RND Guidelines900-1800
-
Upload
jean-hakim -
Category
Documents
-
view
224 -
download
1
Transcript of RND Guidelines900-1800
-
8/3/2019 RND Guidelines900-1800
1/19
1
5/2/2012
Radio NW Design
Guidelines GSM900
Link Budget & Coverage Thresholds
-
8/3/2019 RND Guidelines900-1800
2/19
2
5/2/2012
Agenda
Equipment Characteristics
Cell Coverage Definition
Margins
Design Levels
Coverage acceptance tests
Cell Planning
Propagation Model Power Budget
Power Balance
Cell Size
-
8/3/2019 RND Guidelines900-1800
3/19
3
5/2/2012
Site Equipment
Base StationMaximum Range Standard High Capacity
Max Output power Hybrid comb Filter comb
46.5 dBm 41.5 dBm 44.5 dBm
2 TRU/ant 4 TRU/ant Up to 12 TRU/ant
Mobile Station
MS power class Output power [dBm] Sensitivity [dBm]
2 39 -106
3 37 -106
4 33 -104
5 29 -104
-
8/3/2019 RND Guidelines900-1800
4/19
4
5/2/2012
Site Equipment
Base Station Antenna
Mobile Station Antenna
-
8/3/2019 RND Guidelines900-1800
5/19
5
5/2/2012
Apart from feeders, additional losses arise in jumpers and connectors
Typical values are 0.5 dB for every jumper and 0.1 dB per connector
Site Equipment
Feeders & jumpers
External Diplexer 0.3 dB
-
8/3/2019 RND Guidelines900-1800
6/19
6
5/2/2012
Additional losses to be accounted for include body loss,interference loss, & Rayleigh fading
Cell Coverage
When planning the coverage of a cell it is not sufficient toconsider the MS/BTS sensitivity as planning criterion
-
8/3/2019 RND Guidelines900-1800
7/19
7
5/2/2012
Cell Coverage
Design levels are chosen according to the environment andclutter type
-
8/3/2019 RND Guidelines900-1800
8/19
8
5/2/2012
Cell Coverage
Apart from fast fading, the signal fluctuates in a way that deviatesfrom the global mean according to a normal distribution, thuscalled Log-Normal distribution
-
8/3/2019 RND Guidelines900-1800
9/19
9
5/2/2012
Cell Coverage
-
8/3/2019 RND Guidelines900-1800
10/19
11
5/2/2012
Cell Coverage
Log Normal fading margins for indoor environments
LNF(o+i) = (LNF(o)2 +LNF(i)2)
For Indoor coverage:
http://coverage-cellsize.xls/ -
8/3/2019 RND Guidelines900-1800
11/19
12
5/2/2012
Cell Coverage
Coverage Acceptance Tests
The aim of such tests is to measure signal strength (SS) and estimatewhether the received signal corresponds to requiredSS
Note that power control downlink should be switched off during test
Make sureyou drivetest withpowercontrol
off
-
8/3/2019 RND Guidelines900-1800
12/19
13
5/2/2012
Cell Planning
Propagation model
The standard model is Okumura Hata model:
Lb = 69.55 + 26.16 logf13.82 logHBa(HM) + (44.96.55 logHB) log d
Valid for: 150 f 1500 MHz
HB = base station antenna height [m]
1 d 20 km R = distance from transmitter [km]
30 hb 200 m HM = mobile station antenna height [m]
1 hm 10 m a(HM) = 3.2(log11.75HM)2 - 4.97; a (1.5) = 0
The cell range is the distance R corresponding to maximum allowed pathloss Lpathmax:
R = 10^a, where a = [Lpathmax - Kr + 13.82logHB + a(HM)]/[44.9 - 6.55logHB]
-
8/3/2019 RND Guidelines900-1800
13/19
14
5/2/2012
-
8/3/2019 RND Guidelines900-1800
14/19
15
5/2/2012
Cell Planning
Propagation model
For Urban cells (range less than 1km), COST 231 model is used:
Lpath = 143.2 + 38logR18log(HB 17) [dB]
According to Walfish-Ikegami, the cell range is :
R = 10^a, where a = [Lpathmax - 143.2 + 18log(HB17)]/38
-
8/3/2019 RND Guidelines900-1800
15/19
16
5/2/2012
Cell Planning
Power Budget
Power budget calculates how much power enters a receiver from
a set output power at the transmitter
DL: PinMS = PoutBTS Lf+jLTMA + GantLslantLpath
UL: PinBTS = PoutMS Lpath + Gant + Gdiv Lf+j
-
8/3/2019 RND Guidelines900-1800
16/19
17
5/2/2012
TMA case
Assuming path loss on uplink equals path loss on downlink :
PoutBTS
= PoutMS
+ Gdiv
+ Lf+j
+ LTMA
+ Lslant
+ PinMS
- PinBTS
Cell Planning
Power Balance
When uplink is stronger, the output power of the BTS should be set to maximum. If downlink
is stronger then BTs output power should be adjusted to calculated balanced output power.
sens= Mssens BTSsens= PinMS PinBTS
Path balance implies that
the coverage on uplink path is
equal to coverage on the
downlink path
-
8/3/2019 RND Guidelines900-1800
17/19
18
5/2/2012
Cell Planning
Power Balance
No TMA case
PoutBal = PoutMS + Gdiv + Lslant + sens
The corresponding EIRP is calculated as:
EIRP = PoutBal- Lf+j + Gant- Lslant
http://thingstodo/PBalanceb1.xls -
8/3/2019 RND Guidelines900-1800
18/19
19
5/2/2012
Cell Planning
Cell Size
R = 10^ ,
where = [LpathmaxA + 13.82logHB + a(HM)]/[44.96 .55logHB]
Lpathmax = EIRP
SSdesign
-
8/3/2019 RND Guidelines900-1800
19/19
20
5/2/2012
Questions & Answers