定义：
采用光纤而不是电缆为每一个私人用户提供数据连接的技术。

光纤入户（FTTH）（或者FTTP:光纤到驻地）是指通过光纤为私人用户和小型办公室提供宽带数据连接（例如，提供上网服务，电话，视频点播，有时还包含三网合一服务）。这项技术可以取代现在主导的“光纤到节点”（FTTN），而后者是指数据传输仅仅局限在一些位于交换机处的节点之间，然后在节点处采用铜电缆将信号分配到不同的楼上。 

FTTH基于有源或者无源光学网络。有源网络包含具有功率的光电器件，例如用于交换和路由的光子集成电路，它也可以提供快速的全双工连接。有源网络还可以实现点对点的以太网，这在欧洲很普遍。无源光网络（PONs）是基于无源分离器（放置在光纤功率放大器之后），它将信号分到用户中；不同用户需要的信号可以服用，例如采用时分复用技术。在交换机中实现交换和路由，上行链路数据速率通常比下行链路数据速率小得多。例如考虑上行和下行带宽时，采用何种方案主要是基于用户需求。 

用于“最后一英里（last mile）”的光纤类型需要提供很大的传输容量，可以轻松实现100 Mbit/s是网络连接甚至更高。现今常用的下行链路数据速率标准为1 Gbit/s或者2.5 Gbit/s，可以满足数以百计的用户使用。目前正在发展的新标准速率为10 Gbit/s. 这一容量远远大于目前用户的需求，考虑到所需要的光电器件比传统的电子装置更加昂贵以及更加复杂，许多人在质疑光纤应用于此领域的经济性。而光纤的支持者则指出一旦可以提供这种服务，用户的需求会相应增加并超过预期。已经发现，FTTH是视频点播的基础，需要从主交换机中传输大量的视频数据。从这个角度来看，现在的讨论类似于1990s早期人们讨论PCs中是否需要千兆字节的主存储器。 

对于供应商来说，基本的问题是何时转换成FTTH，从何处开始转换，是同时全部更换还是考虑到经济因素最初先在某些地区开始。要做出决定，不仅要根据已有的基础设施还需要考虑，例如采用宽带服务的前景（在一些特定的目标市场），公共法规，器件价格，系统层面的一些问题，以及一些本地的竞争者的做法等，而这些都很难给出确切的答案。 

日本目前投入了大量资金用来推动FTTH技术的发展。投资商主要来解决增益和技术提高的结合引起的经济上的一些问题，例如采用对弯曲不敏感的光纤晶体光纤和改进的光纤连接器，这样可以是安装系统更简单，甚至实现自行安装。而日本之所以支持FTTH是因为该国人口密度很大，在很小区域的用户数量很多，并且高技术的影响也很大。 

普及FTTH的一个结果是传输视频点播等服务的数据量会极大的增加，因此互联网骨干网的容量也需要相应的提高。 
还有一个缩写为FTTX，其中’X’是占位符，例如，如果为H代表用户，N代表节点，B代表商业，C代表路边，P代表驻地。
 

Acronym: FTTH

Definition: the technology of providing data connections to private homes via optical fibers rather than electric cables

Fiber to the home (FTTH) (or FTTP = fiber to the premises) means providing broadband data connections (e.g. for Internet access, telephony, and video on demand, sometimes combined to triple-play services) to private households and small offices directly with optical fibers. This is a technical alternative to the currently dominant model of “fiber to the node” (FTTN), where a fiber transports data only to some node, located in a central office or in a roadside cabinet, from where the fine distribution to different buildings is done with copper cables.

FTTH comes in different technical forms, being based either on active or passive optical networks. Active networks contain powered optoelectronic components such as photonic integrated circuits e.g. for switching and rooting, and are capable of providing very fast full-duplex connections. They can be used for realizing Point-to-Point (PtP) Ethernet, as is most often used in Europe. On the other hand, passive optical networks (PONs) are based on passive splitters (arranged behind fiber power amplifiers) which distribute signals to the subscribers; the signals for different users may be multiplexed, e.g., with time division multiplexing. Switching and rooting are then performed in a central office, and the uplink data rate is often much smaller than that for downloads. Which approach is more appropriate depends very much on the usage requirements, e.g. concerning download and upload bandwidth, and on the typical proximity of users.

The use of telecom fibers for the “last mile” offers enormous transmission capacities, easily allowing for Internet connections with 100 Mbit/s and even far more. Currently used standards use 1 Gbit/s (EPON), 2.5 Gbit/s (GPON) and 10 Gbit/s (TWDM-PON) downstream data rates, to be shared by some dozens of users. Such capacities are actually far above the current needs of usual customers (including many companies), so that it has been questioned whether the use of fibers is economical in this area, given that the required optoelectronic components are more expensive and more delicate to handle, compared with the usual electrical installations. The proponents of FTTH, however, point out that historically the demand for such commodities has regularly exceeded all expectations once such a service was available and customers found methods to utilize them. It is already expected, for example, that FTTH could be the basis for video on demand, where large amounts of video data can be downloaded from central servers. From such a viewpoint, the current discussion may appear like the question of whether gigabyte harddisks and multi-megabyte main memory for word-processing PCs are really needed – a question which was posed in the early 1990s.

Many FTTH installations are artificially limited in connection speed in conjunction with cheaper monthly rates. That way, the providers can make competitive offers to those who do not need by far the technically possible data rate, and upgrade the connections later on when required by the customer or when competing offers make it necessary. Their connection needs concerning the Internet backbone can then also be kept at a lower level.

For the providers, at least the question remains when to switch to FTTH, and where to begin: everywhere at the same time, or at the beginning only in regions where it appears to be economically most sensible. Obviously, such decisions depend not only on the already existing infrastructure, but also on many questions which are difficult to answer, concerning e.g. the future development of the use of broadband services (perhaps in some designated target market), public regulations, component prices, various issues on the system level, and of course what the local competitors do.

Particularly in Japan, massive investments are currently being undertaken to push the technology of FTTH. Providers try to tackle the economical challenge with a combination of volume gains and technical improvements, such as bend-insensitive photonic crystal fibers and improved fiber connectors, which make it simpler to install such systems, eventually even in a do-it-yourself manner. Factors which greatly support FTTH in Japan are the high population density, which makes it possible to connect many users in a small region, and the widespread fascination for high technology.

A consequence of the increasing use of FTTH will be that the data volumes transferred for services like video on demand will strongly increase, and the capacity of the Internet backbone will have to be expanded accordingly. Unfortunately, that development also tends to increase the electricity consumption of the Internet system – to some extent without actual necessity, because Internet bandwidth is wasted when no financial incentives counteract that trend.

There is also the acronym FTTX, where “X” is a placeholder, e.g. for H = home, N = node, B = business, C = curb, or P = premises.