RF Planning and Drive Test

8/9/2019 RF Planning and Drive Test

1/36

E1E1--E2 CME2 CM

for BSNL internal circulation only



2/36

A cell can be defined

as the area covered

by one sector


a n emen s o a oNetwork

Mobile station

Base Transceiver Station


3/36


4/36

Determine number of cells required for capacity

CAPACITY AND COVERAGE


.

Determine number of cells required for coverage

by using propagation model.


5/36

ERLANG

One erlang ( Erl) is defined as the amount of

traffic generated by the user when he or she

uses one traffic channel for one hour.



6/36

ERLANG TABLES

Commonly used Erlang tables are

Erlang B Erlang C

Erlang B assumes that if calls cannot go through


then they get dropped (i.e. no queuing possible).

Erlang C considers that if a call does not get

through then it will wait in a queue.


7/36

ERLANG TABLES

These tables give information about the traffic

generated by X No. of TRXs for different Grades

of Service.



8/36



9/36

POSSIBLE CHANNEL COMBINATIONS

RT 0

Timeslots

BCCH CCCH TCHSDCCH TCH

0 1 2 3 4 5 6 7

TCH TCHTCH


CMCC SMS SS

RT 1

RT 2

RT 3

TCH

SDCCH

TCH TCH TCH TCH TCH TCH TCH

TCH TCH TCH TCH TCH TCH TCH TCH

TCH TCH TCH TCH TCH TCH TCH


10/36

FREQUENCY RE-USE

Frequency re-use factor depends on

the average number of the transceivers

the total number of frequencies.



11/36

FREQUENCY RE-USE FACTOR

If there are 3 TRX that are used per base station

and the total number of frequencies available is

27.The total number of frequencies available for


re-use is 27/3 = 9


12/36

There are few theoretical models and many

empirical models to predict the propagation path

loss.

PROPOGATION MODELS


Propagation models should be applied with

caution .

Network planning tools will combine these

models with terrain data.


13/36

PROPOGATION MODELS

For Macro Cell

Okumura-Hata model

For Micro Cell


Walfisch-ikegami model


14/36

PROCESS OF RADIO NETWORK

PLANNING

Collection of the input parameters

Pre planning

Site survey


Parameter planning

The final radio network plan involves rest of the

parameters like power budget calculations and

considering path loss calculations.


15/36

OPTIMISATION

Optimization involves monitoring, verifying and

improving the performance of the radio network.



16/36

WHAT IS OPTIMIZATION



17/36

OPTIMISATION

Power amplifiers are located near the

transmission antennas.

The boosters are located near the base station.



18/36

DIVERSITY

Diversity is the most common way to improve

the reception power of the receiving antenna. Major diversity techniques are

space diversity


frequency diversity polarization diversity

(In our field polarisation diversity is being used)


19/36

RADIO NETWORK PLANNING

AND OPTIMIZATION

o Study of methods required for optimization:

o Traffic estimation in terms of erlangs

o Configuration of Time slots of TRX

o Calculation of frequency re use factor


o Application of suitable propagation modelo Methods to improve signal received by MS

o Study of RRM ( Radio resource management)

o Study of KPIs( Key performance parameters)


20/36

MS BTS MSCBSC

RIL3 - CM

RIL3 - MM

RIL3 - RRSCCP

BSSMAP

DTAP

MM

TCAP

DTAP

CM

U

PSCCP

MA

P

I

S

SCCP

BSSMAP

BTSM

RIL 3-RR

BTSMRR


LAPD m

Layer 1 Layer 1

LAPD m LAPD

Um A bis A link BCDEFG

MTP

Layer 1Layer 1

GSM Signaling Protocols Overview

LAPD MTP


21/36

RADIO RESOURCE MANAGEMENT

The radio resource management (RRM) is the

functions related to

mobile location updation


communication management issues such ashandover and roaming procedure handling


22/36

LINK PROTOCOLS

To execute these management functions,

information flow (traffic and signalling) takes

place via three protocols, known as link


protocols .


23/36

LINK PROTOCOLS

LAPDm is present over the MS-BTS connection

LAPD over the BTS-BSC connection.

MTP is used for signalling transport over the


SS7 network.


24/36

STUDY OF KPIs

Once a radio network is designed and

operational, its performance is monitored. The performance is compared against chosen

key performance indicators (KPIs).


After fine-tuning, the results are then applied tothe network to get the desired performance.


25/36

STUDY OF KPIs

KPls can be subdivided according to the areasof functioning, such as

area level cell level

TRX level.


- SDCCH requests

dropped SDCCH total

dropped SDCCH Abis failures

outgoing MSC control handover (HO) attempts outgoing BSC control HO attempts

intra-cell HO attempts, etc.


26/36

DRIVE TEST PROCESS

Selection of the 'live' region of the network

Selection of the drive testing path.

To have the appropriate kits including


Mobile equipment (usually three mobiles) Drive testing software (on a laptop)

A GPS (global positioning system) unit.


27/36

USB2USB1

Short call Long Call

USB3

Idle

Drive Test Equipments for Voice & PS callTools

1. Scanner

2. Drive Test

Software

3.UE

4.PC

5.GPS

DRIVE TEST TOOL PHYSICAL SET UP


Com 1

scanner

GPS

Data Card

PS


28/36

DRIVE TEST PROCESS

Two mobiles are used to generate calls with a

gap of few seconds (usually 15-20 s).

The third mobile is usually used for testing the


coverage.

It makes one continuous call, and if this call

drops it will attempt another call.


29/36

DRIVE TEST PROCESS

To collect enough samples at a reasonable

speed and in a reasonable time.

If there are lots of dropped calls, the problem is


analysed to find a solution for it and to propose

changes.


30/36

OPTIMISATION SOLUTION

Moving antenna locations

Altering antenna heights

Changing ARFCNs


Antenna orientation adjustment

Rectifying the faults in the steps followed before

finalisation of Radio network planning.


31/36

DRIVE TEST TOOL

TEMS offers solutions for

Planning

Development


Troubleshooting

Expanding mobile networks

Optimized networks mean lower operational

costs.


32/36

DRIVE TEST TOOL

TEMS products allow efficient monitoring,

diagnosing and benchmarking in order to make

best use of available resources.


They also enable engineers to troubleshoot

problems quickly.


33/36

TEMS CELLPLANNER UNIVERSAL TEMS Cell Planner Universal is Ericssons tool

for mobile radio network planning.

It is a


highly graphical

easy-to-use

PC-based tool for design

Realization

Optimization of mobile radio networks.


34/36


35/36

TEMS CELLPLANNER UNIVERSAL

It supports for

WCDMA GSM 850,GSM 900,GSM 1800,GSM 1900

iDEN


CDMA,CDMA2000 1xRTT TDMA/AMPS

NMT 450, NMT 900

TACS, and E-TACS.

GPRS and EGPRS (EDGE) in GSM system.


36/36


Documents

RF Planning and Drive Test