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E.G.S.PILLAY ENGINEERING COLLEGE, NAGAPATTINAM.

DEPARTMENT OF INFORMATION TECHNOLOGY

IT6601-MOBILE COMPUTING

16 MARK QUESTIONS

Unit-11. Cellular Systems.

Cellular systems for mobile communications implement SDM. Each transmitter, typically called a base station, covers a certain area, a cell. Cell radii can vary from tens of meters in buildings, and hundreds of meters in cities, up to tens ofkilometers in the countryside. The shape of cells are never perfect circles or hexagons.

Robustness

2. MAC. SDMA TDMA( Question-3) FDMA CDMA( Question-4)

3. TDMA.

Fixed TDM

The advantages of cellular systems. Higher capacity Less transmission power Local interface only

Classical Aloha

Slotted Aloha

Carrier sense multiple access

One improvement to the basic Aloha is sensing the carrier before accessing the medium.Demand assigned multiple access.

PRMA packet reservation multiple access

Reservation TDMA

Multiple access with collision avoidance Multiple access with collision avoidance (MACA) presents a simple scheme that solves

the hidden terminal problem, does not need a base station, and is still a random access Aloha scheme – but with dynamic reservation.

Request to send (RTSclear to send (CTS).

Polling Polling is a strictly centralized scheme with one master station and several slave stations.

The master can poll the slaves according to many schemes: round robin

Inhibit sense multiple accessThe base station only signals a busy medium via a busy tone (called BUSY/IDLE

indicator) on the downlink.

4. CDMA.Code division multiple access (CDMA) systems use exactly these codes to separate different users in code space and to enable access to a shared medium without interference. A code for a certain user should have a good autocorrelation2 and should be orthogonal to other codes.

Coding and spreading of data from sender A

Reconstruction of A’s data

5. Wireless cellular network:

Channel cell Cell sectoring Cell splitting Frequency reuse

Unit-2

1. IEEE 802.11 System and Protocol Architecture.(Nov 11&14)(Apr13)

2. Wireless Local Loop (WLL).(Nov-14)

Multichannel Multipoint Distribution Service (MMDS)(4 Marks)Used mainly between residential subscribers and small business.

Local Multipoint Distribution Service (LMDS)(4 Marks) Appeals to larger companies with greater bandwidth demands

3. IEEE 802.11 MAC.(Apr-May 2013)

4.

5. IEEE 802.11 Physical Layer.(Apr 13)

Unit-31. Mobile Services, Localization and Calling in GSM.

Mobile services: (4 Marks) Bearer services Tele services Supplementary services

Localization: (4 Marks)

MSISDN IMSI TMSI MSRN

Calling:(8 Marks)

2. System Architecture and Protocol Architecture in GSM.

System Architecture of GSM (8 Marks)

Protocol Architecture of GSM (8 Marks)

3. Handover and four types of scenario.

Carry over the signal from Old BTS to New BTS.Four possible handover scenarios in GSM:

Intra-cell handover Inter-cell, intra-BSC handover Inter-BSC, intra-MSC handover Inter MSC handover

Handover Scenario:

4. System Architecture and Protocol Architecture in GPRS.

System Architecture of GPRS (8 Marks)

Protocol Architecture of GRRS (8 Marks)

Unit-41. Mobile IP

IP Packet Delivery

Registration:

Registration request

Registration Reply

Agent Advertisement:

Agent Discovery

Agent Solicitation

Encapsulation&Decapsulation

Tunneling

2. Dynamic Host Configuration Protocol

Simplify the installation and Maintenance.

DHCP provide IP address, address of DNS server, subnet mask.

DHCP provide client server model.

3. Mobile Ad Hoc Routing Protocols

1. Destination Sequence Distance Vector

o Damping

o Sequence Number

2. Dynamic Source Routing

o Route Discovery

o Route Maintenance

3. Least Interference Routing

4. Indirect TCP, Snooping TCP and Mobile TCP.

Indirect TCP

Snooping TCP

Mobile TCP

5. Fast Retransmit / Fast Recovery, Transmission/Timeout Freezing, Selective

Retransmission and Transaction Oriented TCP.

Fast Retransmit / Fast Recovery

Transmission/Timeout Freezing

Selective Retransmission

Transaction Oriented TCP.

Unit-51. WAP-Wireless Application Protocol.

2. WAP Gateway

3. WAP protocols

Wireless Datagram Protocol Wireless Transport Layer Security Wireless Session Protocol

Wireless Transaction Protocol

WTP class o:

WTP class 1:

WTP class 2:

4. WTP: Wireless telephony application

WTA extends the basic WAE application model in several ways: Content push:

Access to telephony functions:

Repository for event handlers:

Security model

5. iMode and SyncML

imode:

SyncML