Speech Technology - June 2008 - (Page 17) COVER STORY Voice and Data Standards in the United States Because U.S. telecom carriers adhere to different standards, their networks have become a wireless labyrinth. Here’s a distilled version: 2G The second-generation digital network is currently the standard network in North America. It’s fine for voice, but too slow for data. 3G The third-generation mobile broadband network is crackling at the pace of DSL. It’s being deployed gradually by carriers. 4G The future of mobile is this ultra-highspeed mobile broadband. GSM The most widely used 2G standard. Devices that take SIM cards run on this network. CDMA A smaller but more robust network. Devices running on CDMA don’t use SIM cards, so you can’t swap out for a different phone. EV-DO CDMA’s 3G network and the strongest and most widespread 3G network running in the U.S. HSPA Stands for HighSpeed Packet Access. It’s currently not that powerful in the U.S., but its data transfer speeds are increasing. WiMax Sprint is the only carrier that plans to deploy it in the U.S. Its release has been delayed to sometime in 2010, if all goes well. LTE Long-Term Evolution has Verizon’s backing and its adoption is moving at a more assured pace than WiMax. Expect it in 2010. Used by: AT&T T-Mobile Used by: Verizon Sprint Used by: Verizon Sprint Used by: AT&T T-Mobile Used by: Sprint Used by: Verizon AT&T T-Mobile the application instructs the user to hold a button and constrains what utterances he might say by modeling possible queries: Say a business near you. Or traffic, directions, map, weather, movies. Tellme opted for this approach, according to senior product manager David Mitby, because even when “very solid smartphone users pick this up for the first time, it’s not clear what to do. It’s not intuitive media yet.” User interface designers creating a multimodal interaction have a particularly difficult time because they have no way of really knowing how a user will interact with a specific handset in a specific scenario. Olvera recently worked on MediVoice, an e-prescription service powered by Nuance Voice Control Healthcare Edition that allows physicians to verbally create and send electronic prescriptions from a range of mobile handsets. With a GUI, the only way physicians can get information is visually. The need to press buttons on their handsets constrains their responses. Stir voice into the mix, and “that’s where things get very interesting,” Olvera says. “You have no control over the user.” During usability tests, Olvera discovered that some physicians treated the voice interface as a turn-taking situation where they would utter quick words, wait until they registered, then say more. Other doctors, however, would give long responses full of information—the patient’s name, the prescription, the dosage, the pharmacy where the patient should pick it up, and the phone number—all in a single set. Still other users would offer quick verbal information, then use the stylus to enter the remaining data. “That’s when we realized [interactions are] very driven by context and the familiarity with the user’s situation and the technology of the devices themselves,” Olvera says. “When you’re restricted to just a phone, it’s straightforward. Everyone knows how a phone works.” On the other hand, not everyone knows how a smartphone works. The same can be said about a medical prescription application. Nuance tested MediVoice in various hospitals and at various intervals throughout the country. Doctors already familiar with an online prescription system typically liked it when it was ported into the handset. “They liked the ability of being able to use it on their device without having to learn a new interface,” Olvera says. Doctors unfamiliar with prescription systems tended to react to the mobile version as if it were a novelty act. “With this particular application, it’s hard to pinpoint every single issue [in usability],” Olvera adds. Reconcilable Differences So how do designers reconcile different devices with different abilities? “With multimodal, the answer is: It depends,” Olvera says. “It’s impossible to blindly decide if a VUI is better than a GUI.” That’s why designers really need to understand that different types of www.speechtechmag.com JUNE 2008 Speech Technology | 17 http://www.speechtechmag.com
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