Quick Overview " Microwave "

Quick Overview " Microwave "

TRANSMISSION SYSTEMS

Introduction To Transmission Systems
•        Transmission systems form the backbone of any networks.
•        Normally transmission systems include SDH, PDH, ATM, Microwaves, leased lines.
•        In GSM normally the core network is located in the same premises and are mostly interconnected by fixed wireline. In huge network consisting of many MSC located at different places the interconnection may be through any of the transmission systems mentioned above.
•        The Access network consists of BSC’s with many BTS’s connected to them in various transmission topologies. Normal practice is to connect various BSC’c to the MSC via fiber and different BTS’s connected to BSC via microwave in Daisy chain, star or any other topology. However there can be many different ways of implementation.

E1

Telecom Interview Question & Answer.

(A)What is ciphering
Ciphering modifies the contents of the eight interleaved blocks through the use of encryption techniques to the particular mobile station and base transceiver station.
Two types of ciphering algorithms, called A3 and A5, are used in GSM to prevent unauthorized network access and privacy for the radio transmission respectively.
How many carrier frequencies are there in GSM-900 and DCS-1800? How much is the separation between the carrier frequencies?
124 carriers.
There are 8 channels in each carrier.
Channel separation is 200 KHz.
What is the Downlink and uplink spectrum is allocated to DCS-1800?
1800 MHz. Up link Frequency 1725-1780 MHZ.
Down link Frequency 1820-1870 MHz