Question 1

Define mobile computing and list its main characteristics.

Accepted Answer

Mobile computing allows transmission of data, voice, and video via a computer or any other wireless-enabled device without a fixed physical link.

Question 2

What is the difference between wired and wireless networks?

Accepted Answer

Wired networks use cables for connection and offer higher bandwidth, while wireless networks use radio waves, providing mobility but generally lower bandwidth and higher error rates.

Question 3

Explain the concept of frequency reuse in cellular networks.

Accepted Answer

Frequency reuse is the process of using the same radio frequencies on radio transmitter sites within a geographic area that are separated by sufficient distance to cause minimal interference.

Question 4

What is handoff in cellular systems? Name two types.

Accepted Answer

Handoff is the process of transferring an ongoing call or data session from one channel connected to the core network to another.

Question 5

Define Mobile IP and state its main purpose.

Accepted Answer

Mobile IP is an IETF standard communications protocol that is designed to allow mobile device users to move from one network to another while maintaining their permanent IP address.

Question 6

What is a care-of address (COA)?

Accepted Answer

A Care-of Address (COA) is a temporary IP address assigned to a mobile node when it moves to a foreign network.

Question 7

Differentiate between proactive and reactive routing protocols.

Accepted Answer

Proactive protocols maintain routing information continuously, while reactive protocols discover routes only when a node needs to send data.

Question 8

What is Bluetooth? List its two main states.

Accepted Answer

Bluetooth is a wireless technology standard for exchanging data over short distances. Its main states are standby and connection.

Question 9

What is Indirect TCP (I-TCP)?

Accepted Answer

Indirect TCP (I-TCP) splits the TCP connection into two parts: a wired connection from the sender to the access point, and a wireless connection from the access point to the mobile host.

Question 10

Explain the hidden and exposed terminal problem in brief.

Accepted Answer

The hidden terminal problem occurs when two nodes cannot hear each other but send data to the same receiver, causing collisions. The exposed terminal problem prevents a node from sending data because it mistakenly thinks the medium is busy.

Question 11

Explain the architecture of GSM in detail.

Accepted Answer

GSM architecture consists of the Mobile Station (MS), Base Station Subsystem (BSS), and Network and Switching Subsystem (NSS).

Question 12

Describe the MAC protocol IEEE 802.11 with its frame format.

Accepted Answer

IEEE 802.11 uses CSMA/CA for MAC, which avoids collisions using RTS/CTS. Its frame format includes frame control, duration, four addresses, sequence control, frame body, and FCS.

Question 13

What are the challenges faced by Mobile Transport Layer? Explain Snooping TCP.

Accepted Answer

Mobile Transport Layer faces high error rates, frequent disconnections, and varying delays. Snooping TCP buffers packets at the base station to retransmit locally without notifying the sender.

Question 14

Discuss the Dynamic Source Routing (DSR) protocol in MANETs.

Accepted Answer

DSR is a reactive routing protocol for MANETs where the sender determines the complete sequence of nodes through which to forward the packet.

Question 15

Explain the working mechanism of Mobile IP with a suitable example.

Accepted Answer

Mobile IP uses a Home Agent, Foreign Agent, and Care-of Address to route packets to a mobile node currently in a foreign network.

Question 16

Describe the concept of Data Dissemination and Broadcasting.

Accepted Answer

Data dissemination is the distribution of information to mobile nodes. Broadcasting involves transmitting data over the airwaves to many receivers simultaneously.

Question 17

Explain the various generations of cellular networks (1G, 2G, 3G, 4G).

Accepted Answer

Generations evolved from analog voice (1G), to digital voice and text (2G), mobile broadband data (3G), to all-IP high-speed networks (4G).

Question 18

What is MANET? Explain Destination Sequenced Distance Vector (DSDV) routing p…

Accepted Answer

MANETs are self-configuring, infrastructure-less networks. DSDV is a proactive routing protocol that uses sequence numbers to prevent routing loops.

Question 19

Discuss the TCP over wireless links. Compare I-TCP, Snooping TCP, and M-TCP.

Accepted Answer

Standard TCP misinterprets wireless loss as congestion. I-TCP, Snooping TCP, and M-TCP are transport layer protocols designed to mitigate these issues.

Question 20

Explain the architecture and working of IEEE 802.11 wireless LAN in detail.

Accepted Answer

IEEE 802.11 defines the physical and MAC layers for WLANs. Architecture includes BSS, ESS, AP, and DS. MAC relies on CSMA/CA.

Question 21

Describe the location management and call setup mechanism in GSM.

Accepted Answer

GSM uses HLR and VLR for location tracking. Call setup involves paging the mobile station, authenticating, and establishing traffic channels.

Question 22

Write detailed notes on Mobile IP. Explain agent discovery, registration, and…

Accepted Answer

Mobile IP enables mobility across networks. It involves Agent Discovery (finding FA/HA), Registration (updating location), and Tunneling (forwarding packets).

Mobile Computing