MW Link Planning Nokia

LOS guidelines_v.0.2 Network Planning Dmitry Zhuravlev

7.07.2004

Microwave Line of Sight Surveys (LOS) PROCEDURE FOR NOKIA’S PARTNERS Astelit project Ukraine

Nokia Network Implementation LOS procedure

1/13


7.07.2004

Prepared by: Dmitri Zhuravlev Revised by

Stefano De Lena

Scope:

LOS procedure for Nokia’s partners, AstelitProject, Ukraine

Status:

Draft

Change History

Version

Date

Handled by

Comments

0.1

04.06.04

DZh

First draft

0.2

07.07.04

DZh

Second version


2/13


7.07.2004

Table of Content 1. 2.

Objective ........................................................................................................................................ 4 LOS SURVEY PROCEDURE ........................................................................................................ 4 2.1 LOS request .............................................................................................................................. 4 2.2 Equipment required. ................................................................................................................... 4 2.3 Results provided by Survey teams ............................................................................................... 5 2.3.1 Completed LOS survey report form ....................................................................................... 5 2.3.2 Continuation sheet .............................................................................................................. 5 2.4 Obvious LOS: .......................................................................................................................... 5 2.4.1 Definition ............................................................................................................................ 5 2.4.2 LOS verification and results ...............................................................................................56 3. LOS theory..................................................................................................................................... 6 3.1 Assessing line of sight ................................................................................................................ 6 3.2 MW antenna height .................................................................................................................... 7 4. Sample of LOS report: ................................................................................................................... 8 4.1 Cover page: ............................................................................................................................. 8 4.2 Continuation sheet................................................................................................................... 9


3/13


7.07.2004

1. OBJECTIVE To carry out LOS surveys for Astelit project in Ukraine as part of mobile cellular network implementation. The surveys are required to proceed with the microwave final design of the TRS access network.

2. LOS SURVEY PROCEDURE There will be a requirement for certain information to be provided by Transmission engineers and results to be returned by the LOS survey teams. All the calculations to obtain the clear LOS are performed according to the ITU-R P.530-10 recommendations. 2.1 LOS request After site’s approval by RF department Transmission engineer sends LOS request with links to be surveyed. It must contain distance, azimuth for each link, site coordinates and some additional info (site photo, site layout etc.) that can help surveyors during LOS performance. On receipt of the above information, the surveyor must: 1. get in touch with the Site Acquisition (who did the site searching, contact info in e-Tracker/TSSR) and plan with the agent the program to visit the sites (new site that is under planning and far end) and carry out the LOS surveys. 2. Have all documentation from the project for necessary sites 2.2 Equipment required. Can be broken down into two separate requirements: 1. City and urban surveys where distances are short and the major problem is buildings. 2. Backbone surveys where distances are greater and the major problem is terrain or short surveys between two greenfield sites, where there is no access to tall buildings and no cranes available. Before performing a LOS survey team has to have following information: site locations, planned antenna height (from the project), direction to the other end of link (azimuth), restrictions to cherry-picker access, etc. 1) One team carrying out short distance LOS survey, should be deployed at each end of the link being surveyed. a) Two people (safety requirement for working on roofs, towers, etc) b) Veichle c) GPS to take accurate position fixes for site and to assist in site location. d) Compass e) High power lamp (~1500000 candles) f) Balloons (min. 1.5mt.), air cylinder, string g) Mirror h) Binoculars i) Analog camera with telephoto lens (80mm-300mm with converter) and tripod j) Mobile phone k) Spare batteries for camera and GPS l) Measuring tape and rangefinder m) Maps (Street maps) 2) The following are the requirements for carrying out a Backbone Survey. This can be accomplished using one team for the whole link, or two teams starting at each end end working towards the middle. a) Two people b) Veichle c) GPS d) Compass e) Binoculars Nokia Network Implementation LOS procedure

4/13


7.07.2004

f) Analogic camera with telephoto lens (80mm-300mm with converter) and tripod g) Mobile phone h) Spare batteries for camera and GPS i) Measuring tape j) Maps (topografical for links under survey) 2.3 Results provided by Survey teams (for obvious LOS see 2.4.): 2.3.1 Completed LOS survey report form (see sample in attachment) a) b) c) d) e) f)

Name of the site Address of the site coordinates taken from TSSR/e-tracker Elevation taken from map Proposed antenna height (agl) and minimum Hant required for this link. Detailed comments for sites A-B and link if necessary (Report on obstacles and reflecting surfaces e.g. Building, Towers, Airports, Trees, Antenna systems in the way, lake, river…).

2.3.2 Continuation sheet 1. Layout of Site a) Marked up Site Survey form with sketch (copy from TSSR or simple hand made during the survey) showing where LOS was taken from and if the location was critical or not (preference have location and height of antennas indicated during TSSR). 2. Photo a) Photo of the building or tower (It should be clearly shown and the same with TSSR report). b) Photographs from each end of the link taken along the line of the path (80mm and 300mm) with the distant end clearly marked. For the links, which have one of two ends greenfield or tower, shall be carry out photo from minimum antenna height point as well. The height of point where photo was done has to be mentioned. If there is no LOS the direction of the distant end should be marked so that obstructions along the path (usually the same) could be clearly seen. c) Photo of Survey position (where photos of path were taken from) So, 4-5 photos per each end of link are required in the report.

2.4 Obvious LOS: 2.4.1 Definition In order to reduce time spent for LOS surveys and speed up the roll out of the project it is acceptable to make oneway LOS survey for obvious LOS defined below. OBVIOUS LOS:

-

-

Far end of the planned MW link is clearly seen, e.g. no vi sible obstruction (trees, building, relief etc.) on line of sight nor close to imaginary Fresnel zone towards far end and the distance is not exceeding three kilometres. Surveyor is sure that far end is according to TRS plan.

2.4.2 LOS verification and results obvious LOS can be checked during TSS by Transmission engineer with following outputs:


LOS survey report (cover page) completed for each MW path checked (if few);

5/13


-

-

7.07.2004

Marked up Site Survey form with sketch (copy from TSSR or simple hand made during the survey) showing where LOS was taken from and if the location was critical or not (locations and heights of antennas indicated during TSS are prefered). Photographs from surveyed site against required far end of the link taken along the line of the path (80mm and 300mm) with the antenna position on the distant end clearly marked. The height of point where photo was done has to be mentioned. Photo of Survey position (where photos of path were taken from)

3. LOS THEORY The importance of accuracy whilst performing LOS survey cannot be stressed too strongly, as errors will turn into costly remedies further down the line. These surveys form the basis of the access network and once implemented into the structure of the network a false positive LOS could lead to re-engineering large areas of the network, with radio frequency and capacity changes. A false negative LOS could result in deployment of more equipment than necessary to reach the engineering objectives. In both cases time and equipment costs will be very high to rectify a mistake made at this stage of the process.

3.1 Assessing line of sight Line of sight for MW link is considered to be clear if 0.6First Fresnel zone clearance is obtained along the length of the path. See fig.1 for explanation of Fresnel zone:

D= ath length

1st Fresnel zone

0.6*1st Fresnel zone

R

Fig.1 The Fresnel zone is considered as a three-dimensional ellipsoid about the axis of the path. The formula for the radius R at any point on first Fresnel zone is: R=17.3 x D1XD2/(F x D) Where: F=Frequency in GHz D1; D2; D – Distances in km When D1=D2, i.e. at the path mid-point R is at its greatest and obviously where we need maximum clearance. Below is a table giving 0.6 first Fresnel zone clearance for various frequencies and distances.


6/13


7.07.2004

0.6 first Fresnel zone clearance in metres in mid-path point Freq./Distance 7 GHz 13 GHz 23 GHz 38 GHz

1 1.97 1.45 1.09 0.85

2 2.79 2.04 1.54 1.2

3 3.41 2.50 1.88 1.46

4 3.94 2.89 2.17 1.69

5 4.4 3.23 2.43 1.89

6 4.83 3.54 2.66 2.07

7 5.21 3.82 2.88 2.24

8 5.57 4.09 3.07 2.39

9 5.91 4.34 3.26 2.54

10 6.23 4.57 3.44 2.67

3.2 MW antenna height Minimum antenna height is considered as minimum height where Line of Sight is possible and shall be defined during LOS survey, see fig.2:

H1 H2 H1 H3 H3 H2

A

Obstacle Fig.2

B

H2,H3 – minimum antenna height for link A-B H1 - lanned antenna height


7/13


7.07.2004

4. SAMPLE OF LOS REPORT: 4.1 Cover page:

Data from e-tracker

Taken with GPS or map


8/13


7.07.2004

4.2 Continuation sheet

Photograph of LOS from Site A to B Site A: Code :

Site B: Name:

ZABA961_N1 Azimuth A-B:

Candidate

ASSIR HOSPITAL

162 o

(1)

Distance (km)

Code:

TO

1.40 km

Name:

701-00-000

Candidate

ABHA EXCHANGE

Line of Sight Established:

YES

Near Field: LOS from Site A to Site B with 80 mm Zoom; Camera Ht: 19 M AGL

Far Field: LOS from Site A to Site B with 300 mm Zoom; Camera Ht: 19 M AGL Nokia Network Implementation LOS procedure

9/13

(1)


7.07.2004

Site A Photograph Sheet Site A:

Photo of Site A

Comments Surveyor: 1. SITE IS A ROOF TOP.


10/13


7.07.2004

Photograph of LOS from Site B to A Site B: Code :

Site A: Name:

701-00-000

Candidate

ABHA EXCHANGE

Azimuth B-A:

342o

(1)

Distance (km)

Code:

TO

ZABA961_N1

1.40 km

Name:

Candidate

NEAR ASSIR HOSPITAL

Line of Sight Established:

YES

Near Field: LOS from Site B to Site A with 80mm Zoom; Camera Ht: 41 M AGL


11/13

(1)


7.07.2004

Far Field: LOS from Site B to Site A with 300mm Zoom; Camera Ht: 41 M AGL

Site B Photograph Sheet Site B:

Photo of Site B

Comments Surveyor: 1. SITE B IS ROOF TOP (EXCHANGE BUILDING). 2. MW AT SITE B WILL BE WALL MOUNTED ON A NEW WALL MOUNT.

Antenna Position Photograph Nokia Network Implementation LOS procedure

12/13


7.07.2004

Antanna Position Site A (22.35 M AGL, MW will be mounted on a new wall mount)

Antenna Position Site B (43 M AGL, MW will be mounted on a new wall mount)


13/13

MW Link Planning Nokia

Recommend Documents