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字体 : 细黑体 Optical Network Engineering Department

Microwave Network Planning

and Design

HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

Contents

Chapter 1 Introduction to Microwave Planning and Design Chapter 2 Microwave Planning and Design Process Chapter 3 Survey for Microwave Planning and Design Chapter 4 Microwave Planning and Design Manual

Calculation Method


Example for the composition of network planning and design of a wireless turnkey project

MSC/VLR

AbisPCU

HLR/AuC

1800MBTS

BSC

PCU (controlling data packets)

900M BTS

Gr

Gs

Transmission network planning

(microwave)

Wireless network

planning (RF)

Site planning (tower)

SGSN GPRSBackbone

Gn

Gn

Abis

Transmission network planning

(optical fibers)

Site planning (civil work)

Introduction to Microwave Planning and Design

BSC


Linear propagation

D

Direct wave Antenna

等于：正常接收电平-门限电平。一般说，平衰落储备应当在35≤ FFM≤ 55（dB)之间

Requirement of microwave transmission:The diffraction capability of the microwave is weak because the wavelength is short. Hence, normal microwave communication can be realized only when the microwave is propagated within the unblocked line of sight (LOS).



(The 1st Fresnel zone shall be free from obstacles when k = 4/3.) (On paths over water surfaces or desert areas, it is recommended t

o have the 1st Fresnel zone free from obstacles when k = 1 (See also ITU-R P.530).)

Distance 50 km

k = 4/3

1st Fresnel zone

Microwave propagation design objective



Clearance

h2

h1d1

d2

dhb

hs

hcKddhb 210785.0

Height of an earth projection: "K" represents the atmospheric refraction factor.

Calculation formula for the path clearance:

hh d h d

dd dK

hc s

1 2 2 1 1 20 0785.

Clearance should be more than the radius of the first Fresnel zone.



Network configuration

8x2 Mbit/s8x2 Mbit/s 2x2 Mbit/s2x2 Mbit/s

2 Mbit/s2 Mbit/s

2 Mbit/s2 Mbit/s

2 Mbit/s2 Mbit/s

2x2 Mbit/s

2x2 Mbit/s

2x2 M

bit/s

2x2 M

bit/s

8 Mbit/s

2x8 Mbit/s

2 Mbit/s2 Mbit/s

2 Mbit/s2 Mbit/s

2x2 Mbit/s

2 Mbit/s2 Mbit/s

1+1

BSC

Topological view of microwave transmission



Contents

Chapter 1 Introduction to Microwave Planning and Design Chapter 2 Microwave Planning and Design Process Chapter 3 Survey for Microwave Planning and Design Chapter 4 Microwave Planning and Design Manual

Calculation Method


Microwave Planning and Design Process

Inputs:1. Requirements for microwave construction specified in the RFQ 2. Microwave related information of the existing network (route location and used frequencies)

Outputs:Feasibility Analysis Review Report for the Turnkey Project - Microwave Planning

Analyzing the feasibility

Contents of work:

1. Reads the RFQ.2. Clarifies the requirements for microwave planning.3. Prepares the Feasibility Analysis Review Report for

the Turnkey Project - Microwave Planning.4. Prepares the tools and software for microwave

planning.

Bidding phase

Analyze the feasibility.


Inputs:1. RFQ2. Site information (including the existing

sites)3. Feasibility Analysis Review Report for

the Turnkey Project - Microwave Planning

Outputs:1. NWP&D Planning in the Bidding Phase -

Microwave Planning2. Preliminary Site Survey Report3. Microwave Equipment Purchase List4. Microwave Planning Solution (including the

Microwave Transmission Route Diagrams and the Microwave Frequency Planning Table)

Designing the microwave

solution

Contents of work:1. Prepares the NWP&D Planning in

the Bidding Phase - Microwave Planning according to the requirements specified in the RFQ and the quantity of sites.

2. Conducts a preliminary site survey (covering all or part of the sites depending on the actual situation), and provides the Preliminary Site Survey Report.

3. Plans microwave routes and frequencies and selects equipment.

4. Prepares the Microwave Equipment Purchase List and the Microwave Planning Solution.

Microwave Planning and Design ProcessBidding phase

Design the microwave solution.


Inputs:1. Documents about the conclusions

of route planning, frequency planning, and equipment selection

Outputs:1. Technical Proposal for Microwave

Transmission Planning

Preparing the bidding documents

Contents of work:1. Prepares the Technical

Proposal for Microwave Transmission Planning.

2. Compiles and reviews the bidding documents.

3. Clarifies the technical microwave part of the bidding documents.

Microwave Planning and Design ProcessBidding phase

Prepare the microwave bidding documents.


Plan transmission routes.

Inputs:1. Contract2. Longitude, latitude, and sea-level

elevation of each site3. 1:50,000 map

Outputs:1. Microwave Transmission

Topological Views2. Site Survey Report

Planning transmission

routes

Contents of work:Drawing:1. Calculates the distance between sites.2. Determines the heights of antennas.3. Checks whether LOS transmission is

available - transmission profiles.4. Draws topological views for microwave

transmission.5. Marks the number of E1s on the

topological views.Site survey: 1. Conducts a site survey for all sites.2. Provides the Preliminary Site Survey

Report.3. Modifies the Microwave Transmission

Topological Views according to the Site Survey Report.

Microwave Planning and Design ProcessImplementation phase


Inputs:1. Contract2. Information of existing microwave sites

(locations and used frequencies)3. Microwave Transmission Topological

Views

Outputs:1. Microwave Frequency Planning Table

Planning frequencies

Contents of work:1. Analyzes possible interference.2. Determines the frequency of each relay sectio

n.3. Determines the polarization mode of each rel

ay section.4. Marks the frequencies used by each relay sec

tion in the transmission route diagrams.5. Prepares the Microwave Frequency Planning

Table.6. Determines Tx high stations and Tx low statio

ns.


Plan frequencies.

Implementation phase


Inputs:1. Microwave equipment, antenna

specifications, and technical parameters2. Attenuation Due to Rain3. Microwave Transmission Topological Views4. Microwave Frequency Planning Table

Outputs:1. Microwave Equipment Purchase List

Selecting equipment

Contents of work:1. Suggests antenna diameters based on

experience.2. Calculates the quality indexes of a relay

section (for example, outage probability).3. If the indexes are not met, select the

antennas with larger diameters and calculate the indexes again.

4. If the indexes are still not met, select high-performance antennas and calculate the indexes again (changing the polarization mode and adopting space diversity).

5. If the indexes are still not met, change the frequencies, or even change the routes or adds a relay site (that is, adding a hop).

6. Provides the Microwave Equipment Purchase List when the quality indexes of the line are met.


Select equipment.Implementation phase


Inputs:1. Documents about the conclusions of

route planning, frequency planning, and equipment selection

Outputs:1. Microwave Transmission Route

Diagrams2. Microwave Equipment Purchase List

Providing support for

placing microwave

equipment POs

Contents of work:1. Provides the engineering purchasing

personnel with the Microwave Transmission Route Diagrams and the Microwave Equipment Purchase List to support PO placing.


Provide support for placing microwave equipment POs.



Inputs:1. Site Survey Report2. Microwave Equipment Purchase List3. Microwave Planning Solution (including

the Microwave Transmission Route Diagrams and the Microwave Frequency Planning Table)

Outputs:1. Proposal for Microwave Transmission

Implementation2. Auxiliary Equipment Survey Report

Preparing the microwave

implementation solution

Contents of work:1. Prepares the Proposal for Microwave

Transmission Implementation.


Prepare the microwave implementation solution.



Contents

Chapter 1 Introduction to Microwave Planning and Design Chapter 2 Microwave Planning and Design Process Chapter 3 Survey for Microwave Planning and Design Chapter 4 Microwave Planning and Design Manual Calculation

Method



① Frequency bands• Learn the microwave frequency bands specified in the RFQ for the selection during the

network planning. If the requirements for microwave frequency bands are not specified in

the RFQ, consult the customer for the microwave frequency bands used in the local area.

② Microwave protection schemes• Learn the microwave protection schemes specified in the RFQ. Check whether 1+1

protection or 1+0 protection is required depending on the capacity.③ Requirements for microwave networking• Check whether special requirements for networking are specified in the RFQ, and whether

the customer requires the chain, star, tree, ring, or other topologies. ④ Requirements for other indexes• Learn the requirements for antenna feeders, transmission capacity (SDH/PDH), and

technical specifications of interfaces.

Acquiring customer demandsRead the requirements for the microwave equipment specified in the RFQ carefully.


Read the documents related to the microwave equipment carefully.

① Overview• Check whether the performance of the microwave products from different vendors can

meet the requirements of the project according to the requirements of the customer for microwave products. For example, check whether SDH microwave frequency bands are consistent with the requirements of the customer, and whether the PDH microwave NMS can meet the demands of the customer.

② Related key points• Operating frequency: Generally, available frequencies range from 2 GHz to 50 GHz.

(Collect the documents about the information of the equipment from the departments that are responsible for the auxiliary products.)

• Frequency stability: Nx10-6 or smaller order of magnitude• Number of channels arranged by the system: It depends on the selected product.

Generally, it meets the CCIR Recommendations.• Channel bandwidth: It depends on the selected product. Generally, it meets the CCIR

Recommendations.• Transmit power: It depends on the selected product.• Receiver sensitivity/threshold level: It depends on the selected product. • Modulation/Demodulation mode: It depends on the selected product.

Acquiring Equipment Information

Survey for Microwave Planning and Design


② Related key points• Digital baseband interface and line code pattern: They depend on the

selected product. Generally, they meet the CCITT Recommendations.• Anti-fading measures: They depend on the selected product.• Anti-interference performance: It depends on the selected product.• System monitoring performance: It depends on the selected product.

Or select other product. • Power consumption of the equipment: It depends on the selected

product.• System structure and installation mode: They depend on the selected

product.• Adaptability to the environment: It depends on the selected product.• System price: It depends on the selected product.• Power indexes, antenna indexes, auxiliary equipment• Delivery capability of suppliers• Capability of suppliers to provide after-sales services

Acquiring Equipment Information



Tools for survey and planning:

① Pathloss planning software② Microwave planning tool in Excel sheets③ GPS④ Compass⑤ Telescope, laser distance meter⑥ Vehicle⑦ Transmitter for the test purpose (seldom used)⑧ Special receiver or spectrum analyzer (seldom used)⑨ Antenna for the test purpose (seldom used)⑩ 1:50,000 or 1:25,000 map (for military purposes and with contour lines)⑪ Traffic map

Acquiring tools for survey and planning



Learn information on the networking of wireless products.① Latitude and longitude of each BTS• The wireless network planning engineers determine this item according to

the requirements for coverage of the customer.② Latitude and longitude of each BSC• The wireless product personnel negotiate and determine this item with the

customer.③ Short-term and long-term requirements for transmission capacity of each

BTS • The wireless network planning engineers determine this item.④ Homing relation between each BTS and the BSC• The wireless network planning engineers and the wireless product personnel

negotiate and determine this item.⑤ Geographical position of each BTS• The wireless network planning engineers determine this item or obtain the

information by conducting a site survey.⑥ Designing a preliminary microwave routing solution• The wireless network planning engineers or the wireless product personnel

design the solution, or compile the solution by using the preceding information.

Acquiring information about networking



Conducting site surveys of microwave lines

Problem to be solved: Check whether the routes for transmitting microwave signals are unblocked.Determine the following parameters:Equipment parameters, available frequency resources, adjacent frequency interference, distance between sites, position, sea-level elevation, antenna height, azimuthReferences:Urban planning, 1:50,000 map, meteorological data of each year, frequency resources, power supply, road traffic information



Instruments for electrical measurement: Compass, GPS, telescope, map, vehicle Transmitter for the test purpose Special receiver or spectrum analyzer Antenna for the test purpose




Survey for Microwave Planning and DesignConducting site surveys of microwave linesTransmitter for the test purpose

Installing astandardhorn antennainto the box


Survey for Microwave Planning and DesignConducting site surveys of microwave lines

Transmitter for the test purpose


You can carry the electrical measurement equipment as shown in the following figure. The load, however, is heavy when you also carry the batteries.



Electrical measurement record:


Pt dBm Br dB Gt dB Pt' dBm D km BL dB Gr dB Pr (dBm)20 2 20 38 1 111 20 -53

20 2 20 38 2 117 20 -59

20 2 20 38 3 121 20 -63

20 2 20 38 5 125 20 -67

20 2 20 38 8 129 20 -71

20 2 20 38 10 131 20 -73

20 2 20 38 15 135 20 -77

20 2 20 38 20 137 20 -79

20 2 20 38 25 139 20 -81

20 2 20 38 30 141 20 -83

20 2 20 38 40 143 20 -85

20 2 20 38 50 145 20 -87

20 2 20 38 60 147 20 -89

符号说明：Pt dBm 发射机线性输出功率。单位 dBm。Br dB 2X(馈线＋接头) 的损耗。单位 dB。Gt dB 发射天线增益。单位 dB。Pt' dBm 等效发射功率。单位 dBm。D km 发射－接收距离。单位公里。BL dB 自由空间损耗。单位 dB。此值与发射频率、传输距离有关。Gr dB 接收天线增益。单位 dB。Pr dBm 接收功率。单位 dBm。Receive power expressed in dBm

Meanings of the symbols:

Linear output power of the transmitter, expressed in dBm

Loss of 2X (feed line + connector), expressed in dBGain of the transmit antenna, expressed in dBEquivalent transmit power, expressed in dBm

Transmit - receive distance, expressed in kmFree space loss, expressed in dB, relevant to the transmit frequency and transmission distanceGain of the receive antenna, expressed in dB


表1序 1/ 50000 站址高程号地形图号 X Y (M)1 a 1 9-50-5-丙 116°05′ 08″ 35°48′ 34″ 3964.85 20417.40 119

2 b 2 10-50-137-丙 116°08′ 02″ 36°03′ 46″ 3992.95 20421.95 41.5

3 c 3 10-50-137-甲 116°14′ 17″ 36°19′ 29″ 4021.88 20431.85 35.5

4 d 4 10-50-126-丙 116°36′ 28″ 36°29′ 56″ 4041.08 20464.87 37.6

5 e 5 10-50-114-丁 116°45′ 19″ 36°47′ 29″ 4073.43 20478.17 22.2

6 f 6 10-50-114-丁 116°59′ 29″ 36°43′ 23″ 4065.90 20499.20 32

7 g 7 10-50-115-丙 117°01′ 54″ 36°40′ 45″ 4060.98 20502.83 26

站址情况调查表

站名单位经度纬度站址座标

Site information:



0

20

40

60

80

100

120

0 5 10 15 20 25 30 35D( km)

Hm

（）

Longitudinal profile:




Site survey is a supplementary measure to the route design.

Site survey is affected by the heights of the tested antennas. Hence, you cannot obtain the required data in certain cases. The RSL, however, is not the unique index for judging a transmission route.



Conduct a survey of the power supplies. Check the usage of the mains supply and the power supply in the office. Check the configuration, capacity, and usage of the existing DC power supply equipment. Check the connection of the power supplies and information about the power supplies that can be connected.Check the electric generators.The requirements for the power supply are as follows: The power consumption must meet the short-term and long-term requirements for the power consumption.Also consider the GSM and other loads with the microwave equipment.Consider the voltage, frequency, and ripple voltage.Consider uniform monitoring of the power supply equipment.

Survey for Microwave Planning and DesignConducting site surveys of microwave sites


Conduct a survey of sites. Determine the accurate position of the microwave equipment and the layout of each BTS. Draw a detailed general layout chart for all the existing microwave equipment.Determine the floor area used by the towers of the existing microwave network and the accurate azimuth of the microwave antennas on the towers.Calculate the opening sizes and positions of towers.Check the marked heights of the existing antennas on the towers.



Conduct a survey of equipment rooms. Collect the following information: Size marks for the route of the grounding cable between the feed line entry of the equipment room and the feed line ladder of the tower Position of the microwave equipment relative to the DDF/AC or DC power distribution equipment, and the routes and sizes of the cables Routes and detailed sizes of the cables that connect the microwave equipment to the centralized monitoring systemInformation of air conditioners


Conducting site surveys of microwave sites


Collect the following meteorological and earthquake data: Highest gust velocity of each year in the local areaLargest thickness of ice accumulation and largest snowfall thickness of each year in the local areaHighest rainfall intensity of each year in the local areaHighest and lowest temperature of each year in the local areaLargest earthquake cracking degree of each year in the local area



Collect information about the interference caused by the electromagnetic environment. Positions and operating frequencies of the satellite earth stations that are already built and are to be built, and the communication azimuth angles and elevation angles of the corresponding communication satellitesSite positions, operating frequencies, and transmit power of the microwave circuits that are already built and are to be builtPositions, several operating frequencies, operating elevation range of each antenna (correspondence between the antenna and frequency), maximum instantaneous transmit power, pulse width, and antenna rotary speeds of the radar stations that are already built and are to be built



Survey for Microwave Planning and DesignConducting site surveys of microwave sitesConduct a survey of wind speeds.


The requirements for towers are as follows: Static load: Quantity of antennas to be mounted, including the azimuth, height, estimated gross weight (including the bracket), and open diameter of each antenna Dynamic load: Wind load (taking the highest historical wind speed in the local area) Load when installing antennas (three to four persons)Ice and snow (including the ice accumulation load)Earthquake-proof: Take the highest historical earthquake intensity in the local area plus one.Lightning protection and grounding: Use lightning arresters (the protection angle being 45 degrees). Build a grounding network and install downleads separately with a grounding resistance ranging from one to ten ohms.



Contents

Chapter 1 Introduction to Microwave Planning and Design Chapter 2 Microwave Planning and Design Process Chapter 3 Survey for Microwave Planning and Design

Chapter 4 Microwave Planning and Design Manual Calculation Method


Input parameters: Latitude and longitude of each BTS/BSC, coordinates of each site, microwave frequency band, transmission capacity of each BTS, protection scheme, and military terrain mapOutput parameters:LOS conditions (longitudinal profiles), outage probability, clearance at key points, fading level (fading margin), antenna height (requirements for the heights of towers), reflection, interference, and othersAdvantages:The planning precision is high, and no special software or tool is required.Disadvantages:The military terrain plan and a site survey are required. The manual calculation is slow. The output information is limited. In addition, you need to have a thorough understanding of microwave communication principles.

Microwave Planning and Design Manual Calculation Method


Applicable scope:Applicable to microwave planning in various conditions, and functions most properly for planning small quantity of microwave hops in the engineering drawing phase

Detailed planning method:Refer to the subsequent slides.



Determining the preliminary solution: Drawing profile diagrams for each relay section: Take each relay section as a unit.

Acquiring the altitude:Determine the accurate positions of base stations (that is, set the horizontal positions of microwave antennas) on the 1:50,000 (or 1:25,000) map that is used for setting microwave sites. Then, mark the two points where microwave relay sites are to be built. Finally, connect the two points by using a straight line. Mark points at appropriate intervals on the straight line from one point of the relay section to the other point. Record the sea-level elevation of the ground at each point (m) and the distance between each point and the start point (km) (including the start point and end point). The recording is complete only after the data of the end point is recorded.



Calculating the distance between sites: You need to calculate the distance between sites (d (km)) when you calculate the circuit parameters of each relay transmission profile. d = √( Y)⊿ 2 + ( X)⊿ 2 In the formula,

⊿Y = YT - YR

⊿X = XT - XR

(YT, XT) and (YR, XR) represent the plane rectangular coordinate

s of the transmit end and the receive end on a 1:50,000 map respectively.



Drawing longitudinal profiles: Use the following formula to draw coordinate diagrams for relay profiles:

⊿ H = (d1 x d2)/(2aK) In the formula,"d1" represents the distance between the obstacle point and the start point of the relay transmission profile (m);"d2" represents the distance between the obstacle point and the end point of the relay circuit (m); "a" represents the radius of the earth (a = 6370 km);"K" represents the equivalent earth radius coefficient of the relay circuit (K = 4/3).Based on the preceding data, you can draw the transmission profile of the relay section on the microwave relay profile.The marked sea-level height of the start point is the marked height of the ground where the tower of the base station is built (or where the tower building is built).



A

Bh1

h2

dd1 d2

hphc

hs

Mh3

h4

h5

h6

Calculating the Fresnel zone: F: Radius of first Fresnel zone (m)

F d dd

1 2



Calculating the height of an earth projection:

As the earth is round, there is a projection between any two points on the surface of the earth, as shown in the followingfigure. The height (H) of the projection between point A and point B changes according to the distance between the twopoints. The following table shows the relation between the projection and the distance. The data in the table is based ontheoretical calculation.

Projection on the surface of the earth

Table 1 Relation between the earth projection and the distance

Distance between Point A and Point B (km) H (m) 20 6 30 13 40 24 50 37 60 53



Determining the transmission type of the profile of each relay section: Determine the transmission type according to the terrain information of the profile of each relay section.

Landform Mountain Area

Hilly Area

Coastal Area/Flat Area

Swamp/Lake/Sea Surface

Type of profile A B C D

Description



Landform category: Category 1 The ground surface is bare and flat, and does not have obstacles. The average roughness is about 1.5 meters. Open sea coast, lake shore, and plain that has no trees growing on it and has sparse vegetation



Landform category: Category 2 The area is open. The average visual range is more than 100 meters. The height of a structure is between 1.5 meters and 10 meters. Airport, green area in parks, farm, and undeveloped suburb with sparse trees



Landform category:

Category 2

A large quantity of buildings, trees, or other structures

exist.

Forest and city



BS1BS2

hÌ ì

h· ¿

hµ Ø d1 d2

hµ ØHhÌ ì Hs

Selecting an obstacle point:Select an obstacle point outside the far field of the antenna opening roughly before the height of the antenna is determined. The point that has the least circuit transmission clearance but has the largest sea-level elevation is the obstacle point on the transmission profile. The height of the obstacle point is the marked sea-level elevation hs.Far field: It refers to the field beyond the point 17.1 x D2/λ away from the antenna opening. In the formula, "D" represents the open diameter of the antenna, and "λ" represents the operating microwave length. "D" and "λ" are expressed in meters.d = d1 + d2



Calculating the clearance at the obstacle point: H = (hr x d2 + d1 x ht)/d - hs - (d1 x d2)/(2aK) In the formula: "H" represents the clearance of the relay transmission profile (m).

"ht" represents the antenna height at the start site of the relay transmission profile (m). ht = htground +

hantenna

"hr" represents the antenna height at the end site of the relay transmission profile (m). hr = hrground + h

rbuilding + hrantenna

"d1" represents the distance between the obstacle point and the start point of the relay transmission profile (m). d1 = Distance between point R and point S"d2" represents the distance between the obstacle point and the end point of the relay circuit (m). d2 = d - d1 "a" represents the radius of the earth. a = 6370 km"K" represents the equivalent earth radius coefficient of the relay circuit. K = 4/3, 2/3, or ∞

"hs" represents the height of the obstacle point (m). hs = hssea-level elevation of the ground + Height of the tree (o

r height of the building)"d" represents the distance between the two sites (m).



Three clearances:

Estimate d1 or d2 for calculating the clearance when the relay profil

e is flat area.

"HMIN" refers to the clearance (m) of the relay transmission profile w

hen k = kmin.

"H4/3" refers to the clearance (m) of the relay transmission profile w

hen k = kmin.

"H∞" refers to the clearance (m) of the relay transmission profile wh

en k = k∞.



Calculating the reflection point: Use the formulas and drawings to calculate the refection point. The formulas are as follows: C = (ht - hr)/(ht + hr) (assuming ht > hr)

M = d2/(4ak)(ht + hr)

In the formulas,"C" and "M" are intermediate parameters;"ht" and "hr" represent the sea-level elevations of the transmit antenna and the receive antenna respectively.Consult drawings with "C" and "M" to obtain "b".



Use the following formulas to obtain "d1" or "d2".d1 = d(1+b)/2 d2 = d - d1

0 0.1 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.2

Finding the reflection point

0.9 0.80.7

0.6

0.5

0.4

0.3

0.2

0.1

Parameter c

b

Param

eter b

Parameter m



Determining the antenna height: Use a trial method to obtain "H", "ht", and "hr". You need to first ensure that the following conditions are met and also need to consider the most economical rule.

KMIN K4/3

Edge profile H ≥ 0 H ≥ H0

Flat area and other

profiles

H ≥ 0.5 H0 H0 x √(6M - 5) ≤ H ≤ H0 x √(6M - 1)

Description M: "M" represents the serial number of an interference lobe on

the curve that reflects how the RSL at the receive end changes

according to the height of the antenna. Take the possible

minimum value when the "KMIN" is met. "K" can be 2/3 when the

statistics about K values are unavailable.



Pay attention to the following points when you select a profile: Ensure that one of the antennas at the transmit end and at the receive end is installed in a high position and the other is installed in a low position. As a result, the reflection point is on the land where φ ≤ 0.5 when "K" equals a value from 2/3 to 4/3. Do not select the profiles whose reflection points are on the flat area, lake, or water surface where φ ≥ 0.7 if possible.



Calculating the spacing between diversity antennas: Consider diversity in the case of profiles where φ ≥ 0.7. The calculation of diversity is provided as follows:

1) Calculate the antenna height when K = Kmin.

2) Consider the fading type of the section.(1) Against the type-K fading(a) K = 4/3

ΔHR = (75 x d)/(fGc(hT - hS - d2T-reflection point/17)) (m)

(b) K = ∞ ΔH = 127 x d/(fGc x (hT - hS)) (m) (c) Take the smaller ΔH value between the two values obtained by using (a) and (b) as the diversity spacing."hS" represents the sea-level elevation of the reflection point (m).

"dT-reflection point" represents the distance between the transmit end and the reflection poin

t (m)."f" represents the operating central frequency of this project (GHz).



Calculating the spacing between diversity antennas: (2) Against the waveguide fading ρ = exp[0.0021 x Δh x f x √0.4d]

Δh = ρ = 0.6(3) Take the smaller value between the two values obtained from (1) and (2) as the diversity spacing of the section.3) The "hs" value includes the height of trees, which is easily neglected.

According to the preceding calculation results, we can provide the routing information table for each solution. The tables can be used as a reference for the subsequent work. In this phase, we focus on preparing the technical information of all the possible microwave relay circuits. After this phase, the preliminary solution is determined.

df 4.00021.0ln



Profile Type

Profile Condition KQ B C

A High and dry mountain areas, large difference between antenna heights, rough ground, and large line clearance

1.58 x 10-4 1.0 1.2

B Inland temperate zone, middle-latitude hilly zone, medium difference between antenna heights, and medium line clearance

1.48 x 10-5 1.0 1.96

C Coastal temperate plain area, small difference between antenna heights, and small line clearance

2.88 x 10-5 1.0 2.20

D Cross-sea circuits 2.29 x 10-6 1.0 3.26

Calculating the Rayleigh fading probability:

PRayleigh = KQfBdC

"PRayleigh" represents the Rayleigh fading probability, "K" represents the climate factor, "Q" r

epresents the terrain factor, "f" represents the frequency, and "d" represents the distance between relay sites.



Calculating the circuit outage probability:

Calculate the circuit outage probability PRayleigh' with the consideration of

the flat fading margin (dB) of the relay circuit (generally, calculating the value only when BER = 10-3)

PRayleigh' = PRayleigh x 10ΔF10-3/10

In the formula, "ΔF10-3" represents the flat fading margin (dB) of the relay circuit when BER = 10-3.



Calculating the flat fading margin: ΔF10-3 = Pr - PBER = 10-3 ΔF10-6 = Pr - PBER = 10-6 "Pr" represents the RSL of the relay circuit (the input port of the receiver) (dB)."PBER = 10-3" represents the threshold level of the receiver (dB) when the BER equals 10-3 (generally provided by the vendor)."PBER = 10-6" represents the threshold level of the receiver (dB) when the BER equals 10-6 (generally provided by the vendor)."ΔF10-3" represents the flat fading margin (dB) when the BER equals 10-3."ΔF10-6" represents the flat fading margin (dB) when the BER equals 10-6.



Calculating the RSL of the relay circuit:

Pr = Pt - Ltcoupler - Ltfeed line + Gt - L0 + Gr - Lrfeed line – Lrsplitter

"Pr" represents the RSL at the input port of the receiver (dB)."Pt" represents the level at the output port of the transmitter (dB)."L0" represents the free space loss (dB).

"Ltcoupler" and "Lrsplitter" represent the coupler loss at the transmit end and the

splitter loss at the receive end respectively (dB).

"Ltfeed line" and "Lrfeed line" represent the feed line loss at the transmit end and t

he feed line loss at the receive end respectively (dB)."Gt" and "Gr" represent the antenna gain at the transmit end and the receive end respectively (dB).



Calculating the free space propagation loss: L0 = 20lg(4πd/λ) or L0 = 92.4 + 20lgf GHz + 20lgl km"L0" represents the free space loss (dB)."d" represents the distance between the sites on the relay section (km)."λ" represents the wavelength of the operating frequency (m)."f GHz" represents the microwave frequency (GHz). "l km" represents the distance between the sites (km).



Calculating the antenna gain: G = 10lg(4πAη/λ2)"G" represents the antenna gain (dB)."A" represents the area of the antenna opening (m2)."η" represents the antenna efficiency (generally 0.5 to 0.7)."λ" represents the wavelength of the operating frequency (m).The "G" value can be provided by the equipment manufacturer.



Calculating the allowed outage probability of a relay circuit: Calculation base: outage probability of the digital section (Pi) when BER = 10 -3

Pi = 0.0075%/280 x Li"Li" represents the length of the relay circuit (km)."280" is the assumed reference digital section (km)."0.0075%" is the allowed outage probability of the assumed reference digital section that is 280 km. Refer to ITU-T G.821.



Analyzing the indexes:

When PRayleigh' meets the requirement of the design specification, the index of th

e relay circuit meets the technical requirement, that is, PRayleigh' < Pi.

When PRayleigh' does not meet the requirement of the design specification, the in

dex of the relay circuit does not meet the technical requirement. In this case, you need to adopt corresponding measures. You need to analyze the causes, determine the fading type, and adopt corresponding measures.



Handling type-K fading: Adopt the following calculation method to calculate the circuit parameters that do not meet the requirement of the design specification in the case of the circuit outage probability caused by type-K fading.

First calculate the minimum antenna height when K = KMIN. The calculation

method is the same as the method of calculating the antenna height. Then, calculate the diversity height difference when k = 4/3 and k = ∞.



Handling the waveguide reflection: Adopt the following calculation method to calculate the circuit parameters that do not meet the requirement of the design specification in the case of the circuit outage probability caused by the waveguide reflection that results from uneven layers.

First calculate the minimum antenna height when K = KMIN. The calculation method is the

same as the method of calculating the antenna height. Then, calculate the spacing between diversity antennas ( h) according to the following ⊿empirical formula:ρ = exp[0.0021 x h x f x √(0.4 x d)] ⊿"f" represents the operating central frequency (GHz)."d" represents the distance between relay sites (km)."ρ" is the related coefficient and is 0.6 generally.Obtain the " h" value by using the preceding formula.⊿



Handling the two types of outage: To calculate the circuit parameters that do not meet the requirement of the design specification in the case of the circuit outage probability caused by type-K fading and the waveguide reflection that results from uneven layers, take the smaller " h" value between the two values obtained by using the ⊿preceding two methods.



Calculating the space diversity gain: IS = S2 x (f/d) x 10 (ΔF10-3 - V)/10 (Generally, IS < 200)"S" represents the central distance between diversity antennas (m)."d" represents the distance between sites (km)."f" represents the operating central frequency (GHz)."ΔF10-3" represents the flat fading margin when BER = 10-3 (dB)."V" represents the gain difference between two diversity antennas (dB).



Calculating the frequency diversity gain: If = 80/(f x d) x (Δf/f) x 10ΔF10-3/10 (generally, If ≤ 5)

"f" represents the central frequency of the channel (GHz)."d" represents the length of the relay section (km)."Δf" represents the spacing between diversity frequencies (GHz)."ΔF10-3" represents the flat fading margin when BER = 10-3 (dB).



Checking the circuit outage probability when the gain is improved:

In the case of space diversity, calculate the Rayleigh fading probability PRayl

eigh S as follows:

PRayleigh S = PRayleigh/IS

In the case of frequency diversity, calculate the Rayleigh fading probability

PRayleigh If as follows:

PRayleigh If = PRayleigh/If

When PRayleigh S < Pi or PRayleigh < Pi, check whether the circuit indexes meet t

he requirements. If the circuit indexes do not meet the requirements, adopt

other measures, for example, the Rake technology.



Calculating the θ azimuth angle: *θT→R, *θT←R ---True north azimuth angle (degree) Obtain the degrees of the azimuth angles by using the plane circular function and the relation between the quadrants occupied by the rays. Consult the drawing and obtain the coordinates of BS1 and BS2.Plain coordinates: (X1, Y1), (X2, Y2) Latitude and longitude coordinates: (N1, E1), (N2, E2)Obtain the degrees of 1 and 2 by using the circular function.∠ ∠

BS1

BS2

1

2

X1£ N£ ©Y1£ E£ ©

X2£ N£ ©Y2£ E£ ©



h1

h2

d

3602 2

1 2( )h hd

dka

3602 2

1 2( )h hd

dka

"a" represents the radius of the earth (6370 km) and "K" represents the atmospheric refraction factor.

Calculating the elevation angle of an antenna:



Calculating the elevation angle:

βT→R = ((hr-ht)/d-d/2ak)*57.3° (degree)

βT←R = ((hr-ht)/d-d/2ak)*57.3° (degree)

In the formula: "d" represents the distance between sites (m). a = 6370 x 103 m, K = 1.15

"*βT→R" and "*βR←T" represent the elevation angles of the transmit antenna a

nd the receive antenna respectively (degree).

"hr" and "ht" represent the sea-level elevations of the transmit antenna and t

he receive antenna respectively (meter) Provide the microwave relay circuit parameter table for each preliminary routing solution.



Calculating the standing-wave ratio in the feed line: In the case of the channel-specific filter, the standing-wave ratio at the wireless input port

(the input port of the polarization splitter) is ρfeed line.

Assume the standing-wave ratio at the input end of the feed line is ρ input. Then, the reflectio

n coefficient Vinput is calculated as follows: Vinput = (ρinput - 1)/(ρinput + 1) Assume the standin

g-wave ratio at the output end of the feed line is ρoutput. Then, the reflection coefficient Voutput

is calculated as follows: Voutput = (ρoutput - 1)/(ρoutput + 1)

Use the following formula to calculate the ρfeed line according to the Vfeed line:

ρfeed line = (1 + Vfeed line)/(1 - Vfeed line)

分路器Splitter



Calculating the power density:

Use the following formula to calculate the power density (Pm) that may be

related to the human body within the near field of the antenna of a microwave site:

Pm = P/лRX2

"RX" represents the minimum distance between the central axis of the antenna

that is operating normally and the position where people may exist within the near field of the antenna (m)."P" represents the maximum power launched by the antenna on any frequency (w).

"Pm" represents the power density that may be related to the human body. To

check whether the power density meets the requirement, refer to the table in the next slide. The power density should be less than the values specified in the table.



Limits obtained after public exposure:

Frequency range (MHz) 30 to 3000 3000 to 15000

Power density (W/m2) 0.4 f/7500

Weight absorption rate per

capita (W/kg)

0.02

Remarks "f" represents the operating frequency

(MHz).



Consider the following issues in the case of circuit networking: Avoid co-channel interference and spurious interference. Arrange the proper polarization for each microwave channel.Generally, adopt the two-frequency scheme to fully utilize frequency resources. That is, adopt the same frequency every two sites in the same direction in the case of the same line. Adopt vertical polarization and horizontal polarization to polarize the channel frequencies. Adopt different polarization modes for the adjacent channels on the same line.Adopt the same polarization direction for the transmit antenna and the receive antenna that are at the same site and are within the same relay section.Alternate the polarization direction hop by hop to reduce the front-back interference between antennas.Alternate the polarization direction every two hops to reduce the over-reach interference.Note: When the signal route deviates from the main direction of the antenna, the polarization decoupling performance deteriorates.



Over-reach interference: On the same microwave line, the over-reach interference must be avoided. You need to arrange sites in a zigzag manner. In addition, the angles formed by the line that connects the first site to the fourth site and the antenna axes of the two sites must be larger than 10 degrees.Radar interference: Antennas should not use the same frequency as the radar to avoid radar interference on the microwave line. In addition, the antennas should not be directly exposed to the radar. In the case of the spurious interference caused by old radars, S/N should be more than or equal to the sum of S/Nallowed and 20 (dB). "S/Nallowed" is the specified value for the microwave system.

Coordinating adjacent microwave circuits:On the microwave line, the mutual interference caused by adjacent microwave circuits that use the same frequency must be avoided. To avoid the interference, the following requirement must be met: S/N ≥ (S/Nallowed + (10 to 20)) (dB) "S/Nallowed" is the specified value for the microwave system.Coordinating satellite earth stations:On the microwave line, the mutual interference caused by adjacent satellite earth stations that use the same frequency must be avoided. To avoid the interference, the following requirement must be met: S/N ≥ 145 to 160 (dB)



When a passive repeater is used, the free space loss is calculated as follows: F = 10G LdB = 92.4 + 20logF (GHz) + 20logd1 + 92.4 + 20logF (GHz) + 20logd2 = 92.4 + 20 + 23.5 + 92.4 + 20 + 14 = 262.3 dB

When no passive repeater is used, the free space loss is calculated as follows: F = 10G

LdB = 92.4 + 20logF (GHz) + 20logd

= 92.4 + 20 + 26 = 138.4 dB

In the case of passive transfer, the free space loss increases by 123.9 dB (262.3 - 138.4).

To reach the RSL of one hop that has the same distance, the gain of each antenna must increase by 62 dB at least. It is difficult, however, to transport, install, and commission the antenna whose diameter is more than three meters.

In actual applications, select a high operating frequency if possible because the gain of an antenna is directly proportional to the frequency when the diameter of the antenna remains unchanged. If conditions permit, ensure that the distance between the passive repeater and one end site is less than 1 km.

Passive repeater with a parabolic reflector — a method of handling obstacles



Example 2: d1 = 19 km, d2 = 1 km, d = d1 + d2 = 20 km

When a passive repeater is used, the free space loss is calculated as follows: F = 10G LdB = 92.4 + 20logF (GHz) + 20logd1 + 92.4 + 20logF (GHz) + 20logd2 = 92.4 + 20 + 25.6 + 92.4 + 20 + 0 = 250.4 dB

When no passive repeater is used, the free space loss is calculated as follows: F = 10G

LdB = 92.4 + 20logF (GHz) + 20logd = 92.4 + 20 + 26 = 138.4 dB

In the case of passive transfer, the free space loss increases by 112 dB (250.4 - 138.4).

In actual applications, select a high operating frequency if possible because the gain of an antenna is directly proportional to the frequency when the diameter of the antenna remains unchanged. If conditions permit, ensure that the distance between the passive repeater and one end site is less than 1 km.

Passive repeater with a parabolic reflector — a method of handling obstacles



Passive repeater with a plane reflector

Passive repeater with a plane reflector — a method of handling obstacles



d1

d2The free space loss of the entire trip is calculated as follows:

L d d as 142 1 20 201 2. log log(km)

(km)

"a" represents the effective area of the plane reflector (m2).

Area A

a A cos 2

Passive repeater with a plane reflector — a method of handling obstacles



Passive repeater (photos)

Passive repeater with a plane reflector Passive repeater with a parabolic reflector



Correcting the incorrect circuit parameters of all the preliminary design solutions: Correct the incorrect circuit parameters of all the preliminary design solutions according to the site survey report, and determine one to two engineering microwave routing solutions.



Determining the circuit parameters of each relay section again: Check all the preliminary solutions according to the site survey report.Calculate d, d1, d2, θ, β, hr, ht, H2/3, H4/3, and H*** again by using different solutions.Provide the technical parameter table for each microwave relay circuit solution again.Provide the transmit power, antenna configuration, and technical specifications of each microwave relay circuit for each primary solution. If the calculation result is unavailable, describe the information in the design document.



Planning of the microwave transmission system in a country: Basic information of the network: The network covers several important cities in the region (including the city networks). Distance between sites: In the case of the city area, the distance between sites is less than seven km. In the case of the inter-city area, the distance between sites is more than 40 km.BSC-BTS:Selecting frequencies: In the case of the city area, the region belongs to region L known from the international rain region map. The average rainfall per hour is large. Hence, select the 15 GHz frequency band. In the case of the inter-city area, select the 7 GHz frequency band because the distance between sites is long.Determining the capacity and the protection scheme:In the case of a BSC, the minimum outgoing capacity is 8xE1 and the protection scheme is 1+1 protection. In the case of other sites, the maximum outgoing capacity is 4xE1 and the protection scheme is 1+0 protection. Selecting repeaters: The terrain information is unavailable. There may be plains and mountain areas. Hence, consider 10% of the total number of sites as the number of repeaters in the case of the 7 GHz system.Selecting the model: In the city, build rooftop masts that are 12 meters high because most of the buildings in the city have four to five floors. In the suburbs and fields, adopt self-support towers. In addition, use containers as equipment rooms.MSC-BSC (not in the same equipment room) and MSC-PSTN: Because a large quantity of E1s are required, microwave transmission cannot meet the requirement. Hence, it is recommended that the customer leases optical fibers.

Planning case in the bidding phase


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