Наиболее употребительные префиксы и суффиксы прилагательных и наречий:
| суффикс или префикс | Значение | пример |
| un-, in-, dis-, non-, il-, im-,ir- | Отрицательное | unequal/неравный/ indirect/косвенный/ dishonest/нечестный/ non-ferrous/не содержащий железо/ |
| pre- | пред, ранее | pre-war/довоенный/ |
| post- | После | post-war/послевоенный/ |
| anti- | анти -, противо- | anti-aircraft/противовоздушный/ |
| inter- | между, взаимно | international/международный/ |
| sub- | под- | submarine/подводный/ |
| super- | сверх- | supersonic/сверхзвуковой/ |
| ultra- | ультра -, сверх- | ultra-short/ультракороткий/ |
| -a(i)ble | возможность подвергнуться действию | changeable/изменчивый/ accessible/доступный/ |
| -al | central/центральный/ | |
| -ant, -ent | different/различный/ resistant/сопротивляющийся/ | |
| -ary, -ory | monetary/денежный/ explanatory/объяснительный/ | |
| -en | название вещества | woolen/шерстяной/ |
| -ful | наличие качества | useful/полезный/ |
| -less | отсутствие качества | homeless/бездомный/ |
| -ic | basic/основной/ | |
| -ish | национальная принадлежность; слабая степень качества | polish/польский/ reddish/красноватый/ |
| -ive | talkative/разговорчивый/ |
| -ous | famous/знаменитый/ | |
| -y | rainy/дождливый/ | |
| -ly | badly/плохо/ partly/частично/ firstly/во-первых/ | |
| -ward(s) | Направление | backward(s)/обратно/ inward(s)/внутрь/ |
Exercise 1. Образуйте наречия от следующих прилагательных.
Easy (просто), usual (обычно), special (особо), north (к северу), regular (регулярно), functional (функционально), home (к дому), main (главным образом), sea (к морю).
Exercise 2. При помощи таблицы подберите подходящий суффикс или префикс к данным словам и образуйте прилагательные. Проверьте себя по словарю.
Form, to insist, value, element, to compare, wax, violet, fruit, Atlantic, important, Scott, hope, to act, complete, fame, brown, possible, economy, essential, human, historic, town, revolutionary, imperialist, sun.
Cellular Communication
Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.
Occupy, entire, height, audio, cause, portion, feature, routing, certain.
Words to be learnt
single- один, одиночный
to hold (held, held) - поддерживать, удерживать
entire- полный, целый, весь
pitch- модуль, высота (звука)
to cause- вызывать, быть причиной
sample- образец, пример
recovered signal- восстановленный сигнал
to distort- искажать
to deliver- доставлять, снабжать
landline- линия проводной связи
to store- накапливать, запасать
feature- особенность, характеристика
call forwarding- динамическая переадресация вызова
debit card- платежная карта
routing element- трассировочный элемент
predominant- преобладающий, доминирующий
interim- промежуточный, временный
Text
Many different types of systems have provided city-wide two-way communications, such as radio systems for taxis or the police. In these systems, a single antenna is located near the center of the city. Each two-way conversation occupied one channel so if there were 100 channels in the city, only 100
simultaneous conversations could be held. To cover the entire city, the antenna is placed on a tall building and emits a very strong signal. In the cellular phone system, the city is divided into smaller sections, or cells. Each cell contains its own antenna and uses only a subset of all the channels. Each antenna is lower in height and emits a much weaker signal so that the same subset of channels can be used in a cell somewhere else within the city.
Cellular telephone systems can be "analog" or "digital". Older systems (AMPS, TACS, NMT) are "analog" and newer systems (GSM, PCS) are "digital". The major difference is in how the audio signal, e.g. your voice, is transmitted between the phone and base station. "Analog" and "digital" refer to this transmission mechanism. In either system, the audio at the microphone always starts out as a voltage level that varies continuously over time. High frequencies (high pitch) cause rapid changes and low freqs cause slow changes. With analog systems, the audio is modulated directly onto a carrier. This is very much like (if not identical) to FM radio where the audio signal (in that case music) is translated to the RF signal. With digital systems, the audio is converted to digitized samples at about 8000 samples per second or so. The digital samples are numbers that represent the time-varying voltage level at specific points in time. With analog transmissions, interference (RF noise or some other anomaly that affects the transmitted signal) gets translated directly into the recovered signal. The neat thing about digital is that the 1s and 0s can not be easily confused or distorted during transmission, plus extra data is typically included in the transmission to help detect and correct any errors.
The cellular network operates on a combination of network hardware and software to operate. They are:
Mobile Base Stations - otherwise known as the cell site. The radio signal of each cell site covers a portion of a service area. A service area can have hundreds of cell sites.
Mobile Switching Centers (MSC) - The MSC connects the voice path for a call. The MSC and cell site work together to determine which radios the mobile phone will use when delivering calls. It interprets the digits entered by the mobile phone user and delivers the call accordingly. As the mobile subscriber moves to new cell site areas, the MSC reconnects the call to a new radio in that cell. It provides the path to the public switched telephony network (PSTN), for delivering calls to land-
line phones or to long-distance numbers. There can be many MSCs in a single service area.
Home Location Register (HLR) - The HLR is a database where the subscriber's feature profile is stored. It will keep information on the subscribers phone number, the electronic serial number of the mobile phone, and the features the customer has (call forwarding, call waiting, 3-way calling, voice mail, etc.). The HLR is a software element. It can be an integral part of the MSC, or stored on a separate platform.
Service Control Point (SCP) - The SCP holds databases that control customer features and services. The HLR is a primary example of a database on the SCP. Some other examples include 800-number lookup services, calling card services, calling number identification, short message service, message waiting indicator, and debit card services.
Signal Transfer Point (STP) - The STP is a network routing element. It takes a message in, checks the routing information, and sends the message toward its destination. STPs use the signaling system seven (SS7) protocol to transport messages.
Protocols - Data messages are formatted in a way that allows switches and network elements to understand them. The formatting follows certain rules and these rules are called a protocol. The predominant protocols used in roaming networks are signaling system seven (SS7), and interim standard-41 (IS-41). We also use X.25 packet switched data, global system for mobile communications (GSM), Ethernet, and the transmission control protocol/internet protocol (TCP/IP) for messaging.
Задание. Выпишите из соответствующих абзацев текста ключевые слова, которые помогут вам:
- объяснить принцип действия системы сотовой связи;
- рассказать о различиях между аналоговыми и цифровыми системами связи;
-перечислить и дать краткую характеристику элементов, составляющих сеть сотовой связи.
Unit 22.
Grammar Revision
