3 g & 4g radio propagation


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3 g & 4g radio propagation

  1. 1. Group Members: Presented by:  M. Jawad Khan BTE01093001  Samiullah BTE01093017  Hafiz M. Yasin BTE01093018
  2. 2. 3G vs 4G
  3. 3. What to learn…?  Overview of 1G  Overview of 2G  What is 3G ?  Why 3G technology ?  Difference & comparison between 1G, 2G, 3G.  Why 3G technology ?  Effects of 3G technology ?
  4. 4. What to learn (contd…?  Benefits of 3G ?  Issue hampering 3G ?  What is 4G ?  What's New in 4G?  Features of 4G Networks ?
  5. 5. Overview of 1G…?  1st generation of wireless telecom  Introduced in the 1980  Provide only analog services  Based on AMPS (Advanced mobile phone service)
  6. 6. Overview of 2G  2nd generation of wireless telecom  Launched in 1991  Provides Digital services for voice Quality  2G introduced data services for mobile  starting with SMS text messages  Based on TDMA (time division multiplexing access)
  7. 7. What is 3G ?  3rd generation of wireless telecom  Mostly used with mobiles and handsets  Faster communication services which includes Voice Fax Internet
  8. 8. Difference 1G, 2G & 3G
  9. 9. Why 3G technology ?  Higher bandwidth enables a range of new applications.  For the consumer Video streaming, TV broadcast Video calls, video clips – news, music, sports Enhanced gaming, chat, location services.  For business High speed teleworking / VPN access Video conferencing Real-time financial information
  10. 10. Effect of 3G technology  Mobile Internet connectivity  Mobile email  Mobile Interview  Multimedia services, such as digital photos taken by and shared via wireless handsets  Wireless application downloading  Real-time multiplayer gaming  Enhanced emergency and location-based services
  11. 11. Benefits of 3G  Higher call volumes and support for multimedia data applications, such as video and photography.  Faster data transfer rates  Free or cheap calls worldwide  Capability to determine geographic position of mobiles and report it  Worthwhile for users that need connectivity on the move
  12. 12. Issues hampering its growth  High spectrum licensing fees for the 3G services  Huge capital required to build infrastructure for 3G services  Health impact because of electromagnetic waves  Prices are very high for 3G mobile services  Will 2G users switch to 3G services?  Takes time to catch up as the service is new.
  13. 13. What is 4G ?  A wireless access technology and is the successor of 3G.  Called "3G and Beyond".  Enables seamless roaming between technologies.  Plans on releasing the first commercial network in 2010.  NTT DoCoMo Company is testing 4G communication at 100 Mbps while moving, and 1 Gbps while stationary.
  14. 14. What's New in 4G ?  Entirely packet-switched networks.  All network elements are digital.  Higher bandwidths to provide multimedia services at lower cost (up to 100Mbps).  Tight network security.
  15. 15. Features of 4G Networks  4G networks are all-IP (Internet Protocol) based heterogeneous networks  This will allow users to:  Select any system at any time and any where  Use Multiple systems at the same time (e.g. GPS and WLANs and CDMA)  A wide range of applications using only one 4G integrated terminal
  16. 16. Features of 4G Networks (contd…)  Support interactive multimedia services: teleconferencing, wireless Internet, etc.  Wider bandwidths, higher bit rates.  Global mobility and service portability.  Low cost.  Scalability of mobile networks (>10 times the capacity of 3G).
  17. 17. Features of 4G Networks (contd…)
  18. 18. 4G features:
  19. 19. 4G Systems Challenges  To migrate current systems to 4G with the features mentioned previously, researchers are facing a number of challenges  These challenges are grouped into the following different aspects:  Accessing Different Networks:  Multimode Devices  Overlay Network  Terminal Mobility  Location Management  Handoff Management
  20. 20.  One of the most challenging problems facing deployment of 4G technology is how to access several and different mobile and wireless networks  There are two possible architectures  Multimode Devices  Overlay Network 4G Wireless Networks Challenges First Challenge:
  21. 21. First Challenge: Accessing Different Networks 1. Multimode Devices Architecture  A single physical terminal with multiple interfaces to access the different wireless networks
  22. 22. 1. Multimode Devices Architecture  Advantages:  Improve call completion  Expand coverage area  Reliable coverage in case of network, link or switch failure  Disadvantages:  Complexity in the hardware of the device  Handoff Mechanism: Performed by the user, device or network
  23. 23. Multimode Devices Architecture
  24. 24. First Challenge: Accessing Different Networks 2. Overlay Network Architecture  A user accesses an overlay network consisting of several UAPs  UAPs Functions:  Select a wireless network based on availability and user choices  Store IPs of user, network and devices
  25. 25. Overlay Network Architecture  Advantages:  Simplify hardware of device  Supports single billing  Disadvantages:  More network devices  Handoff Mechanism between UAPs: Performed by overlay network rather than the user or device
  26. 26. Overlay Network Architecture
  27. 27. 4G Wireless Networks Challenges Second Challenge: Terminal Mobility  In order to provide wireless services at any time and anywhere, terminal mobility is a must in 4G infrastructure  Terminal mobility allows mobile clients to roam across geographical boundaries of the wireless networks  There are two main issues in terminal mobility:  location management  handoff management
  28. 28.  The system tracks and locates a mobile terminal for possible connection  Location management involves handing all the information about  Roaming terminals such as original and current location cells  Authentication information  QoS capabilities Second Challenge: Terminal Mobility 1. Location Management
  29. 29. •) . Horizontal handoff is performed when the terminal moves from one cell to another within the same wireless system. • Vertical handoff is performed when the terminal moves between two different wireless systems (e.g., from WLAN to GSM Handoff Management (cont.) Handoff Management Challenges
  30. 30.  Vertical & Horizontal handoff will increase  System load (increasing control packets)  Packet losses  Handover latency Challenges in Handoff Management
  31. 31. Handoff Management (cont.)
  32. 32. Mobile technology:
  33. 33. Comparison between 3G & 4G
  34. 34. 3G (including 2.5G) 4G Major Requirement Driving Architecture Predominantly voice driven - data was always add on Converged data and voice over IP Network Architecture Wide area cell-based Hybrid - Integration of Wireless LAN (WiFi, Bluetooth) and wide area Speeds 384 Kbps to 2 Mbps 20 to 100 Mbps in mobile mode Frequency Band Dependent on country or continent (1800-2400 MHz) Higher frequency bands (2-8 GHz) Bandwidth 5-20 MHz 100 MHz (or more) Switching Design Basis Circuit and Packet All digital with packetized voice Access Technologies W-CDMA, 1xRTT, Edge OFDM and MC-CDMA (Multi Carrier CDMA) Forward Error Correction Convolution rate 1/2, 1/3 Concatenated coding scheme Component Design Optimized antenna design, multi-band adapters multi-band adapters Smarter Antennas, software multiband and wideband radios IP A number of air link protocols, including IP 5.0 All IP (IP6.0) 3G vs. 4G
  35. 35. Radio Propagation
  36. 36. Overview  Motivation  Effect of propagation  diagram of a radio  Signal Propagation  Large scale path loss  Small scale fading
  37. 37. Motivation for Wireless propagation  Wireless channel is vastly different from wired counterpart  Different access mechanisms  Common channel but …  State of channel at each node can vary drastically  E.g.: Sender thinks that channel is free but receiver senses a busy channel – Packet drop?  Unreliable channel  Highly sensitive to environment (surroundings) and weather  Modest bandwidth  Effects of Propagation has a high impact on higher layer protocols  E.g.: Are the assumptions made by TCP protocol valid under wireless channel?
  38. 38. Signal Propagation Effects  Free-space path loss  Fading  Scattering  Diffraction  Refraction  Multipath propagation
  39. 39. Free-space path loss Free-space path loss (FSPL) is the loss in signal strength of an electromagnetic wave that would result from a line-of-sight path through free space (usually air), with no obstacles nearby to cause reflection or diffraction.
  40. 40. Fading In wireless communications, fading is deviation of the attenuation affecting a signal over certain propagation media. The fading may vary with time, geographical position or radio frequency
  41. 41. Scattering Scattering is a general physical process where some forms of radiation, such as light, sound,
  42. 42. Multipath propagation Multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes atmospheric ducting, ionosphere reflection refraction