下列选项中，不属于局域网接入控制方法的是（）。

下列关于数据字典作用的描述。错误的是（）。

在通信专业中，TDM的英文全称是（），“基带”英文通常翻译为（）。

Wireless telecommunications networks are generally implemented and administered using（）communication.This implementation takes place at the （）level of OSI model network structure.

The maximum data rate of any single wireless link can be described by the shannon’s theorem which is related to the（）in hertz，and the（）on the channel

As with all ITU standards，reduce energy consumption is a key factor taken into account at development stage.Indeed NGNs are believed to offer significant saving（）traditional networks.