Spatial and Temporal Fairness in Heterogeneous HSDPA-Enabled UMTS Networks

The system performance of an integrated UMTS network with both High-Speed Downlink Packet Access users and Release '99 QoS users depends on many factors like user location, number of users, interference, multipath propagation profile, and radio resource sharing schemes. Additionally, the user behavior is an important factor; users of Internet best-effort applications tend to follow a volume-based behavior, meaning they stay in the system until the requested data is completely transmitted. In conjunction with the opportunistic transmission scheme implemented in HSDPA, this has implications to the spatial distribution of active users as well as to the time-average user and cell throughput. We investigate the relation between throughput, volume-based user behavior and traffic dynamics with a simulation framework which allows the efficient modeling of large UMTS networks with both HSDPA and Release '99 users. The framework comprises an HSDPA MAC/physical layer abstraction model and takes network aspects like radio resource sharing and other-cell interference into account

A Picture is Worth a Thousand Words: Practical Use of Videotape in Teaching

Videotapes, through vividly displayed clinical images and teaching interactions, are valuable tools for both learners and teachers. Visual images in combination with verbal instruction have been shown to significantly increase recall and retention. Many clinicians and medical teachers are aware of videotape resources, but have not had a chance to develop their use in medical education. In this paper, we discuss creative applications of videotapes in three major categories: presenting information, triggering discussion, and as a tool for direct self-observation and feedback. Videotapes may be valuable for presenting information in settings of didactic instruction; for triggering discussion during teaching workshops; and for self-observation of patient-doctor interactions and learner-teacher encounters. The article presents learner-centered approaches to review a videotaped clinical encounter in order to enhance value and comfort for the learner and teacher. Sources of tapes include on-site videotaping, published educational tapes and commercial tapes shown in accordance with fair use guidelines, examples of which are referenced. Videotapes add another dimension to traditional sources of physician education