CDMA and OFDMA are the multiple access techniques for the next generation wireless communication systems. In 3G systems CDMA is used and in 4G OFDMA technique is used. Recently in 3G systems Wideband Code Division Multiple Access (WCDMA) is used beca

汽车行驶监控，通过2G 3G 4G 网络将汽车状态信息上传到后台服务器。-Vehicle monitoring, through the 3G 4G 2G network will be the vehicle status information uploaded to the backend server