1、QUESTION ITU-R 211-5/3Propagation data and propagation models in the frequencyrange 300 MHz to 100 GHz for the design of short-rangewireless radiocommunication systems andwireless local area networks (WLAN)(1993-2000-2002-2005-2007-2009)The ITU Radiocommunication Assembly,consideringa) that many new
2、 short-range personal communication systems are being developed whichwill operate indoors as well as outdoors;b) that future mobile systems (e.g. IMT) will provide personal communications, indoors(office or residential) as well as outdoors;c) that there is a high demand for wireless local area netwo
3、rks (WLANs) and wireless privatebusiness exchanges (WPBXs), as demonstrated by existing products and intense research activities;d) that it is desirable to establish WLAN standards which are compatible with both wirelessand wired telecommunications;e) that short-range systems using very low power ha
4、ve many advantages for providingservices in the mobile and personal environment;f) that ultra-wideband (UWB) is an important wireless technology and may have impact onradiocommunication services;g) that knowledge of the propagation characteristics within buildings and the interferencearising from mu
5、ltiple users in the same area is critical to the efficient design of systems;h) that while multipath propagation may cause impairments, it may also be used to advantagein a mobile or indoor environment;j) that there are only limited propagation measurements available in some of the frequencybands be
6、ing considered for short-range systems;k) that information regarding indoor and indoor-to-outdoor propagation may also be of interestto other services,decides that the following Questions should be studied1 What propagation models should be used for the design of short-range systems operatingindoors
7、, outdoors, and indoor-to-outdoors (operating range less than 1 km) including wirelesscommunication and access systems and WLANs ?- 2 -2 What propagation characteristics of a channel are most appropriate to describe its qualityfor different services, such as: voice communications; facsimile services
8、; data transfer services (both high bit rate and low bit rate); paging and messaging services; video services?3 What are the characteristics of the impulse response of the channel?4 What effect does the choice of polarization have on the propagation characteristics?5 What effect does the performance
9、 of the base station and terminal antennas (e.g. directivity,beam-steering) have on the propagation characteristics?6 What are the effects of various diversity schemes?7 What are the effects of the siting of the transmitter and receiver?8 In the indoor environment, what is the effect of different bu
10、ilding and furnishing materialsas regards shadowing, diffraction, and reflection?9 In the outdoor environment, what is the effect of building structures and vegetation asregards shadowing, diffraction, and reflection?10 What effect does the movement of persons and objects within the room, possibly i
11、ncludingthe movement of one or both ends of the radio link, have on the propagation characteristics?11 What variables are necessary in the model to account for different types of buildings(e.g. open-plan, single-storey, multi-storey) in which one or both of the terminals are situated?12 How may buil
12、ding entry loss be characterized for system design, and what is its effect onindoor-to-outdoor transmission?13 What factors can be used for frequency scaling, and over what ranges are they appropriate?14 What are the best ways of presenting the required data?15 What propagation models are most appropriate to evaluate the effect for system designsuch as Multiple Input Multiple Output (MIMO) technology?further decides1 that the results of the above studies should be included in one ore more Recommendationsand/or Reports;2 that the above studies should be completed by 2013.Category: S3
