ELECTRONICS 2: Wireless Communications : SYBCS (Sem 2) : Semester Exam - Most IMP Question/Answers

  Chapter 1: Wireless Communication : Cellular Telephony

1 mark

Q. Define Cell & femtocell.

Answer: 

Cell: It is a small geographical area, typically 2-50km wide, covered by a base station which has been allocated a specific range of bandwidth for wireless communication.

Femtocell: In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. 

Q. What do you mean by MTSO in GSM?

Answer: It stands for Mobile Telephone Switching Office. Currently called as Mobile Switching Centre (MSC).All the cell sites in a region are connected to this central office, where each MSC is connected to a number of BSCs. It controls all the cells and provides the interface between each cell and the main telephone office. It is a part of NSS (Network Switching subsystem) in GSM.

Q. Write the full form of GSM.

Answer: 

--Q. What is handoff with respect to mobile communication.

-Q. Write down any two features of GPRS.

2.5 mark

Q. Draw block diagram of mobile handset.

Q. Write a short note on frequency reuse.

5 mark

Q. What is cell in cellular mobile system ? Explain frequency reuse concept with respect to mobile communication. How does "Handoff " take place in mobile communication.

Q. Draw and explain working of GSM architecture.

-Q. Draw and explain GPRS architecture.

Q. Explain the concept of cellular system and handover concept with reference to mobile communication.

Chapter 2: Short Range Wireless Technologies and Location Tracking

1 mark

Q. What is an active RFID tag?

-An active RFID tag is a type of radio frequency identification (RFID) tag that contains its own power source, typically a battery. Unlike passive RFID tags that rely on the energy transmitted by the RFID reader to power them, active RFID tags have their own power supply, allowing them to actively transmit signals to the reader.

Q. What is the use of RFID model?

- The use of RFID (Radio Frequency Identification) technology is quite diverse and spans across various industries and sectors. Some common applications of RFID include:

1. Supply Chain Management

2. Retail

3. Access Control: RFID cards or key fobs can be used for secure access control to buildings, rooms, parking lots, etc.

4. Healthcare

5. Transportation and Logistics

6. Livestock and Agriculture

Q.. Whiich modulation technique is used in bluetooth?

- Bluetooth uses a frequency-hopping spread spectrum (FHSS) modulation technique. FHSS divides the Bluetooth frequency band into multiple channels and rapidly switches between them in a pseudorandom sequence. This technique helps in reducing interference from other devices operating in the same frequency range.

2.5 mark

Q. Explain piconet and scatternet in bluetooth technologies.

-Piconet: A piconet is a Bluetooth network consisting of one master device and up to seven active slave devices. The master controls communication within the network, while slaves synchronize their communication with the master. Piconets are used to establish small-scale wireless networks for device connectivity and data exchange.

Scatternet: Scatternet is an advanced feature of Bluetooth technology where devices can participate in multiple piconets simultaneously, forming an interconnected network. Devices can act as both master and slave in different piconets, enabling communication between devices indirectly. Scatternets expand the capabilities of Bluetooth by extending network coverage and facilitating communication between devices in different piconets.

Q. Write a short note on Scatternet of Bluetooth

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Q. Write a short note on limitations of RFID system.

-Limitations of RFID:

1) limited range and readability
2) cost considerations
3)data security and privacy concerns
4) integration challenges, and variations in standards.
5) RFID tag range is limited, and readability can be affected by environmental factors.

5 mark

--Q. Explain the components of RFID system.

-Components of an RFID System:

RFID Tags: These are small devices that consist of an integrated circuit and an antenna. Tags can be either passive (powered by the energy from the RFID reader) or active (with their own power source). They store data and transmit it to the RFID reader when prompted.

RFID Reader: The reader emits radio waves to communicate with RFID tags. It captures and interprets the data sent by the tags.

Antenna: The antenna is responsible for transmitting and receiving radio frequency signals between the reader and the tags.

Microcontroller : This resides between the RFID reader and the enterprise applications. It manages the communication between the reader and the back-end systems, processes the collected data, and integrates it into existing databases or software applications.

Q. Explain bluetooth protocol architecture in detail.

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Q. Write in detail transport layer of z wave.

- Here are some key details about the transport layer in Z-Wave:

Mesh Network: Z-Wave utilizes a mesh network topology, where each Z-Wave device acts as a node in the network and can relay messages for other devices.

Source Routing: Z-Wave employs source routing, which means that the transmitting device determines the complete route for a message to reach its destination.

Multichannel Communication: Z-Wave operates in multiple radio frequency channels, allowing devices to switch channels to avoid interference from other wireless devices.

Network Synchronization: The transport layer in Z-Wave uses network-wide synchronization to ensure precise timing and coordination between devices.

Security: Z-Wave incorporates advanced security measures at the transport layer to protect the integrity and privacy of data.

Q. Compare LoRaWAN & Sig fox technologies.

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Chapter 3: IoT Architecture

1 mark

Q. Give any two examples of public cloud.

-Amazon Web Services (AWS): AWS is a comprehensive cloud computing platform offered by Amazon.

Microsoft Azure: Azure is a cloud computing platform by Microsoft that offers various services for building, deploying, and managing applications and services.

Q. What is full form of MQTT?

- MQTT stands for Message Queuing Telemetry Transport.

Q. What is Zigbee?

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2.5 mark

Q. Write a short note on Private cloud.

-A private cloud is a cloud computing environment that is dedicated to a single organization and is not shared with other organizations or the general public. It is designed to meet the specific needs and requirements of that organization. Here are some key aspects of private cloud:

Ownership and Control: In a private cloud, the organization owns and controls the entire infrastructure.

Infrastructure and Deployment: Private clouds can be deployed on-premises within the organization's own data center or hosted by a third-party service provider.

Security and Compliance: Private clouds offer enhanced security and data privacy compared to public clouds.

Resource Scalability: Private clouds provide scalability and flexibility in resource allocation.

Cost Considerations: Private clouds generally involve higher upfront costs compared to public clouds as organizations need to invest in infrastructure and maintenance. However, they can be cost-effective in the long run.

Customization and Integration: Private clouds offer greater customization options, allowing organizations to tailor the cloud environment to their specific applications and workflows.

5 mark

Q. Explain the following topoloies used in Zigbee.

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a. Star

b. Tree

c. Cluster Tree

d. Mesh

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Q. What is ZigBee coordinator?

-network, coordinating communication between devices, and managing various network functions. Here are some key points about the ZigBee coordinator:

Network Formation: The ZigBee coordinator is the device that initiates the formation of a ZigBee network.

Network Management: The coordinator handles network management tasks such as assigning network addresses to devices, managing network security settings, and controlling network parameters.

Routing and Messaging: The ZigBee coordinator determines the routing paths within the network, enabling devices to communicate with each other.

Security: The coordinator plays a crucial role in enforcing security measures within the ZigBee network.

Network Control and Monitoring: The ZigBee coordinator provides control and monitoring capabilities over the network.

Power Management: The coordinator may also be responsible for managing power-saving features within the network.

Q. What is GSM ? Give function of following blocks of NSS of GSM.

a. Visitor location register (VLR)

b. Home location register (HLR)

c. Equipment Indentify Register (EIR)

d. Authentication Centre (AUC)

- The functions of the following blocks of the Network Subsystem (NSS) in GSM:

a. Visitor Location Register (VLR): The VLR is a database that temporarily stores subscriber information when they roam into a specific geographical area covered by the GSM network. Its functions include:

Tracking Roaming Subscribers, Authentication and Authorization, Temporary Subscriber Data Storage.

b. Home Location Register (HLR): The HLR is a central database that stores permanent subscriber information and service profiles. Its functions include:

Subscriber Data Storage, Call Routing and Management, Subscriber Service Management, Authentication and Security,

c. Equipment Identity Register (EIR): The EIR is responsible for managing the International Mobile Equipment Identity (IMEI) numbers of mobile devices. Its functions include:

IMEI Validation, Blacklisting and Whitelisting. \

d. Authentication Center (AUC): The AUC is responsible for authentication and encryption key management in GSM networks. Its functions include:

Subscriber Authentication. Encryption Key Management.

Chapter 4: IoT Applications 

1 mark

Q. Define scalability of IoT system.

- Scalability of IoT system refers to its ability to accommodate an increasing number of devices, users, and data without compromising performance or functionality. It involves the capacity to handle a growing amount of connected devices and manage the increasing volume of data generated by those devices.

2.5 mark

Q. Write a short note on Home automation using IoT.

- Home automation using IOT::

Smart Lighting: IoT-enabled lighting systems allow users to control lights remotely, set schedules, adjust brightness, and even change colors to create desired ambiance and save energy.

Smart Thermostats: IoT-based thermostats enable homeowners to remotely control and schedule heating, ventilation, and air conditioning (HVAC) systems, optimizing energy consumption and creating personalized comfort settings.

Smart Security Systems: IoT-powered security systems integrate surveillance cameras, motion sensors, door/window sensors, and smart locks. Homeowners can monitor their home's security, receive alerts, and control access remotely.

Smart Appliances: IoT-connected appliances such as refrigerators, washing machines, and ovens can be controlled and monitored remotely, offering enhanced convenience, energy efficiency, and automation features.

Voice Assistants: Voice-controlled devices like Amazon Echo or Google Home provide hands-free control over connected smart devices, enabling voice commands for controlling lights, playing music, setting reminders, and more.

5 mark

Q. Draw and explain smart irrigation system for agricultural field.

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