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Summary

Technologies Radio Network Planning Process

Radio Media & Model Tuning

Network Dimensioning

Transmission Planning

Parameter Planning & Optimisation

Network Capacity Evolution

Planning Tools

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Transmission Planning

EXPLAIN CHAPTER 5

Transmission Planning (3)

Network Topologies (2)

Microwave Links (8)

Leased Lines (3)

Cross Connects (3)

Transmission Techniques (4)

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Cost for transmission lines acco

unts for a greatportion of network operational costs per year

design a network that meets the designcriteria with minimum overall costs!

Fixed part design

MSC

BSC Hub

BTS

BSS

BTS

BTS

BTS

Radio part design

BTS

BSS

BTS

BTS

BTS

Transmission PlanningBasics

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Transmission PlanningDifferences of RNP and TNP Viewpoints

Transmission capacity must beplanned for the final phase of thenetwork, not phase by phase.

Suitability of a site for transmission canchange from ideal to useless when

choosing between two neighbouringcandidates

Site changes can cause majorchanges in the transmission networktopology No LOS in the new candidate change

topology Interference problems re-planning of

MW frequencies

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Transmission PlanningInput Data

Customer input Allowed unavailability and performance figures

Transmission media requirements: ownnetwork / leased line

Blocking probabilities

Protection level and type

Existing transmission infrastructure

Growth estimate and/or required spare capacity

Radio Network Planning input

Number of BTSs

Number ofTRXs / BTS

Nominal site locations

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Network TopologiesBasics

Transmission topologies are chosen

based onavailability and protection requirements and

availability of existing lines

Costs vs. fail safety (redundancy)

Real networks usually hybrid solutions

POINT-TO-POINT

MULTIDROP CHAIN LOOP

STAR (CONCENTRATION POINTS)

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Network TopologiesDifferent Philosophies

HighT

ransmissioncosts

BSC used as atransmissionconcentrator

Small BSCs

TRS capacity gain onA-ter

Transmission costsgain

Low Transmissioncosts

BSC used as atransmissionconcentrator has a lowinfluence on total cost

High capacity BSCs

MSC

BTS

BSC

BTS

BTS

BTS

BSC/ MSC

BTS

BTS

BTS

BTS

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Microwave LinksBasics

The preferred media when

building new accessnetwork links

High capacity transmission links

from 2x2Mbps to 16x2Mbps, 34Mbps andSTM-1 (155 Mbps)

Contra:

needs frequency license

environment dependant linkquality (e.g. rainfall)

LOS not always available

Pro:

low operating costs

easy to install

flexible

quick & reliable solution

Terminalstation A

Terminalstation B

Repeaterstation

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Microwave LinksTypes ofMW

Long Haul Radios: ~ 30 - 80 km2 GHz, 7 GHz

Medium Haul Radios: ~ 25 - 45 km10 GHz, 13 GHz, 15 GHz

Short Ha

ulR

adios: ~ 5 - 30 km18 GHz, 23 GHz, 26 GHz, 38 GHz,

Nokia Metrohopper: < 1 km57 GHz(uses oxygen absorption in air to limit

range)

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Microwave LinksModulationMethods

PSK - Phase Shift Keying there are several levels of PSK (2-PSK, 4-PSK,

)

FSK - Frequency Shift Keying

fixed frequency for 0s and another one for 1s

QAM - Quadrature AmplitudeModulation

a mixture of phase and amplitude modulation

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Microwave outages

equipment failuresuse protected equipmenthot / warm / cold -standby

caused by naturetemporary failuresself-recoveryuse protected connections Examples of natural outages:

heavy rainfall zones:most severe in upperbands (2..3dB/km)significant above 10 GHz

multipath fadingproblem with lowerbands

Microwave LinksRadio Link Availability

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Microwave LinksHow to Avoid Interference

Use the highest available frequencyband

Attenuate the Tx power to a minimumjust to meet the required availability

Locate dishes as low as possi

ble withmaintaining the required LOS

Use big dishes

Use different polarisation

Select your channel(s) carefully Maintain High-Low -rule on hub sites

Try to get similar received signal levelsat hub sites

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High-End Low-End

Tx Freq.=f1

Rx Freq.=f2

Tx Freq.=f2

Rx Freq.=f1

f1 > f2

HIHI HILO

LO

Simple rule:

keep all links in

a site "high" or

"low"

Microwave LinksHigh End & Low End

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To verify LOS between two planned sites possibility to use a microwave link

Input site locations planned antenna height

direction to the other end of link restrictions to cherry-picker, etc.

Output LOS/NLOS minimum antenna height exact antenna location (rooftop)

panorama picture withlandmarks and their directions

extra observations(forests,building sites etc.)

Microwave LinksLOS Check

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Line-of-sight path needed between both nodes ofa microwave link

Keep 1st Fresnel zone clear of obstacles

nth Fresnel zone: Ellipse around direct path,where path difference to direct line is n*P/2.

d

b

bd km

f MHzm! 274

[ ]

[ ][ ]

1st Fresnel zone

2nd

3rd

Radius for n-th zone = b * sqrt(n)

Microwave LinksFresnel Zone

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Leased Lines

Transmission lines rented from a 3rd party operator

Leased line provider is usually also a competitor

Contra

high operating costs

unpredictable lead times(installation)

difficult to deploy (may include

digging, groundwork..)

no control over the physical route

or the quality of the link

Pro

no implementation effort for

buyer no extra infrastructure to

buy

long distances are

uncritical

Analyse cost structure of Leased Line tariffs todecide

whether LL or microwave links are more

economical

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Leased LinesCost Examples

Austria

Belgium

Denm

ark

Finland

France

G

erm

any

G

reece

Ireland

Italy

Netherlands

Norway

Portugal

Spain

Sweden

Switzerland

UK

3km

30km

300km

0

500

1000

1500

2000

ECUp

erm

ont

Leased Line Tariffs (Europe)

3km

30km

300km

Leased Line Tariff

10000

12000

14000

16000

18000

20000

22000

24000

26000

28000

30000

0 50 100 150 200 250

km length

USDpermonth

Leased Line costs vary greatly depending oncountry, link length, capacity, LL provider and

the customer

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GENERALRULE forTS

allocation0 : Synchronization

1 - 24 : TCH

25 - 30 : TRX/BCF SIG

31 : Loop control

Max 12 TRX per 2 Mbit frame

Abis

Interface

AirInterface

BSCMSC

AInterface

Ater

Interface

TC SM

Ater

Interface

BTS2

BTS1

bits 1 2 3 4 5 6 7 8

TS

0 Synchronisation

1 BTS 1

2 TRX 1

3 BTS 1

4 TRX 2

5 BTS 1

6 TRX 3

7 BTS 2

8 TRX 1

9 BTS 2

10 TRX 2

11 BTS 212 TRX 3

13 BTS 3

14 TRX 1

15 BTS 3

16 TRX 2

17 BTS 3

18 TRX 3

19 BTS 3

20 TRX 4

21 BTS 322 TRX 5

23 BTS 3

24 TRX 6

25 BTS 1TRX 1 SIG BTS 1 BCF SIG BTS 1TRX 2 SIG

26 BTS 1TRX 3 SIG BTS 2TRX 1 SIG BTS 2 BCF SIG

27 BTS 2TRX 2 SIG BTS 2TRX 3 SIG

28 BTS 3TRX 1 SIG BTS 3 BCF SIG BTS 3TRX 2 SIG

29 BTS 3TRX 3 SIG BTS 3TRX 4 SIG

30 BTS 3TRX 5 SIG BTS 3TRX 6 SIG

31 Loop bits / LCB / MCB

BTS 11+1+1

BTS 21+1+1

BTS 32+2+2

Leased Lines2 Mbit Frame Allocation (Abis)

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Cross-Connects

Transmission equipment to branchdata streams between different linksets

Non-blocking stage each input stream is routed to an output

stream Tasks

switching between link sets switching between timeslots of a PCM trunk dropping & inserting timeslots

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3 x 2 Mbit/slinks

64 kbit/s

channels

1 x 2 Mbit/s

link

n

m

k

i < n+m+k

BSC

Total Traffic (Erl)

Blocking Prob.

i = number of channels

Cross-ConnectsConcentration

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full 2 Mbit/s frames

BSC

not full

2

Mbit/s

frames

Cross-ConnectsGrooming

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Transmission media

Transmission techniques

Transmission methods

Fibre

Coaxial cable

Copper cable

Microwave radioTerrestrial/satellite

PDH SDH

PCM

ISDN ATM

Transmis

sio

nequip

ment T

ransm

issionequipme

nt

HDSL

CATV

Transmission Techniques

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Transmission TechniquesMultiplexing

IT

U- Standard: 8000 samples per sec @ 8bit = 64 kbit/s 32 * 64 kbit/s = 2 Mbit/s line

Lines can be de-/ multiplexed into linesof higher data rates

8Mb

it/s, 34 Mb

it/s, 140Mb

it/s etc...

....

32 * 64 kbit/s

MUX

2 Mbit/s MUX/

deMUX

1 sec1 sec

8 Mbit/s2 Mbit/sMUX/

deMUX

1 sec

....

32 * 64 kbit/s

MUX

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Transmission TechniquesPDH

PDH (Plesiochronous Digital Hierarchy) voice spectrum ~ 4kHz sampling rate 8 kHz 8 bits per sample divided into 32 TS (TDM)

USA : 24 timeslots

Higher Order PDH Bitrates

Europe : 2.048 Mb/sUSA : 1.554 Mb/s

M

U

XM

U

X

140M

34M

34

M

34M

34M

8 M8 M

8 M

8 MM

U

X

2 M

2 M

2 M

2 M

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SDH (Synchronous Digital Hierarchy) all network elements are synchronized to Primary Rate

Clock (PRC)

worldwide standard : interfacing to USA possible

Europe USA STM- 1c (51.7 Mb/s) = STS-1

STM- 1 (155.52 Mb/s) = STS-3 STM- 4 (622.08 Mb/s) = STS-12 STM-16 (2488.32 Mb/s) = STS-48 STM-64 (9953.28 Mb/s) = STS-192

STM-4

STM-1STM-1STM-1STM-

1

Transmission TechniquesSDH