History of Mobile Communication

History of Mobile Communication

What is Cell phone:

A cellular phone is a portable telephone that does not use a wired connection. It connects to a wireless carrier network using radio waves.

A cellular phone network uses a number of short-range radio transmitter-receivers to communicate simultaneously with many cellphones over a large area.

The wireless network is connected to the public telephone system, another wireless carrier network or the Internet for completing calls to another phone or to a computer.

To use a cell phone, need to buy a handset (or mobile communications device) and sign up with a wireless service provider for a calling plan.

Handsets are sold at retail outlets, electronics stores, wireless service dealers and Web-based retailers. Handsets come in a wide variety of styles, sizes, screens, keypads, software and capabilities.

Most cell phones have a color screen for easier navigation and use. Most cell phones can exchange text messages with other mobile devices or e-mail addresses. More advanced phones play games, take digital photographs, access the Internet, have personal digital assistant (PDA) functions, and play music.

History  of cellular  mobile communication:
         The history of wireless follows following hierarchy.After the second world war many national and International projects in the area of wireless communications were triggered off.
 In ancient times the light was modulated either ON or OFF pattern used for wireless communication.Flags were used to signal code words.Smoke signals were used in wireless communication as early as 150 BC.

 In 206 BC Radio transmission was introduced.

 In 1794, Claude Chappe invented Optical Telegraph for long distance wireless communication

 In 1834 – 1874 Philip Reis discovered the Telephone Principle.

 In 1886,Heinrich Hertz demonstrate the wave character of electrical transmission through space.

 In 1906, vaccum tube were invented by Robert Von Lieben.

 In 1937, Guglielmo Marconigave the wireless telegraphy.

 The first network in Germany was , analog A.Netz – in 1958 with 160MHz carrier frequency.

 In 1972 ,the B.Netz followed in Germany using the same 160MHz, here the current location of the mobile receiver should be known.

 In 1981, Nordic Mobile Telephone System(NMT) has been developed with 450MHz carrier.

 In 1982, Inmarsat A satellite has been launched.

 In 1984, Cordeless Telephone(CT1) following  its  Predecessor the CT0 from 1980

 In 1987, CT2 was developed which uses the spectrum at 864MHz and offers a data channel at a rate of 32 Kb/Sec.

 In 1991, ETSI adopted the standard Digital European Cordless Telephone(DECT) for digital cordless telephony with a spectrum of 1880 – 1900 MHz.Now it is renamed as Digital enhanced cordless telecommunications.At that time Code Division Multiple Access (CDMA) also enhanced.

 During 1992, Global System for Mobile communication (GSM) was standardized.

 In 1994, GSM-1800 networks in Europe also known as DCS 1800 (Digital Cellular System) started with a better quality.

 In 1996, HiperLAN (High Performance Radio LAN) whish is standardized by ETSI.

 In 1998, Universal Mobile Telecommunication Systems (UMTS) developed by Europeans.

 In 1999, the 802.11b ,Bluetooth was standardized.

 In 2000, General Packet Radio Service(GPRS) IEEE802.11a was developed.

 In 2001, International Mobile Telecommunications(IMT – d-2000) was standardized

 The year 2007, is the fourth generation the Internet based.

Wireless Communication-Introduction:

Unit 1: Wireless Communicaiton Fundamentals

Wireless Communication-Introduction:

Wireless communication is the transfer of information over a distance without the use of electrical conductors or "wires".The distances involved may be short (a few meters as in television remote control) or very long (thousands or even millions of kilometers for radio communications). When the context is clear the term is often simply shortened to "wireless". Wireless communications is generally considered to be a branch of telecommunications.

Wireless is a term used to describe telecommunications in which electromagnetic waves (rather than some form of wire) carry the signal over part or the entire communication path.

Example:

Cellular phones and pagers: provide connectivity for portable and mobile applications, both personal and business.

Global Positioning System (GPS): allows drivers of cars and trucks, captains of boats and ships, and pilots of aircraft to ascertain their location anywhere on earth.

Snooping TCP

Snooping TCP

• The access point snoops into the traffic and buffers packets for fast re-transmission.
• Transparent extension of TCP within the foreign agent
• Changes of TCP only within the foreign agent
• Buffering of packets sent to the mobile host
• Lost packets on the wireless link (both directions!) will be retransmitted immediately by the mobile host or foreign agent, respectively (so called “local” retransmission)
• 
  

  

  
  The foreign agent therefore “snoops” the packet flow and recognizes acknowledgements in both directions, it also filters ACKs
• Data transfer to the mobile host
• FA buffers data until it receives ACK of the MH, FA detects packet loss via duplicated ACKs or time-out
• Fast retransmission possible, transparent for the fixed network
• Data transfer from the mobile host
• FA detects packet loss on the wireless link via sequence numbers, FA answers directly with a NACK to the MH
• MH can now retransmit data with only a very short delay

Advantages

• End-to-end semantics is preserved.
• Handover is easy. I-TCP requires a careful handover of the system state. Here it falls back to the standard solution if no enhancements.

Problems

• Snooping TCP does not isolate the wireless link as good as I-TCP
• Snooping might be useless depending on encryption schemes
• Data is transmitted twice in case of a paket loss. Once from the FA to the MH and the second time when the ACK finally reaches the CN.
   

Mobile Computing

Mobile Computing Important and Assignment Questions
Write one question from Vth to VIIth unit as assignment 

UNIT V

Syllabus

Database Issues

Database hoarding caching techniques-S computing&adaptation,transactional models, Query processing,Data Recovery Process&QOS.

Objectives

·        It mainly describes Database Issues.

·        It introduces caching techniques to handle database.

·        It also deals with QOS issues.

Important Questions

1(a) The push based broad cast are not suitable for large data size, justify.

  (b) Explain about on demand data scheduling.

2. Explain in detail about caching invalidation mechanism.

3. Write short notes on QOS.

4. Explain in detail about Query Recovery process.

Assignment Questions

1. Explain in detail about caching invalidation mechanism.

2. Write short notes on QOS.

3. Explain in detail about Query Recovery process.

Case Studies

Ø List out the service primitives of QOS.

Ø Discuss various Database Issues.

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UNIT VI

Syllabus

Data dissemination and synchronization, communications asymmetry, classification of data delivery mechanisms, data dissemination broadcast models, selective tuning and indexing methods, Digital audio and video broadcasting(DAB&DVB).Data synchronization- Introduction, software and protocols.

Objectives

·        To introduce data delivey mechanism and data dissemination.

·        Understanding other areas such as DAB and DVB.

·        It also describes several methods on selective tuning and indexing.

Important Questions

1. a) Explain the functions of Hybrid mechanisms with a neat sketch.

    b) Explain Index-based method.

2.  a) Explain the functions of pull based mechanisms with a neat sketch.

    b) Explain about Hash-based method.

3. Describe briefly about selective tuning and indexing technique.

Assignment Questions

1.a) Explain the functions of Hybrid mechanisms with a neat sketch.

    b) Explain Index-based method.

2.  a) Explain the functions of pull based mechanisms with a neat sketch.

    b) Explain about Hash-based method.

Case Studies

Ø Prepare DAB mechanism with real time examples.

Ø Prepare Hybrid  mechanism with real time examples.

UNIT VII

Syllabus

Mobile Adhoc Networks(MANETs):

Introduction,Applications &challenges of a MANET,routing,classification of routing algorithms,algorithms such as DSR,AODV,DSDV,etc.Mobile agents,service discovery.

Objectives

·        Deals with Mobile Adhoc Networks (MANETs)

·        Describes several routing algorithms.

·        Introduces various technologies on routing.

·        Brief description on Mobile Agents.

Important Questions

1  (a) What is MANET? How is it different from cellular system?

    (b) What are the essential features of MANET?

    (c) What are the applications of MANET?

2. (a) Differentiate between AODV and the standard distance vector algorithm.

   (b) Explain about Hybrid routing protocols.

3. (a)What are the applications of MANET.

   (b) Distinguish between proactive and reactive routing protocols.

4. (a) Explain about on-demand multicasting routing protocol.

    (b) Describe MANET. How does a MANET differ from a fixed infrastructure network?

Assignment Questions

1.(a) Differentiate between AODV and the standard distance vector algorithm.

   (b) Explain about Hybrid routing protocols.

2.(a)What are the applications of MANET.

   (b) Distinguish between proactive and reactive routing protocols.

Case Studies

Ø List out various routing algorithms with advantages and disadvantages.

Ø Briefly present various applications of MANET.

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UNIT I

Syllabus

Introduction:Mobile Communications,Mobile computing-Paradigm, Promises/Novel Applications and Impediments and Architecture, Mobile and Handheld Devices, Limitations of  Mobile and Handheld Devices.

GSM-services, system architecture,radio interfaces,protocols,localization,calling,handoverSecurity,new data services-GPRS,CSHSD,DECT.

Objectives

·        The main objective is to know the environment of mobile communications.

·        To differentiate between handheld and mobile devices.

·        To know about the GSM technology.

·        To get an idea on several new data services such as GPRS,DECT etc

 Important Questions

1.     With the help of a neat diagram, explain the reference model of wireless and  

mobile networks.

     2.  Describe the security services that are offered by GSM?

     3.  Describe the handover and services available in GSM.

     4.  Explain in detail about system architecture of GSM with neat sketch.

     5. What do you mean by mobile terminated call (MTC) and mobile originated  

          call (MOC)? Explain.

Case Studies

Ø Construct a LAN by creating a sector,a piconet,area for GSM mobile systems.

Ø List out Mobile and Handheld devices.

Assignment Questions

1. Describe the handover and services available in GSM.

2.  Explain in detail about system architecture of GSM with neat sketch.

3. What do you mean by mobile terminated call (MTC) and mobile originated  

     call (MOC)? Explain. 

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UNIT II

Syllabus

(wireless)medium access control(MAC).Motivation for a specialized MAC (hidden and exposed terminals,near and farterminals),SDMA,FDMA,TDMA,CDMA,MAC protocols for GSM,wireless LAN(IEEE802.11),collision  avoidance(MACA,MACAW) protocols.

Objectives

·        It mainly introduces about several medium access techniques such as frequency,code,time and space.

·        To know about wireless LAN ie: IEEE802.11

It also deals with  collision avoidance protocols.

 Important Questions

1.    Explain multiple access with collision avoidance (MACA) through state machine diagrams.

2.     Explain Networking, Security and link management in Bluetooth.

3.    Explain Code Division Multiplexing and also explain its advantages and disadvantages.

4.    Describe briefly the layers in Bluetooth protocol with a neat sketch.

5. a) Describe fixed TDM algorithm.

b) Explain classical Aloha and slotted Aloha with a neat sketch.

      6. Explain about carrier sense multiple access with collosion detection. What  

           are the schemes introduced to avoid problems of CSMA/CD.

Assignment Questions

1.    Describe briefly the layers in Bluetooth protocol with a neat sketch.

2.    a) Describe fixed TDM algorithm.

b) Explain classical Aloha and slotted Aloha with a neat sketch.

     3. Explain about carrier sense multiple access with collosion detection. What  

           are the schemes introduced to avoid problems of CSMA/CD.

Case Studies

Ø Describe IEEE 802.11 wireless LAN format.

Ø Prepare a brief study on Medium Access Protocols.

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UNIT III

Syllabus

Mobile IP Network Layer:IP and Mobile IP network layers,packet delivery and handover management,location management,registration,tunneling and encapsulation,route optimization,DHCP.

Objectives

·        It mainly deals with Mobile IP Network layer.

·        It deals with several mechanisms such as hanover,registration,tunneling etc.

·        It introduces protocol called DHCP.

 

 

Important Questions

 1. a)Explain in detail about IP packet delivery with a neat sketch.

    b) List and describe the requirements of mobile IP.

2   Explain the header fields of IP-in-IP, minimal, generic routing encapsulation.

3.  Explain briefly about IP encapsulation mechanisms.

4.  Explain about an agent advertisement with neat sketch.

Assignment Questions

1.  Explain the header fields of IP-in-IP, minimal, generic routing encapsulation.

2.  Explain briefly about IP encapsulation mechanisms.

3.  Explain about an agent advertisement with neat sketch.

Case Studies

Ø Present the various formats of Mobile IP registration.

Ø Briefly list out IP Encapsulation mechanisms.

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UNIT IV

Syllabus

Mobile transport layer:

Conventional TCP/IP protocols,Indirect TCP,snooping TCP,mobile TCP,other transport layer protocols for mobile networks.

Objectives

·        It mainly deals with Mobile Transport layer.

·        It compares traditional TCP with mobile TCP.

·        It tells about other protocols for mobile networks.

Important Questions

1.    Explain in detail classical enhancements to TCP for mobility.

     2. a)Explain the concept of fast transmit/fast recovery in traditional TCP.

         b) Describe briefly on congestion control in traditional TCP.

3.     What are the special requirements in transport layer protocols in case

 of 2.5 G/3G mobile networks.

4.      Describe about the indirect TCP.

5.      Explain the concept of M-TCP and also give with its advantages and disadvantages.

6.      Explain snooping TCP and also given its advantages and disadvantages.

Assignment Questions

1.     Describe about the Indirect TCP.

2.      Explain the concept of M-TCP and also give with its advantages and disadvantages.

3.      Explain snooping TCP and also given its advantages and disadvantages.

Case Studies

Ø List out the features of various TCP/IP mechanisms.

Ø Compare various categories of TCP.

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