Cellular And Wireless Communication Acronyms


Published on

Presentation on Cellular And Wireless Communication Acronyms

Published in: Business, Technology
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Cellular And Wireless Communication Acronyms

  1. 1. Presentation On Cellular and Wireless Communication Acronyms Presented By: Zahid Been Aziz
  2. 2. Topic Sequence: GPRS UMTS BSS & PSTN UPLINK , FADING & MAHO
  3. 3. General Packet Radio Service ( GPRS) <ul><li>General Packet Radio Services (GPRS) is a mobile data service available to users of GSM mobile phones . </li></ul><ul><li>It is often described as &quot; 2.5G &quot;, that is, a technology between the second ( 2G ) and third ( 3G ) generations of mobile telephony. </li></ul><ul><li>It provides moderate speed data transfer, by using unused TDMA channels in the GSM network. </li></ul>
  4. 4. GPRS Basics <ul><li>GPRS is packet-switched which means that multiple users share the same transmission channel, only transmitting when they have data to send. </li></ul><ul><li>This means that the total available bandwidth can be immediately dedicated to those users who are actually sending at any given moment, </li></ul><ul><li>Usually, GPRS data are billed per kilobytes of information transceived while circuit-switched data connections are billed per second. </li></ul>
  5. 5. GPRS Basics (continued…….) <ul><li>Figure: GPRS Acess </li></ul>
  6. 6. GPRS speeds and profile <ul><li>Packet-switched data under GPRS is achieved by allocating unused cell bandwidth to transmit data. </li></ul><ul><li>The theoretical limit for packet switched data is 171.2 kbit/s. A realistic bit rate is 30–80  kbit/s . </li></ul><ul><li>A change to the radio part of GPRS called EDGE (sometimes called EGPRS or Enhanced GPRS however it actually stands for Enhanced Data rates for GSM Evolution) allows higher bit rates of between 160 and 236.8 kbit/s. </li></ul>
  7. 7. GPRS speeds
  8. 8. GPRS services and hardware <ul><li>GPRS upgrades GSM data services providing: </li></ul><ul><li>MMS - Multimedia Messaging Service </li></ul><ul><li>Internet Applications for Smart Devices through WAP </li></ul><ul><li>Point-to-point (PTP) service: internetworking with the Internet (IP protocols). </li></ul><ul><li>Short Message Service (SMS): bearer for SMS. </li></ul><ul><li>Future enhancements: flexible to add new functions, such as more capacity, more users, new accesses, new protocols, new radio networks. </li></ul>
  9. 9. Universal Mobile Telecommunications System (UMTS)
  10. 10. UMTS Overview <ul><li>UMTS—What is it? </li></ul><ul><li>UMTS—Its Features </li></ul><ul><li>UMTS—Problems and Issues </li></ul>
  11. 11. UMTS—What is it? <ul><li>Universal Mobile Telecommunications System (UMTS) is envisioned as the successor to Global System for Mobile Communications (GSM). </li></ul><ul><li>UMTS signals the move into the 3G of mobile networks. </li></ul><ul><li>The new network increases transmission speed to 2 Mbps per mobile user and establishes a global roaming network. </li></ul>
  12. 12. UMTS—Its Features
  13. 13. UMTS—Virtual Home Environment
  14. 14. UMTS—Mobility Services ( navigation and localization) <ul><li>First Car with Integrated 3G-UMTS Services </li></ul>
  15. 15. UMTS—Audio & Video Transmission
  16. 16. UMTS—Problems and Issues <ul><li>Some of the rollout problems operators faced included: </li></ul><ul><li>Overweight handsets with poor battery life; </li></ul><ul><li>Problems with handover from UMTS to GSM, connections being dropped or handovers only possible in one direction (UMTS->GSM) with the handset only changing back to UMTS after hanging up, even if UMTS coverage returns; </li></ul><ul><li>Initially poor coverage due to the time it takes to build a network. </li></ul><ul><li>While this is economically feasible in urban areas, it is impossible in less populated suburban and rural areas. </li></ul>
  17. 17. Base Station Subsystem (BSS) & Public Switched Telephone Network (PSTN)
  18. 18. Mobile Network Architecture PSTN / ISDN • • • • • • • • • • MSC MSC BSS BSS BSS BSS • • • • • •
  19. 19. Base Station Subsystem (BSS) Base Station Controller BTS BSC BSS Abis Base Transceiver Station Air Interface/Radio Link
  20. 20. <ul><li>BSS translates between the air interface and the fixed wired infrastructure </li></ul><ul><ul><li>Speech conversion (Transcoding): </li></ul></ul><ul><ul><ul><li>From 13 kbps speech signal 64 PCM digitized signal and vice versa </li></ul></ul></ul><ul><ul><li>Generates and interprets dialing signal </li></ul></ul><ul><li>BSS also separates the packet switch from the PSTN traffic and directs it to the packet switched data networks </li></ul><ul><li>BSS consists of two components </li></ul><ul><ul><li>Base Transceiver Station (BTS) </li></ul></ul><ul><ul><li>Base Station Controller (BSC) </li></ul></ul>Base Station Subsystem (BSS)
  21. 21. Base Transceiver Station ( BTS) <ul><li>BTS is the counterpart of the Mobile Station for physical communication over the air interface </li></ul><ul><ul><li>Components include </li></ul></ul><ul><ul><ul><li>Transmitter </li></ul></ul></ul><ul><ul><ul><li>Receiver </li></ul></ul></ul><ul><ul><ul><li>Signaling equipment </li></ul></ul></ul><ul><ul><li>to operate over the air interface </li></ul></ul><ul><ul><li>Usually located at the center of a cell where the BSS antenna is installed </li></ul></ul><ul><ul><li>One BSS may have from one up to several hundred BTS under its control </li></ul></ul>
  22. 22. Base Station Controller ( BSC) <ul><li>A group of BTS is controlled by a BSC </li></ul><ul><ul><li>Reduces Burden of MSC </li></ul></ul><ul><li>BSC manages radio related functions </li></ul><ul><li>BSC is a high capacity switch that provides services </li></ul><ul><li>such as </li></ul><ul><ul><li>Handoff </li></ul></ul><ul><ul><li>Radio channel assignment </li></ul></ul><ul><ul><li>Transcoding </li></ul></ul><ul><li>Several BSCs are controlled by a single MSC </li></ul>
  23. 23. Public Switched Telephone Network (PSTN) <ul><li>PSTN is the concentration of the world's public circuit-switched telephone networks </li></ul><ul><li>It's also referred to as the Plain Old Telephone Service (POTS) </li></ul><ul><li>PSTN also furnishes much of the Internet's long-distance infrastructure </li></ul><ul><li>Originally PSTN was a network of fixed-line analog telephone systems then converted to digital, and now includes mobile as well as fixed telephones. </li></ul>
  24. 24. Public Switched Telephone Network
  25. 25. PSTN <ul><li>In 1886, this 50-line magneto switchboard, made by Bell Telephone of Canada, was used to switch voice calls in small localities. These instruments were the beginning of the worldwide PSTN </li></ul>
  27. 27. Uplink <ul><li>In telecommunication , the term uplink (U/L) has the following meanings: </li></ul><ul><li>The portion of a communications link used for the transmission of signals from an Earth terminal to a satellite or to an airborne platform. An uplink is the converse of a downlink . An uplink or downlink is distinguished from reverse link or forward link . </li></ul><ul><li>Pertaining to data transmission from a data station to the headend. </li></ul><ul><li>Pertaining to GSM and cellular networks, the radio uplink is the transmission path from the Mobile Station (Cell Phone) to a Base Station (Cell Site). Traffic and signalling flows within the BSS and NSS may also be identified as uplink and downlink. </li></ul>
  28. 28. UPLINK
  29. 29. Fading <ul><li>Refers to the time variation of the received signal power caused by changes in the transmission medium or path. </li></ul><ul><li>Fading is usually caused by reflected waves from the transmitter having different phases from the main signal path. </li></ul><ul><li>The best way to combat fading is to ensure that multiple versions of the same signal are transmitted, received, and coherently combined. </li></ul>
  30. 30. Fading:
  31. 31. MAHO (Mobile Assisted Handoff) <ul><li>In cellular telecommunications, the term handoff refers to the process of transferring an ongoing call or data session from one channel connected to the core network to another without loss or interruption of service. </li></ul><ul><li>Hard Handoff </li></ul><ul><li>Soft Handoff </li></ul>
  32. 32. MAHO (Mobile Assisted Handoff) <ul><li>There are two reasons why a handoff (handover) might be conducted: </li></ul><ul><li>1. If the phone has moved out of range from one base station and can get a better radio link from a stronger transmitter. </li></ul><ul><li>2. If one base station is full the connection can be transferred to another nearby base station </li></ul>
  33. 33. MAHO (Mobile Assisted Handoff) <ul><li>Mobile Assisted Handoff (MAHO) is a handoff technique involving feedback from the mobile station as part of the handoff process. </li></ul>THANK YOU