全球通信 global communications

靈活性 flexibility

端到端的數(shù)字連接 end-to-end digital connectivity

開放網(wǎng)絡(luò) open network

語聲編碼 voice encoding

綜合業(yè)務(wù)數(shù)字網(wǎng) integrated services digital network

系統(tǒng)結(jié)構(gòu) infrastructure

國際標(biāo)準(zhǔn)化組織International Organization for Standardization

通信載體 communication carriers

傳輸媒體 transmission medium

接口設(shè)備 interface equipment

帶寬限制 band limitation

交換設(shè)備 switching equipment

語音編碼 voice encoding

脈碼調(diào)制 pulse code modulation

基本接入 basic access

綜合業(yè)務(wù)數(shù)字網(wǎng) the integrated services digital network

國際標(biāo)準(zhǔn)化組織 the International Organization for Standardization

由于傳輸媒體導(dǎo)致的質(zhì)量下降 degradation due to the transmission medium

4kHz話路中所固有的帶寬限制 band limitations inherent in a 4kHz voice channel

標(biāo)準(zhǔn)化的接口 standardized ports

脈（沖編）碼調(diào)制 pulse code modulation

數(shù)字通信 digital communication

ISDN的標(biāo)準(zhǔn)和系統(tǒng)結(jié)構(gòu) ISDN standards and system architecture

全球通信 global communication

數(shù)字技術(shù)的逐步應(yīng)用 progressive application of digital technology

共同通信載體 public communication carriers

高質(zhì)量 enhanced quality

大量的接口設(shè)備 substantial quantity of interface equipment

帶寬的限制 band limitations

端到端的數(shù)字連接 end-to-end digital connectivity

語音編碼技術(shù) voice encoding techniques

基本接入信令速率 basic access signaling rate

統(tǒng)一的接入 universal access