Q&A: UMA

What is UMA?

What kind of terminal is required for UMA?

What are some additional products that exist in the UMA market?

What are some examples of UMA currently in use?

Is UMA related to IMS, and what is the difference between the two?

How will operators determine the deployment of UMA?

What is UMA?

UMA is a global standard created by the 3rd Generation Partnership Project (3GPP) to provide subscriber access to mobile wireless circuit, packet, and IMS-based services over IP-based networks, such as DSL, cable, and Wi-Fi. This standard allows a subscriber to securely interface in homes and hot spots with an operator's core service network over their IP-based device. UMA solutions, provided by way of a UMA Network Controller (UNC), promote seamless handovers, high levels of service transparency, and a relatively low-impact way of deploying converged services in a 2G GSM/GPRS network while realizing the cost benefits of unlicensed spectrum and internet backhaul. UMA also specifies seamless handovers between GSM and GPRS radios and unlicensed access as well as 3G networks.

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What kind of terminal is required for UMA?

The most common and well-known UMA terminals are dual-mode cellular/Wi-Fi handsets (DMH), equipped with WLAN or Bluetooth as well as the UMA protocol, allowing subscribers to roam and handover between cellular and Wi-Fi networks seamlessly. Because of UMA’s tight integration with GSM and its access technology nature, UMA terminals do not require changes to the application layer of the handset. Also, a common (i.e. Wi-Fi) access point is required for interconnecting the device to the fixed broadband network.

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What are some additional products that exist in the UMA market?

• UMA-enabled femtocells: enabling low cost indoor coverage solutions
• terminal adaptors: UMA-based fixed line VoIP services
• softmobiles: in order to use laptops and broadband connections for voice communications, a USB memory stick with an embedded SIM would be inserted into a USB port on a user's laptop, which would connect over IP to the home mobile service provider.

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What are some examples of UMA currently in use?

UMA services are currently available in the United States and certain European markets, and UMA offerings continue to grow worldwide.

In the U.S., UMA offerings such as T-Mobile’s HotSpot @ Home service provide customers with mobile coverage benefits and unlimited domestic calling over Wi-Fi and Cincinnati Bell’s CB Home Run service works using a dual-mode Wi-Fi and cellular phone that lets users switch between the two networks depending on which one offers the best signal. Unlike VoIP calling, when UMA customers leave home or exit a Wi-Fi hotspot location, their calls are seamlessly transferred onto to that operator’s GSM/GPRS/EDGE wireless network, giving people the freedom to continue their important conversations uninterrupted. Calls also transfer from GSM/GPRS/EDGE onto Wi-Fi.

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Is UMA related to IMS, and what is the difference between the two?

UMA is a complementary solution to IMS. UMA is an access solution that provides roaming between cellular and Wi-Fi networks and helps provide connectivity inside buildings, while IMS and the core network provide the whole service architecture. IMS is an industry standards-based platform for new services that is access technology agnostic. While UMA is a solution for the acute in-building coverage challenge, it is not a complete service platform and should not be compared with IMS as such.

IMS services can be delivered over any access technology, including DSL, Cable, Cellular and Wireless technologies including WiFi and WiMAX. Since IMS is access-agnostic, it can support UMA as well as other access methods, such as native IP access over Wi-Fi.

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How will operators determine the deployment of UMA?

UMA is a specific unlicensed deployment that will be evaluated by each individual operator and their vendor partners. The evaluation will depend on many factors, such as spectrum assets, partners, IMS implementation plans and more. It is possible that some companies will want to deploy an entire IMS strategy instead of simply a UMA portion. Each operator will need to decide how to proceed based on their own strategy. However, IMS and UMA provide considerable options for facilitating fixed-mobile convergence.

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