“大哥大”是手持无线电移动电话设备，它是以无线电波作载体进行信息传递。在一般情况下，每一台无线电移动通信设备只有一个工作频率，这叫“单频无线电台”。对“大哥大”来说，叫“单频手机”。 所谓“双频手机”是指手机信号可以在两个不同的工作频率上使用。针对我国当前 Big Brother is a handheld radio mobile phone device that uses radio waves as a carrier for information delivery. Under normal circumstances, each radio mobile communications equipment has only one operating frequency, called “single-frequency radio.” On the “big brother”, called “single-frequency mobile phone.” The so-called “dual-band mobile phone” refers to the mobile phone signal can be used in two different operating frequencies. For our current