Primary (PSC) Planning Strategy

PREPARED BY PREPARED BY PREPARED BY PREPARED BY ERICSSON RNO TEAM ERICSSON RNO TEAM ERICSSON RNO TEAM ERICSSON RNO TEAM DATE: 21DATE: 21DATE: 21DATE: 21stststst Dec 2010Dec 2010Dec 2010Dec 2010

Ericsson RND | Primary (PSC) Planning Strategy | © Ericsson AB 2010 | 2010-12-21 | Page 2

Agenda

› Introduction

– PSC Planning Strategy

– PSC Group

– PSC Table

– Impact of poor planning

› Current PSC Planning

– Current PSC Planning – Issue Example

› Recommended PSC Planning

› Future PSC Fine Tuning

– Methodology / Optimize PSC Planning.

Introduction

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PSC Planning Strategy

› Primary Scrambling Codes (PSC) are consisting of 512 codes which are from 0 to 511,

each code is unique and this is needed to separate terminals or base stations from each other.

› There are many ways to plan PSC’s. However, the most important factors of PSC planning are consistency, follow pattern and allow for future growth.

› Below is the typical SC planning strategy:

• 8 Color Groups (CG – Clusters)

• 64 PSC per color group

• Maximum number of sites per cluster is 21, with each site having 3 sectors

• One color group is reserved to special events, new sites, IBS and high sites

• Cluster reuse pattern is 1/7

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PSC Group

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PSC table

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Impact of poor planning

› Poor PSC planning will result in the followings

– Intercell PSC Clash

› Meaning the source cell and one of the NBs cell are having the same PSC

– One-Way PSC Clash

› Meaning 2 or more NBs in the same source cell are having the same PSC

– Two-Way PSC Clash

› Meaning call in 2-way SHO and NBs of each 2 active set are having the same PSC

› Any of the above will result in 50/50 chance of drop call

› This will have impact to both CS and PS service.

Current PSC Planning

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Current PSC Planning – Issue example

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Current PSC Planning – Issue example (cont’d)

Example Co-PSC:1

1.9 km

2.4 km

Recommended PSC Planning

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Ericsson Site-PSC DesignMacro Site PSC IBS Site PSC

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Ericsson CELL-PSC DesignMacro Cell PSC IBS Cell PSC

› With this method, we can see the followings

– Systematic and clear PSC Pattern

– Consistency

Future PSC Fine Tuning

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Methodology / Optimize PSC Planning

› As more site integrated to the network, it is necessary to fine-tune the PSC

planning.

– This can be done by either temporary solving the clash or re-create the new PSC.

› In order to sufficient solving PSC issue. The followings critical information is

required

– Site to Site Distance

– Site Status (On-Air / Off-Air)

– Handoff Attempt (need to be collected minimum 3 days, ideally 1 week)

› Network Counter

› WNCS Data

› GPEH Data

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