Asim abdul qayyum

1) Describe paging

2)PSTN stands for

3)NAMPS stands for

4) Briefly explain features of satellite

5) Differentiate between soft handover and hard handover

6) Explain drawbacks of IMTS briefly

7) Describe 3 new features of AMPS

8) Evaluate 3 differences between AMPS and NAMPS

9) Explain roaming

10) Explain frequency re use

Waqar Hassan

Whats is co-channel interface and how it effect on user?and how to overcome it? There are several cells that use the same set Frequencies call co-channel. Interference between signals from these cells is called co-channel interference and it creatre noise during call.To overcome co-channel interface The co-channel cells must be physically separated.

What is roaming and what about FCC is it change or not?

Roaming allows subscribers to operate in mobile phone service areas other than the service area where the service is subscribed. Since FCC are everywhere the same, roamer is receiving information from FCC. What is trunking and what about its benefit?

Trunking is a statistical concept which allows a large number of users to share relatively small number of channels providing access on demand from a pool of available channels. Relatively small number of channels can serve a large number of users since all users are not demanding access and utilization of the system at the same time. What happened if channel is not available for a active mobile user? If a channel is not available immediately the call request may be put in a queue and delayed until a channel becomes available. What is Cellular System Radio Interface and components of its system? The common air interface (CAI) defines communication between BS and MS • Types of channels used in a mobile system: – Forward voice channel (FVC) – Forward control channel (FCC) – Reverse voice channel (RVC) – Reverse control channel (RCC) Difference between hard and soft hand off and which is good in your opnion and why? Channelized wireless systems (such as GSM) have to switch channels in the process of handoff.There is always risk of losing the connection. IS-95, Code Division Multiple Access (CDMA) system provides Soft Handoff. It does not mean changing the channel But rather deciding which base station will handle the connection. This is a unique property of CDMA concept. In hard hand off call transfer on specific time to another channel in next cell if not call will b drop. In my opinion soft hand off is better because it is much advance then the hard hand off. What IMTS provide and what its draw back? 11channels in the 152-158-MHz band, – full-duplex operation, – automatic dialing, and – automatic channel searching. 1969 an additional 12 channels were added in the 454-459-MHz band. In IMTS each base-station antenna was located on a tall structure and transmitted at high power in an attempt to provide coverage throughout the entire service area. Because of these high power requirements, all subscriber mobile units in the IMTS system were instruments that carried large batteries. Define analog and digital communication and describe it.

Analog signals continuous-time signal waveforms. And analog source that produce analog signals .analog signals transmitted directly via carrier modulation over the communication channel and demodulated accordingly at the receiver are called analog communication system. Digital signal are transmitted via digital modulation and demodulated as a digital signal at the receiver and this system is called digital communication system. What is paging system and page ? Paging systems are wireless communication systems that send brief messages to a subscriber • A message is sent to a paging subscriber via the paging system access number by a telephone keypad or modem • The issued message is called a page Satellite Communication System and what its funcation? In a geostationary satellite system, a message signal is transmitted from an earth station via an uplink to a satellite, amplified in a transponder on board the satellite, and then retransmitted via downlink to another earth station.

M umar

Q.1: Name multiple access techniques? Q.2: Define full duplexing? Q.3: Define frequency re-use? Q.4: What is Hand-off? Describe the types of Hand-off? Q.5: What is spectral efficiency? Q.6: What are the drawbacks of IMTS? Q.7:Describe about NAMPS? Q.8: What is function of control channels? Q.9: What I Roaming? and there register? Q.10: What is cellular concept?

Faheem ali

1. Define hard handoff?

2. Define wireless comm?

3. Define antennas?

4. Define duplexing techniques?

5. Define cellular concept?

6. Define frequency reuse?

7. Define 1st generation?

8. Define electromagnetic spectrum?

9. FDD stands for?

10.Define multiplexing techniques?

Waqar ali

1. What are types of radio communication systems.? 2. Describe , Paging, Cordless System.? 3. What you know about Satellite Communication.?

System 4. DfineCellular Coverage and Handoff (Handover).? 5. What you know about Amps (success & Improvements).? 6. Describe Cellular Telephone SystemStructure and is roaming.? 7. Define Scalability.? 8. Describe Channel Assignment.? 9. What is Dwell Time.? 10. Abbrivations of given below stand for what

Maho Gsm Cdma Pstn .

Hamza bin Khalid

Describe control and voice channel?

Two type of channel assignment?

Rules for channel assignment?

What is Dwell time?

What are two types of handover?

What is cell dragging?

What is co-channel interference?

Describe soft & hard handover?

SNR = 20 DB. S=100w,n=? dbm

Snr= 100, s=20db, n=? dbw

H. usman siddiq

1. What is handoff?

2.What is cell?

3.What are types of cells?

4.What are multiplexing techniques?

5.What are duplexing techniques?

6.What are antenna types?

7.Explain disadvantages of IMTS?

8.Difference between AMPS and NAMPS?

9.What is CAI?

10.What is Co channel interference?

Unkown

1.how many types of control chanels write the names ??? ANS.There are two types of control chanels

a.forward control chanel. B.reverse control channnel . 2.Name the types of voice channels?? ANS.There are teo types of voice channels a.forward voice channel b.reverse voice channel 3.What is dwell time? ANS.The time a call can be maintain within a cell without a handover is called dwell time. 4.what is hanover ? write its types. ANS.handover is a process in which call is droped while transfering its data from one base station to the other.It has two types a.soft handover. b.hard handover. 5. Cordless telephone (CT) and how they oprate? ANS.Cordless telephone (CT) is a communication system using radio waves to connect portable handset to a dedicated fixed port (base station) which is connected to PSTN as a normal telephone line (using ordinary telephone numbers). CT provides limited range and mobility in the vicinity of the base station (100 m). 6.what is popular frequency range of satellite communication and what’s reason to use it? ANS.The most popular frequency band for satellite communications is 6GHz for the uplink and 4GHz for the downlink for the following reasons: – Relatively inexpensive microwave equipment – Low attenuation due to rainfall (primary cause of signal degradation) – Insignificant sky background noise (galactic, solar and terrestrial sources produce low noise in the region 1-10GHz). 7.What is cellular communication system and what’s frequency range on which system operate? ANS.Cellular telephones are personally portable devices that may be used in motor vehicles or by pedestrians. Communicating by radio-wave in the 800-900-megahertz band, they permit a significant degree of mobility within a defined serving region that may be hundreds of square kilometers in area.

8.What’s the benefit of frequency re-use? ANS.That gives us the opportunity for the sending and the receiving frequencies assigned to a cell to be reused in other (more distant) cells within the larger geographic area. Thus, the spectral efficiency of a cellular system is increased by a factor equal to the number of times a frequency may be reused within its service area. 9.What is AMPS and what’s its feature? ANS.During this time the American cellular radio system, known as the advanced mobile phone system, or AMPS, was developed primarily by AT&T and Motorola, Inc. AMPS was based on 666 paired voice channels, spaced every 30 kilohertz in the 800-megahertz region. AMPS system employed an analog-frequency modulation, and was designed to support both mobile and portable subscriber units. 10.How cellular telephone make a call? ANS.Mobile station (phone) turned on it scans for the group of forward control channels(FCC) to find the one with the strongest signal Monitors that control channel until the signal drops below usable level Again scans for the strongest control channel and then send voice call on that channel. 11.What’s reason that noise channel added? ANS.Additive noise channel arises from electronic components and amplifier at the receiver of the communication system. Also arises from inference encountered in transmission as in the case of radio signal transmission.

Anss Hassan

Q1.Base station are connected with whom..? Ans.Base station are connected with MSC (mobile switches center). Q2.Did communication connected with Base station or not? Ans.Yes communication connected with base station,All communication are in MSC(mobile switches center). Q3.What are drawback of IMTS? Ans.Height of BS are high to more power consumption transmit. Q4.What is Handoff and its types? Ans.Base station change in Handoff and it is of two types. 1.Hard Handoff. 2.Soft Handoff. Q5.NAMPS stands for? Ans.NAMPS stands for.. Narrow Advance Mobile Phone System.

Q6.What is the abbrevation of HLR and VLR? Ans.The abbrevation of HLR is Home Location Register and VLR stand for visiting location Register. Q7.What is the purpose of Dynamic Channel Assignment? Ans.Dynamic channel reduced the call blockage capacity and increase the capacity of the system. Q8.when did co-channel interference exist? Ans.when frequency of users are same in different channel than co-channel interface exist. Q9.What is GOS and list the method to find it? Ans.Gos stand for Grade of service and following two methods are popular to find it: 1.Probability that a call is blocked. 2.Probability that a call will be delayed than specified quening time. Q10. What is store program control (SPC)?

Ans. It is stored program control systems, a program or set of instructions to the computer is stored in its memory and the instructions are executed automatically one by one by the processor.

Wajahat akmal

Ques 1. What is wireless communication concept ? Ans1.Wireless communication is the transfer of information between two or more points that are not connected by any physical medium.Wireless communications can be via: 1. Radio communication. 2. Microwave communication. 3. Light, Visible and Infrared communication. Ques 2.What do you mean by frequency reuse ? Ans 2.Each cellular Base Station is allocated a group of radio channels to be used. These radio channels can be used by another base station which is at a suitable distance awayform it. Ques 3.What do you mean by Hand-off ? Ans 3.When a mobile moves into a different cell while a conversation is in progress, the mobile Switching Center automatically transfers the call to a new channel belonging to the new Base Station.

Ques 4.Define: (a)FDMA (b) CDMA (c) TDMA ? Ans 4.FDMA: Frequency Division Multiple Access CDMA: Code Division Multiple Access TDMA: Time Division Multiple Access

Ques 5.What are different Duplexing Techniques? Ans 5.There are three types of duplexing tecniques.

1. Simplex: One way communication. 2. Half Duplex: Two way communication, but not at the same time. 3. Full duplex: Ability to transmit or receive signals at the same time.

Ques 6.Name the two Different types of boosters? Ans 6. The two type of boosters are

1. Omni directional antenna: It is located in the centre of the cell. 2. Directional antenna: It is located at the edge of the cell.

Ques 7.What is MSC? Ans7.Mobile Switching Centre (MSC) is the centre where all the calculations of calls aredone e.g Observation of a call, Tracking , Balance checking etc. Ques 8.Define the American Standard and its generations? Ans 8.Following are the generations.

1. I-Gen 80’s AMPs (FDMA) analog. 2. II-Gen 90’s Is-54 (TDMA) IS-95 digitals. 3. III-Gen 2000’s CDMA all digital.

Ques 9.Define the European Standard and its generations? Ans 9.Following are the generations.

1- I-Gen 80’s ETACS (FDMA) analog. 2- II-Gen 90’sGSM(TDMA) digital (GPRS,EDGE) 64-144kbps. 3- III-Gen 2000’s WCDMA (CDMA) all digital. 384kbps-2Mbps.

Ques 10. What is Scalability? Ans 10.A characteristic of a system, model or function that describes its capability to cope and perform under an increased or expanding workload. A system that scales wellwill be able to maintain or even increase its level of performance or efficiency when tested by larger operational demands.

Wahab qayyum

Q1:How many components does commnuication has?

Q2 What is a receiver?

Q3:Write a note on telephone history ?

Q4:Between a pager,a cellular phone and a cordless phone which device will have the longest battery life between charging?why?ging

Q5:What is forward channel?

Q6:Write some examples of wireless communication system?

Q7:What is Fdma and Cdma?

Q8:Write draw back of ITMS?

Q9:what is CAI and types of channel used in mobile system?

Q10:Dwell time depend upon what factors?

M ali

Q#1 WHAT IS CO-CHANNEL INTEREFERENCE AND HOW TO MINIMIZE IT ? Q#2 WHAT IS MEANT BY DWELL TIME ? Q#3 WHAT IS SCALABILITY AND DERIVE ITS FORMULA? Q#4 DIFFERENCE BETWEEN HANDOVER AND HANDOFF? Q#5 DEFINE TYPES OF HANDOVER? Q#6 DEFINE THE PROCESS OF MAKING CALL ? Q#7 WHO IS MORE COMPATIBLE AND LONG LASTING MAHO OR BAHO? Q#8 DESCRIBE THE FUNCTION OF ELECTRICAL COMMUNICATIONSYSTEM (ECS)? Q#9 IF LINEAR POWER PL=1000 WATT THEN WHAT WOULD BE THE POWER IN DNM ,DBW? Q#10 WHAT IS CHANNEL ASSIGNMENT?

Asif Khalid

Define cellular concept ?

Define cell dragging ?

SNR stand for and define its formula ?

Define register and its types also ?

Which thing are send to B.S when a call dial ?

Draw the graph of voice channel and control channel and also draw their graph ?

SNR=20db N= 100mw find S ?

P= 1,000 mw convert into P(dbm) ?

�

�= 20 db where n= 3 & n= 5 find N= ?

Define GOS and its types

Abdul jawad

1) What is dynamic channel assignment?

2) Write doen draw backs of IMTS?

3) Discuss about roaming?

4) Write the factors of dwell time?

5) Differentiate between MAHO and BAHO?

6) Discuss hand over policy ?

7) What is frequency reuse?

8) writ short note on Development of mobile system?

9) what is paging system?

10) What is scalibility?

Unkown

1. Why are electromagnetic waves with very low frequency not used for data transmission in

computer networks?

Low frequency has longer wavelength

Data rates depends upon the bandwidth

2. Differentiate hard and soft handoff?

Hard hand off

Existing connection must be broken before a new connection is established

There is a short break in transmission which can be noticed by the user

Soft hand off

A new connection is established before the old one is released

3.How are guard spaces realized between users in CDMA?

The guard space between a pair of users in CDMA systems is the orthogonality between

their spreading codes. The lower the correlation between any pair of spreading codes is, the

better is the user separation.

4. What are the benefits of reservation schemes?

No other station is allowed to transmit during that slot

Avoidance of congestion

Waiting time is clearly known

5. Define a cell.

In mobile communication, the coverage area is divided into smaller areas which are each

served by it’s own base station. These smaller areas are called cells.

6. What is cellular topology?

Cellular topology refers to infrastructure topology employing frequency reuse concept.

7.What are the various channel allocation techniques used in cellular communication?

Fixed Channel Allocation, dynamic channel allocation and hybrid channel allocation.

8.What is a cluster?

The N cells which collectively use the complete set of available frequencies is

called a cluster.

9.What are the technical issues in planning of a cellular network?

Selection of frequency reuse pattern for different radio transmission techniques

Physical deployment and radio coverage modelling

Plans to account for the growth of the network

Analysis of the relationship between the capacity, cell size and the cost of infrastructure

10.What is cell splitting?

This is the process of subdividing a congested cell into smaller cells, each with it’s own

base station and a corresponding reduction in antenna height and transmitter power. Cell splitting

increases the capacity of a cellular system since it increases the number of times that channels

are reused.

Amir jabbar

Q1) what is modulation? Low frequency signal is super impose with high frequency signal. Q2) what do you mean by Ad-hoc networks? Ad-hoc networks are those wireless Local Area Network that do not require any infrastructure to work. Each node can communicate directly with other nodes. So, no access point is required. Features of Ad-hoc networks are:- a) It has high complexity. b) It has the greatest possible flexibility. c) It has limited range. Q3) explain different types of microwave windows?

a) Radio waves b) Micro waves c) IR d) Visible waves e) U.V

f) X-rays g) r-rays

Q4) what is handoff (handover)? When a mobile moves into a different cell while a conversation is in progress, the Mobile Switching Center automatically transfers the call to a new channel belonging to the new Base Station. Q5) what are the types of handoff (handover) on the basis of power?

a) MAHO (mobile assisted handover) b) BAHO (base station assisted handover )

Q6) what are the types of handoff (handover) on the basis of channels? a) Soft handover (IS96 (CDMA)) b) Hard handover(GSM, AMPS)

Q7) what is channels assignment? 1) Efficient utilized of the spectrum 2) To increase capacity 3) To minimized interference

Q8) define and explain the type of channels assignment? a) Fixed channel assignment :

Blocking probability increase when interrupt accurse b) dynamic channel assignment :

reduce call blocking capacity increase Q9) explain dwell time? The time a call may be maintain within a call without handover . Q10) explain the factors on which dwell time depends ?

a) propagation : Long path, dwell time decrease.

b) interference : Long interference less dwell time.

m. umar sahi

1) Name and Explain the basic componets of Electrical Communication System. Answer: A modern electrical communication system consists of five components; Input Tranducer. Transmitter. Channel. Reciever. Output Tranducer.

2) What is channel and what type of channel is used in modern wireless network . Answer. A channel is a physical medium that is used to send signal from transmitter to Reciever. For example in co axial cable is used to send different channels to a single reciever uses are television cable. A modern wireless network uses either microwaves or radiowaves as a channel to send and recieve signals containing information. 3) What is noise and how it is removed. Answer. Un-necessary information from adjoining bands or static or galactic, atmospheric interference is called noise, It is removed using a filter e.g. Linear Filter Channel. 4) What is the difference between a Transeiver, Reciever and Tansmitter. Answer. A Transmitter can only send signals for example a Television remote control. A reciever can only recieve information like a radio set. A Transiever can do both transmittion and reception for example a Mobile Phone. 5) What are the basic components of mobile phone network. Answer. Mobile station. Base Station. Mobile Switching Centre. Public Switch Telephone Network. 6) What is roaming in the context of cellular communication networks. Answer. If a mobile station with its Mobile identification number i.e. Subscriber identification is module is configured in a certain geographical and the MS has to be used outside that geographical area and its own service is not avaulible then the other services can be used to connect the MS to network without changing device or MIN. 7) What is a channel access method give examples. Answer. is channel access method for shared medium networks. examples are; Time Devision Multiple Access Frequency Devision Multiple Access Code Devision Multiple Access 8) How is Geographical area devided for a wireless network. Answer. A Base Station or BS is an antenna that connects the MS to MSC and then to PSTN.

Geographical area is divided in the form of perfect hexagonals called Celles a bunch of cells together is called a Cluster. Each cell contain a base station either a directional antenna at a corner because its edge excited or an omni directed antenna which is center excited. 9) What is Handoff. give example. Answer.When the mobile station is in area where two cells are interfering with eachother the MS usually changes cell during a single call, ot if the MS is moving at a considerable speed for example if the user is in a moving vehicle, then the MS Switches cells over and over again due to the physical limitation of a cell and does without breaking communication is called Hand OFF. 10) Explain in detail how a call from a MS to a landline phone takes place. Answer. MS sends a call intiation request and details like MIN e.g using a reverse control channel RCC to a Base station. Base station recieves all the information from MS and sends it to a MSC using RCC. MSC verifies the given information then instructs the BS to allocate an unused voice channel to MS, and connects the MS with PSTN. BS sends MS a page message with MIN instructing to move to a voice channel using FCC. MS recieves the information verifies it and moves to the given voice channel. Voice Transmission Begins between MS and phone FVC and RVC.

Shahbaz

1) What is dynamic channel assignment?

2) Write down draw backs of IMTS?

3) Discuss about roaming?

4) Write the factors of dwell time?

5) Differentiate between MAHO and BAHO?

6) Discuss hand over policy?

7) What is frequency reuse?

8) Write short note on Development of mobile system?

9) What is paging system?

10) What is scalability?

Rubi javed

What is handoff? Describe its types?

What is difference between handoff and handover?

Describe the function of MTSO?

What are four types of channels used in mobile system?

What is basic purpose of roaming?

What should a mobile user do who wished to place a call from a radio telephone?

What does IMTS provides us?

Briefly describe the drawbacks of IMTS?

Besides other system why GSM was introduced??

What is RSSI?

Unkown

Question 1: what is electrical communication system?

Answer: Designed to send message and information from a source that generates the message

to one or more destinations

_____________________________________________________________________________________

Question 2: What is main commponents of electrical communications?

Answer:

1. Input source (information transcoder) 2. Transmitter 3. Channel 4. Receiver 5. Output transcoder

_____________________________________________________________________________________

Question 3 : What is wireless communication?

Answer: Wireless communications is a source or a channel of communication which uses radio or electrical signals and pulses to send and receive information.

_____________________________________________________________________________________

Questions 4: What is CAI ( Comman AIR Interface )?

Answer: there are two basic types of basic channels being used :

1. Control channel

Further two types of control channels

1. Forward Control Channels (downlink) 2. Reverse Control Channels (uplink)

2. Voice Channel

Further two types of voice channels.

1. Forward voice Channels 2. Reverse voice Channels

_____________________________________________________________________________________

Question 5 : Give the names of three American Standard?

Answer:

1. Ist Generation 80’s Amp’s (FDMA) analogue 2. 2ndGeneration 90’s Is-54 (TDMA) ,Ice -95 digitals 3. 3rdGeneration CDMA 2000 (CDMA) All digital

___________________________________________________________________________________

Question 6: Give three European standards? Answer:

1. Ist generation 80’s ETACS (FDMA) ,analogue 2. 2nd generation 90’s GSM (TDMA) partially digital ,GPRS systems 3. 3rd generation 2000 WCDMA (CDMA) ,All Digital.

____________________________________________________________________________________

Question 7: What is Dwell time? Answer: The time of active call progress within a Cell until a handover to nighbour Cell is called Dwell time.

_____________________________________________________________________________________

Question 8: how many types of handover ?

Answer: There are two types of handover:

1. Soft Handover In this only CDMA involves and base station is changed but the channel or frequency will be same.

2. Hard Handover In this both the Base stations and frequency channels will be changed. But it is very rare.

_____________________________________________________________________________________

Question 9: how many types of Handover power measurements?

Answer : Two types of Handover power measurements:

1. MAHO(Mobile Assisted Handover) FASTER. 2. BAHO(Base Assisted Handover) SLOWER.

_____________________________________________________________________________________

Question 10: What is Co-Channel Interference?

Answer: The signals of one tower outgoing from its area boundary to another area. The signals leave the boundary and can be received and used at the other side of boundary. It is a

disadvantage that’s why the hexagonal structure is used and preferred for wireless communication.

What is wireless communication concept?Answer.Wireless communicationare not connected by any physical medium. Wireless communications can be via:1. Radio communication. 2. Microwave communication.3. Light, Visible and Infrared co

What do you mean by frequency reuse?

Answer. Each cellular Base Station is allocated a group of radio channels to be used. These radio channels can be used by another base station which is at a suitable distance away from it.

What do you mean by Hand-off?Answer 3. When a mobile moves into a different cell while a conversation is in progress, the Mobile Switching Center automatically transfers the call to a new channel belonging to the new Base Station. Types of hand off:-

age that’s why the hexagonal structure is used and preferred for wireless

m. nazeer

What is wireless communication concept? Wireless communication is the transfer of information between two or more points that

are not connected by any physical medium. Wireless communications can be via:

Microwave communication. Light, Visible and Infrared communication.

What do you mean by frequency reuse?

Each cellular Base Station is allocated a group of radio channels to be used. These radio

channels can be used by another base station which is at a suitable distance away from it.

off? When a mobile moves into a different cell while a conversation is in progress, the

automatically transfers the call to a new channel belonging to the new

age that’s why the hexagonal structure is used and preferred for wireless

is the transfer of information between two or more points that are not connected by any physical medium. Wireless communications can be via:

Each cellular Base Station is allocated a group of radio channels to be used. These radio channels can be used by another base station which is at a suitable distance away from it.

When a mobile moves into a different cell while a conversation is in progress, the automatically transfers the call to a new channel belonging to the new

Wireless communication concept

Diagrammatically represent the GSM architecture? Answer. GSM architecture is as follows:-

What do you mean by Mobile Station Subsystem? Answer. It includes mobile equipment which refers o a physical terminal such as telephone which includes the radio trans-receiver signal processor and the Subscriber Identity Module

What do you mean by Base Station Subsystem? Answer. It consists of one or more BTS and BSC. Each BTS is related to one cell which includes an antenna, a video trans-receiver and a link to BSC.BSC controls multiple BTS units, manages the hand offs of the mobiles and controls paging.

What do you mean by Network and Switching Subsystem? Answer. It controls hand offs between cells in different BSSs, authenticates users , validates and maintains their accounts. It is mainly supported by four databases:- 1. Home Location Register. 2. Visitor Location Register. 3. Authentication Center. 4. Equipment Identity Register.

Wireless communication concept

What do you mean by Ad-hoc networks? Answer. Ad-hoc networks are those wirelesses Local Area Network that do not require any infrastructure to work. Each node can communicate directly with other nodes. So, no access point is required. Features of Ad-hoc networks are:- 1. It has high complexity. 2. It has the greatest possible flexibility. 3. It has limited range.

What are the different types of transmission impairment? Answer 9. When the received signal is not as same as the transmitted signal then it is known as Transmission impairment. Three different types of transmission impairment are:- 1. Attenuation. 2. Noise. 3. Delay Distortion.

What is the difference between 3G and 4G? Answer. Following are the differences between 3G and 4G:- 1. 3G stands for 3rd generation as it is just that in terms of the evolutionary path of the mobile phone industry. 4G means 4th generation. This is a set of standard that is being developed as a future successor of 3G in the very near future. 2. 4G speeds are meant to exceed that of 3G. 3. 3G uses the technique of circuit switching while 4G uses the technique of packet switching.

M. arsalan

What are duplexing techniques briefly explain them?

What are the types of hand off briefly explain them?

Briefly explain development of mobile telephone system ?

Briefly explain I-Gen,II-Gen,III-Gen history and development?

What are the types of Channels briefly explain them?

What are the types of Interference?

What is Dwell time briefly eplain?

Explain Mobile Assisted handover?

Eplain Basic Station Assisted Handover?

Briefly explain cell dragging

MOin mushtaq

• What is Scalability? • What are the two types of hand over measurement? • What was the handover time in first generation mobiles and in a GSM based system? • What is MSC? • What is wireless communication? • Define Hand-Over? • Give a brief explanation of Fixed Channel Assignment? • Define two types of Handover?

What are different Duplexing Techniques?

M. ali minhas

Q1. How to find the nearest co channel neighbors? Ans: Move i cells along any chain of hexagon and then turn 60 degrees counter clockwise and move j cells. Q2. How many types of channel assignments? Ans: There are two types of channel assignments given below.

• Fixed channel assignment • Dynamic channel assignment

Q3. What is fixed channel assignment?

Ans: Any call attempt within the cell can only be served by the unused channels in that cell and the channel borrowing exists in this. Q4. Dwell time is dependent on which factors? Ans: Dwell time is dependent on following factors.

• Propagation • Interference • Distance from BS etc

Q5. What are the ways of handling handover requests? Ans: Ways of handling handover requests are given below.

• Same as initial call requests. • Give it higher priority • Queue requests

Q6. What is handover? Ans: Need to be performed successfully and in frequently as possible and be transparent to users. Q7. What is cellular structure? Ans: Each cell has six equidistant neighbors and there is only certain cluster sizes and cell layouts possible. Q8. What is scalability? Ans: Frequency can be reused as many times as necessary as long as interference between co-channel stations can be kept within acceptable limits. Q9. Briefly, describe frequency reuse? Ans: Process of selecting and allocating channel groups for all base stations within a system is known as frequency reuse or frequency planning. Q10. What are the hexagonal cells? Ans: Hexagon geometry approximates omni-directional base station with free space propagation.

Kamil shehzad

Q1: What does the following stands for: � MSC � PSTN � TDD � CDMA

Q2: Name the types of channel? Q3: (a) If i=2 and j=2 . Find the cluster size?

(b) Find the total number of duplex channels if each cell has 70 channels ? Q4: Mention the steps required to make co-channels with cluster. Q5:What is the difference between full duplex and half duplex? give examples also. Q6: Find SNR IF S= 1000 mW and N=3 dBm Q7: Draw a brief diagram, how Base stations, MSCs and PSTN are connected to each other. Q8: Define cell and its shape. How cells are drawn together in cellular communication(draw)

.mention types of cell. Q9: If P1 = 1000 Watt , P2 = 50 dBW FIND (a) P1 (dBm) (b) P1+ P2 (dBW) Q10: Differentiate between soft handoff and hard handoff?

H. M . usman

Q.1 How many types of Antenna? Q.2 What is meant by Galactic noise? Q. 3 Define Microwave window? Q.4 Define spectrum frequency? Q.5 What are the solutions to provide coverage to users? Q.6 Define handoff/handover? Q.7 Define the two types of Channel assignment? Q.8 Define dwell time? Q.9 Define cluster?

Q.10 What is meant by cell dragging?

m. irfan

Define Cordless System briefly ? Draw a graph of Satellite Systems Noise Level ? Write Drawbacks of IMTS ? What is Dynamic Channel Assignment? Define trunking briefly ? What is dwell time and which number of factors it depends on ? Define Frequency Re-use with structure ? What is Cellular Concept define shortly ? Success of IMTS by AT&T ? Show Path from 2G to 3G Mobile Communication Systems with block diagram ?

Awais shah

Q1, How many types of multiple Access?

ANS, There are three types of multiple Access

A, Frequency division multiple Access (FDMA) B, Time division multiple Access (TDMA)

C, Code division multiple Access (CDMA)

Q2, How many types of Division Duplexing?

ANS, Division Duplexing has two types a, Frequency Division Duplexing (FDD) b, Time Division Duplexing(TDD)

Q3, What is stand for CAI?

ANS, CAI stands for Common Air Interferance.

Q4, What is meant by Half Duplex?

ANS: It is a two way communication but it can receive or transmit a data at a time. E.g: wakie talky

Q5, What is difference between Hard Hand off and Soft Hand off?

ANS, In Hard Hand off frequency change time to time and it is an example of TDMA where, in soft hand off frequency can’t change and it is an example of CDMA.

Q6, Write a note on NAMPS?

ANS, NAMPS is a Narrow band advanced mobile phone system. In this mobile system 10 KHz band frequency provided to each user where 2496 channels were provided. It increase three times capacity of channels compare to AMPS(Advanced mobile phone system).

Q7, What is the frequency range in MTS?

ANS, Frequency range in MTS is 35 MHz to 150 MHz.

Q8, What is a difference between Transceiver and receiver?

ANS, A receiver can only receive information like a radio set.

A Transceiver can do both transmission and reception for example a Mobile Phone.

Q9, What is difference between transmitter and transducer?

ANS, Transmitter can convert electrical signal into a form that is suitable for transmission through the physical channel where as, transducer can convert a source signal into electrical signal that is suitable for transmission.

Q10, What is Scability?

ANS, Frequency is reused as many as time, if we control a co-channel interference.

Moazzam shabbier

Explain the 3 duplexing techniques. Briefly describe Large scale fading and Small scale fading. In trunking theory for mobiles what is meant by the Grade of Service (GOS)? In mobile communication what is the dwell time? Write a short note on Base Station, Mobile Station, and Mobile Switching Center. What is the difference between Mobile Assisted Handover (MAHO) and Base-station Assisted Handover (BAHO)? What is the co channel reuse ratio Q for cluster size N=7 , i=0, j=3? There are two types of channels Control and Voice. Describe Control Channel and its parts Forward Channel and Reverse Channel. Describe Voice Channel. What is a Home Location Register (HLR)? What is a Visitor Locator Register (VLR)? Explain soft-handover and hard-handover.

Javeria raja

Q1:What is electircal communication system ? Q2:What is channel? Q3:How many types are of radio communication system? Q4:Between a pager,a cellular phone and a cordless phone which device will have the shortest battery life between charging?why? Q5:What is control channel? Q6:What is paging? Q7:What is uplink? Q8:What is tdma and tdd? Q9:Why Gsm was needed? Q10:Write short note on cellular concept?

H. asad ali 1) What is dynamic channel assignment?

2) Write down draw backs of IMTS?

3) Discuss about roaming?

4) Write the factors of dwell time?

5) Differentiate between MAHO and BAHO?

6) Discuss hand over policy?

7) What is frequency reuse?

8) Write short note on Development of mobile system?

9) What is paging system?

10) What is scalability?

AMMar

Short Questions

Q1: what are the different types of radio communication systems?

Ans: the different types of radio communication systems are cordless, paging and mobile phone devices.

Q2: what is a cordless system?

Ans: A cordless system is a communication using radio waves to connect portable sets to a fixed port which is connected to PSTN.

Q3: what is the range of cordless systems?

Ans: A cordless system has a limited range of about 100 meters.

Q4: what is a Pager?

Ans: A pager is a device that sends a brief message to its subscriber.

Q5: what is Uplink?

Ans: An uplink is a signal message send by earth to a satellite for communication.

Q6: what is a Downlink?

Ans: A downlink is a signal message send by a satellite to earth.

Q7: what is the optimum frequency to manage communication in the atmosphere?

Ans: The manageable communication frequency in the atmosphere is 1-10 GHz.

Q8: what is the frequency band used nowadays for communication purposes?

Ans: The suitable frequency for communication used in modern mobile systems is about 800-900 MHz.

Q9: what does MSC and PSTN stands for?

Ans: MSC stands for Mobile Switching centre and PSTN is the acronym for Public Switched Telephone Network.

Q10: how are the geographical area served for communications purposes?

Ans: in communication, geographical areas are divided into certain regions known as Cells. Each cell has a hexagonal shape and communication through a mobile phone in a cell is made to its Base Station.

Adnan anwar

What is wireless communication?

Define Wireless communication Applications?

What is broadcasting?

Define cellular network?

Define Wireless network?

What do you mean by frequency reuse?

What do you mean by Hand-off?

Define types of Hand-off?

What do you mean by Mobile Station Subsystem?

What do you mean by Base Station Subsystem?

ABid amjad

Question: 1 Define Microwave window? Question: 2 What is meant by Galactic noise? Question: 3 How many types of Antenna? Question: 4 Define spectrum frequency? Question: 5 Define handoff/handover? Question: 6 What are the solutions to provide coverage to users? Question: 7 Define the two types of Channel assignment? Question: 8 Define cluster? Question: 9 Define dwell time? Question: 10 What is meant by cell dragging?

Abbass samin

Qs 1 (a) what is cell and draw its digram ?? (b) How many parts of cell are there and define each

Qs 2 what is the abbrevation of the following (a) PSTN (b) MSC (c) CAI (d) IMEI

Qs 3 (a) what is Handover and write its type in detail (b) what is dwell time ?

Qs 4 what is duplex and write its two types in detail

Qs 5 In which frequncy band data and call occur ?

Qs 6 (a) what is Co Channel interference ? (b) what is Transparent handover ?

Qs 7 if i=3 and j=2 then find N ?

Qs 8 (a) Write three generation of US standard ? (b) Write three generation of European standard ?

Qs 9 (a) what is channel ? (b) write its types in detail

Qs 10 what is Channel assignment also write its types in detail .

Amir Ishaq

Part B. Short Questions

Q1. What is the difference between Uplink and Downlink?

Ans. An Uplink is a signal message transmitted from earth to the satellite or from Mobile Station to the Base Station and a Downlink is a signal message transmitted from satellite to the earth or from Base Station to the Mobile Station.

Q2. What does the term “Handoff” defines?

Ans. A Handoff or Handover is a situation when a mobile unit going from one place to another and the call, which, it is handling, is automatically rerouted by a central controller aka MTSO from the previous cell to the next cell which it is entering.

Q3. What is the difference between Simplex, Half Duplex and Full Duplex?

Ans. A simplex is a one-way communication E.g.TV or Radio. A half duplex is a two way communication but one end works at a single time e.g. a walkie talkie handset. A full duplex channel is a two way communication in which receiver and transmitter works at the same time e.g. a mobile phone etc.

Q4. What are the different types of multiple access techniques?

Ans. The different types of multiple access techniques are FDMA, TDMA, CDMA,

Q5. What are the durations of different generations of mobile communications systems?

Ans. The first generation of mobile communication evolved in 1990 and the 3G begin in 2000.

Q6. What are the key components of cellular telephone structure?

Ans. The significant components of this system are Base Station, Mobile Station, MSC and PSTN.

Q7 what is Scalability?

Ans. A phenomenon in which a frequency is re-used as many times as possible by keeping the interference less than the extreme limit. As the demand for usage grows, the base stations are increased with a decrease in transmission power.

Q8. How can we find the exact location of a cell in a cluster?

Ans. For this purpose, first we have to move three cells along any side and then turn 60 degree anti-clockwise and then move two cells again to reach the required cell.

Q9. What is dwell time?

Ans. The duration in which a call is maintained with a handoff within a cell is known as Dwell time. It depends upon propagation, interference and distance from the Base Station.

Q10. What is cell Trunking and cell dragging?

Ans. Trunking is a concept which allows a large number of users to share a small number of channels providing access on demand from a pool of channels. Cell dragging is related to users that provide a strong signal to the Base Station but moves to a closer location of another Base Station which results in interference.