Tài liệu GSM doc

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) [...]... subscribers worldwide? Development of mobile telecommunication systems Overview 1 2 3 4 5 INTRODUCTION TO GSM GSM ARCHITECTURE GEOGRAPHICAL NETWORK ORGANIZATION GSM NUMBERING GSM CALLING (MOC, MTC) Overview 1 2 INTRODUCTION TO GSM GSM ARCHITECTURE a b Components Interfaces Components Components GSM is a PLMN (Public Land Mobile Network) RSS (Radio Subsystem): covers all radio aspects BSS (Base Station... ETACS and AMPS networks Later adapted for GSM, and is the first Ericsson GSM phone First all digital mobile “Sandra” First introduced by Ericsson in 1991 First version used in NMT-900 networks, followed by version for ETACS, DAMPS/AMPS Adapted for GSM in 1993 “Jane” Introduced by Ericsson in 1996 Several version manufactured for AMPS, GSM, DCS, PCD1900 /GSM GSM Specification Frequency Band Uplink: 890.. .GSM Supplementary Services 4 Call hold 5 Call waiting 6 Multiparty service 7 Calling line identification presentation / restriction 8 Closed user groups (CUGs) Multiple incompatible networks Before GSM, the technical incompatibilities between networks were due to: operation on different radio frequencies... authentication via chip-card and PIN What are some of disadvantages of GSM? There is no perfect system!! no end-to-end encryption of user data reduced concentration while driving electromagnetic radiation abuse of private data possible roaming profiles accessible high complexity of the system several incompatibilities within the GSM standards What are the trends with mobile phone subscribers worldwide?... NTACS/JTACS 1991 Japan NTT/NTT Hi Cap 1978/88 Japan How did GSM get established CEPT formed a technical study group named Groupe Spécial Mobile The group’s mandate was to: formulate a specification for a pan-European mobile cellular radio system in 900MHz band Tackle the associated technical, economic and logistical problems Objectives of GSM To provide a European “second generation” digital network... network standard Increase the market for Equipment Manufacturers Allow Manufacturing to establish economy of scale Development Timeline 1985 – Digital Coded Speech over radio link chosen as basis for GSM 1986 – Validation Trials held in Paris 1988 – Following successful validation multiple invitations to tender issued 1992 – Commercial Networks Launched First portable units First portable units were... Division Multiple Access (TDMA) (narrow band) Speech coder Regular Pulse Excitation - Long Term Prediction (RPE-LPC) 13kbit/s Diversity Channel coding, Interleaving, Frequency hopping, Adaptive equalization GSM compared to 1G Systems Communication mobile, wireless communication; support for voice and data services Total mobility international access, chip-card enables use of access points of different providers... Mobile Switching Center HLR : Home Location Register VLR : Visitor Location Register PLMN : Public Land Mobile Network Network and Switching Subsystem NSS is the main component of the public mobile network GSM switching, mobility management, interconnection to other networks, system control What are the components of the NSS? Mobile Services Switching Center (MSC) controls all connections via a separated . 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)