3G Network Planning Study with Monte- Carlo Simulation

Transcription

1 3G Network lanning Study with Monte- Carlo Nuno Daniel Cardoso ortugal elecom S.A. 1

2 2 Overview n Objectives. n scenario description. n Load impact on coverage probability. n Noise rise limit. n Handover margin. n BS Antenna tilt angle. n BS Antenna height. n Downlink handover gain. n ilot power. n BS sector aperture. n Voice vs. video impact.

3 Objectives of the erformed Work n Study UMS cellular planning via Monte- Carlo simulation using real terrain database information. n Understand the impact of some WCDMA parameters in the system performance. n Evaluate the effects of using different services in the same cell. n Gain experience in this new technology to better predict and understand the system behavior during the deployment phase. 3

4 errain Morphology and Cells Layout 4 Jersey Island irregular terrain leads to dissimilar cell sizes.

5 arameters Assessed by arameter Default Other values Noise rise limit (db) - limit of the noise rise allowed in the system Handover margin (db) - margin related to the highest signal strength BS antenna tilt (º) - angle of the antenna down tilting BS antenna height (m) - height of the antenna from the ground Downlink soft handover gain (db) - soft handover gain in the downlink ilot power (dbm) - power of the pilot channel BS antenna aperture (º) - angle of the half power beam width 6 3 None

6 Input arameters Other simulation parameters needed for the simulator. arameter Maximum BS x power (dbm) 43 Maximum x power per connection (dbm) 35 Common channels power (dbm) 30 geographical resolution (m) 50 Value erminal background noise (dbm) -99 BS background noise (dbm) -103 Active set size 3 Orthogonality factor 0,7 6

7 Services characteristics Service/erminal ype of service Voice/ Handheld Circuit switched Bit rate (kbps) Mobile speed (km/h) Downlink Eb/No required (db) Uplink Eb/No required (db) Downlink activity factor Uplink activity factor Maximum mobile power (dbm) Mobile dynamic range (db) ower control step size (db) 1 1 Required Ec/Io (db) kbps/da video Circuit switched 7

8 Load Impact on Coverage robability (I) Noise rise limit = 6 db Handover margin = 6 db BS antenna tilt = 0º BS antenna height = 25 m DL soft handover gain = 2 db ilot power = 30 dbm BS antenna aperture = 85º 8

9 Load Impact on Coverage robability (II) n Load impacts on the coverage area (cell breathing effect). n Increasing the traffic density deteriorates the QoS. n Cell load depends of the cell captured traffic (uniformly distributed). n Large cells experience worse coverage probability (they serve more traffic). 9

10 Noise Rise Limit Variation (I) 10 Uplink transmitted power Handover margin = 6 db BS antenna tilt = 0º BS antenna height = 25 m DL soft handover gain = 2 db ilot power = 30 dbm BS antenna aperture = 85º

11 Noise Rise Limit Variation (II) n Increasing the noise rise limit increases the maximum allowed interference in the cell. n More interference allowed means more capacity, but on the other hand it also means less system stability. n he consideration of no noise rise limit leads to the exclusion of terminals due to uplink and/or downlink low level of Eb/No. 11

12 Handover Margin Variation (I) 12 Soft Handover robability Noise rise limit = 6 db BS antenna tilt = 0º BS antenna height = 25 m DL soft handover gain = 2 db ilot power = 30 dbm BS antenna aperture = 85º

13 Handover Margin Variation (II) 13 n he handover margin has a direct impact on the number of terminals in soft/softer handover. n Larger handover regions result in less average transmission power. n Downlink soft/softer handover consequences: l Increases the number of connections. l Leads to a potential increase in the interference (depending on the radio channel status and diversity gain). l Leaves less power 3G Network available lanning Study to with other Monte-Carlo channels.

14 BS Antenna ilt Angle Variation (I) 14 ilot Ec/Io Noise rise limit = 6 db Handover margin = 6 db BS antenna height = 25 m DL soft handover gain = 2 db ilot power = 30 dbm BS antenna aperture = 85º

15 BS Antenna ilt Angle Variation (II) 15 n he antenna tilting angle affects the signal path loss. n Increasing the down tilting angle decreases the interference area. It also leads to an average decrease on the Ec level, resulting in an overall decrease of Ec/Io. n he uplink transmitted power increases in average with the increase of the tilt angle. n he softer handover region increases and the soft handover region decreases.

16 BS Antenna Height Variation (I) 16 Uplink transmitted power Noise rise limit = 6 db Handover margin = 6 db BS antenna tilt = 0º DL soft handover gain = 2 db ilot power = 30 dbm BS antenna aperture = 85º

17 BS Antenna Height Variation (II) n Similar effects as experienced for the tilt angle variations. n he impact is more dependent on the terrain profile. n Lower antenna heights lead to larger softer handover regions. 17

18 Downlink Handover Gain Variation (I) 18 Downlink Eb/No failure probability Noise rise limit = 6 db Handover margin = 6 db BS antenna tilt = 0º BS antenna height = 25 m ilot power = 30 dbm BS antenna aperture = 85º

19 Downlink Handover Gain Variation (II) n Directly affects the downlink performance. n Higher gains allow less downlink average transmission power, leading to more available resources to other channels. 19

20 ilot ower Variation (I) 20 ilot Ec/Io Noise rise limit = 6 db Handover margin = 6 db BS antenna tilt = 0º BS antenna height = 25 m DL soft handover gain = 2 db BS antenna aperture = 85º

21 ilot ower Variation (II) n he pilot power level sets cell coverage area. n It affects directly the Ec/Io level. n If more power is allocated to this channel less power is available for traffic channels. n Higher pilot powers result in higher interference levels. 21

22 BS Sector Aperture Variation (I) 22 Softer Handover robability Noise rise limit = 6 db Handover margin = 6 db BS antenna tilt = 0º BS antenna height = 25 m DL soft handover gain = 2 db ilot power = 30 dbm

23 BS Sector Aperture Variation (II) n he radiation pattern depends on the antenna type and characteristics. n A wider sector aperture allows larger softer handover regions. n Larger apertures increase the interference level. 23

24 Voice vs Video Service (I) Uplink ransmitted ower 24

25 Voice vs Video service (II) ilot Ec/Io 25

26 Conclusions (I) n Coverage quality depends of traffic density. n Higher noise rise limit allows more capacity but also more interference. n Increasing the handover margin reduces the transmission power but increases downlink resources utilization and the interference. n he antenna tilting and height define Ec/Io level and the interference captured. 26

27 Conclusions (II) 27 n he cell size is defined by the pilot power that also causes interference. n he downlink handover gain mirrors the advantages of soft/softer handover. n he antenna sector aperture sets the captured interference and softer handover area. n For the same cell total throughput, the video service produces less interference than voice but the terminals transmitted power is considerably higher.

28 hank you for your attention! 28