Showing papers by "Preben Mogensen published in 1994"

Practical considerations of using antenna diversity in DECT

Abstract: Performance of different antenna diversity techniques which can be applied in DECT is investigated. Test-equipment that complies with the DECT physical-layer (radio interface) has been developed in order to do measurements under real conditions. Diversity measurements were performed in three office buildings and two industrial buildings. We have concluded that antenna diversity (of a kind) must be employed in DECT to mitigate the effect of both fast fading and time dispersion. >

Specific Cooperative Analysis and Design in General Hypermedia Development

Abstract: Cooperative analysis and design is often considered only to be applicable in settings where a system is being developed solely for the 'user' participants in the process. This paper, however, argues that there are good prospects in applying cooperative analysis and design techniques in specific use settings to inform development of general products. We discuss the application of cooperative - i.e. participatory - analysis and design in development of a general hypermedia framework, the DEVISE Hypermedia (OHM). A single engineering company managing one of the largest bridge/tunnel construction projects in the world was chosen as the user organization. We demonstrate how specific activities informed the general hypermedia framework and application design. Use scenarios and prototypes with example data from the users' daily work were used as sources both to trigger design ideas and new insights regarding work practice. Mutual challenging characterised the interaction between specific cooperative analysis and design activities and general development activities. People working across boundaries facilitated this interaction, and prototypes, scenarios, and concise bullet list notes were used as mediating artefacts rather than comprehensive requirement and design specifications.

Measurement results from using DECT in a RLL application

Abstract: The paper briefly describes the initial measurements made for a field trial, where DECT is to be used in a radio local loop application. The field trial takes place in a residential area and includes approximately 50 subscribers. >

Antenna configuration measurements for DECT micro-cells

Abstract: The paper shows results from DECT propagation measurements in an outdoor micro-cell environment. The potential performance gain by using planar directional antennas compared to dipole antennas is shown. Radio channel impairments such as fast-fading, time dispersion, corner diffraction loss, and interference in relation to DECT are discussed.

Evaluation of low effort dispersion-reduction techniques for DECT in telepoint environments

Abstract: Uncommon DECT diversity combiners are compared with more usual DECT combiners. Soft combining provides good performance and switched pattern diversity seems to have a good performance potential in moderate spatially dispersive environments. >