SE S09 Project GSM Domain

8/9/2019 SE S09 Project GSM Domain

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SOFTWARE ENGINERING

Spring 2009

GSM Simulation Domain

March 02, 2009


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MOLDELING & SIMULATION

Mathematical or Empirical Model of aSystem is Modeling

Implementation of a model on thecomputer is simulation

Simulation does not necessarily meanactually duplicating a physical system

Depending on the level of detail simulationmay just mimics a physical system

Level of detail of simulation is guided by thepurpose.


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BOOK for GSM Domain

Pages 23-58

GSM Switching Services and Protocols 2nd

EditionBy Jorg Eberspacher, Hans-Jorg Vogel and

Christian Bettsetter

John Wiley and Sons, LTD 2001PDF is in the shared folder


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Cellular

Limited Channels

GSM 25 Mz in 900 Mz range

Max 125 Channels of 200 kHz each

Large Number of Subscribers

Solution: Reuse of Channels

Signal Strength drops sharply away from the

transmitter

A particular Signal of a certain frequency can be reused if thetransmitters are located sufficiently far apart

Create Cells (Radio Zones) and reuse s frequency in those

cells that are sufficiently far apart


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Cell Conti

Assign A sub set of channels Ci

(frequencies) to each cell such that no 2

neighboring cell will have the same subset but

Ci can be reused again in cells which are

far enough apart

Co-Channel Interference One frequency

interferes with another cells frequency


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Cells Ddistance

part canreusefrequencies


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Signal To Noise Ratio (SNR)

SNR = Useful Signal /Disturbing Signal =

(Useful Signal)/(Neighboring Cell

Interference + Noise) Neglecting the noise SNR = Useful

Signal / Neighboring Cell Interference

SNR = 1/6(R/D) -y Where R is the radius of

the cell and D is the distance of Frequency

reuse and 2 y 5;


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Cell Clusters


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SNR for k Cells/Cluster


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Traffic Capacity Blocking Probability (a call will be blocked) =

(Erlang Formula)

N = total number of channels

A = U H where U = Number of users; =

Average number of calls/second and H =

average duration of a call

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GSM System Hierarchy


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GSM Architecture


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GSM Basics

System Architecture Fixed Installed Structure

Radio Network Base Station Subsystem (BSS)

Mobile Switching Network Switching and Management SubSystem (SMSS)

Management Network Operation and Manage Sub System(OMSS)

Mobile Subscribers over Radio Interface - MobileStations (MS)

Mobile Equipment Subscriber Identity Module (SIM)

Subscriber ID

Call Number


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Base Station Subsystem (BSS)

Base Transceiver Station (BTS)

One Per Cell

Antenna

Transmitter

Receiver

Simple signaling and protocol processing

Base Station Controller (BSC) Provides controls for the BTS

Services more than one BTS


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BSS


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Mobile Switching Network (MSS)

Mobile Switching Center

Routing

Allocation and Administration of radioResources

Subscriber Identification

Service Features Processing


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MSS


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Home and Visitor Location

Registers (HLR & VLR) HLR (one per PLMN))

Stores Every Subscribers Data

Subscription and Permissions (Permanent Data)

Current Location of the MS (Temporary Data)

VLR (One per MSC)

MS is registered on entering a location area

(MSC) Provides Roaming and faster local connection


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Management Network Operation

and Manage Sub System (OMSS) Monitoring

Configuration

Fault and Performance Management


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Project

GSM Simulator and CELL

Optimization (GSMSim) Simulate the working and management of

a typical GSM Network

Provide Rudimentary NetworkManagement Capabilities

Perform CELL Optimization


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GSMSim Modules

GSM System (GS)

Simulate a typical GSM network

GSM Network Management System (GNMS)

rudimentary network management capabilities

GSM Performance & Fault Management System

(GPFS)

Manage the performance and fault aspects

GSM Cell Optimizer (GCO).

Manage the cell optimization functions


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GSM System (GS) [group 1]

The GSM System Engineer log in to the system

Mobile Stations (MS), (BTS ), BSC and MSC will be graphically displayed on aSatellite map of Lahore. Color coding will be used to identify currently setupCells.

Cell Working

Engineer can make changes (location and numbers) to the GSM set up Monitors traffic between Network Elements e.g. MS to BTS

Can display different parameters on the screen

Communication Protocols Communication between Network Elements can be configured to use one of the given

protocols

Cell Configuration All the cell parameters are configurable from the screen

User Interface Interactions

Interacts with the other modules via a Application Programming Interface (API)


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GSM Network Management

System (GNMS) [groups 2]

The GSM NSM

Provides Controls for the currently managed

GSM System

Monitoring

Configuration

Performance and Fault Management.

User Interface Interfaces to other modules


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GSM Performance & Fault

Management System (GPFS)

[group 3]

Manage Performance and faultparameters.

Generate Alarms at any Network Element

Monitoring of Alarms of all Network Elements

Monitoring of QOS parameters to manageperformance

User Interface

Interfaces with other modules


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GSM CELL Optimizer (GCO)

[group 4] Optimize GSM Cell parameters

Tracks signal strength, position and time

parameters

Provides controls for changing these

parameters

User Interface

Interfaces with other modules

Documents

SE S09 Project GSM Domain