zgo-05!02!009 concentric circle technology feature guide zxg10-ibsc (v12.2.0)20131225

ZGO-05-02-009 Concentric

Circle Technology

Feature Guide

ZGO-05-02-009 Concentric Circle Technology

ZTE Confidential Proprietary 1


Version Date Author Reviewer Notes

V1.0 2013/04/23 Ding Jie

GU Commercial

System Supporting

Dept.

Not open to the third party

V1.1 2013/12/25 Chen

Xiangliu Gu Yuhui Modify the BTS version in Section 1.

© 2013 ZTE Corporation. All rights reserved.

ZTE CONFIDENTIAL: This document contains proprietary information of ZTE and is not to be disclosed or used

without the prior written permission of ZTE.

Due to update and improvement of ZTE products and technologies, information in this document is subjected to

change without notice.


2 ZTE Confidential Proprietary

TABLE OF CONTENTS

1 Feature Attribute ............................................................................................... 6

2 Overview ............................................................................................................ 6

2.1 Feature Introduction ............................................................................................. 6

2.2 License Control .................................................................................................... 7

2.3 Correlation with Other Features ........................................................................... 7

3 Technical Description ....................................................................................... 7

4 Parameters and Configurations ..................................................................... 11

4.1 Parameter List ................................................................................................... 11

4.2 Parameter Configuration .................................................................................... 12

4.2.1 SubCell ID.......................................................................................................... 12

4.2.2 Frequency Band of Sub-cell ............................................................................... 12

4.2.3 Sub-cell Handover Algorithm (High Speed) ........................................................ 13

4.2.4 Sub-cell Handover Algorithm (Middle Speed) ..................................................... 13

4.2.5 Sub-cell Handover Algorithm (Low Speed)......................................................... 14

4.2.6 The MAX Value of Path Loss of Inter-Sub-Cell Handover .................................. 14

4.2.7 The Min Value of Path Loss of Inter-Sub-Cell Handover .................................... 14

4.2.8 The MAX of Time Advance of Inter-Sub-Cell Handover ..................................... 15

4.2.9 The MIN of Time Advance of Inter-Sub-Cell Handover ...................................... 15

4.2.10 N Value of Sub-Cell Handover ........................................................................... 16

4.2.11 P Value of Sub-Cell Handover ........................................................................... 16

4.2.12 Inter Site Handover to SubCell2 Permitted ......................................................... 17

4.2.13 Measure BCCH When in Sub-Cell2 ................................................................... 17

4.2.14 Good C/I ............................................................................................................ 18

4.2.15 P Value to Judge GOOD C/I .............................................................................. 19

4.2.16 N Value to Judge GOOD C/I .............................................................................. 19

4.2.17 BAD C/I .............................................................................................................. 19

4.2.18 P Value to Judge Bad C/I ................................................................................... 20

4.2.19 N Value to Judge BAD C/I .................................................................................. 21

5 Related Counters and Alarms ........................................................................ 21

5.1 Related Counters ............................................................................................... 21

5.2 Related Alarms .................................................................................................. 29

6 Engineering Guide .......................................................................................... 29

6.1 Application Scenario .......................................................................................... 29

6.2 Configuration Description ................................................................................... 29

6.3 Feature Validation .............................................................................................. 32



6.3.1 CS on subcell1 and subcell2 .............................................................................. 32

6.3.2 Cell reselection between Co-BCCH ................................................................... 33

6.3.3 Handover between subcell1 and subcell2 .......................................................... 34

6.4 Feature Turn off ................................................................................................. 34

6.5 Network Impact .................................................................................................. 34

7 Abbreviation .................................................................................................... 35

8 Reference Document ....................................................................................... 36



FIGURES

Figure 6-1 Creation Interface of Cell Configuration ...............................................................30

Figure 6-2 Check Interface of Sub-cell Configuration 1 .........................................................30

Figure 6-3 Creation Interface of Sub-cell Configuration 2 .....................................................31

Figure 6-4 TRX Creation Interface of Sub-cell ......................................................................31

Figure 6-5 Sub-cell Handover Parameters ............................................................................32

TABLES

Table 4-1 Parameter List ......................................................................................................11

Table 4-2 Configuration rule of Subcell ID ............................................................................12

Table 4-3 Configuration rule of f Frequency Band of Subcell ................................................12

Table 4-4 Configuration rule of Sub-cell Handover Algorithm (High Speed) ..........................13

Table 4-5 Configuration rule of Sub-cell Handover Algorithm (Middle Speed) ......................13

Table 4-6 Configuration rule of Sub-cell Handover Algorithm (Low Speed) ..........................14

Table 4-7 Configuration rule of The MAX Value of Path Loss of Inter-Sub-Cell Handover ....14

Table 4-8 Configuration rule of The MIN Value of Path Loss of Inter-Sub-Cell Handover .....14

Table 4-9 Configuration rule of The MAX of Time Advance of Inter-Sub-Cell Handover .......15

Table 4-10 Configuration rule of The MIN of Time Advance of Inter-Sub-Cell Handover ......15

Table 4-11 Configuration rule of N Value of Sub-Cell Handover ...........................................16

Table 4-12 Configuration rule of P Value of Sub-Cell Handover ...........................................16

Table 4-13 Configuration rule of Inter Site Handover to SubCell2 Permitted .........................17

Table 4-14 Configuration rule of Measure BCCH When in Sub-Cell2 ...................................17

Table 4-15 Configuration rule of Good C/I ............................................................................18

Table 4-16 Configuration rule of P Value to Judge GOOD C/I ..............................................19

Table 4-17 Configuration rule of N Value to Judge GOOD C/I ..............................................19

Table 4-18 Configuration rule of BAD C/I..............................................................................19



Table 4-19 Configuration rule of P Value to Judge Bad C/I ...................................................20

Table 4-20 Configuration rule of N Value to Judge BAD C/I .................................................21

Table 5-1 Counters list .........................................................................................................21



1 Feature Attribute

BSC Version: [ZXG10-iBSC GSM (V6.30.102)]

BTS Version: [Unrelated with BTS version ]

Property: [Optional]

Related Network Element:

NE Name Related or Not Special Requirements

MS -

BTS √

BSC √

MSC -

MGW -

SGSN -

GGSN -

HLR -

Dependent Function: [None]

Exclusive Function: [None]

Note: [There are special requirements on CN or other NEs]

2 Overview

2.1 Feature Introduction

During the mobile telecommunication development, in medium- and large-sized

cities, especially in downtown districts, network suffers heavy congestion; conflict

between user number and frequency resources becomes increasingly fierce. BTSs

in the areas are relatively concentrated, which makes it difficult to construct new

stations. Some new technologies are imperatively to be developed. The concentric



circle technology solved the problem well. It selects the best inner cell radius and

adopts the closer multiplexing mode, improving channel utilization, optimizing

system capacity and alleviating intra-network interference.

To reduce the co-frequency and adjacent frequency interference brought by

improving frequency multiplexing ratio, concentric circle technology controls the

transmit control. It also effectively resolves the near-far effect at cell edge. While

enhancing coverage, the intelligent concentric circle technology can improve

spectrum utilization.

2.2 License Control

None license control for this feature in UR12 Release.

2.3 Correlation with Other Features

This feature is functionally related to the following features:

ZGO-04-02-001 Dynamic BTS Power Control

ZGO-04-02-002 Dynamic MS Power Control

The specific descriptions are as follows:

Relation with Power Control: Power control’s target range shall not conflict with

handover decision algorithm’s threshold of this feature. Power control takes

precedence over the handover decision. That is, perform power control first, if it fails,

execute handover.

3 Technical Description

The concentric circle divides a common cell into two layers: Outer layer and inner

layer.



Subcell 1

Subcell2

The coverage area of outer layer (namely the sub-cell 1) is the same with that of

conventional cells. It provides common channels (BCCH and CCCH) and carries

peripheral traffic of BTS. The inner layer (namely the sub-cell 2) covers areas around

BTS and carries large traffic around BTS. BSC decides whether the MS adopts

resources of inner or outer layer by calculating the signal level and quality in the

measurement report. Outer and inner layers have a co-location site and share the

same BCCH. And the frequency and transceiver of cell are two independent systems,

BCCH must be configured at outer layer.

Inter-sub-cell handover can be based on path loss and TA or CI. Path loss- and

TA-based handover can be applied in dual-band networking, extension cell or concentric

circle cell; CI-based handover can be used in concentric circle cell (sub-cells must have

the same band). When both of handover methods are available, ping-pong handover

might occur. Therefore, if cell with sub-cell configured supports both of handover

methods, it can only select one method.

1) Path loss- and TA-based handover

A) When current MS is in sub-cell 1,

Decision criterion formulas (1) and (2) simultaneously

nPathLossMi (n) PathLoss

(1)



inSubCellTAM TA(n)

(2)

In formula (1), PathLoss indicates the path loss (calculated by formula (3)), and

PathLossMin indicates the path loss threshold for handover from sub-cell 1 to

sub-cell 2; In formula (2), TA(n) indicates the current TA vale, and Sub-cellTAMin

indicates the TA threshold for handover from sub-cell 1 to sub-cell 2.

PathLoss is calculated by following formula:

PathLoss = BSTXPWR – AvRxLevDL (3)

Where, BSTXPWR refers to the actual transmit power of BTS; AvRxLevDL refers to the

current DL average level. BSTXPWR is calculated by following formula:

BSTXPWR = PowerClass + 110 - 2*PwrReduction - 2*BSPower (4)

Where, PowerClass means the transmit power level of TRX, which can be acquired from

TRXType message in instance data measurement report; PwrReduction means the

static adjustment power level of TRX; BSPower means the dynamic adjustment power

level of TRX; 110 is the adjustment value of DBS and background.

The triggering conditions are as follows:

If current MS having an ongoing call is located in sub-cell 1, and TA ≤ Sub-cellTAMin

threshold, and path loss calculated by DL level ≤ PathLossMin threshold, Sub-cellP

in Sub-cellN satisfy the formula, and MS supports sub-cell 2 band, handover is

decided and the call is handed over to sub-cell 2.

B) When current MS is in sub-cell 2,

Decision criterion formulas (5) or (6):

xPathLossMa (n) PathLoss

(5)

axSubCellTAM TA(n)

(6)




If Sub-cellP PathLoss and TA of Sub-cellN satisfy the above formulas, handover is

decided and the call is handed over from sub-cell 2 to sub-cell 1. In formula (5),

PathLossMax indicates the path loss threshold for handover from sub-cell 2 to sub-cell 1;

In formula (6), Sub-cellTAMax is the TA from sub-cell 2 to sub-cell 1.

2) C/I handover

A) When current MS is in sub-cell 1,

If C/I value is relatively big, the calling radio link has better signals. In this case, the call

can be handed over to sub-cell 2 to absorb traffics.

Decision criterion formulas (7):

GoodCiThs CI(n)

(7)

Where, the C/I (calculated by formula (8)) is acquired from the DL level (not the

average value after being averaged) of the latest measurement report; GoodCiThs is

the C/I threshold during handover from sub-cell 1 to sub-cell 2.

CI = AvRxLevDL +2*BSPower - interfLevel (8)

Among which, avRxLevDL is the average value of DL level; BSPower is the BS

power.


If C/I≥GoodCiThs, GoodCiP of GoodCiN satisfy the formula (8), and MS supports

sub-cell 2 band, handover is decided handover is decided and the call is handed over to

sub-cell 2.

B) When current MS is in sub-cell 2,

If C/I value is relatively small, the calling radio link has poor signals. In this case, the call

can be handed over to sub-cell 2 to avoid call drop.

Decision criterion formulas (9):



BadCiThsCI(n)

(9)


If BadCiP of BadCiN satisfy the formula (9), C/I handover is decided, and the call is

handed over from sub-cell 2 to sub-cell 1. Amongwhich, BadCiThs is the path loss

threshold during handover from sub-cell 1 to sub-cell 2.

4 Parameters and Configurations

4.1 Parameter List

Table 4-1 Parameter List

SN Name Figure

1 Sub-cell ID Figure 6-3

2 Frequency Band of Subcell Figure 6-3

3 Subcell handover aigorithm(HighSpeed) Figure 6-5

4 Subcell handover aigorithm(MilddleSpeed) Figure 6-5

5 Subcell handover aigorithm(LowSpeed) Figure 6-5

6 The MAX of path loss Figure 6-5

7 The MIN of path loss Figure 6-5

8 The MAX of time advance Figure 6-5

9 The MIN of time advance Figure 6-5

10 N value of Subcell handover Figure 6-5

11 P value of Subcell handover Figure 6-5

12 Inter Site handover to Subcell2 permitted Figure 6-5

13 Measure BCCH when in subcell2 Figure 6-5

14 GOOD C/I Figure 6-5

15 GOOD value P Figure 6-5

16 GOOD value N Figure 6-5

17 BAD C/I Figure 6-5



18 BAD value P Figure 6-5

19 BAD value N Figure 6-5

4.2 Parameter Configuration

4.2.1 SubCell ID

Table 4-2 Configuration rule of Subcell ID

Full name Subcell ID

Abbreviation Subcell ID

Description

For a dual-band cell, this parameter describes which sub-cell the

TRX belongs to. For a non-dual-band cell, this parameter is set as

the sub-cell 1. This parameter cannot be modified after the sub-cell

is created.

If concentric circle cell is enabled, set this parameter according to

actual requirement.

Managed object Sub-cell

Value range When it is 1, the value range is the sub-cell 1;

When it is 2, the value range is the sub-cell 2.

Unit NA

Default value no

4.2.2 Frequency Band of Sub-cell

Table 4-3 Configuration rule of f Frequency Band of Subcell

Full name Frequency Band of Sub-cell

Abbreviation Frequency Band of Sub-cell

Description


actual requirement, usually, the sub-cell 1 and 2 select the same

band.

Managed object Sub-cell



Value range

When the value of DCS1800/PCS1900 supported (FuncExt) is

DCS1800, the value range is GSM900, EXT900, DCS1800 and

GSM850.

Unit NA

Default value GSM900M

4.2.3 Sub-cell Handover Algorithm (High Speed)

Table 4-4 Configuration rule of Sub-cell Handover Algorithm (High Speed)

Full name Sub-cell Handover Algorithm (High Speed)

Abbreviation Sub-cell Handover Algorithm (High Speed)

Description This parameter selects the handover algorithm for sub-cell in high

speed place.

Managed object Sub-cell handover

Value range Handover algorithm based on concentric circle (0)

Handover algorithm based on Path Loss and TA (1)

Unit NA

Default value 1

4.2.4 Sub-cell Handover Algorithm (Middle Speed)

Table 4-5 Configuration rule of Sub-cell Handover Algorithm (Middle Speed)

Full name Sub-cell Handover Algorithm (Middle Speed)

Abbreviation Sub-cell Handover Algorithm (Middle Speed)

Description This parameter selects the handover algorithm for sub-cell in

middle speed place.




Unit NA

Default value 1



4.2.5 Sub-cell Handover Algorithm (Low Speed)

Table 4-6 Configuration rule of Sub-cell Handover Algorithm (Low Speed)

Full name Sub-cell Handover Algorithm (Low Speed)

Abbreviation Sub-cell Handover Algorithm (Low Speed)

Description This parameter selects the handover algorithm for sub-cell in low

speed place.




Unit NA

Default value 1

4.2.6 The MAX Value of Path Loss of Inter-Sub-Cell Handover

Table 4-7 Configuration rule of The MAX Value of Path Loss of Inter-Sub-Cell Handover

Full name The MAX Value of Path Loss of Inter-Sub-Cell Handover

Abbreviation The MAX of path loss

Description

It is one of sub-cell handover parameters, indicating the threshold

of handover from sub-cell 2 towards sub-cell 1 due to path loss.


actual requirement.


Value range 0 ~ 150

Unit dB

Default value 126

4.2.7 The Min Value of Path Loss of Inter-Sub-Cell Handover

Table 4-8 Configuration rule of The MIN Value of Path Loss of Inter-Sub-Cell Handover

Full name The MIN Value of Path Loss of Inter-Sub-Cell Handover

Abbreviation The MIN of path loss



Description

It is one of the sub-cell handover parameters, indicating the

minimum path loss. If byPathLoss ≤ PathLossMin and TA ≤

SubCellTAMin, the sub-cell 2 channel will be selected first; if

byPathLoss > PathLossMin or TA > SubCellTAMin, only the

channel of the sub-cell 1 is available.


actual requirement.


Value range 0 ~ 150

Unit dB

Default value 120

4.2.8 The MAX of Time Advance of Inter-Sub-Cell Handover

Table 4-9 Configuration rule of The MAX of Time Advance of Inter-Sub-Cell Handover

Full name The MAX of Time Advance of Inter-Sub-Cell Handover

Abbreviation The MAX of time advance

Description


threshold of handover from sub-cell 2 towards sub-cell 1 due to

TA.


actual requirement.


Value range 0 ~ 63

Unit NA

Default value 1

4.2.9 The MIN of Time Advance of Inter-Sub-Cell Handover

Table 4-10 Configuration rule of The MIN of Time Advance of Inter-Sub-Cell Handover

Full name The MIN of Time Advance of Inter-Sub-Cell Handover

Abbreviation The MIN of time advance



Description


threshold of handover from sub-cell 1 towards sub-cell 2 due to

TA.


actual requirement.


Value range 0 ~ 63

Unit NA

Default value 0

4.2.10 N Value of Sub-Cell Handover

Table 4-11 Configuration rule of N Value of Sub-Cell Handover

Full name N Value of Sub-Cell Handover

Abbreviation N value of Subcell handover

Description

This parameter is one of the conditions used to decide

inter-sub-cell handover. The judgment process is as follows: For

the latest N value of sub-cell handover sample average values, if

Sub-cellP (P value of sub-cell handover parameter) of the

Sub-cellN values satisfy the condition, then perform handover.


actual requirement.


Value range 1 ~ 10

Unit NA

Default value 4

4.2.11 P Value of Sub-Cell Handover

Table 4-12 Configuration rule of P Value of Sub-Cell Handover

Full name P Value of Sub-Cell Handover

Abbreviation P value of Subcell handover



Description

This parameter is one of the conditions used to decide

inter-sub-cell handover. The judgment process is as follows: For

the latest N value of sub-cell handover sample average values, if

Sub-cellP (P value of sub-cell handover parameter) of the

Sub-cellN values satisfy the condition, then perform handover.


actual requirement.


Value range 1 ~ 10

Unit NA

Default value 3

4.2.12 Inter Site Handover to SubCell2 Permitted

Table 4-13 Configuration rule of Inter Site Handover to SubCell2 Permitted

Full name Inter Site Handover to SubCell2 Permitted

Abbreviation Inter Site handover to Sub-cell2 permitted

Description

The parameter indicates whether inter-site handover to sub-cell 2

is permitted.


actual requirement.


Value range 0: Not permitted

1: Permitted

Unit NA

Default value 0: Not permitted

4.2.13 Measure BCCH When in Sub-Cell2

Table 4-14 Configuration rule of Measure BCCH When in Sub-Cell2

Full name Measure BCCH When in Sub-Cell2

Abbreviation Measure BCCH when in sub-cell2



Description

This parameter indicates whether to allow the sub-cell to enable

the BCCH measurement feature.


actual requirement.


Value range Not permitted (0)

Permitted (1)

Unit NA

Default value Not permitted (0)

4.2.14 Good C/I

Table 4-15 Configuration rule of Good C/I

Full name Good C/I

Abbreviation Good C/I

Description

If system adopts concentric circle technology to get serial average

values, it can decide whether to perform handover.

The currently good C/I value of special layer frequency is one of

causes to bring concentric circle handover. The judgment process

is as follows: The current call is on ordinary TRX (frequency point),

if P C/I of N is greater than the threshold, perform the handover

from ordinary TRX to special TRX due to Good C/I.


actual requirement.


Value range

Threshold: 0 ~255;

0: -127 dB;

1: -126 dB;

……

255: 128 dB

Unit NA

Default value 133



4.2.15 P Value to Judge GOOD C/I

Table 4-16 Configuration rule of P Value to Judge GOOD C/I

Full name P Value to Judge GOOD C/I

Abbreviation GOOD C/I value P

Description

The parameter defines relative P value of GoodCiP.


actual requirement.


Value range 1-31

Unit NA

Default value 3

4.2.16 N Value to Judge GOOD C/I

Table 4-17 Configuration rule of N Value to Judge GOOD C/I

Full name N Value to Judge GOOD C/I

Abbreviation GOOD C/I value N

Description

The parameter defines relative N value of GoodCiP.


actual requirement.


Value range 1-31

Unit NA

Default value 2

4.2.17 BAD C/I

Table 4-18 Configuration rule of BAD C/I

Full name BAD C/I

Abbreviation Bad C/I



Description

If system adopts concentric circle technology to get serial average

values, it can decide whether to perform handover.

The currently bad C/I value of special layer frequency is one of

causes to bring concentric circle handover. The judgment process

is as follows: The current call is on special TRX (frequency point),

if P C/I of N is less than the threshold, perform the handover from

speical TRX to ordinary TRX due to bad C/I.


actual requirement.


Value range

Threshold: 0 ~255;

0: -127 dB;

1: -126 dB;

……

255: 128 dB

Unit NA

Default value 130

4.2.18 P Value to Judge Bad C/I

Table 4-19 Configuration rule of P Value to Judge Bad C/I

Full name P Value to Judge Bad C/I

Abbreviation BAD C/I value P

Description

The parameter defines relative P value of BadCiP.


actual requirement.


Value range 1-31

Unit NA

Default value 3



4.2.19 N Value to Judge BAD C/I

Table 4-20 Configuration rule of N Value to Judge BAD C/I

Full name N Value to Judge BAD C/I

Abbreviation BAD C/I value N

Description

The parameter defines relative N value of BadCiP.


actual requirement.


Value range 1-31

Unit NA

Default value 2

5 Related Counters and Alarms

5.1 Related Counters

Table 5-1 Counters list

EMS Counter ID Counter Description

C901060016 Number of SDCCH handover attempts due to large TA

and wastage

C901060017 Number of SDCCH handover attempts due to small TA

and wastage

C901060039 Number of TCH/F handover attempts due to large TA

and wastage

C901060040 Number of TCH/F handover attempts due to small TA

and wastage

C901060062 Number of TCH/H handover attempts due to large TA

and wastage

C901060063 Number of TCH/H handover attempts due to small TA

and wastage

C901090108 Number of intra-cell inner-circle-to-outer-circle

handover attempts

C901090109 Number of intra-cell inner-circle-to-outer-circle



handover success

C901090110 Number of intra-cell outer-circle-to-outer-circle

handover attempts


handover success

C901090112 Number of intra-cell inner-circle-to-inner-circle

handover attempts

C901090113 Number of intra-cell inner-circle-to-inner-circle

handover success


handover attempts


handover success

C901130001 Number of available TCH/Fs in the second sub cell

C901130002 Number of unavailable TCH/Fs in the second sub cell

C901130003 Number of available TCH/Hs in the second sub cell

C901130004 Number of unavailable TCH/Hs in the second sub cell

C901130005 Number of handover attempts from the first sub cell to

the second sub cell

C901130006 Number of handover execution from the first sub cell to

the second sub cell

C901130007 Number of handover success from the first sub cell to

the second sub cell

C901130008 Number of handover attempts from the second sub cell

to the first sub cell

C901130009 Number of handover execution from the second sub

cell to the first sub cell

C901130010 Number of handover success from the second sub cell

to the first sub cell

C901130011 Number of handover attempts in the second sub cell

C901130012 Number of handover execution in the second sub cell

C901130013 Number of handover success in the second sub cell

C901130014 Number of outgoing inter-cell handover attempts of the

second sub cell

C901130015 Number of outgoing inter-cell handover execution of

the second sub cell

C901130016 Number of outgoing inter-cell handover success of the



second sub cell

C901130017 Handover attempts due to UL receiving strength of the

full rate second sub cell

C901130018 Handover attempts due to DL receiving strength of the

full rate second sub cell

C901130019 Handover attempts due to UL quality of the full rate

second sub cell

C901130020 Handover attempts due to DL quality of the full rate

second sub cell

C901130021 Handover attempts due to PBGT of the full rate second

sub cell

C901130022 Handover attempts due to traffics of the full rate

second sub cell

C901130023 Handover attempts due to UL interference of the full

rate second sub cell (on TCH/F)

C901130024 Handover attempts due to DL interference of the full

rate second sub cell (on TCH/F)

C901130025 Handover attempts due to Good CI of the full rate

second sub cell (on TCH/F)

C901130026 Handover attempts due to Bad CI of the full rate

second sub cell (on TCH/F)

C901130027 Handover attempts due to path loss and too large TA

of the full rate second sub cell (on TCH/F)

C901130028 Handover attempts due to path loss and too small TA

of the full rate second sub cell (on TCH/F)

C901130029 Handover of forced transfer handover attempts of the

full rate second sub cell (on TCH/F)

C901130030 Handover attempts due to other causes of the full rate

second sub cell

C901130031 Handover attempts due to UL receiving strength of the

half rate second sub cell

C901130032 Handover attempts due to DL receiving strength of the


C901130033 Handover attempts due to UL quality of the half rate

second sub cell

C901130034 Handover attempts due to DL quality of the half rate



second sub cell

C901130035 Handover attempts due to PBGT of the half rate

second sub cell

C901130036 Handover attempts due to traffics of the half rate

second sub cell

C901130037 Handover attempts due to UL interference of the half

rate second sub cell

C901130038 Handover attempts due to DL interference of the half

rate second sub cell

C901130039 Handover attempts due to C/I of the half rate second

sub cell

C901130040 Handover attempts due to C/I of the half rate second

sub cell

C901130041 Handover attempts due to path loss and too large TA

of the half rate second sub cell

C901130042 Handover attempts due to path loss and too small TA

of the half rate second sub cell

C901130043 Number of forced transfer handover attempts of the


C901130044 Handover attempts due to other causes of the half rate

second sub cell

C901130045 Number of attempts of TCH/Fseizure the second sub

cell(used for assignment)

C901130046 Number of TCH/F seizure success of the second sub

cell (used for assignment)

C901130047 Number of TCH/F seizure failure of the second sub cell

(used for assignment)

C901130048 Number of attempts of TCH/F seizure of the second

sub cell(used for handover)

C901130049 Number of TCH/F seizure success of the second sub

cell (used for handover)

C901130050 Number of TCH/F seizure failure of the second sub cell

(used for handover)

C901130051 Number of TCH/H seizure attempts of the second sub


C901130052 Number of TCH/H seizure success of the second sub




C901130053 Number of TCH/H seizure failure of the second sub


C901130054 Number of TCH/H seizure attempts of the second sub


C901130055 Number of TCH/H seizure success of the second sub


C901130056 Number of TCH/H seizure failure of the second sub


C901130057 Number of TCH/F call drops in the second sub cell

C901130058 Number of TCH/H call drops in the second sub cell

C901130059 TCH/F busy time in the second sub cell

C901130060 TCH/H busy time in the second sub cell

C901130061 Number of TCH/F assignment attempts of the second

sub cell

C901130062 Number of TCH/F assignment success of the second

sub cell

C901130063 Number of TCH/F handover attempts of the second

sub cell

C901130064 Number of TCH/F handover success of the second

sub cell

C901130065 Number of TCH/H assignment attempts of the second

sub cell

C901130066 Number of TCH/H assignment success of the second

sub cell

C901130067 Number of TCH/H handover attempts of the second

sub cell

C901130068 Number of TCH/H handover success of the second

sub cell

C901130069 TCH/F of the first sub cell seizure success when prefer

the second sub cell (used for assignment)

C901130070 TCH/F of the first sub cell seizure success when prefer

the second sub cell (used for handover)

C901130071 TCH/H of the first sub cell seizure success when prefer

the second sub cell (used for assignment)

C901130072 TCH/H of the first sub cell seizure success when prefer



the second sub cell (used for handover)

C901130073 Number of inter-cell handover attempts to the Second

sub cell directly from the cell in the same site

C901130074 Number of inter-cell handover execution to the second

sub cell directly from the cell in the same site

C901130075

Number of inter-cell handover success to the success

to the second sub cell directly from the cell in the same

site

C901130076 Number of inter-cell handover attempts to the second

sub cell directly from another site

C901130077 Number of inter-cell handover execution to the second


C901130078 Number of inter-cell handover success to the second


C901130079 Number of inter-BSC handover attempts to the second

sub cell directly from another BSC

C901130080 Number of handover execution to the second sub cell

directly from another BSC

C901130081 Number of handover success to the second sub cell

directly from another BSC

C901130082 Number of handover to the first sub cell too fast after

handover from another cell in the same site

C901130083 Number of handover to the second sub cell too fast

after handover from another cell in the same site

C901130084 Number of handover to the first sub cell too fast after

handover from another site

C901130085 Number of handover to the second sub cell too fast

after handover from another site

C901130086 Sample of sub cell 2 level low 30dB or below than

BCCH

C901130087 Sample of sub cell 2 level low 29dB than BCCH































C901130116 Sample of sub cell 2 level equal BCCH

C901130117 Sample of sub cell 2 level high 1 dB than BCCH

















C901130132 Sample of level difference between sub cell 2 and

BCCH

C901130133 Sum of level difference between sub cell 2 and BCCH

C901130135 Highest of level difference between sub cell 2 and

BCCH

C901130136 Number of handover attempt from FR to HR (V3) due

to high load in sub cell 2

C901130137 Number of handover from FR to HR (V3) due to high

load in sub cell 2

C901130138 Number of handover success from FR to HR (V3) due


C901130139 Number of handover attempt from FR to HR (V1) due


C901130140 Number of handover from FR to HR (V1) due to high

load in sub cell 2

C901130141 Number of handover success from FR to HR (V1) due


C901130142 Number of handover attempt from HR (V3) to FR due

to bad quality in sub cell 2

C901130143 Number of handover from HR (V3) to FR due to bad

quality in sub cell 2

C901130144 Number of handover success from HR (V3) to FR due


C901130145 Number of handover attempt from HR (V1) to FR due


C901130146 Number of handover from HR (V1) to FR due to bad

quality in sub cell 2

C901130147 Number of handover success from HR (V1) to FR due




C901130149 Lowest of level difference between sub cell 2 and

BCCH

5.2 Related Alarms

This feature has no related alarms.

6 Engineering Guide

6.1 Application Scenario

This feature offers a solution to address frequency multiplexing in areas with dense

traffic in the case of frequency resource shortage and network overload. With the

gradual maturity of GSM technology, the concentric circle technology also gradually

becomes mature and finds wide application in medium- and large-sized cities with

large traffic and scarce frequency resources.

6.2 Configuration Description

1. GSM Logical Configuration—GSM Cell Configuration, create a cell. The

configuration interface is shown below.



Figure 6-1 Creation Interface of Cell Configuration

2. GSM Logical Configuration——Subcell, check subcell 1 and create subcell 2. The

configuration interface is shown below.

Figure 6-2 Check Interface of Sub-cell Configuration 1



Figure 6-3 Creation Interface of Sub-cell Configuration 2

3. GSM Logical Configuration—GSM Cell Configuration—Trx, create 2 TRXs

belong to sub-cell 2 and sub-cell 2. The configuration interface is shown below.

Figure 6-4 TRX Creation Interface of Sub-cell



4. GSM Logical Configuration—GSM Cell Configuration—Subcell Handover

Control. The configuration interface is shown below.

Figure 6-5 Sub-cell Handover Parameters

6.3 Feature Validation

6.3.1 CS on subcell1 and subcell2 of concentric circle

Test Item CS on subcell1 and subcell2 of concentric circle

Precondition 1. check CN is healthy;

2. check BSC is healthy;

3. check SDR is healthy;

4. check default cell configuration and parameters in

BSC;

5. MSs are ready;

6. ensure good radio environment;

Test Steps 1. Create 1 concentric circle cell and 2 trxs in each

subcell in Subcell.

2. Block all TCH of subcell1.

3. Make a CS call.



4. Unblock all TCH of subcell1 and block all TCH of

subcell2.

5. Make a CS call.

Anticipative Result 1. In step 3, CS call can be setup successfully in

subcell2.

2. In step 5, CS call can be setup successfully in

subcell1.

Test Result 1. CS service on subcell1 and subcell2 of concentric

circle is normal.

Parameters Setting Default parameters

6.3.2 Cell reselection between Co-BCCH

Test Item Cell reselection between Co-BCCH





BSC;

5. MSs are ready;


Test Steps 1. Create 2 concentric circle cells and 2 trxs in each

subcell in Subcell.

2. Set “Cell reselection offset” as “60” of co-bcch cell1in

GSM Cell Configuration.

3. Set “Cell reselection parameter indication” as “1” of

co-bcch cell1 in GSM Cell Configuration.

4. check which cell MS reselect;

5. Set “Cell reselection offset” as “60” of co-bcch cell2in

GSM Cell Configuration.





8. check which cell MS reselect;

Anticipative Result 1. In step 4, MS will choose cell1;

2. In step 8, MS will choose cell2;

Test Result 1. Cell reselect between Co-BCCH subcells



successfully.


6.3.3 Handover between subcell1 and subcell2

Test Item Handover between subcell1 and subcell2





BSC;

5. MSs are ready;


Test Steps 1. Create 1 concentric circle cell and 2 trxs in each

subcell in Subcell.

2. Set “Subcell handover algorithm” as “Concentric

handover” in Subcell Handover Control.

3. Set “Good C/I” as “80” in Subcell Handover Control.

4. Make a CS call in subcell1 and open signalling trace.

5. Set “Bad C/I” as “200” in Subcell Handover Control.

6. Make a CS call in subcell2 and open signalling trace.

Anticipative Result 1. In step 4, CS handover from subcell1 to subcell2.

2. In step 6, CS handover from subcell2 to subcell1.

Test Result 1. Handover between subcell1 and subcell2 can be

performed successfully.


6.4 Feature Turn off

To turn off the feature, only configure one subcell in one cell.

6.5 Network Impact

Characteristics of common concentric circle:



1. Network structure keeps unchanged;

2. Some special handover algorithm should be added, but it’s simple to implement;

3. No special requirements imposed on MS;

4. Network capacity can be only improved by 10-30%, and is related to traffic

distribution. It’s difficult for the inner circle to absorb indoor traffic due to its small

power;

5. It suits outdoor areas with highly concentrated traffic around BTSs.

Characteristics of intelligent concentric circle:

1. As a kind of concentric circle, IUO can reuse the existing site address, making slight

changes on network and imposing no special requirements on MS;

2. System has to add measurement and estimation on C/I and special handover

algorithm;

3. System capacity can be improved by 20-40%, which is related to traffic distribution

and traffic load super layer absorbs. And the quality is ensured as well;

4. Super layer can user closer multiplexing method. When frequency is wide enough,

some frequencies are reserved for micro cell;

5. It suits for areas with highly concentrated traffic around BTSs.

7 Abbreviation Abbreviations Full Characteristics

BCCH Broadcast Control Channel

BSC Base Station Controller

BTS Base Transceiver Station

C/I Carrier/Interference

TA Timing Advance

MSC Mobile services switching centre

SDCCH Stand-alone Dedicated Control Channel



8 Reference Document

ZXG10 iBSC (V6.30.10) Base Station Controller Performance Counter Reference

ZXG10 iBSC (V6.30.10) Base Station Controller Radio Parameter Reference

zgo-05!02!009 concentric circle technology feature guide zxg10-ibsc (v12.2.0)20131225

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