isdn isdn broadband isdn
Isdn宽带Isdn
以上为机器翻译结果，长、整句建议使用 人工翻译 。
One problem is "spectrum incompatibility" among myriad broadband designs--T1, ISDN and nine or so flavors of DSL. Their signals move along copper wire in overlapping frequency and modulation schemes.
FORBES: Magazine Article
应用推荐
模块上移
模块下移
不移动