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—The design and simulation of coding schemes, Medium Access Control (MAC), and link-layer protocols for future industrial wireless local area networks can be supported by some understanding of the statistical properties of the bit error patterns delivered by a wireless link (which is an ensemble of transmitter, channel, receiver, modems). We present results(More)
This publication explores the degree of accuracy to which the propagation delay of WLAN packets can be measured using today's commercial, inexpensive equipment. The aim is to determine the distance between two wireless nodes for location sensing applications. We conducted experiments in which we measured the time difference between sending a data packet and(More)
SUMMARY Quality models predict the perceptual quality of services as they calculate subjective ratings from measured parameters. In this article, we present a new quality model that evaluates VoIP telephone calls. In addition to packet loss rate, coding mode and delay, it takes into account the impairments due to changes in the transmission configuration(More)
IEEE 802.11b compliant WLAN technology is increasingly used for cordless telephone services. Often, a WLAN phone is moved during a call. In the present paper we explore to what extent slow user motion influences the wireless link quality. We conducted extensive measurements with speech over commercial WLAN equipment using an experimental environment(More)
—In this paper we present an algorithm that measures the round trip times of IEEE 802.11 MAC packets in order to trilaterate WLAN nodes. We show that if we use packet sequences (e.g., RTS, CTS, DATA and ACK) instead of packet pairs (e.g., DATA and ACK), the TOA measurements can be implemented more easily and a higher observation rate can be achieved. In(More)
Losing VoIP packets or speech frames decreases the perceptual speech quality. The statistical relation between randomly lost speech frames and speech quality is well known. In cases of bursty and rate-distortion optimized losses, a precise quality model is required to relate losses to quality. In the present paper, we present a model that is based on the(More)
The continuous tracking of mobile systems via active or passive RFID is a desirable but difficult to achieve objective. In this paper, we present our experimental results of positioning techniques using passive UHF RFID, Bluetooth, and WLAN. We thereby employ three orthogonal measuring techniques: detection rates, signal strength, and round trip time. The(More)
—The next generation of mobile access networks will support different access technologies like UMTS, WLAN, WiMax and LTE. Optimal handover decisions between different access networks have to take various types of information into account, such as the load of possible target cells. However, collecting this information and transporting it to mobility(More)