问题 问答题 简答题

简述一下质量切换门限参数QMRG的含义?

答案

参考答案:

信号质量的切换门限。在信号质量原因引起的切换中,为了保证切换后的通话质量,GSM系统规定当目标小区的信号质量比原小区高于QMRG值时,才进行切换。该参数取值从-24dB到24dB,步长1dB,当设置为24时,实际上已不能切换,如IUO的干扰区,由于干扰区必须是邻区,若不希望该邻区进行切换,可将QMRG设置成24。当基站收到的手机信号的质量(误码率)低于设定的值时就启动切换过程;在判决目标小区时,只要该邻区收到的手机信号的质量与服务小区收到的手机信号的质量相同,就将话务切往该邻区。

单项选择题

On May 29, 1973, Thomas Bradley, a black man, was elected mayor of Los Angeles. Los Angeles is the third largest city in the United States, with a population of three million. About sixteen percent of the city’s population are black.

News of this election appeared on the front pages of newspapers everywhere in the United States. Here is how one major newspaper reported the event.

LOS ANGELES ELECTS BRADLEY MAYOR UNSEATING YORTYBLACK WINS 56% OF VOTES

Bradley called his victory over Yorty "the fulfillment of a dream". During his childhood and youth, people had kept telling him, "You can’t do this, you can’t go there, because you are a Negro. " Nevertheless he had won a decisive victory over a man who had been won 43.7 percent.

Los Angeles voters have had many opportunities to judge. Thomas Bradley had to form an opinion of him. The son of a poor farmer Texas, he joined the Los Angeles police force in 1940. During his twenty-one years on the police force he earned a law degree by attending school at night. He was elected to the city council ten years ago.

At the time of the Los Angeles election, three other American cities already had black mayors, but none of those cities had as large a population as Los Angeles. Besides, the percentage of blacks in those other cities was much larger. Cleveland, Ohio, had thirty-six percent black when Carl Stokes was elected mayor of Cleveland in 1967. In the same year Richard Hatcher was elected mayor of Cary. In Newark, New Jersey, sixty percent of the population were black when Kenneth Gibson was elected in 1970. Thus election of a black mayor in those cities was not very surprising.

In Los Angeles thousands of white citizens voted for Thomas Bradley because they believed he would be a better mayor than the white candidate. Bradley had spent forty-eight of his fifty-five years in Los Angeles. Four years ago Bradley lost mayoral election to Yorty. This time Bradley won.

From the passage we can infer that people()

A. voted for Bradley because of his black color

B. didn’t care much about his color when they voted

C. voted for him to give a chance to fulfill his dream

D. voted for Bradley because they trust him

单项选择题