The WLAN system HiperLAN/2 (H/2) was standardized by the ETSI project BRAN during the last years. Due to the high data rate (up to 54Mbit/s on the air interface) and the possibility to support QoS this system fulfills the requirements of mobile users in a multimedia world. H/2 operates in the 5GHz band which o?ers indoors 19 and outdoor 9 frequency channels. These frequency channels may be used also by other systems, as for example by IEEE 802.11a, so that the resulting number of channels can be significantly reduced. H/2 o?ers link adaptation to adjust the modulation and coding scheme according to the interference. This leads to a high dependency between the available capacity and the load in the neighbor cells. Under these circumstances two approaches to deal with the radio resources are developed and evaluated. The first approach distributes the interference uniformly, by reducing the transmission power and selecting a more robust modulation/coding scheme. This reduces the variance of the interference which makes the selection of an appropriate modulation/coding scheme easier. The second approach uses maximum transmission power to reduce the transmission time as much as possible. If a frequency channel is not completely used the remaining time can be assigned to other access points. A method developed in this work allows to multiplex several neighbor access points on the same frequency channel. These approaches are based on a di?erent view of a channel. While the first applies frequency channel (FDM), the second uses FDM/TDM channels. Based on this, di?erent approaches for channel assignment are evaluated and their ability to support service classes is examined. In addition the spectral e?ciency of the H/2 of system and its dependence on di?erent parameters is evaluated in this work.
Kanalvergabe und Sendeleistungssteuerung bei HiperLAN/2
Reihe : ABMT
Bandnummer : 37
ISBN : 978-3-86130-165-3