MR Averaging and Voting Part1

7/28/2019 MR Averaging and Voting Part1

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CUSTOMER SUPPORT SERVICES DIVISION

Network Operations Engineering2July 2000

Overview

Measurement Reporting

BSS Measurement Averaging

Voting Mechanism

Decision Processes

Application of Different Averaging Algorithms


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MS / BSS Handover & Power Control

UL & DL Measu rements Taken

Averages Produced

A Number of Averages Compared Against Threshold

Thresho ld Exceeded

Power Output Adju sted / Handover Triggered


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Information Sent to MS

Contents of SYS INFO 5

3 versions: 5, 5bis, 5ter

BA bit - toggles every neighbour list update Contain list of all neighbour frequencies

If


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Information Sent to MS

Contents of SYS INFO 6

Cell identity & Location Area: MCC, MNC, LAC

Cell Options PWRC

DTX (may, shall, shall not)

Radio Link timeout in 4 frame (1920ms) blocks

NCC permitted, bitmap of 8 allowed NCC (upper 3bits of BSIC)

MS is only allowed to report neighbours with theseNCCs


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MS Measurement Report

28 2 0 0 17 0 17 0 34 23 66 . . . . . . . 28 26 66

Timing

Advance

Power

Level

BA

Used

DTX

Used

Rxlev &

Rxqual

Full

Rxlev &

Rxqual

Sub

RXLEV

FREQ

Index BSIC

Ncell 1Ncell 6


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MS Measurement Cycle

25 24 23 22 21 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 02019

SACCH

120ms

25 24 23 22 21 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0201925 24 23 22 21 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 02019

IDLEIDLE

Multi-frame

1 Multi-frame =SACCH

4 x 26-Multi-frame

Frame sent every 4.615ms

104 Multi-frame = 480ms

96 frames for Speech/ Data

4 frames for SACCH - Measurement report 4 idle frames to decode BSIC of neighbours

No DTX = 100 frames out of 104 (4 idles)

DTX = 12 frames (4 SACCH + 8 SID)


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MS Measurement Cycle

0 1 2 3 4 7 2 3 4 6 7 0 1 2 3 4 5 6 7 0 15 56 0 1

5 6 7 0 1 4 7 0 1 3 4 5 6 7 0 1 2 3 4 5 62 23 5 6

SAMPLE PERIOD

UPLINK

DOWNLINK

2 ms1ms

TDMA FRAME

Change from DLto UL frequency

Measure 1 neighbour

frequency


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Decoding the BSIC


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Neighbour Reporting Process

MS to synchronise to and demodulate surrounding BCCH carriers & identifythe BSIC

MS shall use at least 4 spare frames per SACCH period to decode the BSIC.

MS shall demodulate the SCH on the BCCH carrier of each surrounding celland decode the BSIC as a minimum at least once every 10 seconds.

If the MS detects one or more BCCH carriers, among the six strongest withoutBSIC, then the MS shall as a matter of priority attempt to decode their BSICs(devote all search frames for a period up to 5 seconds.

If the BSIC on a surrounding cell BCCH carrier is not decoded for more thanthree successive attempts, it will be considered lost.

When a BCCH carrier is found to be no longer one of the 6 strongest, timing

and BSIC information shall be retained for at least 10 seconds. The reported parameters (RXLEV) shall be the average of the received signal

strength measurement samples in dBm taken within the SACCH reportingperiod.

The MS shall transmit the MR to the BSS in the next SACCH message block.


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Contents of Measurement Report-BTS

Measurement report number (0 to 255) RxLev UL (full and sub)

DTX used

RxQual UL (full and sub)

BTS Power level (2dB steps below max power of HW)

MS Power (reported by MS in layer 1 header)

Timing Advance (reported by MS in layer 1 header)

Measurement Report from MS Relative Timing Advance (full and sub)


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What Is Not in Measurement Reports

Detection of neighbours/ interferers co-channel withserving cell

Detection of co-channel neighbours/ interferers withsimilar RX Levels

Cannot decode BSIC unless C/I > 7dB

Detection of non-GSM neighbours

MS only reports signals with de-codeable BSIC

Cannot identify unknown cells, only know the BCCH/BSIC


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BSS Processing & Threshold Comparisons

Reported by MS DL Received Signal Strength (TCH/SDCCH)

DL Quality (TCH/SDCCH)

DL Surrounding Cell Rxlev (Neighbour BCCH)

Performed by RSS

UL Received Signal Strength (TCH/SDCCH)

UL Quality (TCH/SDCCH)

MS-BTS Distance Interference Levels in Idle Timeslots

Processed value every SACCH multiframe (480ms)


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BSS Processing & Threshold Comparisons

RXQUAL Range

BER ASSUMED BER

0= less than 0.2% 0.14%1= 0.20.4% 0.28%

2= 0.40.8% 0.57%

3= 0.81.6% 1.13%

4 = 1.63.2% 2.26%5 = 3.26.4% 4.53%

6 = 6.412.8% 9.05%

7 = greater than 12.8% 18.1%


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HREQAVE The number of reported averages required to produce one rolling average as one

instance of HREQT

HREQT The number of averages retained in the Handover software task, needs to be at

least equal to the n parameter for that particular threshold

INTAVE The number of interference averages, reported by the DRCU, that are used to

produce one rolling averages every 480 mS

HREQT & HREQAVE have a maximum value of 32, althoughHREQT * HREQAVE for the same averaging process must equal 32 or less(HREQT * HREQAVE 32)


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HREQAVE and HREQT must be defined for:

Rxqual UL/DL: Handover (ho) & Power Control (pc)

Rxlev UL/DL: Handover (ho) & Power Control (pc)

Surrounding Cell DL: Handover (s_cell)

Timing Advance: MS to BSS timing advance (rel_tim_adv)

INTAVE and HREQT must be defined for:

Idle Interference UL: Idle Channel Processing

Command:chg_act_alg_data ,


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Averaging (HREQAVE & HREQT)

-80 -82 -81 -81 -81 -79 -82 -83 -83 -79

MEASUREMENT REPORTS

hreqave = 4

480ms 480ms

DLRxLev

hreqt = 3

-81

-81

-80

. . . .

. . . .

DLRxLev

Re-averages

VOTING: p out of n re-averages below DL RxLev

threshold needed to trigger HO!

hreqt = 3


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N and P Voting Mechanism

Voting occurs for each decision process everySACCH multiframe (480ms)

N Defines the number of BSS produced averages required for a decision

to be made

P

Defines the minimum number of BSS produced averages, overthreshold value, to cause a positive trigger

N = HREQT


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Voting (N & P)

n = HREQT

p


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HREQAVE/HREQT and N/P Relationship

-86 -88 -88 -91 -91 -92 -94 -96 -97 -98

MEASUREMENT REPORTS

HREQAVE = 4

HREQT = 3

Threshold

L_RXLEV_DL_H = 20 (-90 dBm)

480ms480ms

DLRxLev

-89 -91-86

. . . .-85 -87 -88 -89 -91 -91 -94 -95 -97 -98 -99

-87 -89 -92

-89 -91 -93

-91 -93 -97

HO TriggerN=3

P=2

HO TriggerN=3

P=3

480ms

-86.5 -89 -91.25

AVERAGES always

truncated & rounded

down.

No floating point

operations in HDPC


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Effect of Correct N & P Settings

Mobile using

less power

Before

After

Modified N &

P settings will

help the

effectiveness of

power control


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Measurement Reporting & Processing

When RSS does not receive expected MR from MS(DL measurements), action is controlled by:

missing_rpt flag=1: report missing, no DL voting, no

PBGT calculated. For UL, averaging and decision makingwill progress in the normal way

missing_rpt flag=0: report repeated, voting continues,PBGT calculated

Flag should be set to 0, otherwise only UL intra-cellHO can be performed if UL fails!


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Measurement Reporting & Processing

-80 -81 -81 -81 -79 -83 -83 -79

MEASUREMENT REPORTS

hreqave = 4

480ms 480ms

DLRxLev

hreqt = 3

-81-80

-80

. . . .

. . . .

DLRxLev

Re-averages

Report missing

FLAG=1

No DL voting

No PBGT calculated

-79

Report missing

FLAG=0

Voting continues

PBGT calculated

Repeated


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BSS Averaging Mechanism

Command: chg_act_alg_data ,

Parameter Averaging Mechanisms

Hreqave 0 031 ALL

Hreqt 1 031 ALL

qual_weight

2 0255 Only Rxqual_pc/ho

Note: Only required if quality weighting

decision_alg_num=1

qual_pwr_flag

3 0/1 Only Rxqual_ho

Note: This can only be set to 1 ifdecision_alg_num = 1

qual_margin_flag 4 0/1 Rxqual_ho

Interfere_ho

adj_qual_margin 6 -63 to +63

dBs

Rxqual_ho

Interfere_ho


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BSS Averaging Mechanism

Command: chg_act_alg_data ,

Parameter Description used for

qual_weight Weighting factor when using algorithm number 1. The

weighted algorithm will only apply when the reported

averages are full values i.e. not sub (DTX). It causes themost recent reported averages to be repeated a number

of times, as per the weighting factor, before an average

is calculated by the averaging mechanism.

rxqual_dl_ho

rxqual_dl_pc

rxqual_ul_horxqual_ul_pc

qual_power_flag If enabled, will allow a handover only when BTS or

mobile is operating at full power. Qual_power_flag

cannot be set to 1 if decision_alg_num equals 0.

rxqual_dl_ho

rxqual_ul_ho

qual_margin_flag If disabled, the call will be handed over to the best

neighbor available, which may have a weaker signal

level than the serving cell.

rxqual_dl_ho

rxqual_ul_ho

adj_qual_margin Additional receive level that the best neighbor may be

below the serving cell.

rxqual_dl_ho

rxqual_ul_ho


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BSS Decision Process

Averaging Mechanism Decision process

rel_tim_adv decision_1_tim_adv_av_alg

surround_cell decision_1_p_bgt_rxlev_av_h (neighboring cell of Criteria 2)

decision_1_ncell_rxlev_av_calc (Criteria 1)

rxlev_dl_ho

decision_1_p_bgt_rxlev_av_h (serving cell of Criteria2)

decision_1_dl_rxlev_av_h (DL rxlev Handover)decision_1_dl_rxlev_av_ih (DL interference Handover)

rxlev_ul_ho decision_1_ul_rxlev_av_h (UL rxlev Handover)

decision_1_ul_rxlev_av_ih (UL interference Handover)

rxlev_dl_pc decision_1_dl_rxlev_av_p

rxlev_ul_pc decision_1_ul_rxlev_av_p

rxqual_dl_ho decision_1_dl_rxqual_av_h

rxqual_ul_ho decision_1_ul_rxqual_av_h

rxqual_dl_pc decision_1_dl_rxqual_av_p

rxqual_ul_pc decision_1_ul_rxqual_av_p


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Pointing Averaging Mechanisms to

Decision Processes (HO)

Activity Link Enable Averaging Decision Threshold Voting Notes

Quality Handover Up

Down

ul_rxqual_ho_allowed

dl_rxqual_ho_allowed

rxqual_ul_ho

rxqual_dl_ho

decision_1_ul_rxqual_av_h

decision_1_dl_rxqual_av_h

l_rxqual_ul_h

l_rxqual_dl_h

P6, N6

P6, N6

Used by

interference

handover as

well

Level Handover Up

Down

ul_rxlev_ho_allowed

dl_rxlev_ho_allowed

rxlev_ul_ho

rxlev_dl_ho

decision_1_ul_rxlev_av_h

decision_1_dl_rxlev_av_h

l_rxlev_ul_h

l_rxlev_dl_h

P5, N5

P5, N5

--


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Pointing Averaging Mechanisms to

Decision Processes (PC)

Activity Link Enable Averaging Decision Threshold Voting

Power Control due

to Level

Up

Down

ms_power_control_allowed

bts_power_control_allowed

rxlev_ul_pc

rxlev_dl_pc

decision_1_ul_rxlev_av_p

decision_1_dl_rxlev_av_p

l_rxlev_ul_p

u_rxlev_ul_p

l_rxlev_dl_p

u_rxlev_dl_p

P1, N1

(increase)

P2, N2

(decrease)

Power Control due

to Quality

Up

Down



rxqual_ul_pc

rxqual_dl_pc

decision_1_ul_rxqual_av_p

decision_1_dl_rxqual_av_p

l_rxqual_ul_p

u_rxqual_ul_p

l_rxqual_dl_p

u_rxqual_dl_p

P3, N3

(increase)

P4, N4

(decrease

)


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Averaging & Voting Mechanism

Activity Link Enable Averaging Decision Threshold Voting Notes

Quality Handover UpDown ul_rxqual_ho_alloweddl_rxqual_ho_allowed rxqual_ul_horxqual_dl_ho decision_1_ul_rxqual_av_hdecision_1_dl_rxqual_av_h l_rxqual_ul_hl_rxqual_dl_h P6, N6P6, N6 Used byinterferencehandover aswell

Level Handover UpDown

ul_rxlev_ho_alloweddl_rxlev_ho_allowed

rxlev_ul_horxlev_dl_ho

decision_1_ul_rxlev_av_hdecision_1_dl_rxlev_av_h

l_rxlev_ul_hl_rxlev_dl_h

P5, N5P5, N5

--

InterferenceHandover

UpDown

interfer_ho_allowedinterfer_ho_allowed

rxlev_ul_horxlev_dl_ho

decision_1_ul_rxlev_av_ihdecision_1_dl_rxlev_av_ih

u_rxlev_ul_ihu_rxlev_dl_ih

P7, N7P7, N7

Relevantqualityhandover musttrigger first

Distance Handover -- ms_distance_allowed rel_tim_adv decision_1_tim_adv_av_alg ms_max_range P8, N8 Uplink only

Power BudgetHandover

SourceNeighbor

pwr_handover_allowedrxlev_dl_hosurround_cell/per neighbor

decision_1_pbgt_rxlev_av_h handover_margin-- No voting as

lastest hreqtused

Power Control dueto Level

Up

Down



rxlev_ul_pc

rxlev_dl_pc

decision_1_ul_rxlev_av_p

decision_1_dl_rxlev_av_p

l_rxlev_ul_pu_rxlev_ul_pl_rxlev_dl_pu_rxlev_dl_p

P1, N1(increase)P2, N2(decrease)

--

Power Control due

to Quality

Up

Down



rxqual_ul_pc

rxqual_dl_pc

decision_1_ul_rxqual_av_p

decision_1_dl_rxqual_av_p

l_rxqual_ul_pu_rxqual_ul_p

l_rxqual_dl_pu_rxqual_dl_p

P3, N3(increase)

P4, N4(decrease)

--

Criteria 1 -- -- surround_cell decision_1_ncell_rxlev_av_calc -- -- --

Criteria 2 -- -- rxlev_dl_hosurround_cell

decision_1_pbgt_rxlev_av_h-- -- --

Note:PBGT HO - per neighbor averaging as defined in the add-neighbor is only active if

the chg_element use_neighbor_pbgt_hreqave is set to 1


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Application of Different Averaging

Algorithms

Criteria 2 (serving cell):

chg_ele decision_1_p_bgt_rxlev_av_h

chg_act_alg_data rxlev_dl_ho

DL Rxlev handover: chg_ele decision_1_dl_rxlev_av_h


DL Interference handover:

chg_ele decision_1_dl_rxlev_av_ih



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Algorithms

Criteria 2:

decision_1_pbgt_rxlev_av_h = 1

DL Interf HO:

decision_1_dl_rxlev_av_ih = 1

DL RxLev HO:

decision_1_dl_rxlev_av_h = 1


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CUSTOMER SUPPORT SERVICES DIVISIONNetwork Operations Engineering

32July 2000


Algorithms

Criteria 2:

decision_1_pbgt_rxlev_av_h = 0

DL RxLev HO:

decision_1_dl_rxlev_av_h = 1

DL Interf HO:

decision_1_dl_rxlev_av_ih = 2


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33July 2000


Algorithms

Criteria 1 for every handover:

chg_ele decision_1_ncell_rxlev_av_calc

chg_act_alg_data surround_cell

Criteria 2 for every handover:

chg_ele decision_1_p_bgt_rxlev_av_h

chg_act_alg_data surround_cell


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34July 2000


Algorithms

Criteria 1:

decision_1_ncell_rxlev_av_calc = 0

Criteria 2:

decision_1_p_bgt_rxlev_av_h = 0


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Algorithms

Criteria 1:

decision_1_ncell_rxlev_av_calc = 0

Criteria 2:

decision_1_p_bgt_rxlev_av_h = 1

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MR Averaging and Voting Part1

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