26 词条
主页 > 产品类别 > 移动通信 > 2G wireless network
2G wireless network
Second-generation (2G) digital cellular networks used by mobile phones. 2G networks was developed as a replacement for first generation (1G) analog cellular networks, and the GSM standard originally described a digital, circuit-switched network optimized for full duplex voice telephony. This expanded over time to include data communications, first by circuit-switched transport, then by packet data transport via GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for GSM Evolution or EGPRS).
2G wireless network的贡献者
2G wireless network
子带编码
移动通信; 2G wireless network
一种以信号频谱为依据的波形编码方法，它首先用一组带通滤被器将输入信号按频谱分开，然后让每路子信号通过各自的自适应PCM编码器ADPCM编码，经过分接和解码再复合成原始信号。 ...
循环不定位
移动通信; 2G wireless network
一种信道选接方式，基台。谯所有空闲信道发出室词信号，各移动台自动对各信道扫描，当基台呼叫时，任选一空闲信道停止发送空闲信号，各移动台要经扫描一周后先后都停于该信道上，方能进行选择呼叫，只有被叫移动台接续通话，因此接续速度慢。当移动台呼叫时，扫描到有空闲信号的信道就停住，占用。各移动台是通过各个空闲信道分散呼叫的，因此很少发生“同抢”问题。但基台的所有信道是常开启的，因此将造成功率浪费和相互干扰。 ...
