Wireless

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Wireless

  1. 1. Contents <ul><li>Introduction </li></ul><ul><li>Definition </li></ul><ul><li>Development of wireless network </li></ul><ul><li>Kinds of networks </li></ul><ul><li>Network components </li></ul><ul><li>Operation </li></ul><ul><li>Applications </li></ul>
  2. 2. INTRODUCTION The increasing demands of the voice & data end users are driving the development of new networking techniques that accommodate mobile voice & data users who move throughout buildings,cities or countries.
  3. 3. wireless networking The term wireless networking refers to technology that enables two or more terminals to communicate using standard network protocols, but without network cabling. Strictly speaking, any technology that does this could be called wireless networking .
  4. 4. DEVELOPMENT OF WIRELESS NETWORKS <ul><li>It is based on analog technology. The 1G </li></ul><ul><li>cellular system uses FM modulation. </li></ul><ul><li>1G wireless system provide analog speech & </li></ul><ul><li>inefficient , low rate data transmission. </li></ul><ul><li>The speech signals are usually digitized </li></ul><ul><li>using a standard time division multiplex </li></ul><ul><li>format for transmission between the base </li></ul><ul><li>station & MSC & from MSC to PSTN. </li></ul>I. FIRST GENERATION:
  5. 5. II. SECOND GENERATION : <ul><li>It employs digital modulation. examples of </li></ul><ul><li>global wireless system include: GSM.TDMA, & </li></ul><ul><li>CDMA US standards. </li></ul><ul><li>It reduces computational burden of MSC by </li></ul><ul><li>introducing base station controller (BSC) </li></ul><ul><li>Inserted B/W several base stations & MSC’s. </li></ul><ul><li>It provides dedicated voice & signalling trunks </li></ul><ul><li>B/W MSC’s and MSC & PSTN. </li></ul><ul><li>2G wireless N/W specifically design to provide </li></ul><ul><li>paging & other data services such as FAX & </li></ul><ul><li>high data rate N/W access. </li></ul>
  6. 6. III. THIRD GENERATION: <ul><li>The aim of 3G wireless N/W is to provide a </li></ul><ul><li>single set of standards that can meet a wide </li></ul><ul><li>range of applications & provide universal </li></ul><ul><li>access. </li></ul><ul><li>3G use Broadband integrated service digital </li></ul><ul><li>N/W (B-ISDN) which is a computer N/W </li></ul><ul><li>framework designed around the concept of </li></ul><ul><li>CCS. </li></ul><ul><li>This generation N/W’s carry many type of </li></ul><ul><li>information such as voice, data & video. </li></ul>
  7. 7. Kinds of wireless networks 1.Adhoc or peer-to-peer network. 2.Wireless networking with access point.
  8. 8. An Ad-Hoc, or Peer to Peer wireless network consists of a number of computers each equipped with a wireless networking interface card. Each computer can communicate directly with all of the other wireless enabled computers.
  9. 9. Each computer with a wireless interface can communicate directly with all of the others. Ad-Hoc or Peer-to Peer Networking.
  10. 10. Infrastructure wireless network A wireless network can also use an access point, or base station. In this type of network the access point acts like a hub, providing connectivity for the wireless computers.
  11. 11. Types of access points Hardware access points. Software access points.
  12. 12. Hardware Access Point
  13. 13. Software Access Point
  14. 14. Wireless Networking Components Stations: A station (STA) is a network node that is equipped with a wireless network device. Access points: A wireless AP is a wireless network node that acts as a bridge between STA and a wired network. Ports: A port is a channel of a device that can support a single point-to-point connection.
  15. 15. <ul><ul><li>When a wireless adapter is turned on, it begins to scan across the wireless frequencies for wireless APs and other wireless clients in ad hoc mode. </li></ul></ul><ul><ul><li>Next, the wireless adapter switches to the </li></ul></ul><ul><li>assigned channel the selected wireless AP </li></ul><ul><li>and negotiates the use of a port. This is </li></ul><ul><li>known as establishing an association. </li></ul>Wireless operation basics
  16. 16. Packet switching <ul><li>Connectionless services exploit the fact that dedicated resources are not required for message transmission. </li></ul><ul><li>It is the most common technique used to implement connectionless services & allows a large number of data users to remain virtually connected to the same physical channel in the network. </li></ul><ul><li>Packet switching breaks each message into smaller units for transmission & recovery. </li></ul>
  17. 18. A wireless computer can &quot;roam&quot; from one access point to another, with the software and hardware maintaining a steady network connection by monitoring the signal strength from in-range access points and locking on to the one with the best quality. Roaming A user can move from Area 1 to Area 2 transparently. The Wireless networking hardware automatically swaps to the Access Point with the best signal.
  18. 19. <ul><li>If the signal strength of the wireless AP is too low, the error rate too high. </li></ul><ul><li>The signal can weaken as either the wireless adapter moves away from the wireless AP or the wireless AP becomes congested with too much traffic or interference. </li></ul><ul><li>By switching to another wireless AP, the </li></ul><ul><li>wireless adapter can distribute the load to </li></ul><ul><li>other wireless APs, increasing the </li></ul><ul><li>performance for other wireless clients. </li></ul>
  19. 20. Roaming
  20. 21. Applications <ul><li>Satellite Communication </li></ul><ul><li>Wireless Local Loop (WLL) </li></ul><ul><li>Cellular Wireless Network </li></ul><ul><li>Mobile IP </li></ul>
  21. 22. Satellite communication <ul><li>The basis of a satellite communications system is a satellite based antenna in a stable orbit above earth. </li></ul><ul><li>The antenna sys on or near earth are called EARTH STATIONS. </li></ul><ul><li>Transmission from an earth station to satellite is called UPLINK & from satellite to earth station is called DOWNLINK </li></ul>
  22. 23. Advantages <ul><li>The area of coverage </li></ul><ul><li>The conditions are more time invariant thus having more precision </li></ul><ul><li>Transmission cost is independent of distance </li></ul><ul><li>Very high data rates are available </li></ul><ul><li>The quality of transmission is extremely high </li></ul>
  23. 24. Network Configurations <ul><li>Point to Point link :- </li></ul><ul><li>Satellite is used to provide point to point link between two ground based antennas. </li></ul><ul><li>Broadcast Link :- </li></ul><ul><li>Satellite provides communication between one ground based transmitter & many receivers . </li></ul>
  24. 28. Bibliography <ul><li>Basic needs and Network Topologies </li></ul><ul><li>Networking Essentials (MCSE) </li></ul><ul><li>Computer Networks (Tanenbaum) </li></ul><ul><li>Network Devices </li></ul><ul><li>Data communication and networking </li></ul><ul><li>(B.Forouzan) </li></ul><ul><li>Networking Essentials (MCSE) </li></ul><ul><li>Protocols </li></ul><ul><li>Douglas C Comer </li></ul><ul><li>Wireless Communication and Networks </li></ul><ul><li>William Stallings </li></ul>

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