what is HDX?
First and foremost, HDX is not a feature or a technology -- it is a brand. Short for "High Definition Experience," HDX is the umbrella term that encapsulates several different Citrix technologies.
HDX came to be because Citrix is finally getting competitive pressure on its Independent Computing Architecture (ICA) protocol. ICA has always had a good reputation and has generally been perceived as a differentiator for Citrix.
But now, Microsoft's Remote Desktop Protocol Version 7 is leaps-and-bounds better than any previous version, and VMware is just a few months away from releasing a software version of Teradici's PC-over-IP protocol.
Citrix's reaction to these competitive pressures has been to elevate the conversation above the protocol. Citrix must think, "What's the goal of improving a remote display protocol, when the goal of a protocol is to provide a great user experience?"
In other words, a great user experience is more than just a protocol, and Citrix created the HDX brand to discuss all the elements -- in addition to ICA -- that Citrix claims allow it to deliver the best user experience.
Citrix has created several sub-brands under HDX, such as HDX MediaStream, HDX RealTime and HDX 3D. Each of these brands has a variety of technologies under it. For example, HDX Plug-in-Play supports client USB devices, multiple monitors, client printers, client drive mapping, local port mapping, smart cards and scanners.
There are too many aspects of HDX to list here -- more than 60, according to Citrix. In addition, the "Adaptive Orchestration" feature of HDX is another generic brand that refers to the fact that most of the various HDX components can adjust
从数据中心到设备：贯穿始终的先进优化技术
针对XenDesktop和XenApp产品而开发的Citrix HDX采用了一系列的新技术，旨在为虚拟桌面和应用实现用户的高清体验。HDX技术建立在Citrix 交付中心系列产品的基础上，针对用户丰富多彩的媒体应用而开发。
这些技术贯穿在整个端到端的交付系统中。数据中心内的HDX旨在利用服务器的处理能力和可扩展性，无论端点设备的能力高低，均可实现卓越的图形和多媒体性能。网络上的HDX技术将先进的优化技术与Citrix ICA虚拟交付协议等加速能力以及其他第三方技术相结合，通过高延时、低带宽环境在内的任何一种网络，提供一种绝佳的用户体验。设备上的HDX技术则旨在利用端点设备的计算能力，以最有效的方式改善用户体验。
HDX技术共有6个类别，它们协同工作，在各种用户情境下提供最佳使用体验。这6个类别各自包含一套丰富的新技术和原有技术，并融入到Citrix 交付中心产品系列中。
·HDX MediaStream 媒体流技术——将经过压缩的流媒体发送至终端，并在本地播放，由此提升多媒体性能。
·HDX RealTime——采用先进的双向编码和流媒体技术，改善实时通讯，以避免对终端用户体验造成不良影响。
·HDX 3D——利用数据中心和设备上基于软件和硬件的处理能力，全面优化性能，从对图形密集型的二维环境到高级三维地理空间应用。
·HDX即插即用——实现虚拟环境下所有本地设备的简化连接，包括USB、多显示器、打印机和用户自行安装的外设等。
·HDX广播——通过包括高延时、低带宽环境在内的任何一种网络，提供可靠而高性能的虚拟桌面及应用加速。
·HDX 智能缓存——为整个基础架构上对带宽敏感的数据和图形提供缓存，并根据需要从最高效的地点，用透明的方式交付，由此优化在复合用户环境下的性能和网络利用率。
Citrix 还设计了HDX框架，利用其创新性的“自适应协调”技术，实现这6大领域之间的无缝互动。
·HDX自适应协调——感知数据中心、网络和设备的基础能力，动态地运用最佳的Citrix HDX技术组合，以确保在各种独特的用户情境下实现高清使用体验。
