新干线网络，由日本铁路运营，目前经由1500英里的轨道已连接起日本的主要城市。

The Shinkansen network, operated by Japan Railways, now connects most major Japanese cities via almost 1, 550 miles of track.

youdao

在联通的干线网上，原有的SDH环网结构已经不能满足当前的容量要求，必须改造成ason网络，特别是中东部地区。

Over Unicom's backbone network, original SDH loop network architecture already fails to meet present capacity requirement, which must be transformed into ASON, especially for the central-east regions.

youdao