Pengaruh Modulasi Adaptif Coding (AMC) Untuk Perencanaan Coverage femtocell LTE di AKATEL Purwokerto

Pada penelitian ini digunakan tiga skema modulasi yang berbeda untuk mengetahui pengaruhnya terhadap cakupan didalam ruangan, modulasi tersebut yaitu QPSK, 16QAM, dan 64QAM serta dengan membandingkan dua frekuensi yang digunakan yaitu 700MHz dan 2600MHz. Untuk propagasi yang digunakan dalam perhitungan yaitu menggunakan propagasi Cost 231 Multiwall Model yang memperhitungkan loss dinding agar hasil yang dicapai pada perhitungan dapat disesuaikan dengan kondisi di lapangan.. Hasil dari penelitian tersebut ditunjukkan hasil coverage dan jumlah femtocell yang dibutuhkan dengan melihat pengaruh modulasi adaptif coding yang dihasilkan dan membandingkan kedua frekuansi yaitu pada frekuensi 700MHz coverage yang dihasilkan yaitu 409,6691 m2 dan jumlah femtocell sebanyak 6 femtocell BS. Serta pada frekuensi 2600MHz coverage yang dihasilkan yaitu 29,6965 m2 dan jumlah femtocell sebanyak 72 femtocell BS. Dengan modulasi yang digunakan adalah 64QAM dengan code rate 4/5

Sumber PDF File :
https://www.academia.edu/6825984/Pengaruh_Modulasi_Adaptif_Coding_AMC_Untuk_Perencanaan_Coverage_femtocell_LTE_di_AKATEL_Purwokerto

LOS Survey Process Tutorial

  Survey Process consists of five basic steps;

a) Prepare the Site documentation
b) verify the Site location
c) Finding Problems in-between the path
d) Path profile
e) Overall survey report.
Site Documents
a) Site location maps to be find with Location Land Mark.
b) If it is existing site means, get site information from other customer.
Collection of details of the proposed site;
a) Observe the Absolute Mean Sea Level, height of tower, heights of antenna and angles.
b) Take photographs of site, it used for verification in future.
c) Marking of tower center from minimum three reference points
transmitters and receivers Antennae frequencies.
e) Soil samples can be taken for laboratory testing. This will be useful for economical design of the tower.
Identification of critical points along the path
a) On the maps two sites are joined by a thin straight line.
b) Determine the height, width of all obstructions along the path and HASL at each point for all potential obstructions.
c) Visit every likely critical point to ascertain its height and check other parameters.
d) Determine the width of water bodies, other reflecting points falling along the route.
e) Take mirror tests if after calculations, it is found, that, it is feasible
Generating LOS path profile;
a) It can be manually or by computerized software.
b) Hop wise data required is given below.
About hop
AMSL of each site
Hop distance (If co-ordinates are fed to computer software, you get hop distance    and azimuth angles)
HASL of each obstruction and its height including near-end obstructions, Clearance criteria being adopted. Say  Cl=k 4/3 + 100% FFZ and OR Cl=k 2/3 + 60% FFZ
Frequency band of operation.
c) With the above parameters antenna heights in each direction of operation can be worked out and hence the tower height at each sight.
Generating LOS report
a) Site Data( Height, Angle , Azimuth)
b)Any Disturbance in Path
c)Photograph about Site for Future Identification.
Detailed Survey Report
a) Determine following parameters.
Transmitter power, Size and gain of antenna’s for main and diversity, transmission line losses, Receiver threshold  Signal to noise ratio, Fade Margin
b)The complete exercise can be worked out manually with the help of a calculator or different Software’s available for Path Loss Calculations.

Microwave Link Traffic Tutorial

a) Microwave Link connects two cellular network sites.
b) It carries two types of traffic: Voice and Data.
C) Commonly each BTS site has one E1 (2 Mbps) of transmission capacity.
d) PDH or SDH are the two standards for traffic capacity over Microwave Link in terms of E1. 2 x 2 (2E1), 4 x 2 (4E1), 8 x 2 (8E1), 16x 2 (16E1), STM1 etc.

E) PDH Transmission rates
E1-2 Mbps
E2-8 Mbps
E3-34 Mbps
E4-140 Mbps
E5-565 Mbps
f) SDH Transmission rates
STM-1-155.52 Mbps
STM-4-622.08 Mbps
STM-16-2488.32 Mbps
STM-64-9953.28 Mbps

Figure : Microwave Link Traffic

PCM Planning;
1) PCM planning is basically Capacity, Equipment & Network Topology planning.
2) Information required for PCM planning
a) Permit blocking possibility at various interfaces
b) Location of the equipment in the site and their configurations.
c) Current traffic load in the site.
d) About the LOS between the sites.
3) Capacity of a microwave link depends on the number of E1 (2Mbps) data carried from one site to another.

Topology Planning;
For cities < 4 sites
all hops shall be in a star topology employing 16×2 radios in 1+0 configuration.

Figure : Topology Planning

For cities >5 & <8 br="br" sites="sites">All hops shall be in a star topology employing 16×2 radios in 1+0 configuration.

Figure : Topology Planning

For cities >9 till 14 sites
PDH rings are considered for cities > 9 till 14 sites.

Figure : Topology Planning

For cities >15 till 28 sites
SDH rings are considered for cities > 15 to 28 sites.

Figure : Topology Planning

For cities > 29 to 6 sites
SDH rings are considered for cities > 29to 56 sites.

Figure : Topology Planning

For cities > 57 to 110 sites

Figure : Topology Planning

BoM
1) Inputs for Transmission Planning;
Count of new town and existing towns sites and the subscribers in each site.
From the above data, the number of BSCs required is to be calculated.
The final capacity for each route or link
2)Nominal Transmission Plan
Based on the above inputs, the planner should prepare the nominal connectivity plan by plotting all the new sites on the tool and BSCs can be fixed.
After nominal connectivity plan it is known how many 7GHz/15GHz/18GHz/23GHz links are required.
Based on the above the MW requirement can be given as BoM

Equipment Requirement;
1) Indoor/Outdoor Unit Estimation
Generally one BTS gives one E1.
The microwave hop would be about 20% over the number of BTS, for upgrade, last mile connectivity.
IDU should be 30% more than no. of MW hops.
2) Metro hub Estimation
Each Metro hub can cater for one 16E1 loop.
For dimensioning assume 6 – 8 BTS per Metro hub as some BTS may have more than 1E1. The Metro hub is configured with 1 FIU and 3 RRI cards.
In case of a mixed Microwave network and if the ring origination/termination hops at the BSC/hub site are non-Nokia, then the Metro hub configuration would be 3 FIU + 3 RRI.
3)  Each hop requires one or more antennas (with cable and accessories) as per diversity/protection configuration.

Microwave Antennae Installation Tutorial

 

Microwaves;
Microwaves are electromagnetic waves with frequencies ranging from 300 MHz to 300 GHz.
Frequency bands used for Microwave transmission are 7G/8G/11G/13G/15G/18G/23G/26G/32G/38G.
It is used for transmitting and receives the signals in point-to-point communication systems.

Figure : Microwave

Microwave Link;
Microwave links is used for transmitting and Receive high data capacity .Microwave is used instead of transmission lines.

Figure : Microwave Link

Microwave Link Installation consideration;
1) Line Of Sight
2) Fresnel Zone
3) Antenna height
4) Frequency band
5) Capacity
6) Modulation
7) Polarization
8) Antenna size
9) Trans and receive level
10) Orientation angle
11) Antenna alignment
12) Installation tools
13) Installation Material

Figure : Microwave Link Installation

Calculation of antenna diameter;
Calculation shows that 90 cm antenna is required.

Figure : Antennae Diameter

Approximately Hop Distances;

Figure : Hop Distance

Microwave Communication System components;
IDU, RF Unit, ODU, Microwave Antenna, IF cable, Pole for instillation.

Figure : Components used for Instillation