信息技术 用户场所通用布线 第9903部分: 信道和链路建模

[中文适用范围]： ISO/IEC TS 11801-9903:2025 规定了在一对平衡布线内部及两对平衡布线之间混合模式传输参数的限值建模方法。本文档详细描述了矩阵建模方法，并解释了如何通过S到T矩阵和T到S矩阵的转换来转换矩阵。此外，本文档还包含了所使用的术语和定义、特定参数的建模方法、替代计算方法以及信噪比（SNR）的建模。本文档还描述了如何通过链参数和替代方法及公式，将组件电缆和连接器的传输参数组合成布线链路和通道的传输参数。S参数限值矩阵公式被涵盖，这些公式可以转换为T参数限值矩阵，用于链参数链路和通道限值公式。这些公式适用于所有传输参数，用于构建完整的差分模式、混合模式和共模链路和通道模型。本文档讨论了用于建模的术语和定义，以及如何对特定传输参数进行建模。还解释了替代计算模型，并介绍了信噪比建模。第二版取消并替换了2021年发布的首版。本版属于技术修订版。与前一版相比，本版包括以下重大技术变更：a）扩展了指定参数的列表，包括混合模式模式转换及相关不平衡衰减参数；b）新增了一个信息性附录，涵盖信噪比及其与S参数矩阵通道模型的关系。 [外文原描述]： ISO/IEC TS 11801-9903:2025 establishes modelling of limits for mixed-mode transmission parameters within and between two pairs of balanced cabling. This document consists of a detailed description of matrix modelling and gives explanations on how to convert matrices, by using the S to T and T to S matrix conversion. Further it consists of terms and definitions used, how specific parameters are modelled, alternative calculation and signal-to-noise ratio (SNR) modelling. Chain parameters and alternative approaches and formulas are described for combining component cable and connector transmission parameters into cabling link and channel transmission parameters. S-parameter limit matrix formulas are covered, which can be transformed into T-parameter limit matrices for use in chain parameter link and channel limit formulas. The formulas are applicable to all transmission parameters for forming complete differential-mode, mixed-mode, and common-mode link and channel models. Terms and definitions used for modelling are discussed, together with how modelling is done for specific transmission parameters. Alternative calculation models are explained, and the SNR modelling introduced. This second edition cancels and replaces the first edition published in 2021. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the expansion of the list of specified parameters to include mixed-mode mode-conversion and related unbalance attenuation parameters; b) the addition of an informative annex covering the topic of signal-to-noise ratio and its relation to the S-parameter matrix channel model.