ETSI TR 126 914:确定在网络环境中优化IP多媒体电话服务质量和效率的机会 质感；为开发一组可选的向后兼容工具提供基础，以实现此类优化。优化的多媒体电话针对许多不同的系统配置和操作条件， e、 g.GERAN，UTRAN，GERAN，UTRAN，GAN和不同PLMN之间的互通。在各种用例中 对于多媒体电话，本文件的主要重点是语音通话，但也包括其他内容 核心媒体组件，如视频。 特别是，有优化机会的领域包括处理退化的 信道、延迟抖动、数据包丢失、效率、与其他语音系统的互通等。范围包括提出保持向后兼容性的解决方案，以确保无缝互通 使用CS域中的现有服务，如CS语音电话和3G-324M，以及终端 早期的3GPP版本。与传统媒体格式保持一致可以避免转码，甚至可以实现至少 部分优化收益。因此，所有优化都基于中指定的默认编解码器 3GPP TS 26.235[3]和3GPP TS 26.141[6]。本文件中确定的优化主要解决以下问题。媒体传输和信号。大部分时间都在啜饮 信令超出范围，由其他3GPP组处理。有关注册到网络和/或 通电或其他情况下的IMS也不包括在内。本文件本身未规定优化工具，但将规定为对现有工具的修订 （预发布7）技术规范（3GPP TS 26.235[3]和3GPP TS 26.236[4]），以及可能的新技术规范 规格。此外，通过IMS优化的多媒体电话的特征将在 单独的技术报告。

ETSI TR 126 914:identifies opportunities for optimization of service quality and efficiency of Multimedia telephony over IP in a qualitative sense;provides the basis for developing a set of optional backward-compatible tools implementing such optimizations.The optimized multimedia telephony targets many different system configurations and operating conditions, e.g. GERAN, UTRAN, inter-working between GERAN, UTRAN, GAN, and different PLMNs. Of the various use cases for multimedia telephony, the main focus of the present document is on voice calls, but the focus also includes other core media components, such as video. In particular, areas with optimization opportunities include handling of degraded channels, delay jitter, packet losses, efficiency, inter-working with other voice systems, etc.The scope includes proposing solutions that maintain backward compatibility in order to ensure seamless inter-working with existing services available in the CS domain, such as CS voice telephony and 3G-324M, as well as with terminals of earlier 3GPP releases. Alignment with legacy media formats avoids transcoding and even allows realizing at least parts of the optimization gains. All optimizations are hence based on the default codecs specified in 3GPP TS 26.235 [3] and 3GPP TS 26.141 [6].The optimizations identified in the present document address mainly. media transport and signalling. Most of the SIP signalling is out of scope and is handled by other 3GPP groups. Issues regarding registration to the network and/or to IMS at power-on or at other occurrences are not included either.The optimization tools are not specified in the present document per se, but will be specified as amendments to existing (pre-Release 7) Technical Specifications (3GPP TS 26.235 [3] and 3GPP TS 26.236 [4]) and possibly new Technical Specifications. Furthermore, a characterization of the optimized multimedia telephony over IMS will be available in a separate Technical Report.