CBSE Class 10 Computer Science Mobile Technologies

Choose the correct alternative.

Question. which technology is used to connect subscriber to nearest telephone exchange through using radio link?
(a) CDMA
(b) WLL
(c) GSM
(d) Wi-Fi
Answer : B

Question. which is the world’s most widely used cellphone technology?
(a) GPS
(b) GPRS
(c) GSM
(d) CDMA
Answer : C

Question. in TDMA, T stands for
(a) time
(b) third
(c) technology
(d) triple
Answer : A

Question. CDM“ uses …………… waves.
(a) radio
(b) micro
(c) infrared
(d) electromagnetic
Answer : D

State whether these statements are true or false.

Question. Wi-Fi a wireless version of Ethernet.
Answer : true

Question. wireless communication involves transmitting signals using microwaves.
Answer : False

Question. wireless spectrum is allocated by government and international organizations.
Answer : True

Question. presently, 3G network is available in limited countries and areas.
Answer : False

Fill in the blanks.

Question. GSM standard was developed as a replacement of ………. Analog cellular networks.
Answer : 1G

Question. MM“ started with ………….. generation of mobile technologies.
Answer : second

Question. ……… cards are interchangeable modules.
Answer : SIM

Question. GSM standard was developed by …………
Answer : ETSI

Very Short Answer Type Questions

Question. Expand:
(a) GPRS
(b) FDMA
Answer : GPRS: General Packet Radio Multiple Access
FDMA: Frequency Division Multiple Access

Question. What is GSM?
Answer : GSM (Global System for Mobile communications) is a technique that uses TDMA which allows 8 simultaneous calls on the same radio frequency.

Question. differentiate SMS and MMS.
Answer : SMS
SMS is short messaging server
It is limited to 160 bytes
Uses 2G with GPRS
MMS
MMS is multimedia messaging service
No size limit
Uses 3G

Question. write one characteristic each for 2G and 3G Mobile Technologies.
Answer : 2G: first digital cellular system with data speeds up to 64 kbps.
3G: with speeds upto 2 Mbps, it allows voice and video calls.

Question. what is SIM?
Answer : SIM (Subscriber Identification Module) are inter changeable modules which store subscriber wireless provider information.

Question. give the difference between 3G and 4G.
Answer : the speed of 4G is about 10 times faster than 3G. we can stream audio and video content using 4G.

Short Answer Type Questions

Question. Write two advantages of 4G over 3G mobile communication technologies in terms of speed and services.
Answer : Speed: 4G offers speed of more than 10 Mbps while 3G around 3 Mbps.
Services: it can prioritise services to offer flawless performance. Ex: VoIP is prioritized over other data to offer flawless calling experience.

Question. What is CDMA?
Answer : code division multiple access (CDMA) is a digital cellular technology that uses spread spectrum techniques.
Unlike competing systems, such as GS, that use TDMA, CDMA does not assign a specific frequency to each user.
Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo random digital encode are encoded with a pseudo random digital sequence. CDMA consistently provides better capacity for voice and data communications than other commercial to connect at any given time, and it is the common platform on which 3G technologies are built.

Question. Differentiate between TDMA and CDMA.
Answer : TDMA 
1. TDMA is short for time division multiple access
2. TDMA chops or divides the channel into sequential time portions as each user has its respective right turn for channel use 
CDMA
1. CDMA is for code division multiple access.
2. CDMA uses a process called spread spectrum scattering of digital bits in pseudorandom manner and collecting them for interpretations.

Question. What is the difference between baseband and broadband?
Answer : Baseband
1. entire bandwidth of the cable is consumed by a signal
2. digital signals
3. bidirectional trans-mission
4. no frequency division multiplexing possible
MMS
1. signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously
2. analog signals
3. unidirectional transmission
4. frequency division multiplexing possible.

Question. Explain Global System for Mobile GSM communications.
Answer : GSM is a digital mobile telephony system that is widely used in Europe and other parts of the world.
GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA).
GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time other streams of user data, each in its own time slot.
It operates at either the 900 MHz or 1800 MHz frequency band.

Question. What is SMS?
Answer : Short message service (SMS) is a text messaging service component of phone, web, or mobile communication systems, using standardized communications protocol that allow the exchange of short text messages between fixed line or mobile phone devices.
Including spaces, text messages traditionally can’t exceed 160 characters.

Question. Explain the features of 4G.
Answer : the main features of 4G (fourth Generation) are:
Capable of provide 10 Mbps - 1 Gbps speed
High quality streaming video
Combination of Wi-Fi and Wi-Max
High security
Provides any kind of service at ant time as per user requirements anywhere
Expanded multimedia services
Low cost per bit
Battery use is more
Hard to implement
Needs complicated hardware
Expensive equipment required to implement next generation network.

Question. Explain WLL.
Answer : wireless local loop (WLL) is a term for the use of a wireless communications link for delivering plain Old telephone service (POST) and/or broadband internet to telecommunications customers. 
This is simply a wireless connection of a telephone in a home or office to a fixed telephone network. 
Using industry technology, it is an implementation of subscriber loops to connect devise over a multiply access radio system to the public switched telephone network (PSTN).
It differs from a standard local loop in that the connection to the telephone system in made wirelessly instead of with cables.

Question. Explain the features of 2G?
Answer : the features of second generation, 2G:
Data speed was upto 64 kbps.
Used digital signals.
Enabled services such as text messages picture messages and MMS (Multimedia Message Service).
Provided better and capacity than 1G.
Unbale to handle complex data such as videos.
Required strong digital signals to help mobile phones work. If there was no network coverage in any specific area, digital signals were weak.

Question. What are the proposed applications of 5G?
Answer : applications of 5G are beyond our imagination. User never experienced ever before such high value technology which includes all type of advanced features.
Some of the proposed applications of 5G (fifth Generation) are:
Charge our mobile using our own hear beat.
Feel our parent’s sugar level with our mobile
Know the exact time of our child birth in nano seconds.
View our residence in our mobile when someone enters and also when someone opens our intelligent car.
Sense tsunami/earthquake before it occurs.
Access our office desktop, Laptop, car, bike using or mobile.
Identify our stolen mobile within nanoseconds
Our mobile car shares our workload, identify the best server and also intimate us before the call drops.

Question. Explain the features of 3G.
Answer : the main features of 3G (third generation) are:
Speed 2 Mbps
Typically called smart phones
Increased bandwidth and data transfer rates to accommodate web based applications audio and video files.
Provides faster communication
Send/receive large email messages
High speed web/more security/video conferencing/3D gaming
Large capacities and broadband capabilities
TV streaming/mobile TV/phone calls

Long Answer Type Questions

Question. Write a short note on the generations of mobile technologies.
Answer : 1G (first Generation) was introduced in 1980 and was based on narrow band analog cellular technology. It sued circuit switching and only voice calls were available. It used CDMA (Code Division
Multiple Access). Each user was allocated a unique code sequence. The sender conceded the signal using the given code. The receiver also had the unique code and used it to decode the data. 2G (second Generation) was introduced in 1990 and was based on GSM technology. It sed circuit switching but provided paging, SMS voicemail and fax services. GSM (global system for mobile communications) is a combination of FDMA and TDMA. SMS (subscriber identification module) cards are interchangeable modules which store subscriber and wireless provider information.
The 3G (third generation) systems are also known as universal mobile telecommunications system (UMTS) as they have a single network standard. 3G mobiles use both circuit and packet switched networks. it allows video, audio, and graphics applications. Video streaming was introduced. They provide data rates up to 2 Mbps the clarity is more and is close to a real conversation. 4G (fourth Generation) systems provide speed of up to 10 Mbps and prioritize services. Ex: all resources are allocated to video calls to enhance the quality of the service. 5G (fifth generation) offers high speed, enormous capacity, capability, low latency and pro video the bearer for many applications.

Question. Write a short note on mobile technologies.
Answer : mobile technology is indispensable in the modern workplace. Due to its versatility, it offers a range of benefits, but also comes with considerable risks to the business. It is essential to consider both advantages and disadvatages of using mobile technology in business. Examples of mobile IT devices include:
Laptop, tablets and netbook computers
Smartphones
Global positioning system (GPS) devise
Wireless debit credit card payment terminals
Advantages: higher efficiency and productivity of staff
The quality and flexibility of services offered to customer
The ability to accept payments wirelessly
Improved networking capabilities
Disadvantages:
Costs: new technologies and devices are often costly to purchase and require ongoing maintenance and upkeep.
Workplace distractions: as the range of technologies and devices increases, so does the potential for them to disrupt productivity and work flow in the business. Increased IT security needs: portable devices are vulnerable to security risks, especially if they contain sensitive or critical business data.