GSM Radio Channel Structure

This diagram shows that the GSM system uses a single type of radio channel. Each radio channel in the GSM system has a frequency bandwidth of 200 kHz and a data transmission rate of approximately 270 kbps. This example shows that each radio communication channel is divided into 8 time slots (0 through 7). This diagram shows that a simultaneous two-way voice communication session requires at least one radio channel communicates from the base station to the mobile station (called the forward channel) and one channel communicates from the mobile station to the base station (called the reverse channel). This example also shows that some of the radio channel capacity is used to transfer voice (traffic) information and some of the radio channel capacity is used to transfer control messages.

Normal Burst Structures

This figure shows the field structures of the normal burst used in the GSM system. This diagram shows that the field structure is different for the normal burst, synchronization burst, and the frequency correction bursts. The fields transmitted during the normal burst include initial tail bits (ramp-up time), training sequence, flag bits, user data bits, final tail bits, and guard period. This diagram shows that the first 3 bits of the time slot are dedicated to the gradual increase of transmitter power level (ramp-up). For the normal burst, this is followed by the information (user data) bits. The flag bits indicate if the normal burst has been replaced with FACCH signaling information. This diagram shows that some of the bits in the center of the burst are used as training bits (to allow equalizer training). At the end of the transmitted burst there are tail bits (for error protection) and 3 guard period bits that are used during the gradual reduction of the RF transmitter signal (ramp-down).

Fast Associated Control Channel (FACCH) Signaling

This figure shows that GSM FACCH signaling replaces (steals) speech frames and replaces them with control information. This example shows the FACCH messages is divided and transmitted over 8 sequential channel bursts and that the speech information that would normally be transmitted is discarded. When received, the FACCH message is reassembled into its original message structure.

Table of Contents

Global System for Mobile Communication

GSM Services

Voice Services -Full Rate Voice -Half Rate Voice -Enhanced Full Rate Voice -Voice Privacy -Voice Group Call Service (Dispatch) -Voice Broadcast Service (VBS) Data Services -Circuit Switched Data -Packet Switched Data -Fax Services Multicast Services Short Messaging Services -Point to Point Messaging -Point to Multipoint Messaging -Cell Broadcast Messaging -Executable Messages -Flash Messages Location Based Services (LBS)

GSM Products (Mobile Devices)

Mobile Telephones Mobile Equipment (ME) Subscriber Identity Module (SIM) PCMCIA Air Cards Embedded Radio Modules External Radio Modems

GSM Radio

Frequency Allocation Frequency Reuse Time Division Multiple Access (TDMA) RF Power Control

Digital Audio and Baseband

Analog to Digital Conversion (ADC) Digital Speech Compression (Speech Coding) Channel Coding -Cyclic Redundancy Check Sum (CRC) -Block Code

-Convoultional Coding Echo Cancellation

Radio Channels

Radio Channel Bandwidth Modulation Duplex Channels Radio Channel Structure Time Slot Structure -Normal Burst -Random Access Burst (Shortened Burst) -Frequency Correction Burst -Synchronization Burst Frame Structure MultiFrame Structure -Traffic Multiframe Structures -Control Multiframe Structures -Superframe -Hyperframe Slow Frequency Hopping Discontinuous Reception (Sleep Mode) Discontinuous Transmission (DTx) Operation Dynamic Time Alignment (Timing Advance)

Logical Channels

Traffic Channels -Traffic Channel (TCH) Control Channels -Beacon (Broadcast) Channels (BCH) -Common Control Channels (CCCH) Dedicated Control Channel Signaling -Stand Alone Dedicated Control Channel (SDCCH) Traffic Channel Signaling -Slow Associated Control Channel (SACCH) -Fast Associated Control Channel (FACCH) -DTMF Signaling

GSM Network

Base Stations -Radio Antenna Towers -Radio Equipment -Communication Links Repeaters

Switching Centers -Mobile Switching Center (MSC) -Serving General Packet Radio Service Support Node (SGSN). .-Gateway GPRS Support Node (GGSN) Network Databases -Home Location Register (HLR) -Visitor Location Register (VLR) -Equipment Identity Register (EIR) -Administration Billing Center (ABC) -Authentication Center (AuC) -SMS Center (SMSC) -Group Call Register (GCR) Wireless Network System Interconnection -Public Switched Telephone Network (PSTN) -Public Packet Data Network (PPDN) -Interworking Function (IWF) Customized Applications for Mobile Network Enhanced Logic (CAMEL)

GSM System Operation

Mobile Telephone Initialization (Initial Registration) Updating Location (Registration) Waiting for Calls (Idle) Cell Reselection -Location Update System Access Mobile Call Origination (Mobile Originated Call) Mobile Assisted Handoff (MAHO)(Moved from GSM Radio) Transferring Calls (Handoff/Handover) Receiving Calls (Mobile Terminated Call) Conversation Mode Connected Mode Authentication

GSM Evolution

General Packet Radio Service (GPRS) Enhanced Data for Global Evolution (EDGE) Wideband Code Division Multiple Access (WCDMA) UMTS Long Term Evolution (UMTS LTE)

Appendix 1 – Acronyms

1G - First Generation AB - Access Burst ACCH - Associated Control Channel Ack - Acknowledgment Message AGCH - Access Grant Channel AIN - Advanced Intelligent Network ALS - Alternate Line Service AM - Amplitude Modulation AOC - Advice Of Charge AuC - Authentication Center BAIC - Barring of All Incoming Calls BAOC - Barring of All Outgoing Calls BCH - Broadcast Channel BS - Base Station BS - Bearer Services BSC - Base Station Controller BSCS - Business Support And Control System BSS - Base Station Subsystem BTA - Basic Trading Area BTS - Base Transceiver Station CAI - Common Air Interface CAMEL - Customized Applications For Mobile Enhanced Logic CAPs - Competitive Access Providers CARE - Customer Account Record Exchange CBCH - Cell Broadcast Channel CC - Convolutional Coding CCBS - Customer Care and Billing System CCCH - Common Control Channel CDMA - Code Division Multiple Access CDMA2000 - Code Division Multiple Access 2000 CDR - Call Detail Record CEPT - Conference Of European Postal And Telecommunications Administrations CLI - Calling Line Identification CLID - Calling Line Identification Display CLIR - Calling Line Identification Restriction CPP - Calling Party Pays CUG - Closed User Group DB - Dummy Burst

DCCH - Dedicated Control Channel DCS - 1800 - Digital Cellular System 1800 MHz DCS - 1900 - Digital Cellular System 1900 MHz DECT - Digital Enhanced Cordless Telephone DL - Downlink DOC - Department Of Communications DRx - Discontinuous Reception DSP - Digital Signal Processor DTE - Data Terminal Equipment DTx - Discontinuous Transmission E911 - Enhanced 911 E - commerce or ECommerce - Electronic Commerce EDACS - Enhanced Digital Access Communication System EDGE - Enhanced Data Rates For Global Evolution EDGE Compact - Enhanced Data Rates For Global Evolution Compact EFR - Enhanced Full Rate EHR - Enhanced Half Rate EIR - Equipment Identity Register Email or e - Mail - Electronic Mail EQ - Equalization ESS - Electronic Switching System ETSI - European Telecommunications Standards Institute FACCH - Fast Associated Control Channel FACCH/F - Full Rate Fast Associated Control Channel FACCH/H - Half Rate Fast Associated Control Channel FCB - Frequency Correction Burst FCC - Federal Communications Commission FCCH - Frequency Correction Channel FEC - Forward Error Correction FH - Frequency Hopping FM - Frequency Modulation FPLMTS - Future Public Land Mobile Telephone System FR - Full Rate FW - Firmware GCR - Group Call Register GGSN - Gateway GPRS Support Node GP - Guard Period GPRS - General Packet Radio Service GSM - Global System For Mobile Communications GTP - GPRS Tunneling Protocol GUI - Graphic User Interface

HANDO - Handover HDML - Handheld Device Markup Language HLR - Home Location Register HPU - Hand Portable Unit HR - Half Rate HSCSD - High Speed Circuit Switched Data HSN - Hopping Sequence Number HTML - Hypertext Markup Language IDN - Integrated Digital Network IMEI - International Mobile Equipment Identifier IMSI - International Mobile Subscriber Identity IN - Intelligent Network ISDN - Integrated Services Digital Network ISI - Inter Symbol Interference ITU - International Telecommunication Union IWF - Interworking Function Kc - Cipher Key L_CH - Logical Channel LAC - Location Area Code LAN - Local Area Network LATA - Local Access And Transport Area MAHO - Mobile Assisted Handover MCC - Mobile Country Code ME - Mobile Equipment MM - Mobility Management MMI - Man Machine Interface MNC - Mobile Network Code MOSMS - Mobile Originated Short Message Service MOU - Memorandum Of Understanding MPP - Mobile Party Pays MS - Mobile Station MSC - Mobile Switching Center MSCM - Mobile Station Class Mark MSIC - Mobile System Identification Code MSISDN - Mobile Subscriber ISDN MTP - Message Transfer Part MTSMS - Mobile Terminated Short Message Service Multiframe - Multiple Timeframe Multifunction SIM - Multi - Function Subscriber Identity Module Card MWI - Message Waiting Indicator Nack Message - Negative Acknowledgement Message

NANP - North American Numbering Plan NB - Normal Burst Net - Internet NM - Network Management NMC - Network Maintenance Center NMC - Network Management Center NMT - Nordic Mobile Telephone NSS - Network Switching Subsystem NT - Network Termination NTIZ - Network Identity And Timezone OMC - Operations And Maintenance Center OTAP - Over The Air Programming PCMCIA - Personal Computer Memory Card International Association PCN - Personal Communications Network PCS - Personal Communication Services PHS - Personal Handiphone System PIN - Personal Identification Number PLMN Code - Public Land Mobile Network Code PM - Phase Modulation PPP - Point - To - Point Protocol PSTN - Public Switched Telephone Network PTN - Public Telephone Network PUK - Personal Unblocking Key QAM - Quadrature Amplitude Modulation RAB - Random Access Burst RACE - Research In Advanced Communications In Europe RACH - Random Access Channel Ringtone - Ring Tone ROAM - Roaming RSS - Radio Sub - System SACCH - Slow Associated Control Channel SC - Smart Card SCADA - Supervisory Control And Data Acquisition SCH - Synchronization Channel SDCCH - Stand - Alone Dedicated Control Channel SDMA - Spatial Division Multiple Access SGSN - Serving General Packet Radio Service Support Node SGSN - Serving GPRS Support Node SIM - Subscriber Identity Module SMS - Short Message Service SMSC - Short Message Service Center

SNMP - Simple Network Management Protocol Softkeys - Soft Keys SP - Signaling Point SRES - Signed Response SS - Supplementary Services SS7 - Signaling System 7 STP - Signaling Transfer Point TA - Transaction Capabilities TACS - Total Access Communications System TAP - Transferred Account Procedures TCH - Traffic Channel TCH/F - Full Rate TCH TCH/F - Traffic Channel Full Rate TCH/H - Half Rate Data TCH Timeslot - Time Slot TS - Time Slot TSI - Time Slot Interchange Switching UL - Uplink UMTS - Universal Mobile Telecommunications System URL - Universal Resource Locator US TDMA - IS - 136 USSD - Unstructured Supplementary Service Data VAD - Voice Activity Detection VBS - Voice Broadcast Service VGCS - Voice Group Call Service VLR - Visitor Location Register VM - Voice Mail VMS - Voice Mail System WAP - Wireless Access Protocol WCDMA - Wideband Code Division Multiple Access WIN - Wireless Intelligent Network