Cellular telecommunication

Тема 5.7. СОТОВАЯ СВЯЗЬ (CELLULAR TELECOMMUNICATION)

1. Отработка новой лексики. Особенности перевода интернациональных слов.

2. Словообразование.

3. Чтение.

4. Говорение. Работа с устными высказываниями по теме.

Отработка новой лексики. Особенности перевода интернациональных слов.

ЗАДАНИЯ

1.1. Найдите транскрипцию приведённых ниже слов в англо-русском словаре. Произнесите слова в соответствии с транскрипцией (см. Приложение1). Прослушайте слова (см. Введение.п. 2). (Find a transcription of the following words in the English-Russian dictionary. Say the words according to the transcription (see Application1). Listen to the words (see Introduction. item2.)

exhibit – представлять, показывать

cell- ячейка, клетка, элемент

reuse – повторное использование

increase – увеличение, увеличивать

track – трек; отслеживать

thus – таким образом

demand – требовать; требование

split – расщепление; делить

customers – клиенты, покупатели

discontiguous - несоприкасающийся

irregular shapes - неправильные формы

low transmitting power – низкая мощность передачи

1.2. Найдите в тексте «CELLULAR TELECOMMUNICATION» указанные в задании 1.1. слова. Запишите слова в контексте (см. Введение. п.1). (Find words pointed in the task 1.1. in the text «CELLULAR TELECOMMUNICATION». Write down the words in a context (see Introduction. item1.)

CELLULAR TELECOMMUNICATION

All cellular radio systems exhibit several fundamental characteristics.

The geographic area served by a cellular radio system is broken up into smaller geographic areas, or cells. Uniform hexagons most frequently are employed to represent these cells on maps and diagrams; in practice, though, radio waves do not confine themselves to hexagonal areas, so that the actual cells have irregular shapes.

All communication with a mobile or portable instrument within a giv­en cell is made to the base station that serves the cell.

Because of the low transmitting power of battery-operated portable instruments, specific sending and receiving frequencies assigned to a cell may be reused in other cells within the larger geographic area. Thus, the spectral efficiency of a cellular system (that is, the uses to which it can put its portion of the radio spectrum) is increased by a factor equal to the number of times a frequency may be reused within its service area.

As a mobile instrument proceeds from one cell to another during the course of a call, a central controller automatically reroutes the call from the old cell to the new cell without a noticeable interruption in the signal recep­tion. This process is known as handoff. The central controller, or mobile telephone switching office, thus acts as an intelligent central office switch that keeps track of the movement of the mobile subscriber.

As demand for the radio channels within a given cell increases beyond the capacity of that cell (as measured by the number of calls that may be sup­ported simultaneously), the overloaded cell is " split" into smaller cells, each with its own base station and central controller. The radio-frequency alloca­tions of the original cellular system are then rearranged to account for the greater number of smaller cells.

Frequency reuse between discontiguous cells and the splitting of cells as demand increases are the concepts that distinguish cellular systems from other radiotelephone systems. They allow cellular providers to serve large metropolitan areas that may contain hundreds of thousands of customers.

fundamental _______________

hexagons__________________

diagram___________________

instrument_________________

battery____________________

controller__________________

signal_____________________

system____________________