Tổng quan Gsm

GSM is a Second Generation (2G) digital radio cellular network  Time Division Multiplexing / Multiple access (TDM/TDMA) are employed  TDM / TDMA allows:  One frequency channel to be subdivided  Multiple conversations over a single physical channe

04/2009 Overview 1. INTRODUCTION TO GSM 2. GSM ARCHITECTURE 3. GEOGRAPHICAL NETWORK ORGANIZATION 4. GSM NUMBERING 5. GSM CALLING (MOC, MTC) Overview 1. INTRODUCTION TO GSM a. What is GSM b. GSM services c. History d. GSM advantages and disadvantages What is GSM?  GSM (Global System for Mobile communication) is a Worldwide Digital Cellular Communications Network  formerly: Groupe Spéciale Mobile (founded 1982)  used in over 184 countries  The GSM network provides for  mobile voice communication  international roaming  mobile fax  text messaging  data services What is GSM?  GSM is a Second Generation (2G) digital radio cellular network  Time Division Multiplexing / Multiple access (TDM/TDMA) are employed  TDM / TDMA allows:  One frequency channel to be subdivided  Multiple conversations over a single physical channel GSM Subscriber Services Two basic types: 1. Telephony (Teleservices) Mainly voice services providing capability to communicate with other subscribers 2. Data (Bearer services) Capacity necessary to transmit appropriate data signals between two access points creating an interface to the network GSM Subscriber Services GSM supports the following subscriber services: 1. Dual tone multi frequency (DTMF) tone signaling scheme used for control purposes E.g. Remote control of an answering machine 2. Facsimile group III GSM supports CCITT group III Facsimile Special fax converter forms junction between standard analogue fax and GSM FAX GSM Subscriber Services 3. Short Message Services (SMS) Messaging facility consisting of maximum 160 alphanumeric characters to or from a mobile station to another 4. Cell Broadcast Variation of SMS where maximum number of alphanumeric characters is 93 Can be broadcast to users in a certain geographical area. E.g. Traffic congestion warnings GSM Subscriber Services 5. Voice Mail Answering machine within the network controlled by the subscriber Security code needed to access 6. Fax Mail Subscriber can receive fax messages at any fax machine 7. Emergency number common number mandatory for all service providers free of charge connection with the highest priority (pre-emption of other connections possible) GSM Supplementary Services  GSM supports comprehensive list of supplementary services supporting both data and voice services  The following compromises a partial list: 1. Call forwarding 2. Barring of outgoing calls 3. Advice of charge (AoC) . TO GSM 2. GSM ARCHITECTURE 3. GEOGRAPHICAL NETWORK ORGANIZATION 4. GSM NUMBERING 5. GSM CALLING (MOC, MTC) Overview 1. INTRODUCTION TO GSM a. What is GSM. INTRODUCTION TO GSM a. What is GSM b. GSM services c. History d. GSM advantages and disadvantages What is GSM?  GSM (Global System for Mobile communication)