Main HO Causes [Compatibility Mode]

Multiband-Multilayer Optimization � Algorithms and Associated Parameters 1 � 2 � 1

Handover Cause 2: UL Quality

� CAUSE 2: too low quality on the uplink

AV_RXQUAL_UL_HO > L_RXQUAL_UL_H + OFFSET_RXQUAL_FH

and AV_RXLEV_UL_HO <= RXLEV_UL_IH

and MS_TXPWR = min (P, MS_TXPWR_MAX)

QUAL

LEV

All Rights Reserved © Alcatel-Lucent 2007

GSM

BSS B11 Multilayer and Multiband GSM Network Radio

Optimization

� Size of window for averaging quality: A_QUAL_HO

� Size of window for averaging level: A_LEV_HO


and EN_RXQUAL_UL= ENABLED


6 Main Standard Handover Algorithms

Handover Cause 3: UL Level

� CAUSE 3: too low level on the uplinkQUAL

LEV

AV_RXQUAL_UL_HO <= L_RXQUAL_UL_H + OFFSET_RXQUAL_FH

and AV_RXLEV_UL_HO < L_RXLEV_UL_H



GSM


Optimization




and EN_RXLEV_UL= ENABLED



Handover Cause 4: DL Quality

� CAUSE 4: too low quality on the downlinkQUAL

LEV

AV_RXQUAL_DL_HO > L_RXQUAL_DL_H + OFFSET_RXQUAL_FH

and AV_RXLEV_DL_HO <= RXLEV_DL_IH

and BS_TXPWR = BS_TXPWR_MAX


GSM


Optimization




and EN_RXQUAL_DL = ENABLED



Handover Cause 5: DL Level

� CAUSE 5: too low level on the downlinkQUAL

LEV

AV_RXQUAL_UL_HO <= L_RXQUAL_DL_H + OFFSET_RXQUAL_FH

and AV_RXLEV_UL_HO < L_RXLEV_DL_H



GSM


Optimization




and EN_RXLEV_DL= ENABLED



Handover Cause 15: UL Interference

� CAUSE 15: High interference on the uplink

AV_RXQUAL_UL_HO > THR_RXQUAL_CAUSE_15 + OFFSET_RXQUAL_FH

and AV_RXLEV_UL_HO > RXLEV_UL_IH

and EN_CAUSE_15 = ENABLED


GSM


Optimization




and [ no previous intracell handover for this connection failed or EN_INTRACELL_REPEATED = ENABLED ]



Handover Cause 16: DL Interference

� CAUSE 16: High interference on the downlink

AV_RXQUAL_DL_HO > THR_RXQUAL_CAUSE_16 + OFFSET_RXQUAL_FH

and AV_RXLEV_DL_HO > RXLEV_DL_IH



GSM


Optimization




and [ no previous intracell handover for this connection failed or EN_INTRACELL_REPEATED = ENABLED ]



New Parameters for Causes 15 & 16

� CAUSE 15 and CAUSE 16:

� THR_RXQUAL_CAUSE_15 (or 16) and EN_CAUSE_15 (or 16) are specific to variable computed by the BSC :

� THR_RXQUAL_CAUSE_15 (or 16) =

� L_RXQUAL_XX_H for a non AMR call (same threshold as CAUSE 2 or CAUSE 4)

� L_RXQUAL_XX_H_AMR for an AMR Narrow Band call

� L_RXQUAL_XX_H_AMR_WB_GMSK for an AMR Wide Band call

B10


GSM


Optimization

� L_RXQUAL_XX_H_AMR_WB_GMSK for an AMR Wide Band call

� EN_ CAUSE _15 (or 16) =

� EN_INTRA_XX for a non-AMR call

� EN_INTRA_XX_AMR for an AMR Narrow Band call

� EN_INTRA_XX_AMR_WB_GMSK for an AMR Wide Band call



Handover Cause 12: Power Budget

�Definition of PBGT HO :

� Possible targets depends also on the cells band type :

Serving Band Type

Target Band Type

EN_MULTIBAND_PBGT_HO= Enable

EN_MULTIBAND_PBGT_HO= Disable


GSM


Optimization

= Enable = Disable

GSM Any GSM

DCS Any DCS



Handover Cause 12: Power Budget [cont.]

� Based on Power budget equation

PBGT(n) = AV_RXLEV_NCELL(n) - AV_RXLEV_PBGT_HO

- (BS_TXPWR_MAX – AV_BS_TXPWR_HO)

- (MS_TXPWR_MAX(n)* – MS_TXPWR_MAX*)

(A)

(B)

(C)


GSM


Optimization

� Size of window for level averaging: A_PBGT_HO

- (MS_TXPWR_MAX(n)* – MS_TXPWR_MAX*)

- PING_PONG_MARGIN(n, call_ref)

(C)

(D)




� A Handover cause 12 is detected only if the following conditions are met :

if EN_TRAFFIC_HO(0,n) = DISABLED

then PBGT(n) > HO_MARGIN(0,n) + OFFSET_HO_MARGIN_INNER (*)


GSM


Optimization


and AV_RXLEV_PBGT_HO ≤ RXLEV_LIMIT_PBGT_HO

and EN_PBGT_HO = ENABLED




� In case the feature "Traffic HO" is enabled, the previous condition is modified :

if EN_TRAFFIC_HO(0,n) = ENABLED

then PBGT(n) > HO_MARGIN(0,n) + OFFSET_HO_MARGIN_INNER (*)+ max(0, DELTA_HO_MARGIN(0,n))


GSM


Optimization


and AV_RXLEV_PBGT_HO ≤ RXLEV_LIMIT_PBGT_HO

and EN_PBGT_HO = ENABLED

max(0, DELTA_HO_MARGIN(0,n)) is always positive � it increases the HO_MARGIN(O,n)




� DELTA_HO_MARGIN(0,n): evaluated according to the traffic situation of the serving cell and the neighboring cell n (Traffic_load(n)) in the following way:

If Traffic_load(0) = high and Traffic_load(n) = low,

� DELTA_HO_MARGIN(0,n) = - DELTA_DEC_HO_MARGIN

If Traffic_load(0) = low and Traffic_load(n) = high,

(A)


GSM


Optimization

� Philosophy:

This mechanism aims at penalizing cause 12 detection when the traffic in the serving cell is low and is high in the cell n

If Traffic_load(0) = low and Traffic_load(n) = high,

� DELTA_HO_MARGIN(0,n) = + DELTA_INC_HO_MARGIN

Else DELTA_HO_MARGIN(0,n) = 0

(B)

(C)



Handover Cause 28: Fast Traffic HO [cont.]

� CAUSE 28: Fast Traffic Handover

AV_RXLEV_NCELL(n) > L_RXLEV_NCELL_DR(n) + max (0, [MS_TXPWR_MAX(n) - P])

and t(n) > FREELEVEL_DR(n)



GSM


Optimization

� Size of window for averaging level: A_PBGT_DR

� Same thresholds and window as Cause 20 (FDR)

� EN_CAUSE_28 is an internal HOP process variable, ENABLED when a request is queued


and EN_FAST_TRAFFIC_HO = ENABLED


8 Better Conditions Handover Algorithms for MBML Networks

Cause 21: Preferred Band

� Capture handover

� Improved in B7 (anti ping-pong)

� Send traffic in preferred cells, even though the call is fine in classical cells

� May be triggered

� From Classical band cells

� Towards Preferred Band cells

Cell 900


GSM


Optimization

� Towards Preferred Band cells

� Note : It can be triggered between

different layers or not

Cell Cell 1800


8 Better Conditions Handover Algorithms for MBML Networks

Cause 21: Preferred Band [cont.]

� Cause 21: high level in the neighboring cell in the preferred band

AV_RXLEV_NCELL(n) > L_RXLEV_CPT_HO(0,n)

and TRAFFIC_LOAD(0) = MULTIBAND_TRAFFIC_CONDITION

and TRAFFIC_LOAD(n) ≠ HIGH


GSM


Optimization

� Averaging window: A_PBGT_HO

� MULTIBAND_TRAFFIC_CONDITION can take 3 values: ANY_LOAD (default), HIGH, NOT_LOW

� Anti ping-pong: not checked when T_INHIBIT_CPT is running

and TRAFFIC_LOAD(n) ≠ HIGH

and EN_PREFERRED_BAND_HO = ENABLE


End of Module


GSM


Optimization

End of ModuleAlgorithms and Associated Parameters

Documents

Main HO Causes [Compatibility Mode]