pawel trs workshop 11-09-2004

8/11/2019 Pawel TRS Workshop 11-09-2004

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NOKIA 2004 TRS workshop 11-09-2004 NOKIA/CUSTOMERCONFIDENTIAL

Transmission lanning

Workshop

ASTELIT PROJECT

11-09-2004

Pawel Kaparski



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Transmission Planning



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Transmission PlanningBasics

• Cost of transmission lines represents a great portion ofnetwork operational costs per year

• design a network that meets the design criteria withminimum overall costs!

Radio part design

BTS

BSS

BTS

BTS

BTS

Fixed part design

MSC

BSC Hub

BTS

BSS

BTS

BTS

BTS



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Transmission PlanningDifferences of RNP and TNP Viewpoints

• Transmission capacity must be planned for the final phase

of the network, not phase by phase (“spare capacity”concept).

• Suitability of a site for transmission can change from ideal touseless when choosing between two candidates of thesame nominal site.

• Site changes can have serious consequences in thetransmission network topology

No LOS in the new candidate change topology

Interference problems re-planning of MW frequencies


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Transmission PlanningInput Data

Customer input

• Frequency band available for MW links

• Allowed unavailability and performance figures

• Transmission media requirements: own network / leased line

• Protection level and type (for MW links)

• Existing transmission infrastructure• Growth estimate and/or required spare capacity

• A-bis planning strategy (one PCM dedicated/site or 2M sharing)

Radio Network Planning input

• Number of BTSs

• BTSs configuration (number of TRXs / sector)

• Nominal site locations


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Network TopologiesBasics

• Transmission topologies are chosen based on availability andprotection requirements and availability of existing lines

• Compromise between costs and quality of the network

• Real networks usually hybrid solutions

POINT-TO-POINT

MULTIDROP CHAIN LOOP

STAR (CONCENTRATION POINTS)



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Microwave LinksHow to Avoid Interference

• Choose correct strategy in topology

planning: reduce concentration ofmicrowave antennas at any single site.

• Attenuate the Tx power to a minimum just to meet the required availability.

• Use big dishes in critical case.

• 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

HI

HI HILO

LO

Simple rule:keep all links in

a site "high" or

"low"

Microwave LinksHigh End & Low End

R l f h i li k l i



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Results of the microwave link planning“MW Call-Off”

“Call-off” for a MW link is the form prepared by the TRS planner and to bedelivered to Nokia implementation team. It contains all the technical

information about the link design (calculated with the Link planning tool).The call-off can be created manually or using the Nokia database tool – CellTracker. The following info have be contained into call-off:

• Hop lengths

• Antenna sizes

• Antenna heights

• Antenna directions

• Frequency band and link channel

• High/Low end

• Polarization

• Configuration (1+0 or 1+1)• Total unavailability

• Power levels (Tx/Rx)

• Composite fade margin (CFM)



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Link budget sampleLink Code : 229

« TIM SP - MW design report »

Flexihopper 15 GHz-- -- -ITU-R-P530-7

Calculated hop from: CPVN01 CPJE01

Site data:

Latitude: 22°53'11.05"S 22°53'22.98"S

Longitude: 047°07'6.94"W 047°06'8.51"W

Hop length: km

Ground level: 640 680 m

Antenna heights: 35 36 m

Path azimuth: 101.6 281.6 °

Terrain Roughness

Losses:

Antenna branching loss dB

Probability that BER>10 -̂ 6:

Performance (only rain, %)

Year: 0.0002475 0.0003389 %

Perfor mance (only rain, sec)

Year: 78 107 s

Total performance (rain + equipment, %):

Worst month: 0.0051959 0.0058507 %

Year: 0.0033607 0.0034522 %Total performance (rain + equipment, sec):

Worst month: 1639 1845 s

Year: 1060 1089 s

ITU-R-P530- 7 related data:

Percentage pl %

Geoclimatic factor

Rainrate (0.01%) mm/h

Signal levels (BER>10 -̂6):

Receiving signal level dBm

Receiver threshold power -82 -82 dBm

Flat fade margin 47.9 47.9 dB

Threshold degradation: 0.0 0.0 dB

Effective fade margin: 47.9 47.9 dB

Radio related data:

Transmitter output power 18 18 dBm

Tx attenuator: 7 7 dBm

Transmited power 11 11 dBmChannel information

Channel Number: C24 C24

Center Frequency: 22.17250 23.40450 GHz.

23.40450 22.17250 GHz.

Configuration: 1+0 1+0

Capacity: 4x2 4x2

Antenna data:

Antenna Elevation: 1.38 -1.38

Antenna type: VHLP2-220 VHLP2-220

Antenna diameter: 0.6 0.6 m

Antenna gains 40.1 40.1 dBi

Polarization VERTICAL VERTICAL

1.71

-34.1

0.5

0.00000563

120

20



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Technical Site Survey for TRS Engineer



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Introduction - TSS

• The purpose of TSS is to ensure that the sites are suitable for

microwave transmission use• This task should be performed by transmission engineers

• TSS is the only point in time when all involved engineers candecide and agree on site configuration (site design – RF Eng.,TRS Eng., CW Eng., SA Eng.)

• The result of TSS is a TSSR-report which contains all agreeddesign details of site configuration



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• Topology map of the network in the area of the site

• Printed copies of path profiles of the MW links

Additionally, site specific:

• number of dishes

• diameter of the dishes

• required height of the dishes

• azimuths

TRS Engineer duties before TSS



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TRS Engineer duties during TSS

• Pre-LOS check (if there are any obvious obstacles in the azimuths ofinterest)

• Locate poles for MW dishes

• Determine required height of the poles (installation height of the disheson the pole)

• Make photos in the azimuths of interest (in the case of Obvious LOS,TRS Engineer can make photos of the far end site and prepare LOSReport after TSS)

• As a summary of TSS, TRS engineer should provide all informationrequested to creating site drawings (pole position and pole height,

number, diameter, and azimuth of dishes for each pole).



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Min 2000mm if able to

walk in front of dish

Min 100mm

Min 600mm

Min 200mm

Min 100mm

MW

Dish

MW

Dish

MW

Dish

GSM Whenever it is possible, MW antenna andRF antenna will use the same pole.

Usually, MW dish is below RF sector

antenna because of easier maintenanceIn case of LOS problems, MW dish could beabove RF sector antenna.

TRS engineer can propose a separate polefor MW dishes (if it is necessary ).

Minimum spacing between MWantennas and RF antenna



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TRS Engineer duties after TSS

• Preparing TSD report (including site sketch)

• Request LOS survey for the MW links from/to visited site.

• Updating TRS nominal plan



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Example of BTS site - Rooftop

Ridged Rooftop Flat Rooftop



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Example of BTS site - Tower

Lattice Tower

Monopole



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Line-Of-Sight (LOS) Survey for MicrowaveRadio Links in Cellular Transmission

Networks



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Introduction - LOS

• The purpose of Line-of-Sight (LOS) survey is to ensure that the

sites are suitable for microwave transmission use• This task is normally performed by transmission engineers

preferably involve in desktop analysis of such microwave links

• In cellular transmission network, line-of-sight is usuallyperformed between BSC to BTS, and between BTS to BTS

• All BTSs belonging to a certain BSC area must have atransmission link established to the BSC in that area. Atransmission link carries the cellular traffic between each node



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Nature of Microwave Radio Links

Microwave radio links in cellular networks require a direct Line ofSight (LOS) between two radio antennas. Performing this surveyensures that the sites are suitable for microwave transmissionuse. In addition, the surveys provide technical informationregarding microwave antenna height and location.



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LOS and Fresnel Zone

• Not only must there be a straight unobstructed line between two antennas, the firstFresnel zone must also be clear. The amount of clearance depends on the frequency butas a general rule of thumb, frequencies above 10 GHz must be 100% clear.

• The radius of the Fresnel zone is frequency dependent. It is small at high frequenciesand large at low frequencies. Antenna heights should be designed so that the firstFresnel zone is free from obstructions.

line of sight path

first Fresnel zone at 10 GHz

first Fresnel zone at 2 GHz



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• Table below shows some examples of the first Fresnel zone radii at differentfrequencies and distances. It can be seen that Fresnel zone clearance greatly effectsthe antenna heights

Radius of 1st Fresnel zone, r

freq. distance

2.5 km 5 km 10 km 20 km 2 GHz 9.7 m 13.7 m 19.4 m 27.4 m

7 GHz 5.2 m 7.3 m 10.4 m 14.6 m

18 GHz 3.2 m 4.6 m 6.5 m 9.1 m

38 GHz 2.2 m 3.1 m 4.4 m 6.3m

Radius of 1st Fresnel zone, r

freq. distance

2.5 km 5 km 10 km 20 km 2 GHz 9.7 m 13.7 m 19.4 m 27.4 m

7 GHz 5.2 m 7.3 m 10.4 m 14.6 m

18 GHz 3.2 m 4.6 m 6.5 m 9.1 m

38 GHz 2.2 m 3.1 m 4.4 m 6.3m



LOS t d



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LOS pre-study• Computer tools are available to

assist in the selection and design oftransmission sites. They calculatethe minimum antenna heights

which will meet specified outageperformance objectives.

• These results are based ondigitised data (terrain models) butare not 100% reliable due toinaccuracies in the digital map. Thetool‟s usefulness primarily is toreject the more obvious situationswhere a LOS does not exist e.g. a

large hill between two sites.Furthermore, it can not predictfuture obstructions such asbuildings and chimneys which maylie directly on the path.

• As the profile only provides a roughLOS indication, the link should beconfirmed by field survey. In urbanenvironments where sites are

generally located on rooftops,reliable path profiles are usuallyunobtainable.

• The current profile toolrecommended to be used is theNetAct Planner (Link Planner)

Site Access



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Site Access

• Access to sites can often create more delays to LOS surveythan poor weather. The site negotiator or person responsiblefor site access must contact the owner before proceeding tothe sites to arrange meeting times, supply of keys and contactpersons.

• They must also explain that the survey is weather dependentand may be cancelled at the last minute due to insufficientvisibility, requiring further access negotiation at a later date.Discretion and patience should be exercised at all times.

Transmission site types



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Transmission site types

• Type 1. Flat-roofed building

factory, residential, water tower

easy access of personnel and equipment

• Type 2. Climbing structure

tower or mast

climbing certificate normally required

• Type 3. Greenfield

no infrastructure; future tower/mast site

cranes, telescopic masts, balloons required

helicopters sometimes used in difficult terrain

Transmission sites are usually divided into three types:

Survey Requirements



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Survey Requirements• Global Positioning System (GPS) receiver and accessories

• Binoculars

• Compass

• Single Lens Reflex (SLR) camera and 70-300mm zoom lens

• Mirror or “flashing beacon” (min. 1 million candle power)

• Cellular phone (or VHF radios)

• 50m Measuring tape

• Maps (road and topographical)

• Inclinometer for measuring heights of objects

• Crane („cherry-pickers‟)

• Balloon and gas

Greenfield sites



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Rooftop LOS Procedure

1. Establish bearing of link (GPS coords, plot or profile)

2. Make preliminary observation using compass and binoculars to

check rough viability of LOS3. If path seems unobstructed, make contact with adjacent team

4. Describe own site and use lamp etc. to make identification easier

5. Record height and position of antenna on the site sketch

6. Make photos of far end site (with and without zoom)

7. If no LOS is possible, record as such and proceed with next link

Mast/Tower LOS Procedure



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Mast/Tower LOS Procedure

1. Establish bearing of link (GPS coords, plot orprofile)

2. Make preliminary observation using compass andbinoculars to check rough viability of LOS

3. Climb to minimum antenna height specified inprofile or where LOS is achieved taking intoaccount Fresnel zone clearance

4. Photograph (lamp or balloon)

5. If no LOS record as such and photographobstruction

6. Proceed with the next check

Greenfield site LOS Procedure



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Greenfield site LOS Procedure

1. The type of equipment is usually decided inadvance e.g. cranes, large helium balloons

2. Establish bearing and distance of link

3. Set up crane or instrument over proposedsite and extend boom to specified antennaheight

4. If no height is given, extend to suitable heightfor viewing (max. height)

5. Identify adjacent site

6. Determine minimum antenna height by slowlydescending to where LOS is visible and givessufficient Fresnel zone clearance (measureobstruction height to check Fresnel zoneclearance)

7. Record height and photograph the link

8. Record antenna location on site sketch

9. If No LOS, record as such andphotograph/note obstruction

10. Proceed with the next check

LOS Report



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LOS Report

• LOS or NO-LOS confirmation

• photograph of hop

• site plan which indicates the exact location and minimum height ofmicrowave antenna

• type of tower, mast or pole to be used

• hop bearing and distance

• future possible obstructions (photographed or listed)

• other relevant site information e.g. site name, ID, address, coordinates

The LOS report is made to provide physical evidence thatthe link has been surveyed in the field. It also shows the

evidence (or lack of) LOS. The report should include thefollowing details:

LOS report cover page



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LOS report cover pageLOS cod: Requested by:

LOS Name: Date of LOS request:

Name of Site A Name of Site B

Address of Site A Address of Site B

ID_A (old code) Cand A ID_B (old code) Cand A

BSC area of Site A BSC area of Site B

Site Easting Site Easting

Site Northing Planned h_Aagl 3 8 S it e Nor thing Planned h_B agl 45

Azimuth A -> B Azimuth B -> A

Dish size A: m Dish size B: m

Proposed frequency: GHz Length: m

Los result:DO0003 DO0019

Coordinates: Map X GPS Coordinates: Map X GPS

Site Easting Site Easting

Site Northing Site Northing

Proposed Hant. site A Proposed Hant. site B

Min. Hgt Required site A Min. Hgt Required site B

Survey Method:

Team:

Comments: Comments:

SITE A: SITE B:

Signature: Signature:

Date of survey : LOS Supervisor sign.:

General Comments:

The place of the poles on both sites for t ransmission doesn't have obstacles.

LOS OK

C.BAYKAN02.08.04

Cenk BAYKAN

DO0003-DO0019 02.08.04

DO0003 DO0019

Artema St. Hotel Ukraine Gurova,6

DO0003 DO0019

37° 48' 10,0'' 37° 47' 52,2''

0.3 0.3

48° 00' 35.8'' 48° 00' 15.0''

213° 33°

760

LOS OK

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37° 48' 10,7'

48° 00' 36.5''

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There is clear LOS from the place of the pole

mentioned at the sketch.

There is clear LOS from the place of the pole

mentioned at the scetch.

Burak ALTINDAL

Optical one sided LOS.

pawel trs workshop 11-09-2004

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