12. initial parameter planning

1 © Nokia Siemens Networks Presentation / Author / Date

Initial parameter planningMODULE 12

PRE-PLANNING

DETAILED PLANNING

Propagation measurementsCoverage prediction

Load estimationTraffic distributionPlanned Service and QoS definition

Post-launch optimisation

Measurement surveys

Statistical performance analysis

Quality Efficiency Availability

POST-PLANNING

Coverage and Capacity Planning

Dimensioning

Requirements and strategy for coverage, capacity and quality

PER SERVICE

Network configuration

Pre-launch optimisation

Measurements

ConfigurationPlanningConfigurationPlanning

Node-B Configuration

Antenna line configuration

Power budget

PER SERVICE

Site selection and planning

Site acquisition

Parameter Planning

Area/cell specific

Handover strategies

Other RRM


Dimensioning process

Objectives

After this module the participant shall be able to:-

•Understand main principles of scrambling code

planning

•Understand main principles of neighbour planning in

3G


Module Contents

• Scrambling code planning

• Neighbour planning principles


Module Contents


• Neighbour planning principles


Scrambling code

• Each cell within the radio network plan have to be assigned a primary scrambling code

• The 512 downlink primary scrambling codes are organised into 64 groups of 8

• Group 0 = SC 0…7

• Group 1 = SC 8…15

• …

• Group 63 = SC 504…511


Scrambling code planning rules

• Main target to achieve sufficient isolation between cells which are assigned the same scrambling code

• Ensure that a UE never simultaneously receives the same scrambling code from more than a single cell

• UE never receives a scrambling code from one cell while it is expecting to receive the same scrambling code from second cell

• SHO failures

• Scrambling code planning may require co-ordination at international borders

• Scrambling code planning can be completed independently for each RF carrier

• An important part of scrambling code planning is to perform checks that neighbour lists do not include duplicate scrambling codes

• Measured (neighbour) cell is identified by the scrambling code only


Scrambling code planning strategies

• Scrambling code planning strategies• Maximise the number of neighbours belonging to the same code group

• Maximise the number of neighbours belonging to different code groups

• Possible effect on cell synchronisation procedure• During cell selection, cell re-selection and soft handover

• The difference is likely to be dependant upon the UE implementation


Example – SC plan for ROC configuration

• Strategy: Maximise the number of neighbours belonging to the same code group• When upgrade ROC Node B CEC Node B

• Additional four scrambling codes from each group• Two SCs for future expansion

Group 0

Group 2

Group 3

Group 4

Group 1

sc32

sc33

sc17

sc16

sc25

sc24

sc8

sc9

sc0sc1

Group 0

Group 2

Group 3

Group 4

Group 1

sc32

sc33

sc17

sc16

sc25

sc24

sc8

sc9

sc0sc1


Scrambling code planning methods

• Using a radio network planning tool• NetAct Planner is able to plan scrambling codes according to a specific

strategy

• Using a ‘home-made’ tool

• Manually• For small areas (e.g. less tan 30 sites)

• Consideration should be given to moving the scrambling code plan to and from the live network


Module Contents


• Neighbour planning principles• 3G Intra-frequency neighbour list planning

• 3G Inter-frequency neighbour list planning

• 2G neighbour list planning


Neighbour planning and planning process

• In general it is recognised that high quality neighbour lists are critical to the performance of the network

• It is often assumed that neighbour lists will be refined during pre-launch or post-launch optimisation

• Initial neighbour list planning does not have to be very accurate

• Impact upon pre-launch optimisation have to be recognised

• Pre-launch optimisation is usually limited to a specific drive route• Neighbours which are required away from the drive route must be identified

during the planning process

• It is difficult to generate ideal neighbour lists during the neighbour list planning because of differences between predicted and actual propagation

• Pre-launch or post-launch optimisation required


Module Contents






3G Intra-frequency neighbour list

• 3G intra-frequency neighbour list planning is absolutely critical to network performance

• 3G intra-frequency neighbours are used for intra-frequency cell re-selection, softer handover, soft handover and intra-frequency hard handover

• Excessive neighbours increase the UE measurement time and may lead to important neighbours being deleted during soft handover

• Specification allows the network to specify a maximum of 32 intra-frequency cells for the UE to measure

• Serving cell + 31 Intra-frequency neighbours when not in soft handover

• 2-3 serving cells + 30-29 neighbours in soft handover

• Missing neighbours result in unnecessarily poor signal to noise ratios


Neighbour planning tools

• Neighbour list planning can be completed using • Planning tool, e.g. Netact Planner which utilises

• Propagation predictions• Minimum CPICH Ec/Io requirements• Inter-cell interference• Maximum allowed neighbour list size

• A ‘home-made’ tool• Make use of distance and antenna azimuth rather than path loss

• Using the 2G neighbour plan • In networks which are primarily co-sited with existing 2G sites

• Manually• Small networks (e.g. less than 30 sites)

• Intra-frequency neighbour lists should always be generated such that every neighbour relationship is bi-directional


Module Contents






3G Inter-frequency neighbour list

• Inter-frequency neighbours are used for inter-frequency cell re-selection and inter-frequency handover.

• The Nokia RNC allows a maximum of 48 inter-frequency neighbours to be defined with a maximum of 32 on any one RF carrier.

• The Nokia RNC instructs the UE to measure neighbours from one RF carrier at a time for inter-frequency hard handover.

• Missing neighbours result in potentially failed inter-frequency hard handovers and cell re-selections

• Do not generate the high levels of interference which are associated with missing intra-frequency neighbours

• Excessive neighbours increase the UE measurement time and may lead to important neighbours being deleted during soft handover.


3G Inter-frequency neighbour planning

• Same tools can be used as with intra-frequency neighbour planning

• Inter-frequency neighbour plan can be based upon the existing intra-frequency neighbour plan

• If the second RF carrier is being introduced subsequent to network launch

• The intra-frequency neighbour plan should have already been tuned during pre-launch and post-launch optimisation

• The second or third RF carrier is typically introduced at traffic hotspots• Part of the capacity upgrade process

• Upgrading a relatively small number of sites, or small clusters of sites

• The inter-frequency neighbour lists can be generated manually from the existing intra-frequency neighbour lists


Module Contents






2G neighbour list

• GSM neighbours are used for inter-system cell re-selection and inter-system handover.

• 3GPP specifications and the Nokia RNC allow a maximum of 32 inter-system neighbours to be defined

• Missing neighbours result in potentially failed inter-system handovers and cell re-selections

• Do not generate the high levels of interference which are associated with missing intra-frequency neighbours

• Excessive number of neighbours increase the UE measurement time and may lead to important neighbours being deleted during soft handover

• If an operator has both GSM900 and DCS1800 networks then it is possible to define inter-system neighbours only for the GSM900 layer or only for the DCS1800 layer


2G neighbour list planning

• Inter-system neighbour list planning can be completed using a planning tool or using a ‘home-made’ tool

• UE requires only one good 2G neighbour in each location of the cell coverage

• If 3G sites are co-sited with 2G sites then GSM neighbour lists configured within the RNC can be based upon those configured within the BSC


Module 12 – Initial parameter planning

Summary

•Main target of the scrambling code planning is to

achieve sufficient isolation between cells which are

assigned the same scrambling code

•High quality neighbour lists are critical to the

performance of the network

12. initial parameter planning

Documents

g neighbour list planning

planning process

neighbour cell

planning site acquisition

duplicate scrambling

ideal neighbour lists

g intrafrequency neighbours

high quality neighbour