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UMA enables dual-mode handsets

Dec 19, 20052 mins
Cellular NetworksNetwork Security

* Unlicensed Mobile Access brings cost and performance advantages to mobile services

UMA enables dual-mode handsets By Rajeev Gupta

UMA enables dual-mode handsetsBy Rajeev Gupta

Enterprise mobility is a boon for productivity and flexibility in the workplace, but also represents a significant expense to the bottom lines of most organizations. For IT managers, the promise of mobile and Wi-Fi convergence looks to lower cellular costs while increasing the performance of mobile voice and data applications.

Unlicensed Mobile Access (UMA) brings cost and performance advantages to mobile services and offers four benefits: discounts for services delivered over the IP network, minimal impact to enterprise IT support staff or additional capital equipment, increased mobile performance, and seamless, high-quality in-building coverage.

UMA is the 3rd Generation Partnership Project (3GPP ) standard that specifies access to, and mobility of, mobile/Wi-Fi convergence. UMA enables mobile operators to deliver their existing services, whether based on circuit, packet, Session Initiation Protocol or IP Multimedia Subsystem (IMS), over unlicensed spectrum technologies, including Bluetooth and 802.11. Users will be able to roam between cellular networks and public and private unlicensed wireless networks using dual-mode mobile handsets. The UMA specification defines a new network element – the UMA Network Controller – as well as protocols that provide for the secure transport of GSM and General Packet Radio Service signals over IP. Known as TS 43.318 in the 3GPP standards body, the specification has been approved for inclusion into the upcoming 3GPP Release 6.

As with all new mobile/Wi-Fi solutions, a new dual-mode handset equipped with a Wi-Fi radio is required to access the service. For initial use, the handset must be configured with the enterprise access keys (the Service Set Identifier, user name and security keys), which are then stored in a profile on the handset, along with a home or hot-spot profile or both. The dual-mode handset periodically looks for Wi-Fi access points to associate with; when there is a match and signal strength and parameters are met, the handset initiates the Wi-Fi attach procedure based on the profile.

To read more about UMA, please go to:

Gupta is vice president of engineering for Kineto Wireless. He can be reached at