pressed video has a more stringent BER requirement than speech; that is, it requires a lower error rate. W-CDMA has specified the use of ITU-T Recommendation H.324M as the standard for videotelephony. ITU-T Recommendation H.324 is a standard for multiplexing audio, video, user data applications, and system control onto a data stream suitable for transport in the public switched telephone network (PSTN) or a wireless circuit-switched network. 10.3.1.2 Streaming class. Streaming data are processed as a steady and continuous stream. Typically, this approach is used for large multimedia files downloaded from the Internet. Using this class of service, the receiving browser can start displaying the data before the entire file is sent. The receiver has to collect data and send them to the ap- plication in a steady stream. Streaming applications are very asymmetric, with one direction sending almost all the data. Picture a multimedia application where the subscriber watches an audio/video presentation and clicks a mouse once or twice a minute to direct the trans- mission. These applications tolerate more delay, and they can handle more jitter, that is, more variation in delay (described in Sec. 17.1), than symmetric conversational services. Some of these services are designed and targeted for lower bit rates, 28.8 kbps, whereas others are aimed at a high-end market, offering over 100 kbps. 10.3.1.3 Interactive class. Interactive class is designed for a person or a machine on- line requesting information from remote equipment. This includes World Wide Web browsing, database retrieval, and server access. The key quality element in this class of service is the duration of the round-trip time from the subscriber stimulus to the data response. Location-based services fall into this category. Finding the nearest gas station or ho- tel, or even a local map, depends on knowing the location of the user terminal. This can be obtained through cell coverage-based positioning using radio propagation delays or through network-assisted