Mobile local search may be screen-based using the keypad and display on the mobile device, or voice-based using spoken commands that are interpreted by a
speech recognition application.
Screen-based search using the keypad to enter search terms into a form on the mobile screen is the most common access method today. It has the advantages of working in a noisy environment and avoiding speech interpretation problems. But the user has to enter search terms using a small keypad typical of most mobile devices, with results displayed on a small screen. Screen-based search may be awkward for people with coordination or vision handicaps. Screen-based search may be supported by a specialized application such as
where.com running on the handset, by an SMS short code, or by a
WAP or
XHTML-MP website page on a remote server displayed by the handset browser. Although most search tools today are based on handset software, the trend seems to be towards web-based services. Also, when the consumer receives a reply to his search request, the most common way of delivery is via
SMS.
Voice-based search is becoming viable due to advances in
speech recognition technology. It is useful for people who have difficulty using the small keypad, or who need to get information while driving. Spoken prompts guide the users through the local directory to find an entry. The service may include fallback to a live operator if the speech technology has difficulty understanding what they are looking for, or a 'silent agent' may assist the speech recognition software. Results may be spoken and/or delivered to the handset in
SMS or
MMS format, where they may be stored for future reference. Most often, voice-based search uses the voice channel to deliver the caller's utterance to a server-based search application. In some cases, a small application on the mobile device undertakes the first part of speech recognition, breaking down the utterance into a series of elementary components or '
phones', and then sending the phones over the data channel to a server application.
Multimedia-based search will be prevalent as a hybrid form of both "voice-based" and "screen-based" search that will establish a time-memory tradeoff in the implementation process of fast-evolving mobile equipment. == Types of information ==