in future high-speed self-routing photonic networks based on all-optical time division multiplexing (otdm) it is highly desirable to carry out packet switching, clock recovery and demultplexing in the optical domain in order to avoid the bottleneck due to the optoelectronics conversion. in this paper we propose a self-routing otdm node structure composed of an all-optical router and demultiplex...

in this paper the problem of minimizing the total transmitting power subject to a fixedtotal bit rate in ofdm systems is considered. upper bounds on transmitting power and bit rate ofeach subcarrier can also be taken into account. in practice, the number of bits of each subcarriershould be integer and nonnegative. in this paper an analytical optimal solution is derived for thecase of assuming t...

A highly e cient algorithm termed adaptive forward-backward vector quantization (AFBVQ) is developed for variable bit rate quantization of linear predictive coding (LPC) coe cients and integrated with the FS1016 Federal Standard Code Excited Linear Predictive (CELP) coder. This results in a high performance low bit rate speech coder called as AFBVQ-CELP which brings in two-fold bit rate reducti...

This paper presents a new high-quality, variable-rate vocoder in which the average bit-rate is parametrically controllable. The new vocoder is intended for use with data-voice simultaneous channel (DVSC) applications, in which the speech data is transmitted simultaneously with video and other types of data. The vocoder presented in this paper achieves state-of-the-art quality at several differe...

We consider a two-priority queueing system which represents an ATM node serving both variable bit rate (VBR) and unspeciied bit rate (UBR) traac. We determine the (transmission or link) capacity necessary for each traac type to guarantee prespeciied quality of service (QoS) requirements. This is done by means of a steady state performance analysis of the tail distribution of the buuer occupanci...

Wimax (IEEE 802.16) is a broadband technology in which service provider features have the ability to maximize air link utilization and system throughput. To attain Quality of Service (QoS), Call Admission Call schemes (CAC) and Bandwidth allocation mechanisms are important due to random variation of channel conditions and user demands. In this work several bandwidth allocation and CAC mechanism...

A variable bit rate characteristic waveform interpolation (VBR-CWI) speech codec with about 1.86kbps average bit rate which combines closed-loop multimode techniques is presented in this paper. Each kind of characteristic waveform (CW) surface is regarded as only rapidly evolving waveforms (REWs), only slowly evolving waveforms (SEWs) or mixed REWs plus SEWs in different cases of CWs evolving p...

We consider a multi-service broadband system in which the services form diierent traac classes. The superimposed traac is carried by a link of xed bit-rate. The services are of constant bit-rate (CBR) as well as of variable bit-rate (VBR). The VBR services are characterized as ON/OFF sources. We derive approximate algorithms for the computation of blocking probabilities at call and at burst lev...