Answer / senthil

global system for mobile communication

Answer / shikha

GSM is the globel system of organation . It consists of
M.S,BSC MSC ,OMC,FIXED Phone.Mobile station is carried by
the subscriber.and base station subsystem control the radio
link with mobile station . The main part of system is
mobile switching center perform switching of calls between
the mobile and fixed or mobile network use. and operational
and maintainence center oversees the proper operation and
set up of the network. The MS and BSC communicate across
the um link or air interface and BSC&MSC communicate across
A interface.

Answer / vasmatkar@hotmail.com

GSM works on combination of FDMA & TDMA technology.

Call flows from
mobile station-->cell site-->BSC(base transciver)-->MSC
(main switching centre)-->BSC-->cell site--> to recipent
mobile.

Answer / ashish kr pandey

GSM means global system of mobile communication
its is work on uplink and downlink. its work on two
frequency is 900Mhz and 1800MHZ .900mhz frequency are ms to
bts its uplink and 1800 freq is bts to ms .its downlink

Answer / mani

Mobility Management is one of the major functions of a GSM
or a UMTS network that allows mobile phones to work. The aim
of mobility management is to track where the subscribers
are, so that calls, SMS and other mobile phone services can
be delivered to them.

GSM (Global System for Mobile communications: originally
from Groupe Spécial Mobile) is the most popular standard for
mobile phones in the world. Its promoter, the GSM
Association, estimates that 82% of the global mobile market
uses the standard. GSM is used by over 3 billion people
across more than 212 countries and territories.Its ubiquity
makes international roaming very common between mobile phone
operators, enabling subscribers to use their phones in many
parts of the world. GSM differs from its predecessors in
that both signalling and speech channels are digital, and
thus is considered a second generation (2G) mobile phone
system. This has also meant that data communication was easy
to build into the system.

Answer / vinit panchal

gsm stands for global system for mobile .
in this system particular area is divided into a cluster
1 cluster is called a 7 cell this cell are arranged in hexagon shape. so we can use frequency reuse concept . in each cell there is a one bts for handling calls in that area.in our mobile sim(subscriber identification module) is there.when we are calling then mobile will send the signal to bts is the up link and bts send this signal via bsc,msc,hlr,vlr,auc,eir,pstn in sequence in this sequence our completely bio-data it will check and when authentication is done then it will transfer our call to our called user. when bts send signal to our called user from it's nearby area then the signal between bts and called user is down link.

Answer / rehan

GSM is a global system for mobile communication. it has
three major terms. they are switching system,base station
system and operating and support system. it is a 2G technology.
freq range is 900 MHZ to 1500MHZ

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(1) Instrument is a device for determining (a) the magnitude of a quantity (b) the physics of a variable (c) either of the above (d) both (a) and (b) (2) Electronic instruments are preferred because they have (a) no indicating part (b) low resistance in parallel circuit (c) very fast response (d) high resistance in series circuit (e) no passive elements. (3) A DC wattmeter essentially consist of (a) two ammeters (b) two voltmeters (c) a voltmeter and an ammeter (d) a current and potential transformer (4) Decibel is a unit of (a) power (b) impedance (c) frequency (d) power ratio (5) A dc voltmeter may be used directly to measure (a) frequency (b) polarity (c) power factor (d)power (6) An accurate voltmeter must have an internal impedance of (a) very low value (b) low value (c) medium value (d) very high value (7) The insulation resistance of a transformer winding can be easily measured with (a) Wheatstone bridge (b) megger (c) Kelvin bridge (d) voltmeter (8) A 100 V voltmeter has full-scale accuracy of 5%. At its reading of 50 V it will give an error of (a) 10% (b) 5% (c) 2.5% (d) 1.25% (9) You are required to check the p. f. of an electric load. No p.f. meter is available. You would use: (a) a wattmeter (b) a ammeter, a voltmeter and a wattmeter (c) a voltmeter and a ammeter (d) a kWh meter (10) The resistance of a field coil may be correctly measured by using (a) a voltmeter and an ammeter (b) Schering bridge (c) a Kelvin double bridge (d) a Maxwell bridge (11) An analog instrument has output (a) Pulsating in nature (b) Sinusoidal in nature (c) Which is continuous function of time and bears a constant relation to its input (d) Independent of the input quantity (12) Basic charge measuring instrument is (a) Duddel's oscillograph (b) Cathode ray oscillograph (c) Vibration Galvanometer (d) Bailastic Galvanometer (e) Battery Charging equipment (13) A.C. voltage can be measured (using a d.c. instrument) as a value obtained (a) by subtracting the d.c. reading from it's a.c. reading. (b) Using the output function of the multimeter (c) By using a suitable inductor in series with it (d) By using a parallel capacitor with it (e) None of the above (14) A moving coil permanent magnet ammeter can be used to measure (a) D. C. current only (b) A. C. current only (c) A. C. and D. C. currents (d) voltage by incorporating a shunt resistance (e) none of these (15) Select the wrong statement (a) the internal resistance of the voltmeter must be high (b) the internal resistance of ammeter must be low (c) the poor overload capacity is the main disadvantage of hot wires instrument (d) the check continuity with multimeter, the highest range should be used. (e) In moving iron voltmeter, frequency compensation is achieved by connecting a capacitor across its fixed coil. (16) Which of the following instrument is suitable for measuring both a.c. and d.c. quantities. (a) permanent magnet moving coil ammeter. (b) Induction type ammeter. (c) Quadrant electrometer. (d) Moving iron repulsion type ammeter. (e) Moving iron attraction type voltmeter. (17) Swamping resistance is used in moving coil instruments to reduce error due to (a) thermal EMF (b) temperature (c) power taken by the instrument (d) galvanometer sensitivity. (18) A power factor meter is based on the principle of (a) electrostatic instrument (b) Electrodynamometer instrument (c) Electro thermo type instrument (d) Rectifier type instrument. (19) A potentiometer recorder is used for (a) AC singles (b) DC signals (c) both (a) and (b) (d) time varying signals (e) none of these. (20) Transformers used in conjunction with measuring instruments for measuring purposes are called (a) Measuring transformers (b) transformer meters (c) power transformers (d) instrument transformers (e) pulse transformers. (21) Leakage flux in an electrical machine is measure by (a) Ballistic galvanometer (b) Flux meter (c) Either (a) or (b) (d) Vibration galvanometer (e) CRO (22) A C.R.O. is used to indicate (a) supply waveform (b) magnitude of the applied voltage (c) B.H. loop (d) all of these (e) Magnitude of the current flowing in it. (23) An oscillator is a (a) an amplifier having feedback network (b) a high gain amplifier (c) a wide band amplifier (d) a untuned amplifier (e) None of these (24) Distortion can be measured by (a) Wave meter (b) Digital filters (c) Wein bridge circuit (d) Bridge T filter circuit (25) Series connected Q- meter is preferable for measurement of components having (a) high impedance (b) low impedance (c) both (a) and (b) (d) high frequency (e) low capacitance (26) A potentiometer is (a) an active transducer (b) a passive transducer (c) a secondary transducer (d) a digital transducer (e) a current sensing transducer (27) The basic components of a digital voltmeter are: (a) A/D converter and a counter (b) A/D converted and a rectifier (c) D/A converter and a counter (d) Ramp generator and counter (e) Comparator (28) Which of the following electrical equipment cannot convert ac into dc (a) diode (b) converter (c) transformer (d) mercury arc rectifier (29) Voltage measurement are often taken by using either a voltmeter or (a) an ammeter (b) an ohmmeter (c) an oscillator (d) a watt-meter (30)The electric device which blocks DC but allows AC is called: (a) capacitance (b) inductor (c) an oscilloscope (d) a watt-meter (31 ) The range of an ammeter can be extended by using a (a) shunt in series (b) shunt in parallel (c) multiplier in series (d) multiplier in parallel (32)A device that changes one form of energy to another is called (a) rheostat (b) oscillator (c) transducer (d) varicap (33) Aquadag is used in CRO to collect (a) primary electron (b) secondary electron (c) both primary and secondary (d) none of above (34) A vertical amplifier for CRO can be designed for (a) only a high gain (b) only a broad bandwidth (c) a constant gain time bandwidth product (d)all of the above (35) One of the following is active transducer (a) Strain gauge (b) Selsyn (c) Photovoltic cell (d) Photo emissive cell (36) The dynamic characteristics of capacitive transducer are similar to those of (a) low pass filter (b) high pass filter (c) band pass filter (d) band stop filter (37) Thermocouples are (a) passive transducers (b) active transducers (c) both active and passive transducers (d) output transducers (38) The size of air cored transducers as compare to iron core counter part are (a) bigger (b) smaller (c) same (39) From the point of view of safety, the resistance of earthing electrode should be: (a) low (b) high (c) medium (d) the value of resistance of electrode does not effect the safety (40) In CRT the focusing anode is located (a) between pre accelerating and accelerating anodes (b) after accelerating anodes (c) before pre accelerating anodes (d) none of above (41) Which transducer converts heat energy into electrical energy (a) I. 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