Abstract This paper discusses indoor WLAN DSSS radio range testing relating antenna type, radiated power, and transmitter/receiver separation to the IEEE 802.11 compliance range at the 2.4 GHz ISM band frequencies. Indoor range performance is shown to depend not only on transmit power and transmission rate, but on the product’s response to multipath and obstructions in the environment along the...

This paper describes the development and operation of a dual-band time~domain radar system used to measure indoor multipath propagation characteristics in several office buildings and factories. The system operates at 1.3 GHz and 4.0 GHz, and uses 4 ns rms pulses to provide estimates of indoor radio channel impulse responses. The effects of ante.nna diversity, .frequency scaling, and topography...

Initial theoretical studies of multi-spacecraft radio tomographic imaging of the magnetosphere have shown the potential scientific value of the technique. We report a series of multistatic radio propagation experiments with the goal of testing and verifying the capabilities of radio tomography. These experiments focused specifically on measuring the plasma-induced rotation of the wave polarizat...

The characteristics of the propagation in indoor environments at a carrier frequency of 24 GHz are investigated by means of wideband directional measurements. The data shows that indoor radio propagation is dominated by impinging waves that exhibit discrete character. Furthermore, a global characterization of the investigated radio environment suitable for stochastic channel modeling by means o...

Scope This Recommendation provides an introduction to propagation-related aspects of the design and operation of digital radio-relay systems, drawing on information from Radiocommunication Study Group 3 texts and measurements conducted by administrations. Annex 1 explains the role of multipath fading as the dominant propagation factor for digital radio-relay systems operating at frequencies bel...

Worldwide Interoperability for Microwave Access (WiMAX) technology has gained growing interest due to its applications and advantages. It is fast emerging as a last-mile problem solution for broadband access technology. This paper presents operation scenarios for the deployment of a Fourth Generation (4G) WiMAX system in a typical sub-Saharan African environment. This has been specified based o...

| If two in-phase plane waves arrive at an antenna from di erent directions, the resulting signal is not necessarily the coherent sum of the two incoming signals. This is due to the fact that the antenna radiation pattern is actually a complex quantity containing amplitude and phase properties. Thus, it can be stated that antenna phase characteristics may vary as a function of direction. In fre...

Designers of low-power radio systems for use in urban areas would benefit from accurate computer-based predictions of signal loss due to shadowing. This paper presents a propagation prediction method that exploits a building database and considers the three-dimensional profile of the radio path. Models and algorithms are provided that allow the application of Fresnel-Kirchhoff diffraction theor...

Digital modulation plays a significant role in efficient wireless communication. It allows the transmission of digital data via air on high frequency carrier waves. The worst case communication channel is usually in the urban environment where there are many obstacles. Due to the obstacles and reflectors, the transmitted signal arrives at the receiver from various directions over a multiplicity...

A comprehensive review of radio wave attenuation in forest environments is presented in this paper. The classic analytical methods of propagation loss modeling and prediction are described first. This provides information on the physical processes that the radio waves undergo while propagating through a forest. The focus of this paper is on the review and summary of the experimental work done i...