InterDigital Software Will Help Make Cell vs. Wi-Fi Choices on Phones

Having both cellular and Wi-Fi available for mobile data may be the best of all possible worlds, but software that helps your phone make the right choice between them is even better, according to InterDigital.

On Tuesday, the longtime wireless technology supplier announced availability of its Smart Access Manager (SAM) client, which can combine information about signal strength and other factors with carrier policies to decide when to automatically shift a phone from one type of network to another. SAM's greatest strength is that it's based on industry standards, so handset makers and carriers can implement it in a consistent way, according to InterDigital. It's available now for Android and Windows Phone.

Mobile operators are trying to take advantage of Wi-Fi networks run by themselves and others so they can improve their subscribers' mobile data experiences and take some of the strain off their cellular networks. But technologies for taking handsets from one type of infrastructure to the other are still in the early stages. InterDigital said it built SAM around the ANDSF (Access Network Discovery and Selection Function) standard so carriers and phone makers aren't saddled with many different proprietary systems to handle that function.

SAM is client software to be built into smartphones and tablets and included in connection manager applications for laptops. It works with servers in the mobile operator's network to make and carry out decisions about what network to use for data service. Those decisions can take into consideration the strength of a nearby Wi-Fi signal, whether that network is owned by the carrier, and the carrier's policies toward the subscriber and the application they are using.

Though a carrier's own infrastructure can provide some information about signal strength or availability of its own 3G, 4G and Wi-Fi networks, any data about a third-party Wi-Fi system needs to come from the handset, said Jim Nolan, executive vice president of research and development at InterDigital. Other information that could someday be used to make network choices, such as the state of battery life, also comes from the handset, he said.

Because of the early state of ANDSF development, the only decisions it makes now are between using cellular or Wi-Fi for all of the phone's data traffic. A future version of ANDSF coming in the next year to 18 months should be able to assign some applications to Wi-Fi and some to cellular based on policies, needs and current conditions, Nolan said. Still later versions are expected to be able to combine the capacity of two different networks to give one demanding application a fatter wireless pipe. InterDigital has implemented these capabilities on its own, but not in the standards-based product, he said.

InterDigital demonstrated SAM at Mobile World Congress in February with Alcatel-Lucent's lightRadio system, which uses that company's 5780 Dynamic Services Controller Wi-Fi Control Module to send carrier policies to subscribers' devices. SAM has been tested on and is available for Windows Phone and for Android versions 2.3 (Gingerbread), 3 (Honeycomb) and 4 (Ice Cream Sandwich). If Apple asks for it, potentially because of requests from carriers with the iPhone, SAM will be implemented for iOS, Nolan said.

InterDigital has deep roots in digital mobile technology and claims about 8,800 patents. Last year the company sued Nokia, Huawei Technologies and ZTE claiming patent infringement, and it reportedly has been a target for acquisition by Google for its patent portfolio.

Stephen Lawson covers mobile, storage and networking technologies for The IDG News Service. Follow Stephen on Twitter at @sdlawsonmedia. Stephen's e-mail address is stephen_lawson@idg.com

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