ISSN:1047-9627    

DOI:10.1002/dac.4510050302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA codec for digital transmission of HDTV is described. The bit‐rate compression algorithm is based on advanced techniques such as spatial discrete cosine transform (DCT), temporal differential PCM (DPCM), variable length coding. The codec is designed to operate with both the interlaced studio systems 1125/60 and 1250/50, and, thanks to the inherent flexibility of the packet structure, a wide range of line bit‐rates can be used as a compromise between video quality and bit‐rate constraints of the digital transmission link. The flexibility of the HDTV codec is highlightened through examples of applications over satellite digital links in practical situa

ISSN:1047-9627    

DOI:10.1002/dac.4510050303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis article deals with the first generation of HDMAC ENCODER equipment. Methods for bandwidth reduction, processing to obtain a compatible picture and the test concept for the encoder will be presented. In addition, the 140‐Mbit/s transmission system for HDMAC will be described and future methods for transmission and application of HDMAC illustrate

ISSN:1047-9627    

DOI:10.1002/dac.4510050304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis report discusses a pulse density modulation (PDM) video transmission system. PDM is a one‐bit digital coding scheme with advantages of transparency due to an inherently extended signal bandwidth and relatively simple decoding; these make it ideal for a variety of applications.The system outlined is designed to carry a single analogue video channel, together with several sound channels, over a 140 or 280 Mbit/s digital transmission‐link. An alternative option to the sound channels will be to carry a 2.048 Mbit/s data channel. Since the analogue video input will be PDM coded, this will enable the system to carry video formats which have a flat base‐band frequency response requirement of in excess of 20 MHz (such as HDTV), allowing a large degree of flexibility i

ISSN:1047-9627    

DOI:10.1002/dac.4510050305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA general model for the description of traffic processes in packet communication networks is presented in this paper. The packet traffic generated by a network component is described in terms of a generalized Bernoulli process whose intensity depends on the state of the component. When the state space of the component is large, an approximate traffic characterization is proposed based on the dominant states. The latter characterization is shown to be well performing for the considered examples of practical network components. Based on the proposed general model, an analysis approach for multi‐component communication networks is presented. Numerical results illustrate the inaccuracy of the widely adopted i.i.d. modelling, the effectiveness of the proposed general model and the significant complexity reduction through the adoption of the approximate on

ISSN:1047-9627    

DOI:10.1002/dac.4510050306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper presents the problems in the implementation of multipoint connections at switching level using the example of an ATM switching network. By choosing the proper routeing mechanism and the appropriate architecture of the switching element, a switching network can gradually be adapted to an increasing share of multipoint traffic. The first section describes the problems with the handling of multipoint connections within a multiple stage connection oriented switching network. In particular this refers to the routeing of the cells through the switching network. Several alternatives on this issue are discussed. Both, the selected approach based on a differentiated self‐routeing mechanism and the corresponding cell format are introduced. In the second part of this article several switch architectures are compared in respect of their multipoint capability. It is demonstrated that at present the most promising solution are switching elements based on the principle of central buffering. A single chip solution using this concept is employed in the presented switching networ

ISSN:1047-9627    

DOI:10.1002/dac.4510050307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractError control in high speed communication networks is usually applied either as a link‐by‐link scheme or an end‐to‐end scheme. The performance of such schemes is analyzed in this paper. The impact of errors due to transmission errors as well as dropped packets due to buffer overflow is incorporated in the

ISSN:1047-9627    

DOI:10.1002/dac.4510050308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1047-9627    

DOI:10.1002/dac.4510050309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1047-9627    

DOI:10.1002/dac.4510050301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY