and then authenticate the caller. Home location registers (HLRs), which are databases of subscriber information, currently perform these functions only when wireless subscribers travel in their home networks, or, in some cases, when roaming on networks employing similar technology.

COPS provides a generic interface to key HLR functions, translating user data and signaling technologies from cellular protocols to Internet protocols (IP) and vice versa automatically. This allows several protocol-specific gateways to be built, each allowing data stored on the HLR to be accessed by a different type of network. Building an HLR with this software architecture allows for customer databases that can be updated automatically, accessed by multiple network types, and support both voice and high-speed data services.

Signaling protocols

With COPS, if a mobile operator were to change the type of signaling protocols used on the telecommunications switches of a particular network, the HLR associated with the previous signaling protocol would still be able to communicate with the network. This would allow operators to provide services across multiple network types without interruptions or the addition of multiple HLRs. 

"With this technology breakthrough, carriers will be able to more easily migrate from one network protocol to another without replacing the HLR," said Krishan Sabnani, vice president of Bell Labs' Networking Research Laboratory. "Additionally, callers will be able to use their phones the same way on a guest network -- including networks in other countries and regions -- that they do at home."