The document provides an overview of the Global System for Mobile Communication (GSM) standard. It describes GSM as an integrated European mobile system that enables international roaming. The key objectives of GSM are outlined as well as the basic system elements, including mobile stations, base station systems, and mobile switching centers. The document also discusses concepts such as frequency reuse, cellular networks, handover, and multiple access methods used in GSM like TDMA.
2. Unit 1 Overview GSM System Standards GSM Services Basic System Elements and Principles
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4. Unit 1 Section 1 Basic System Elements and Principles
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7. Layout of a Basic Cellular Network To Telephone Network Radio Link Land Links Mobile-services Switching Centre Mobile Station (Mobile Unit) Base Station System(Cell site) MSC MS BSS MSC BSS BSS BSS BSS BSS BSS BSS MS
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14. Radio Frequency (RF) Channel Reuse 1,5,9,… 2,6,10,... 3,7,11,... 1,5,9,… 3,7,11,... 4,8,12,... 2,6,10,... Subscriber Set MSC Other PLMN Other MSCs
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20. Frequency Allocation For sectored cells the frequencies must be allocated so that cells do not use adjacent frequencies
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30. Multiple Access Methods Frequency Division Multiple Access (FDMA) Frequency 1 ch Frequency 2 ch Frequency N ch Time Division Multiple Access (TDMA) Time Time Time Slot 1 Slot 2 Slot N ch ch ch Code Division Multiple Access (CDMA) Code Sequence 1 ch Code Sequence 2 ch Code Sequence N ch
33. MAC Alternatives - CDMA Code 1 Code 2 Code 3 Code 4 All Channels Share Same RF Band Ch 1 Ch 2 Ch 3 Ch 4 Power Freq
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37. Channels for Two-Way Communications Frequency Division Duplex Uplink Downlink 1 2 3 Uplink RF carrier channels 1 2 3 Downlink RF carrier channels frequency Frequency separation between uplink and downlink channel pairs
38. Digital Radio System Information Transmit Processing Modulation Processing Information Input Information Receive Processing Demodulation Processing Information Output Receiver Transmitter Received RF Signal Transmitted RF Signal
39. Physical Channel Structure Used in P-GSM900 Frequency 1 ch ch Slot 0 Slot 1 ch ch Slot 7 Frequency 2 ch ch ch ch Frequency 124 ch ch ch ch Downlink Frequency 1 ch ch Slot 0 Slot 1 ch ch Slot 7 Frequency 2 ch ch ch ch Frequency 124 ch ch ch ch Uplink 992 Duplex Physical Channels Available Time Domain ARFCN 1 Frequency Domain
41. Simplified Digital TDMA Implementation Downlink Timeslot detection and Baseband processing Mod Time MUX Baseband Processing 1 Baseband Processing M M time slots d1 f Mod Time MUX Baseband Processing 1 Baseband Processing M M time slots dN f Demod d1 f Combiner Timeslot detection and Baseband processing Demod dN f MS MxN MS 1 Mobile Receivers Base Transmitters N frequency carriers M time slots
