DOI : 10.17577/IJERTV6IS010085
- Open Access
- Total Downloads : 454
- Authors : Gemechu Dengia, Tofik Jemal, Sherwin N. Catolos
- Paper ID : IJERTV6IS010085
- Volume & Issue : Volume 06, Issue 01 (January 2017)
- Published (First Online): 02-02-2017
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License:
This work is licensed under a Creative Commons Attribution 4.0 International License
Microwave Link Design between Jimma Main Campus and Agaro Branch
1 Gemechu Dengia
1Leturer
Electrical and Computer Engineering Department, Mizan-Tepi University,
P.O.Box:378, Tepi, Ethiopia
2 Tofik Jemal
2Asst.Professor
Electrical and Computer Engineering Department, Director for Postgraduate, Research and Publication, JiT, Jimma University,
-
ox: 378, Jimma, Ethiopia.
3 Sherwin Catolos
3Asst. professor
Electrical and Computer Engineering Department, JiT, Jimma Universities,
P.O.Box: 378, Jimma, Ethiopia.
Abstract- Microwaves are widely used for point to point communications, because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other.
The aim of the thesis was to provide microwave radio link operating at microwave frequencies Jimma main and Agaro campuses, with the minimum objective reliability 99.999%. The designed link depends on Geo context-profiler for path profile analysis, Feko suite 5.5 for rectangular waveguide design, and link budget calculator. In the analysis there are parameters, which are significant in design of microwave link establishment: free space loss calculation, path profile analysis, fade margin, frequency planning, attenuation, rain fading predictions, reflection points calculation, , tower heights, Signal to Noise Ratio, Fresnel zone and link budget calculation. Fresnel zone clearance was considered at least at 60% of the first Fresnel zone.
Keywords: Sites selection, path profile analysis, Tower heights calculation, links budget, reflection point calculations, Systems (Transmitter, Receiver, RF repeater) products specifications, floured out waveguide designed
-
INTRODUCTION
Microwave communication is a cost-effective, can be rapidly installed, can cross complicated terrains, and efficient means to connect two or more wireless points together over a variety of terrains and space, where continuous runs of cable or fiber type transmission lines would not be practical or even possible.
The point to point microwave communication describes that transmission take place among two and provides dedicated point to point connectivity using directional antennas. In order to design point to point microwave link system, there are several technical choices that we considered for instances the microwave LOS link, the link budget, free space path loss on the link analysis.
A.Objectives General objective
The aim of the thesis is to design point to point microwave link between Jimma main to Agaro branch campuses. The planning of a link must take into account cost, equipment availability, and Line of sight propagation availability. A Microwave link design methods; frequency planning, link budget, Rain fading, fade margin, outages and availability calculations.
Specific objective
-
To analysis and find out; sites location, path profile analysis, tower heights, rain fading, and reflection point substantiation, clearance verification
-
To plan the frequencies of the link depending on the hop length, rain fading
-
To design horn antenna at 8.5GHz and 10.7GHz frequencies
-
To list the equipments products specifications
-
Statement of the problem
Recently, the main focus of the computer center is shifted to the newly built campus-wide network of the university. From the conception to the implementation of the network infrastructure, the computer center has been eagerly participating in every activity. In fact, the network project was under the direct supervision of the computer center since the beginning.
-
Scope and limitations of the study
The links from main campus to site A of transmitting terminals, and site B to the receiving terminals were intended to connect by optical fiber. Repeater is located at Yebu 13.8 km from site A and 19 km distances from site B. The design is limited to by the geocontex-profiler for path profile analysis and determination of tower heights,Feko suite 5.5 for antenna feed design. The path round walk would be conducted to verify the line of sight clearance, assess the reflective potential surfaces; such as flat terrain, and water bodies and manmade obstructions.
The type of soil would not be taken into consideration because of the inavailability of measuring instruments.
-
-
FUNDAMENTAL PARAMETERS IN MICROWAVE LINK
-
METHODOLOGY
The process is iterative and goes through many redesign phases before the required quality and availability are achieved.
-
Line of Sight
For any point-to-point radio communication; the general setup requires Microwave antennas to be placed in a high position. It is very important to find out a visible path between sites before establishing the links. Figure 1 show a line of sight where one microwave antenna has a direct link to another antenna placed at far end.
Fig.1. Atypical line of sight microwave link
-
Free Space Loss
Signal power is diminished by geometric spreading of the wave front. The power of the signal is spread over a wave front, the area of which increases as the distance from the transmitter increases. Therefore, the power density diminishes. Free Space Loss is normally addressed when designing a link budget and the formula is given by;
FSL = 92.4 + 20 log f + 20 log D
Where f=frequency in GHz, D =distance is given in km, FSL=free-space loss dB
-
Fresnel Zone
The First Fresnel Zone is an ellipsoid-shaped volume around the line of sight path between transmitter and receiver. It defines a volume around the LOS that must be clear of any obstacle for the maximum power to reach the receiving antenna. For a line of sight; the main beam has to be clear at least 60% of the First Fresnel Zone was considered.
Fig.2. first Fresnel Zone of microwave link
The radius of the first Fresnel Zone at a given point can be calculated as:
r=17.3
Where r is the radius of the Zone in meters, d1and d2 are distances from the obstacle to the link end points in meters and D is the hop distance in km and f is the frequency in GHz.
Fig.3. Microwave link design development
-
Frequency planning
Microwave links of short distances are generally allocated with higher frequencies and while for long hop distances or so we use lower frequencies.
-
Link Budget
The performance of any communication link depends on the quality of the equipment being used. Link budget is a way of quantifying the link performance.
-
Rain Fading
Rain attenuation is one of the series issues in microwave links. Rain attenuation increases with increase Hop length and the frequency. Jimma is a weather condition of precipitation 59%, humidity 63%, temperature 23degree centigrade, wind 3km/hr and light thunderstorm and rain.
-
Gas Absorption
A major difference in propagation through the real atmosphere versus free space is that there is air present. The two absorption peaks present in the frequency range of commercial radio links are located around 23 GHz, water molecules and 60 GHz, oxygen molecules.
-
Vapor Density
This variable reflects the humidity of the atmosphere in which the link is deployed. An average value of 7.5 is the default, though the table below reflects some other typical conditions from which to choose.
Table1. Vapor density at different temperature
-
Ground Reflection
The influence of reflection is that the ground can reflect some of the signals from the antenna to the receiving antenna .i.e. water surface and smooth ground have strong influence of reflection.
Changing the antenna heights can move the location of the reflection point. The formulas for getting the reflection point:
X , Y
Where p=first antenna height, p=second antenna height, D=distance of the first site to the second site
-
The possibility of future building construction along the path,
-
The relationship of the site to any commercial, military or private airport within several kilometers.
-
Site A
Site A is located inside Jimma University, main campus 110m from main ICT center. Its exact location is at 4103.9N latitude and 5111.6E longitude. Any vehicle via two-way lane of a distance can reach the site 10 meters from the main road. Actually, the proposed site was near to the ICT center and power lines.
Where d1=D, d2=D-d1, = reflection point, D1 and d2 are distance of the site from the reflection point.
-
-
-
Fade Margins
Determining sufficient fade margin is the most important step in microwave link design. If the margin is too small, the link will be unstable as a result, sufficient availability of the link or quality of the provided services cannot be guaranteed.
Fade margin using Barnett-Vienna Equation;
Equation considers the non-ideal and less predictable
-
Repeater site
Fig.5.Site A
characteristics of radio wave propagation:
FM = 30 log D + 10 log (6ABf) 10 log (1 R) 70
Where FM=Fade Margin, 30 log D = multi-path effect, 10 log (6ABf) = terrain sensitivity as shown table 1 below, 10 log (1 R) = reliability objectiveness.
Table2. A and B values
Repeater is located at Yebu town, 13.8 kilometers from site
A. Its exact location is at 4442.4N latitude and 036 4439.4E longitudes, and at an elevation of 2098 meters above sea level. The site is 100 and 400meters distance from small and main roads respectively and 200 meters away from the commercial power line.
Actually, the selected site was mountainous and surrounded by corns and tree fields. There is no airport within site and a round, no high structures that may cause potential obstruction of signal.
-
-
ICROWAVE LINK DESIGN PROCESSES
To reach the stage where a radio link can be deployed and brought into service, several steps must be successfully completed.
-
SITE B
Fig.6.Repeater site
-
Sites selections
Selection of a suitable microwave radio site encompasses a number of issues. The following factors should be considered:
-
Geographical location for possible line of sight path obstruction,
It is located at Agaro town, campus under constructions. Its exact location is at 5123.8N Latitude and 036 3650.6E Longitude. A vehicle can reach the site, and 400meters from the main road. The site is 200 meters away from the commercial power line. Actually, future building construction could not reach the selected area.
-
-
Path profile analysis
The path profile used to determine the height of the towers of the link, ensure free of obstructions, and not subject to the propagation losses from the radio phenomena. Elevation profile is generated from the geo-context profiler for the particular LOS path between sites. In this section site A to repeater and to site B path profiles were analyzed.
-
Site A to repeater site
Path profile was considered by 107meters and 92 centimeters from each following obstruction between these sites where considerations took place as shown table 1 below.
-
Repeater site to Site B
Path profile was considered by 148meters and 59 centimeters from each following obstruction between these sites where considerations took place.
-
Earth Curvature (Eb) = where k = , tree height
+ ATG=15.24 meters
-
First Fresnel Zone (F1) = 17.3 x
-
Total Extended Height = elevation + earth curvature +
-
F1 + Tree Height plus ATG
Table3. Path profile from site A to repeater
obstacle
Differences of d1s (km)
Dist. From Tx.d1(km)
Dist. from – Rx.d2 (km)
elevation(m)
Earth curvature (eb) (m)
first Fresnel clearance F1(m)
tree height
+ATG(m)
total extended height (m)
1
0
0
13.8
1768.79236
0
0
15.24
1784.03236
2
0.10792
0.10792
13.6920799
1760.11243
0.086920625
1.730615356
15.24
1777.169963
3
0.10792
0.2158402
13.5841598
1753.3988
0.172471045
2.437795266
15.24
1771.24907
4
0.10792
0.3237603
13.4762397
1751.30896
0.256651259
2.973793662
15.24
1769.779405
5
0.10792
0.4316804
13.3683196
1747.69873
0.339461268
3.420064103
15.24
1766.698256
6
0.10792
0.5396005
13.2603995
1744.36584
0.420901071
3.808282412
15.24
1763.835028
7
0.10792
0.6475206
13.1524794
1742.13306
0.500970668
4.154753678
15.24
1762.028781
8
0.10792
0.7554407
13.0445593
1739.54321
0.579670088
4.469197809
15.24
1759.832081
9
0.10792
0.8633608
12.9366392
1738.71277
0.656999274
4.757968653
15.24
1759.367736
10
0.10792
0.9712809
12.8287191
1741.79041
0.732958225
5.02549382
15.24
1762.788857
11
0.10792
1.0792011
12.720799
1744.42957
0.807547034
5.275007058
15.24
1765.75212
12
0.10792
1.1871212
12.6128788
1744.99927
0.880765609
5.508956031
15.24
1766.628989
13
0.10792
1.2950413
12.5049587
1748.23499
0.952613972
5.729247782
15.24
1770.156847
14
0.10792
1.4029614
12.3970386
1746.67126
1.023092135
5.93740269
15.24
1768.871759
15
0.10792
1.5108815
12.2891185
1741.32886
1.092200086
6.134656287
15.24
1763.95714
16
0.10792
1.618802
12.1811984
1736.96472
1.159937838
6.322029087
15.24
1759.686689
17
0.10792
1.726722
12.0732783
1737.26025
1.226305378
6.500375551
15.24
1760.226935
18
0.10792
1.834642
11.9653582
1739.71533
1.291302718
6.67041976
15.24
1762.917055
19
0.10792
1.942562
11.8574381
1736.85083
1.354929846
6.832781555
15.24
1760.278541
20
0.10792
2.050482
11.749518
1735.91699
1.417186775
6.987996474
15.24
1759.562175
21
0.10792
2.158402
11.6415979
1737.7948
1.478073491
7.136530823
15.24
1761.649404
22
0.10792
2.266322
11.5336778
1734.62891
1.537590008
7.278793622
15.24
1758.68529
23
0.10792
2.374242
11.4257577
1734.42627
1.595736314
7.41514582
15.24
1758.677152
24
0.10792
2.482162
11.3178376
1739.57874
1.652512419
7.545907857
15.24
1764.017156
25
0.10792
2.590083
11.2099175
1748.84094
1.707918313
7.671365576
15.24
1773.460226
26
0.10792
2.698003
11.1019974
1760.62097
1.761954006
7.791775222
15.24
1785.414701
27
0.10792
2.805923
10.9940773
1757.66357
1.814619489
7.907367387
15.24
1782.625561
28
0.10792
2.913843
10.8861572
1743.99072
1.86591477
8.01835044
15.24
1769.114988
29
0.10792
3.021763
10.7782371
1760.6814
1.915839842
8.124913238
15.24
1785.96215
30
0.10792
3.129683
10.670317
1747.10071
1.964394712
8.227227562
15.24
1772.53233
31
0.10792
3.237603
10.5623969
1760.6814
2.011579371
8.325450029
15.24
1786.258426
32
0.10792
3.345523
10.4544767
1769.55786
2.05739383
8.41972386
15.24
1795.274979
33
0.10792
3.453443
10.3465566
1773.26709
2.101838078
8.510180267
15.24
1799.119108
34
0.10792
3.561363
10.2386365
1776.13818
2.144912125
8.596939766
15.24
1802.120035
35
0.10792
3.669284
10.1307164
1778.12793
2.186615962
8.680113196
15.24
1804.234659
36
0.10792
3.777204
10.0227963
1779.74146
2.226949597
8.759802721
15.24
1805.968207
37
0.10792
3.885124
9.91487621
1790.62512
2.265913026
8.836102595
15.24
1816.967138
38
0.10792
3.993044
9.80695611
1790.59314
2.303506246
8.9090999
15.24
1817.045746
39
0.10792
4.100964
9.69903601
1782.854
2.33972926
8.978875193
15.24
1809.412608
40
0.10792
4.208884
9.5911159
1774.12256
2.374582071
9.045503042
15.24
1800.782644
41
0.10792
4.316804
9.48319579
1777.9574
2.408064677
9.109052506
15.24
1804.714515
42
0.10792
4.424724
9.37527569
1793.49207
2.440177074
9.169587583
15.24
1820.34183
43
0.10792
4.532644
9.26735558
1798.82275
2.470919268
9.227167614
15.24
1825.760841
44
0.10792
4.640565
9.15943548
1798.09973
2.500291254
9.281847583
15.24
1825.12187
45
0.10792
4.748485
9.05151537
1797.01379
2.528293036
9.333678468
15.24
1824.115765
46
0.10792
4.856405
8.94359527
1806.61902
2.55492461
9.382707477
15.24
1833.796651
47
0.10792
4.964325
8.83567516
1814.59961
2.580185981
9.428978325
15.24
1841.848774
48
0.10792
5.072245
8.72775506
1818.29456
2.604077144
9.472531423
15.24
1845.611164
49
0.10792
5.180165
8.61983495
1817.65918
2.626598103
9.513404106
15.24
1845.039182
50
0.10792
5.288085
8.51191485
1821.17761
2.647748854
9.551630775
15.24
1848.616992
51
0.10792
5.396005
8.40399474
1827.04553
2.667529401
9.587243088
15.24
1854.540305
52
0.10792
5.503925
8.29607464
1831.90796
2.685939741
9.620270073
15.24
1859.454169
53
0.10792
5.611846
8.18815453
1835.97791
2.702979877
9.650738279
15.24
1863.571623
54
0.10792
5.719765
8.08023443
1843.35754
2.718649805
9.678671864
15.24
1870.994866
55
0.10792
5.827686
7.97231432
1858.45984
2.732949529
9.704092721
15.24
1886.136881
56
0.10792
5.935606
7.86439422
1869.41968
2.745879046
9.727020547
15.24
1897.132577
57
0.10792
6.043526
7.75647411
1871.12219
2.757438359
9.747472939
15.24
1898.867104
58
0.10792
6.151446
7.64855401
1859.70093
2.767627464
9.765465445
15.24
1887.474021
59
0.10792
6.259366
7.5406339
1850.63403
2.776446365
9.781011644
15.24
1878.431491
60
0.10792
6.367286
7.4327138
1858.73083
2.783895059
9.794123182
15.24
1886.548853
61
0.10792
6.475206
7.32479369
1868.84583
2.789973548
9.804809829
15.24
1896.680609
62
0.10792
6.583126
7.21687359
1869.1355
2.794681831
9.813079506
15.24
1896.983259
63
0.10792
6.691046
7.10895348
1860.62158
2.798019908
9.81893832
15.24
1888.47854
64
0.10792
6.798967
7.00103338
1845.25659
2.79998778
9.822390585
15.24
1873.11897
65
0.10792
6.906887
6.89311327
1831.80762
2.800585445
9.823438838
15.24
1859.671641
66
0.10792
7.014807
6.78519317
1844.39709
2.799812905
9.822083849
15.24
1872.258991
67
0.10792
7.122727
6.6772731
1871.28516
2.79767016
9.818324625
15.24
1899.141151
68
0.10792
7.230647
6.569353
1891.39075
2.794157209
9.8121584
15.24
1919.237063
69
0.10792
7.338567
6.461433
1900.20337
2.789274058
9.803580642
15.24
1928.036224
70
0.10792
7.446487
6.353513
1910.94995
2.783020703
9.79258501
15.24
1938.765557
71
0.10792
7.554407
6.245593
1920.78357
2.775397146
9.779163346
15.24
1948.57813
72
0.10792
7.662327
6.137673
1929.01721
2.766403385
9.763305648
15.24
1956.786921
73
0.107921
7.770248
6.029752
1934.76233
2.756039319
9.74499984
15.24
1962.503368
74
0.10792
7.878168
5.921832
1929.28235
2.744305139
9.724232438
15.24
1956.990886
75
0.10792
7.986088
5.813912
1914.48914
2.731200756
9.700987473
15.24
1942.161324
76
0.10792
8.094008
5.705992
1909.56494
2.71672617
9.675247089
15.24
1937.196915
77
0.10792
8.201928
5.598072
1910.52307
2.700881381
9.64699131
15.24
1938.110944
78
0.10792
8.309848
5.490152
1910.23132
2.683666389
9.616197962
15.24
1937.771188
79
0.10792
8.417768
5.382232
1918.84094
2.665081194
9.582842585
15.24
1946.328866
80
0.10792
8.525688
5.274312
1929.63269
2.645125796
9.546898322
15.24
1957.064715
81
0.10792
8.633608
5.166392
1939.75427
2.623800194
9.508335815
15.24
1967.126408
82
0.10792
8.741529
5.058471
1948.97827
2.601104173
9.467122674
15.24
1976.286498
83
0.10792
8.849449
4.950551
1951.36243
2.577038153
9.42322489
15.24
1978.60269
84
0.10792
8.957369
4.842631
1957.60547
2.551601929
9.376604384
15.24
1984.773675
85
0.10792
9.065289
4.734711
1968.62366
2.524795503
9.327220327
15.24
1995.715673
86
0.10792
9.173209
4.626791
1978.23816
2.496618873
9.275028577
15.24
2005.249807
87
0.10792
9.281129
4.518871
1968.87817
2.46707204
9.219981454
15.24
1995.805227
88
0.10792
9.389049
4.410951
1947.65259
2.436155004
9.162027491
15.24
1974.49077
89
0.10792
9.496969
4.303031
1943.11536
2.403867765
9.101111157
15.24
1969.860335
90
0.10792
9.604889
4.195111
1949.6167
2.370210323
9.037172549
15.24
1976.264082
91
0.10792
9.71281
4.0871905
1961.32458
2.335182513
8.97014672
15.24
1987.869914
92
0.10792
9.82073
3.97927
1975.79565
2.298784486
8.899964218
15.24
2002.234403
93
0.10792
9.92865
3.87135
1996.81702
2.261016422
8.82655009
15.24
2023.144583
94
0.10792
10.03657
3.76343
2008.7644
2.221878155
8.749822669
15.24
2034.976105
95
0.10792
10.14449
3.65551
2009.62573
2.181369685
8.669693985
15.24
2035.716796
96
0.10792
10.25241
3.54759
2011.61462
2.139491011
8.586068814
15.24
2037.580184
97
0.10792
10.36033
3.43967
2018.21912
2.096242135
8.498843945
15.24
2044.054202
98
0.10792
10.46825
3.33175
2023.68018
2.051623055
8.407907346
15.24
2049.379706
99
0.10792
10.57617
3.22383
2029.31055
2.005633772
8.313137212
15.24
2054.869318
100
0.10792
10.68409
3.11591
2037.18835
1.958274287
8.21440086
15.24
2062.60103*
101
0.10792
10.79201
3.00799
2032.44812
1.909544598
8.111553458
15.24
2057.709218
102
0.10792
10.89993
2.90007
2024.44568
1.859444706
8.004436541
15.24
2049.54956
103
0.10792
11.00785
2.79215
2031.89514
1.80797461
7.892876282
15.24
2056.835992
104
0.10792
11.115771
2.684229
2036.73901
1.755133816
7.776680359
15.24
2061.510828**
105
0.10792
11.223691
2.576309
2032.60071
1.700923302
7.6556399
15.24
2057.197271
106
0.10792
11.331611
2.468389
2017.91284
1.645342585
7.529520169
15.24
2042.327705
107
0.10792
11.439531
2.360469
2000.27209
1.588391665
7.398061401
15.24
2024.498548
108
0.10792
11.547451
2.252549
2001.63184
1.530070541
7.260973615
15.24
2025.66288
109
0.10792
11.655371
2.144629
2017.64514
1.470379215
7.117931582
15.24
2041.473452
110
0.107919
11.76329
2.03671
2023.57703
1.409318257
6.968570063
15.24
2047.194915
111
0.107922
11.871212
1.928788
2024.66541
1.346885368
6.812467591
15.24
2048.064758
112
0.10792
11.979132
1.820868
2027.20557
1.283083419
6.649156855
15.24
2050.377807
113
0.10792
12.087052
1.712948
2035.26917
1.217911268
6.478089681
15.24
2058.205166
114
0.10792
12.194972
1.605028
2040.9165
1.151368913
6.29863412
15.24
2063.606507
115
0.10792
12.302892
1.497108
2038.08252
1.083456355
6.110051101
15.24
2060.516027
116
0.10792
12.410812
1.389188
2042.39429
1.014173594
5.911467158
15.24
2064.559928
117
0.10792
12.518732
1.281268
2046.85059
0.94352063
5.701837448
15.24
2068.735944
118
0.10792
12.626652
1.173348
2033.60425
0.871497463
5.479894474
15.24
2055.19564
119
0.107918
12.73457
1.06543
2037.77856
0.798105466
5.244079588
15.24
2059.06075
120
0.10792
12.84249
0.95751
2054.71094
0.723341918
4.992418092
15.24
2075.666698
121
0.107923
12.950413
0.849587
2040.00903
0.647206031
4.722374332
15.24
2060.618614
122
0.10792
13.058333
0.741667
2030.22461
0.569702039
4.430604851
15.24
2050.464916
123
0.10792
13.166253
0.633747
2039.14404
0.490827844
4.112479323
15.24
2058.98735
124
0.10792
13.274173
0.525827
2062.198
0.410583445
3.761316239
15.24
2081.609898
125
0.10792
13.382093
0.417907
2082.58545
0.328968843
3.366793777
15.24
2101.521212
126
0.10792
13.490013
0.309987
2083.9624
0.245984039
2.911337777
15.24
2102.359724***
127
0.10792
13.597933
0.202067
2075.56079
0.161629031
2.359928344
15.24
2093.322348
128
0.10792
13.705853
0.094147
2084.0918
0.07590382
1.617226871
15.24
2101.024928
***
***
13.8
0
2098.000
0
0
15.24
2113.240
Table4. Path profile from repeater to Site B
obstacle
Differences of d1s in
(km)
Dist. From Tx.-d1(km)
Dist. from Rx.-2 (km)
elevation (m)
Earth curvature
(eb)(m)
first Fresnel clearanceF1(m)
tree height
+ ATG (m)
total extended height (m)
0
0
19
2097.93579
0
0
15.24
2113.17579
2
0.148594
0.148594
18.851406
2087.58398
0.16477681
1.142519542
15.24
2104.131281
3
0.148595
0.297189
18.702811
2067.35718
0.32695704
1.614184394
15.24
2084.538319
4
0.148594
0.445783
18.554217
2061.24121
0.4865385
1.975022593
15.24
2078.942772
5
0.148595
0.594378
18.405622
2045.07288
0.64352334
2.278315894
15.24
2063.234715
6
0.148594
0.742972
18.257028
2051.16797
0.79790945
2.544724269
15.24
2069.750602
7
0.148594
0.891566
18.108434
2069.78491
0.94969789
2.784852376
15.24
2088.759462
8
0.148594
1.04016
17.95984
2050.77197
1.09888866
3.005007486
15.24
2070.115869
9
0.148595
1.188755
17.811245
2038.9939
1.24548274
3.209303614
15.24
2058.688683
10
0.148595
1.33735
17.66265
2059.65332
1.38947912
3.400597821
15.24
2079.683397
11
0.148594
1.485944
17.514056
2065.13647
1.53087685
3.580976255
15.24
2085.488328
12
0.148594
1.634538
17.365462
2064.71216
1.66967691
3.752013473
15.24
2085.373849
13
0.148595
1.783133
17.216867
2082.33423
1.80588022
3.91493328
15.24
2103.295042*
14
0.148594
1.931727
17.068273
2073.80054
1.93948493
4.070711189
15.24
2095.050733**
15
0.148593
2.08032
16.91968
2049.9812
2.0704911
4.220101607
15.24
2071.511794
16
0.148596
2.228916
16.771084
2049.18262
2.1989022
4.363864561
15.24
2070.985384
17
0.148594
2.37751
16.62249
2045.19385
2.32471389
4.502439232
15.24
2067.261001
18
0.1486
2.52611
16.47389
2028.79773
2.44793284
4.636322189
15.24
2051.121985
19
0.14859
2.6747
16.3253
2014.97839
2.56854588
4.765910143
15.24
2037.55285
20
0.14859
2.82329
16.17671
2025.81189
2.68656139
4.891544007
15.24
2048.629995
21
0.148598
2.971888
16.028112
2028.77124
2.80198551
5.013520497
15.24
2051.826746
22
0.148594
3.120482
15.879518
2013.70105
2.91480883
5.13210087
15.24
2036.98796
23
0.1485948
3.2690768
15.730923
2037.17676
3.02503506
5.247515676
15.24
2060.689309***
24
0.1485942
3.417671
15.582329
2026.1853
3.13266317
5.359968593
15.24
2049.917935
25
0.148595
3.566266
15.433734
2004.76294
3.23769417
5.469642901
15.24
2028.710277
26
0.148594
3.71486
15.28514
1991.22314
3.34012678
5.576702703
15.24
2015.379974
27
0.148594
3.863454
15.136546
1994.92993
3.43996172
5.981549802
15.24
2019.591443
28
0.1485949
4.0120489
14.987951
1987.72302
3.53719957
6.354245937
15.24
p>2012.854468 29
0.1485941
4.160643
14.839357
1967.90613
3.63183923
6.700158563
15.24
1993.478126
30
0.148595
4.309238
14.690762
1976.28271
3.72388176
7.023245594
15.24
2002.269842
31
0.148594
4.457832
14.542168
1975.04395
3.81332599
7.326528169
15.24
2001.423799
32
0.148594
4.606426
14.393574
1961.73706
3.90017256
7.612373138
15.24
1988.489606
33
0.148595
4.755021
14.244979
1955.75842
3.98442202
7.882677693
15.24
1982.865523
34
0.148594
4.903615
14.096385
1955.83228
4.06607323
8.138990945
15.24
1983.27734
35
0.1485947
5.0522097
13.94779
1945.97729
4.14512714
8.382595846
15.24
1973.745018
36
0.1485943
5.200804
13.799196
1919.55408
4.22158316
8.614570674
15.24
1947.630231
37
0.148594
5.349398
13.650602
1891.83948
4.29544136
8.835831623
15.24
1920.210751
38
0.148595
5.497993
13.502007
1876.3656
4.36670235
9.047164456
15.24
1905.019467
39
0.148594
5.646587
13.353413
1859.29834
4.43536519
9.24925042
15.24
1888.222955
40
0.148594
5.795181
13.204819
1855.06238
4.50143036
9.44268265
15.24
1884.246491
41
0.148595
5.943776
13.056224
1862.0802
4.56489829
9.48975131
15.24
1891.37485
42
0.148594
6.09237
12.90763
1856.81458
4.6257681
9.536319083
15.24
1886.216662
43
0.148595
6.240965
12.759035
1854.28247
4.68404064
9.582394016
15.24
1883.788905
44
0.148594
6.389559
12.610441
1851.31274
4.73971511
9.627983046
15.24
1880.920442
45
0.148595
6.538154
12.461846
1847.04834
4.79279225
9.805613579
15.24
1876.886746
46
0.148594
6.686748
12.313252
1861.91174
4.84327136
9.975980106
15.24
1891.970995
47
0.148594
6.835342
12.164658
1855.35864
4.89115281
10.13945317
15.24
1885.629249
48
0.148595
6.983937
12.016063
1834.98547
4.93643688
10.29635902
15.24
1865.45827
49
0.148594
7.132531
11.867469
1843.92871
4.97912297
10.44699448
15.24
1874.594828
50
0.148595
7.281126
11.718874
1835.69299
5.01921166
10.5916265
15.24
1866.543831
51
0.148594
7.42972
11.57028
1806.24377
5.0567024
10.73049763
15.24
1837.270974
52
0.148594
7.578314
11.421686
1784.43872
5.09159547
10.8638296
15.24
1815.634146
53
0.148595
7.726909
11.273091
1788.1698
5.12389108
10.9918234
15.24
1819.525514
54
0.148594
7.875503
11.124497
1804.17932
5.15358879
11.11466331
15.24
1835.687573
55
0.148595
8.024098
10.975902
1823.0708
5.18068902
11.23251894
15.24
1854.724009
56
0.148594
8.172692
10.827308
1824.3667
5.20519138
11.34554537
15.24
1856.157436
57
0.148594
8.321286
10.678714
1809.20813
5.22709608
11.45388525
15.24
1841.129111
58
0.148594
8.46988
10.53012
1811.12427
5.24640311
11.55767097
15.24
1843.168342
59
0.148595
8.618475
10.381525
1813.3468
5.26311257
11.65702357
15.24
1845.506938
60
0.1485947
8.7670697
10.23293
1802.81921
5.2772243
11.68118261
15.24
1835.017621
61
0.1485943
8.915664
10.084336
1776.78149
5.28873832
11.70507335
15.24
1809.015306
62
0.148594
9.064258
9.935742
1769.92908
5.29765464
11.7288769
15.24
1802.195609
63
0.148595
9.212853
9.787147
1774.48975
5.30397333
11.75205609
15.24
1806.785776
64
0.148594
9.361447
9.638553
1778.57739
5.3076943
11.84287225
15.24
1810.967959
65
0.148595
9.510042
9.489958
1771.87891
5.3088176
11.92956797
15.24
1804.357292
66
0.148594
9.658636
9.341364
1752.45679
5.30734321
11.95060892
15.24
1784.954739
67
0.1485945
9.8072305
9.1927695
1752.01697
5.30327114
11.97140249
15.24
1784.531641
68
0.1485945
9.955825
9.044175
1761.50928
5.29660139
11.99194005
15.24
1794.037819
69
0.148595
10.10442
8.89558
1757.27234
5.28733391
12.01223317
15.24
1789.811906
70
0.14859
10.25301
8.74699
1746.12781
5.27546917
12.09095027
15.24
1778.734227
71
0.1486
10.40161
8.59839
1718.07727
5.26100585
12.16579525
15.24
1750.744072
72
0.14859
10.5502
8.4498
1679.28394
5.24394588
12.23684017
15.24
1712.004722
73
0.148597
10.698797
8.301203
1664.46997
5.2242874
12.30415051
15.24
1697.238409
74
0.148593
10.84739
8.15261
1676.54199
5.20203178
12.36778655
15.24
1709.351811
75
0.1486
10.99599
8.00401
1690.69824
5.17717729
12.42780581
15.24
1723.543225
76
0.14859
11.14458
7.85542
1679.69043
5.14972686
12.44225183
15.24
1712.522408
77
0.148594
11.293174
7.706826
1684.18799
5.11967806
12.45647522
15.24
1717.004142
78
0.148595
11.441769
7.558231
1706.07312
5.08703136
12.47047795
15.24
1738.870629
79
0.148594
11.590363
7.409637
1715.64368
5.05178721
12.48426007
15.24
1748.419724
80
0.148595
11.738958
7.261042
1720.68567
5.01394512
12.49782187
15.24
1753.437436
81
0.148592
11.88755
7.11245
1705.50037
4.97350618
12.51116522
15.24
1738.225038
82
0.148597
12.036147
6.963853
1691.28357
4.93046814
12.5242901
15.24
1723.978328
83
0.148594
12.184741
6.815259
1695.99463
4.88483328
12.53719676
15.24
1728.656659
84
0.148594
12.333335
6.666665
1694.01123
4.83660075
12.54988702
15.24
1726.637718
85
0.148595
12.48193
6.51807
1684.66467
4.7857702
12.56236084
15.24
1717.252804
86
0.148594
12.630524
6.369476
1673.15332
4.73234232
12.5746184
15.24
1705.700281
87
0.148595
12.779119
6.220881
1652.13208
4.67631639
12.5866615
15.24
1684.635058
88
0.148594
12.927713
6.072287
1633.22559
4.61769315
12.63269438
15.24
1665.715973
89
0.148594
13.076307
5.923693
1650.71436
4.55647225
12.64367041
15.24
1683.154498
90
0.148595
13.224902
5.775098
1671.63562
4.49265324
12.65443548
15.24
1704.022709
91
0.148594
13.373496
5.626504
1678.96448
4.42623698
12.66498944
15.24
1711.295704
92
0.148594
13.52209
5.47791
1666.18811
4.35722306
12.6753324
15.24
1698.460666
93
0.148595
13.670685
5.329315
1668.95361
4.28561098
12.68546584
15.24
1701.16469
94
0.148594
13.819279
5.180721
1672.19507
4.2114017
12.69538954
15.24
1704.34186
95
0.148595
13.967874
5.032126
1655.48828
4.13459423
12.70510449
15.24
1687.56798
96
0.148594
14.116468
4.883532
1672.34705
4.0551896
12.71461066
15.24
1704.356846
97
0.148592
14.26506
4.73494
1682.02917
3.97318842
12.75055949
15.24
1713.992923
98
0.1486
14.41366
4.58634
1679.45325
3.88858502
12.78320744
15.24
1711.36504
99
0.148591
14.562251
4.437749
1668.38318
3.80138911
12.81257932
15.24
1700.237147
100
0.148595
14.710846
4.289154
1657.7229
3.71159317
12.83869783
15.24
1689.513191
101
0.148594
14.85944
4.14056
1666.72644
3.61920017
12.86158294
15.24
1698.447224
102
0.1486
15.00804
3.99196
1674.98022
3.52420561
12.86680097
15.24
1706.611231
103
0.14859
15.15663
3.84337
1672.22546
3.42661983
12.87181824
15.24
1703.763902
104
0.14859
15.30522
3.69478
1665.62793
3.32643651
12.87663512
15.24
1697.071001
105
0.148598
15.453818
3.546182
1648.36633
3.22365007
12.88125156
15.24
1679.711235
106
0.148594
15.602412
3.397588
1616.75122
3.11826869
12.88566792
15.24
1647.995157
107
0.148595
15.751007
3.248993
1596.96155
3.01028891
12.88988577
15.24
1628.101723
108
0.148593
15.8996
3.1004
1627.66748
2.89971293
12.8939013
15.24
1658.701095
109
0.148595
16.048195
2.951805
1635.02527
2.78653778
12.89771859
15.24
1665.949525
110
0.148595
16.19679
2.80321
1632.52283
2.67076492
12.90133666
15.24
1663.334929
111
0.148594
16.345384
2.654616
1643.60376
2.55239517
12.90475548
15.24
1674.30091
112
0.148595
16.493979
2.506021
1632.69397
2.43142693
12.9079753
15.24
1663.273372
113
0.148591
16.64257
2.35743
1631.15491
2.30786434
12.91099636
15.24
1661.613768
114
0.148597
16.791167
2.208833
1640.21936
2.18169905
12.91381862
15.24
1670.554878
115
0.148593
16.93976
2.06024
1650.5614
2.05293948
12.91644231
15.24
1680.770783
116
0.148596
17.088356
1.911644
1648.03943
1.9215796
12.91886761
15.24
1678.119876
117
0.148594
17.23695
1.76305
1634.83533
1.78762381
12.9210945
15.24
1664.784045
118
0.148595
17.385545
1.614455
1611.3219
1.65106941
12.92312315
15.24
1641.136092
119
0.148594
17.534139
1.465861
1612.70947
1.51191827
12.9249537
15.24
1642.386345
120
0.148595
17.682734
1.317266
1629.99084
1.37016849
12.92658614
15.24
1659.527599
121
0.148594
17.831328
1.168672
1639.22144
1.22582199
12.92802058
15.24
1668.615278
122
0.148592
17.97992
1.02008
1634.30896
1.07887981
12.93177971
15.24
1663.559619
123
0.1486
18.12852
0.87148
1632.71021
0.92933192
12.9323746
15.24
1661.811912
124
0.14859
18.27711
0.72289
1619.31543
0.77719647
12.92980571
15.24
1648.262432
125
0.1486
18.42571
0.57429
1619.01904
0.622453
12.92407112
15.24
1647.805567
126
0.14859
18.5743
0.4257
1636.08496
0.46512232
12.91516669
15.24
1664.70525
127
0.14859
18.72289
0.27711
1639.1322
0.30519412
12.91244459
15.24
1667.589841
128
0.1486
18.87149
0.12851
1634.48438
0.14265736
12.90952344
15.24
1662.776556
***
***
0
19
0
0
0
0
0
-
-
Tower heights calculations
Microwave tower is a structure built to enhance wireless communication, for them to work. They have to go long path using interconnecting pattern and can be located anywhere.
Tower heights calculation of the Site A to repeater site As shown in Fig.8, the sites A, peak obstruction height, and repeater site are at Elevations of 1769, 2037 and 2098meters above sea level respectively.
Fig.8. Tower heights calculation of Site A and Repeater
Values from the tables above; e1 =1769m, D=13.8km, e0=2037.2 m, d1=10.68 km, e2=2098m, d2=3.116km, F=10.7GHz, k=4/3, TG=15.24m
Eb = = =1.958m
F1 = 17.3 = 17.3 =8.214m
H=0.6F1= =4.928 m
H01 = Eb + TG + e0 =1.958m +15.24m+2037.2m= 2054.4
m
p=a1+e1= a1+1769m, p=a2+e2= a2+2098m
Assuming a1= a2= a
H= =
4.928m= a=35
.6 m=a1=a2 Where
Eb=Earth bulge, F1=First Fresnel zone,
H=the first Fresnel zone at 60% clearance, TG=Tree growth
e0=elevation of the obstruction, e1=elevation of the site A e2=elevation of the repeater site, a1=the first tower heights
a2=the second tower heights, p= the height site A and elevation
p= the height of repeater site and elevation, H01=first peak obstruction height
Antenna orientation calculation
C
C=036 5111.6 must be positive C= 0 632.2 = 0.108944
79.914
7835.4184776
X10.07859°
Y 169.90678
Fig.9.The first hop antenna orientations
Tower heights calculation of the repeater with site B epeater site, peak obstruction height, and Site B are at elevations 2098, 2082, and 1628meters above sea level respectively.
Fig.10.Tower heights calculation of Repeater and Site B
Values from the tables above; e1=2098m, D=19km, e0=2082.33 m, d1=1.78km, e2=1628m, d2=17.22km, F=8.5GHz
Eb = = =1.803m
F1 = 17.3 =17.3 =7.54 m
H=0.6F1= 0.6 =4.522 m
H01= Eb + TG + e0 =1.803m +15.24m+2082.33m= 2099.37 p=a1+e1= a1+2098m, p=a2+e2= a2+1628m
Assuming a1= a2= a
H= =
4.522m= a=49.
92 m=a1=a2
The second hop antenna orientation calculation
C
C= = 0.130222
0.864227358
6483.216898
X ;
Y
Site R: N ( or N
(
Fig.11.The second hop antenna orientations
-
-
ANALYSIS AND RESULTS
The analysis of the two hop lengths consist of the following steps: free space loss, link budget, rain attenuation, fade margin, and Fresnel zone calculations.
-
Site A to Repeater site
Fig.12. Design flowchart
Step 1-Requirement Determination Transmission requirements: Maximum data rates > 155 Mbps
Minimum required availability: 99.999% Ray parameters:
10.7GHz
Modulation 16 QAM; BW=28MHz; Ps (10-6) =-80.8 dBm Tx/Rx spacing 490MHz, TX power=26 dBm
Step 2-Free space loss calculation
FSL = 92.4 + 20 log f (GHz) + 20 log D (km) =92.4 + 20 log 10.7 + 20 log 13.8=135.8 dB
Step 3-Rain attenuation
For 99.999% availability in rain zone J the rain rate is R0.001=55 mm/hr
For f=10.7 GHz kh=0.017; h=1.227; kv=0.017; v=1.178
0.001
Vertical polarization
Site B: S ( W or S
R0.001 = kv .Rv
= 0.017 * (55)1.178 = 1.924dB/km
( W Horizontal polarization
R0.001 = kh .Rh0.001 = 0.017 ·*(55)1.227 = 2.32 dB/km
Step 4 link budget
The link budget is a calculation involving the gain and loss factors associated with the antennas, transmitters, transmission lines and propagation environment.
Vertical polarization
0.001
R0.001 = kv .Rv
= 0.005 * (55)1.303 = 0.926 dB/km
Fig.13. Link budget of Site A to Repeater
Site A Link Budget
Transmitter Gain: The diameter of 1.8m, and the gain,
G = 17.8 + 20 log (fGHz) + 20 log (dm) = 17.8 + 20 log 10.7
+ 20 log (1.8) = 43.5 dB
Wave Guide Loss
Elliptical waveguide type (WR90),
LWG (TX) =40 m+3m-2 m +1 m+5 m =47 m ) = 4.58
dB
Branching loss
Branching loss (LbTx=2 dB)
Radome loss
Radome loss (LrTx=0.5dB)
Repeater site Link budget
GR = 17.8 + 20 log (fGHz) + 20 log (dm)
= 17.8 + 20 log (10.7) + 20 log (1.8) = 43.5dB
Wave Guide Loss
LWG(R) =40m+3m-2m +1 m+5m =47 m ) =4.58 dB
Branching loss
Branching loss (LbR =2 dB)
Radome loss
Radome loss (LrR=0.5dB Miscellaneous losses Miscellaneous Loss (Lmisc=2dB)
-
Repeater site to site B
Link parameters: Data rates: >155Mbps
Minimum required availability: 99.999% Ray parameters:
8.5GHz
Modulation 16QAM; BW=28MHz; Ps (BER 10-6)
= -80.6dBm
Tx/Rx spacing = 490MHz TX power=28 dBm
Step 2-Free space loss calculation
FSL = 92.4 + 20 log f (GHz) + 20 log D (km) =92.4 + 20 log 8.5 + 20 log 19=136.6 dB
Step 3-Rain attenuation
For f=8.5 GHz kh=0.0057; h=1.316; k=0.0050; v=1.303
Horizontal polarization
R0.001 = kh .Rh0.001 = 0.0057 *(55)1.316 = 1.112 dB/km
Step 4 link budget
Fig.14. Link budget of Repeater site to Site B
Repeater site link budget Antenna gain
The diameter of reflector antenna 1.8m, and the gain, G = 17.8 + 20 log (fGHz) + 20 log (dm) = 41.5 dB Wave Guide Loss
LWG(R) and
5.84dB/100m loss,
LWG(R) = 187ft ) =57m ) = 3.33dB
Branching loss
Branching loss (LbR=2 dB)
Radome loss
Radome loss (LrR=0.5dB)
Site B Link budget Gain
GRx = 17.8 + 20 log (fGHz) + 20 log (dm) = 17.8 + 20 log
(8.5) + 20 log (1.8) = 41.5dB
Wave Guide Loss
LWG =57 m 57 m
() = 3.33dB
Branching loss
Branching loss (LbRx =2 dB)
Radome loss
Radome loss (LrRx =0.5dB)
Miscellaneous losses
Miscellaneous Losses (Lmisc=2dB), e.g antenna misalignment, TX variation loss,
-
Reflection Point Calculation
The formulas for getting the reflection point
X ,
Where d1= D, =reflection point, D and d1 are distance of the site from the reflection point.
X , Y
= = =0.5, D1=0.5*13.8=6.9 km
d2=D-d1=13.8 km -6.9 km=6.9 km , y
= = =0.5, d1= D, d2=D-d1,
D1=0.5*19=9.5 km, d2=19-9.5=9.5km
-
-
RESULTS
Clearance verification of site A, repeater and site B
From the determined path profile, hop length, the frequency planned, and tower height calculations we have got the following Fresnel zone clearance.
Fig.15. Clearance verification of site A to repeater
The second result was from longer hop length than that of the first hop length relatively.
Fig.16. Clearance verification of repeater to site B
-
Transmitter
The voice or data channels are combined by a multiplexing. This signal is frequency modulated to an IF in the indoor unit and by elliptical wave guide to the outdoor unit and then up converted to the RF for transmission through the atmosphere.
Fig.17. Transmitters blocks diagram
Table 5.Transmitter products and specifications
-
RF repeater
In order to overcome the problems of line-of-sight and power amplification of weak signals, microwave systems use repeaters depending on non-line of sight and interferences. The repeater is placed in line-of-sight of the transmitting and receiving stations. The data signals are received, mixed with local oscillator, and re-transmitted to the receiver.
Fig.16. RF repeater block diagram
Based on the repeater block diagram above the parameters product and specifications are given.
Table 6.RF repeater products and specifications
Fig.17.Receivers block diagram
Table7.Receiver products and specifications
D. Horn antenna simulation and design
The basis for this given design was to implement standard gain horn, directivity, electric and magnetic waves in near and far field propagations using Feko suite 5.5. The horn antenna we designed for the link was subjected to the following constraints:
perating frequency at 8.5GHz and10.7GHz, Maintain gain of 20 dB over the frequency
imensions of rectangular waveguide (in mm): width x height x length 42 x 35 x 75 respectively
-
Receiver
The reverse process of the transmitter occurs at the receiver. In this part the products: down converter, demodulator and demultplexer are introduced in table 5.3 above.
-
At 10.7GHz flared out waveguide design
As shown Fig.18 below the mesh of flared out wave guide and electric field density with respect to the colors starting from the center, on top left numerical values. The right figure is the gain of far field at 10.7GHz frequency. Vertically at zero degree the gain is greater than elsewhere.
Fig.18. waveguide model and gain in polar plane
-
At 8.5GHz flare out waveguide design
-
From the graph of Fig.19 below as angles increases right and the electric field decreases. 3.84 mesh size of flared out wave guide and electric field density with respect to the colors starting from the center to the edges, on top left numerical values. The right figure is the gain at 8.5GHz frequency. The waveguide is vertically polarized, at zero degree the gain is greater actually less than at 10.7GHz frequency.
Fig.19. Waveguide model and gain in polar plane at 8.5GHz
-
-
CONCLUSION
-
In this thesis, the designed point to point microwave link communication between Jimma Main Campus and Agaro branch by means of geo-context profiler for path proile datas, feko suite 5.5 for flared out waveguide feeder design. Microwave link works on LOS and is not the same as optical line of sight; as a result it requires more clearance than optical line of sight to accommodate the characteristics of microwave signals; such as line of sight, Fresnel zone clearance, and free space loss considerations. The path profile for the two hop lengths were analyzed; The path profile for Site A to repeater is intended to use 107meters and 92 centimeters from each obstructions within the path, and 148meters and 59 centimeters for Repeater Site to Site B . The tower height calculations, angle of elevations and azimuth, Link budget calculations,
signal to noise ratio calculations, reflection point calculations were also conducted.
The designed rectangular horn antennas have directional radiation pattern, ability to achieve high gain and directivity.
Reflection points that account for response signal fading are devised for different antenna heights, choosing high elevation of repeater site that is line of sight with both transmitter and receiver.
A. Future works
The designed microwave link in this thesis is depended on the transmission of only data and audio, video is not included. Therefore, further research could focus on video transmission and reception as with data and audio in wireless communication system of the link. Within the path of multipath/rain fading, Doppler shift, phase error, etc. was not considered that can be added to the channel, in order to closely simulate real life systems.
ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to my adviser Dr:-ing Tofik Jemal and Co adviser Ing. Sherwin catlos, for their guidance, support, advice and encouragement right the way throughout the thesis. This thesis would not have been possible without their help, and their experiences have been valuable.
REFERENCES
-
http://www.microwave-link.com/
-
Lehpamer,H.: Microwave transmission network, Second edition, ISBN: 0071701222, McGraw-Hill Professional, 2010.
-
http://ethw.org/Microwave_Link_Networks
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Sanjeeva Gupta, 1957, Microwave Engineering. Mc-Graw-Hill.
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Specific attenuation model for rain for use in prediction methods, Rec. ITU-R P.838-2.
-
Harvey Lehpamer, 2010, Microwave Transmission Networks:
Planning, Design, and Deployment, Second Edition, Mc-Graw Hill
-
Axonn Global Data Solution, path Loss Calculation, [Online]. Available: http://www.axonn.com/pdf/path-loss-calculations.pdf [Accessed: August 25, 2009]
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Lenkurt electric co., inc.san carols, 1970, engineering considerations for microwave communications systems
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http://www.technologyuk.net/telecommunications/communication- technologies/radio-and-terrestrial-microwave.shtml
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Matthew M. Radmanesh, 1942, Radio Frequency. & Microwave Electronics. Mc-Graw
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Christopher Haslett, 2007, Essentials of radio wave propagations,
Cambridge university, Dina Elassal, principle of Digital Microwave
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http://www.radiowaves.com/en/product/sp6-8
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http://www.radiowaves.com/en/product/sp6-10