(2004). This document specifies a speech codec suitable for robust voice communication over IP. The codec is developed by Global IP Sound (GIPS). It is designed for narrow band speech and results in a payload bit rate of 13.33 kbit/s for 30 ms frames and 15.20 kbit/s for 20 ms frames. The codec enables

We use the measured round trip delays of small UDP probe packets sent at regular time intervals to characterize the end-to-end packet delay and loss behavior in the Internet. By varying the interval between probe packets, it is possible to study the structure of the Internet load over different time scales. In this paper, the time scales of interest range from a few milliseconds to a few minutes. Our observations agree with results obtained by others using simulation and experimental approaches. For example, our estimates of Internet workload are consistent with the hypothesis of a mix of bulk traffic with larger packet size, and interactive traffic with smaller packet size. The interarrival time distribution for Internet packets is consistent with an exponential distribution. We also observe a phenomenon of compression (or clustering) of the probe packets similar to the acknowledgement compression phenomenon recently observed in TCP. Our results also show interesting and less expected...

This document is provided for general informational use. No responsibility is assumed by the authors with regard to the accuracy of the information contained herein. The documentation described herein may be used, copied, or transcribed without fee or prior agreement provided that acknowledgement or reference is made of the source. Sun is a trademark of Sun Microsystems, Inc. UNIX is a trademark of AT&T. DECstation is a trademark of Digital Equipment Corporation. This package is based on the UNIX operating system. We appreciate any comments or corrections- they can be sent to Andy C. Hung at

..................................................................... 3 1.1.2 Video Input Source ...................................................................... 3 1.1.3 Memory Buffer ............................................................................ 4 1.1.4 Video CODEC ............................................................................. 7 1.1.4.1

integrated circuits, Codecs, digital-analog conversion, digital filters, mixed analog-digital integrated circuits, subscriber loops. I.

Sampling rates from 8 kHz to 96 kHz Low power: 7 mW record, 7 mW playback, 48 kHz at 1.8 V 6 analog input pins, configurable for single-ended or differential inputs Flexible analog input/output mixers Stereo digital microphone input Analog outputs: 2 differential stereo, 2 single-ended stereo, 1

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In the context of the RESUME-project a scalable wavelet-based video decoder was built to demonstrate the benefits of reconfigurable hardware for scalable applications. Scalable video means that the quality of service (QoS), i.e., the frame rate, resolution, color depth,... of the decoded video can easily be changed by only decoding those parts of the video stream that contribute to the desired QoS. With the emergence of high-performance FPGAs (Field Programmable Gate Array), both the required performance for real-time decoding and flexibility, by allowing reconfiguration, are offered. Since the amount of calculations scales with the QoS, energy dissipation is expected to scale similarly. To investigate the relation between QoS and energy dissipation we actually measured the energy dissipation of a scalable video decoder implementation on a FPGA. The measurements show how dissipation effectively scales with the QoS, but also depends on the decoded data and the used design method. This is illustrated by comparing two different implementations of the inverse discrete wavelet transform (IDWT).

Wireless video systems have applications in cellular videophones, surveillance systems, and mobile patrols. The design of a wireless video system must consider two important constraints: low bit rate and low power dissipation. The ITU-T H.263 video codec standard is suitable for low bit rate

Variable bit-rate (VBR) compressed video traffic is expected to be a significant component of the traffic mix in integrated services networks. This traffic is hard to manage because it has strict delay and loss requirements while simultaneously exhibiting burstiness at multiple time scales. We show that burstiness over long time scales, in conjunction with resource reservation using one-shot traffic descriptors, can substantially degrade the loss rate, end-to-end delay, and statistical multiplexing gain of a connection. We use large-deviation theory to model the performance of multiple time-scale traffic and to motivate the design of renegotiated constant bit rate (RCBR) service. Sources using