But the picture phone has been mostly a perpetual prototype to date.

但迄今为止,大多数的可视电话长期以来一直停留在原型机的水平.

These wideband subscriber loop systems would provide access to services such as picture-phone, video entertainment.

这些宽带用户环路系统将为可视电话、视频娱乐节目等业务提供通路。