In an integrated network of ATM-LANs and ATM-WANs, both public and private networks that belong to different management domains with different management policies are used for communication between end systems. Although network management that covers end-to-end communication over the whole integrated network is needed, it is difficult to manage the configuration, know the status of communication connection, and handle the provisioning at the total network level. Moreover, it is not easy to isolate faults and monitor performance among the heterogeneous networks. We propose a cooperative end-to-end management method that makes good use of CNM (customer network management) services of ATM-WAN, and combines them with ATM-LAN management services. Our proposal includes: (1) end-to-end management based on the network partitioning concept, (2) ATM-WAN abstraction and modeling from the viewpoint of ATM-LAN customers at the network level, and (3) a couple of new managed objects for CNM services.

This paper describes a 15/30 Mbit/s TV codec with a new approach to high-efficiency coding for TV signals, i.e., median adaptive prediction. The 15/30 Mbit/s codec, commonly applicable to NTSC, PAL, and SECAM (525/60 and 625/50) systems, uses adaptive prediction incorporating a motion-compensated interframe, an interfield, and an intrafield predictor. Its performance for digital transmission is presented. This universal codec is designed, based on CCIR recommendations concerning digital TV coding parameters for studios (Rec. 601) and general principles on long-distance digital TV transmission (Rec. 604). A field trial of 15 Mbit/s digital TV transmission using this codec between earth stations with a 30 m diameter antenna and a 5 m diameter antenna is reported.

Seeing-while-talking has been a dream of mankind for over a 100 years since the invention of telephone. In the past, various trials were performed in spite of the difficulty in installing the network for the actual service. However, with the progress of ISDN and the advancement of digital signal processing technology, the environment has been changing rapidly. In this paper, an integrated visual communication system is described for the enhanced communication service at 64 kbits/s, the fundamental bit rate of ISDN. The roles of state-of-theart compression of the audio and video signals are discussed and an integrated transmission method based on the priority of the information content is proposed.

As a high efficiency coding method for TV signals, variable length coding, such as Huffman coding, is extremely effective. However, when this variable length coding is applied to an actual TV codec which requires high-speed real-time processing, maximum word length will be limited for the hardware configuration. This correspondence describes an algorithm for the construction of a modified Huffman code with limited maximum word length by means of a "top-down" procedure meeting this requirement instead of the conventional "bottom-up" algorithm.

This paper describes the results of theoretical studies made on performance of various kinds of intrafield two-dimensional transform codings (Hadamard, cosine, and slant) for carrier chrominance signals, by introducing a new measure (transform coefficients of zero variance) for such coding performances. In addition, a comparative study of the performance of these transform codings is performed for different sampling frequencies(2f_{sc}, 3f_{sc}, 4f_{sc})with the same transmission rate, taking into account the tradeoff between the number of bits assigned to a picture element at each sampling frequency and the autocorrelation between adjacent picture elements.

Since DPCM and transform coding are two fundamental approaches to high-efficiency (bit reduction) coding, it is important to clarify the basic coding characteristics of these approaches and the differences between them in order to utilize the high-efficiency coding method effectively. It is important to compare them not only from the standpoint of coding performance as optimized coding schemes based on the statistics of the input picture signal, but also from that of the robustness of coding performance for the variation of picture statistics to be coded. This paper theoretically compares the robustness of the coding performance of DPCM having a two-dimensional predictor with that of a two-dimensional Hadamard transform coding in an intrafield coding method of the NTSC composite signal. The comparison provides theoretical evidence that transform coding is more stable than DPCM, and this tendency is marked at lower bit rates such as 1 or 2 bits/pel, while DPCM has a higher coding performance for pictures with high autocorrelation.

Since differential-pulse-code modulation (DPCM) and orthogonal transform coding (OTC) are the most fundamental methods of high-efficiency coding (bit-reduction method), it is important to clarify the basic coding characteristics of these methods and the difference between them in order to utilize the bit-reduction method effectively. This paper theoretically as well as experimentally compares the coding efficiency of a DPCM having a two-dimensional predictor with that of a two-dimensional Hadamard transform coding method (HTC) in the intrafield coding of the NTSC composite signal. The comparison evidenced that the distinctive difference in coding characteristics between DPCM and HTC depends greatly on the power level of carrier chrominance signals. That is, it is confirmed theoretically and experimentally that the coding efficiency of the HTC is far lower than that of the DPCM in the case of a signal having a high power level carrier chrominance signal such as a color-bar signal.

This paper proposes a new approach to the composite coding of the NTSC color TV signal, i.e., an interfield-intrafield adaptive prediction. First, concerning prediction efficiency for various moving pictures, an advantage of this coding scheme over interframe coding is clarified theoretically and experimentally. This adaptive prediction gives very good and stable performance for still to violently moving pictures. A 30 Mbit/s. codec, based on this idea, and its performance are presented. Field transmission testing through an INTELSAT satellite using this codec is also described. The picture quality is satisfactory for practically all the pictures expected in broadcast TV programs, and it is subjectively estimated to be a little better than that of the half-transponder FM transmission now employed in the INTELSAT system.

This paper introduces a new technique for TV standards conversion called "adaptive intra-frame line interpolation". The configuration and the performance of a digital converter developed by using the technique are also described. In the present converter, an input picture is divided into still and moving areas by measuring frame difference signals, and suitable interpolation parameters are adaptively chosen for each area. This method brings good results to both areas. Especially, the converter has enabled the converted picture to recover high vertical resolution of more than 350 TV lines in still pictures, which has never been obtained by any conventional intra-field line interpolation.