gsm-p&o_i&ii_01_200909 gsm gprs edge basic principles

8/7/2019 GSM-P&O_I&II_01_200909 GSM GPRS EDGE Basic Principles

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Objective

At the end of this course, you will be able to:

Learn GSM development history

Learn and master network structure of GSMsystem and functions & principles of different

portions

Learn and be familiar with GSM wireless

channel and protocol Learn and be familiar with main service call

process for GSM


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Content

Chap.1: GSM Overview

Chap.2: GSM Network Structure

Chap.3: Interfaces and Protocols

Chap.4: GSM Radio Channel

Chap.5: Basic Service and Signaling Process

Chap.6: Voice Processing and Key Radio

Technology

Chap.7: GPRS and EDGE


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This chapter mainly introduces some basic information for

GSM, including GSM development history, supported

service type, specification, and system features.

Chap.1: GSM Overview

GSM Basic Concepts

Services Supported by GSM System

GSM Specification


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GSM Area Division Concepts GSM composition

Mobile Switching System (MSS)

Base Station Subsystem (BSS)

Operation & Maintenance Subsystem (OMS) Mobile Station (MS)

GSM System Number


This section introduces network structure of GSM system

and basic functions of various NEs.


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Relationship between Areas in GSM


GSM Area Division Concepts


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GSM System Composition


GSM composition

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The MSS consists of such entities as the mobile switching

center (MSC), home location register (HLR), visitor location

register (VLR), equipment identity register (EIR), authenticationcenter (AUC) and short message center (SMC).


Mobile Switching System (MSS)


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BSS serves as a bridge between the NSS and MS. It performs

wireless channel management and wireless transceiving. The

BSS includes the Base Station Controller (BSC) and BaseTransceiver Station (BTS).


Base Station Subsystem (BSS)


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The OMS consists of two parts: Operation & Maintenance

Center System (OMC-S) and OMC-Radio (OMC-R). The

OMC-S serves the NSS, while the OMC-R serves the BSS.


Operation & Maintenance Subsystem (OMS)


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The MS consists of mobile terminals and Subscriber Identity

Module (SIM) card.


Mobile Station (MS)


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GSM System Number

GSM system number contains:

Mobile Subscriber ISDN Number (MSISDN)

International Mobile Subscriber Identity (IMSI) Mobile Subscriber Roaming Number (MSRN)

Handover Number

Temporary Mobile Subscriber Identification (TMSI)

Location Area Identification (LAI)


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This chapter introduces GERAN interfaces, User

plane/control plane protocol stack at PS and CS.

Interfaces

PS-Domain Protocol Stack

CS-Domain Protocol Stack



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Interfaces

GSM interfaces


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User plane protocol stack at PS domain


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Control plane protocol stack at PS domain


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User plane protocol stack at CS domain


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Chap.3: GSM RadioChannel


Control plane protocol stack at CS domain


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GSM Working Frequency Band

Structure of GSM Radio Frame

Physical Channel and Logical Channel

System Messages


This section introduces GSM radio frame, channel concept,

division & function for different channels, mapping

combination mechanism between channels.


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Currently, the GSM communication system works at

900MHz, extended 900MHz and 1800MHz. 1900MHzband is adopted in some countries.


GSM Working Frequency Band


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There are five layers for structure of GSM radio frame, that is, timeslot,

TDMA frame, multiframe, super frame, and hyper frame.


Structure of GSM Radio Frame

Hierarchical frame structure in GSM system


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GSM uses TDMA and FDMA technologies for physical channel,

as shown in the figure below.


Physical Channel and Logical Channel


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System message falls into 12 types: type1, 2, 2bis, 2ter, 3,

4, 5, 5bis, 5ter, 6, 7, 8.


System Messages


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Mobile subscriber state

Location Update

Typical Call and Handover Process

Basic Signaling Process


This section introduces GSM terminal start, position register /

update, service call and handover service implementation and

signaling interaction process.


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MS starts, network does "Attach" marks on it

MS shutdowns, separated from network

MS Busy


The mobile subscriber has three states as follows:

Mobile subscriber state


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Location Update at Same MSC Office

Location Update

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Call process



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Handover process



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Location Update Process of MS


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Mobile-Originated Call and Called

Party On-hook Process


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Mobile-Terminated Call and Calling

Party On-hook Process


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Inter-cell Handover Process


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Voice Processing

Frequency multiplexing

Adaptive equalizing

Diversity Receiving

Discontinuous Transmission (DTX)

PowerControl

Timing Advance

Frequency Hopping Technology

Chap.6: Voice Processing and Key Radio Technology

This section describes basic voice processing for GSM, and

several key radio enhanced technologies.


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Voice Processing


Voice Processing in the GSM System


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Frequency multiplexing


Frequency multiplexing is the core concept of the cellular mobile radio

system. In a frequency multiplexing system, users at differentgeographical locations (different cells) can use channels of the same

frequency at the same time (see the figure above).


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Adaptive equalizing


Equalizer can do equalizing at frequency domain and time domain.

GSM uses time domain equalizing, enabling the better performance in

whole system.


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Diversity Receiving


Diversity reception technology is commonly used in GSM. Diversity

consists of different forms: Space diversity, frequency diversity, time

diversity and polarity diversity.


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Discontinuous Transmission (DTX)


The DTX mode accomplishes two objectives: Lower the total

interference level in the air and save the transmitter power.

Speech Frame Transmission in DTX Mode


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PowerControl


Power control means to control the actual transmitting power (keep itas low as possible) of MS or BS in radio propagation, so as to reduce

the power consumption of MS/BS and the interference of the entire

GSM network.

PowerControl Process


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Timing Advance


In the GSM, the MS requires three intervals between timeslots whenreceiving or transmitting signals. See the figure below.

Uplink and Downlink Offset of TCH


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Frequency Hopping Technology


Frequency hopping (FH) refers to hopping of the carrier frequencywithin a wide frequency band according to a certain sequence.

Basic Structure of FH

Ch 7 GPRS d EDGE


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Definition and Feature

Inheritance and Evolution

GPRS Radio Channel

Radio Link and Media Access Control Flow

Terminal and Application


This section describes evolution of GSM technologies: basic concept,

network structure, radio channel, and basic application of GPRS and

EDGE.

Ch 7 GPRS d EDGE


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The General Packet Radio Service (GPRS) is the packet data

service introduced in GSM Phase2+.

The GPRS has the following features:

Seamless connection with IP network

High rate

Always online and flow charging

Mature technology

Ch 7 GPRS d EDGE


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Enhanced Data Rate for GSM Evolution (EDGE) is a kind oftechnology for transition of GSM to 3G.

The EDGE has the following features:

EDGE neither changes GSM or GPRS network structure nor

introduces new network element, but only upgrades the BSS.

EDGE does not change the GSM channel structure, multiframestructure and coding structure.

EDGE supports two data transmission modes: packet service

(non-real time service) and circuit switching service (real time

service).

EDGE adopts octal 8PSK modulation technology, supports303% of GMSK payload, and provides higher bit rate and

spectral efficiency.

Compared with GPRS, EDGE adopts new coding mode.

Ch 7 GPRS d EDGE


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Inheritance and Evolution


Each standard for current 2G has a set of methods to upgrade2G network into 3G:

(1) Evolution route to CDMA 2000 may be IS95 (orCDMA One)

CDMA20001x CDMA 2000-3x or WCDMA.

(2) Evolution route to WCDMA may be GSM GPRS EDGE

WCDM A.

(3) Evolution route to TD-SCDMA is not obvious now. It ispossible to implement smooth transition based on GSM MAP

network, also compatible to ANSI41 and transited to 3G.

Chap 7 GPRS and EDGE


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GPRS RadioChannel


This section introduces GPRS physical channel, GPRS logic

channel, mapping of logical channel combination in the physical

channel, and GPRS channel coding.

Chap 7: GPRS and EDGE


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Radio Link and Media Access Control Flow


This section introduces paging flow, TBF setup flow, GPRS

suspend/resume flow, and TBF release flow.

Chap 7: GPRS and EDGE


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Terminal and Application


The GPRS MSs fall into three categories: Type A, B, and C.


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gsm-p&o_i&ii_01_200909 gsm gprs edge basic principles

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