Alcatel's Parameter

Dual band networks Parameters and optimization

Mobile Communication Division

MCD/CO/OC

Table

of contents (1)

 Introduction 



Presentation of the algorithms and parameters 

neighbouring cells list and monitoring



idle mode



B5 radio algorithms



classmark handling

Parameters and configurations 

dual band parameter parameterss



configurations



other aspects


MCD/CO/OC

Table

 S pecial

sets of parameters



zone exit on preventive handover



capture threshold threshold set on a per cell basis

 Tuning





idle mode



connected mode



other aspects

Problems of B5 release 

detection of better condition handover causes



cause 21 and micro 1800 cells


MCD/CO/OC

of contents (2)

Introduction


MCD/CO/OC

Introduction

(1)

BSS release 5 : Multiband B SC 900 and 1800 MHz

cells connected to the same BSC Single

band Dual band

Dual band

BS

1800 MHz cell and B CCH

BSC Mobile Communication Division

MCD/CO/OC

BS 900 MHz cell and B CCH

Introduction



(2)

Few parameters are necessary to operate a dual band network : 

neighbouring cells list and monitoring



idle mode



call set-up



handover



classmark handling

 It

is possible to reuse parameters


900

MCD/CO/OC

and 1800 MHz default radio

Presentation of the algorithms and parameters


MCD/CO/OC

Neighbouring cells list (1)  Sending

of neighbouring cells list in each frequency band is necessary to allow : 

20

monitoring

800



re-s re -sel elec ecti tion on in id idle le mo mode de



hand ha ndov over er in de dedi dica cate ted d mo mode de

798

45

805 2


MCD/CO/OC

Neighbouring cells list (2)  Idle

mode : BCCH, SYS I NFO 2, 2ter and 2bis

805

BCCH 1800 SI 2 and 2bis : 1800 neighbouring cells SI 2ter : 900 neighbouring cells

BCCH 900 SI 2 : 900 neighbouring cells SI 2ter and 2bis : 1800 18 00 neighbouring cells

20


MCD/CO/OC

Neighbouring cells list (3) 

Dedi De dica catted mod odee : 805

SACCH, SYS I NFO

5, 5bis and 5ter

SACCH 1800

5 and 5bis : 1800 neighbouring cells SI 5ter : 900 neighbouring cells SI

SACCH 900

5 : 900 neighbouring cells SI 5ter and 5bis : 1800 18 00 neighbouring cells SI

20


MCD/CO/OC

Neighbouring cells list (4)

 A

BSS parameter enables sending of SI 2bis/2ter and

5bis/5ter : E N_ I NTERBA ND _NEIGH


MCD/CO/OC

SI

Neighbouring cells monitoring (1)  It

is necessary to tell to a dual band MS how to report neighbouring cells : 

a MS reports to the BTS 6 neighbouring cells



classical behaviour in a single band network : 6 strongest cells



problem in a dual band network : 

case where the MS only reports cells belonging to the same frequency band



no interband HO


MCD/CO/OC

Neighbouring cells monitoring (2)  Use 

of one parameter set on a per cell basis :

MULTIBA ND _ REPOR TI NG : 

4 values : ±

0 = 6 strongest cells irrespective of the frequency band

±

1 = 1 strongest cell (non serving cell frequency band) + 5 strongest cells (serving cell frequency band) + strongest cells

±

2 = 2 strongest cells (non serving cell frequency band) + 4 strongest cells (serving cell frequency band) + strongest cells

±

3 = 3 strongest cells (non serving cell frequency band) + 3 strongest cells (serving cell frequency band) + strongest cells


MCD/CO/OC

Idle

mode parameters (1)

 Very

important to direct M S to the desired layer not only in dedicated mode but also in idle mode to





take full advantage of each layer



avoid handovers

Dual band MS are phase 2 MS : it is possible to use the parameter CELL _ BAR _QUALIFY and the C2 criterion


MCD/CO/OC

Idle

 Cell

selection, use of CELL _ BAR _QUALIFY :



set on a per cell basis



only understood by phase 2 MS

 

 

mode parameters (2)

broadcasted on the BCCH 2 values : 

0 = normal priority



1 = lower priority

interacts with CELL _ BAR _ ACCESS a phase 2 MS selects the suitable ( C1 > 0 ) cell with the highest belonging to the list of highest priority


MCD/CO/OC

C1

Idle

 Cell

mode parameters (3)

selection, use of CELL _ BAR _QUALIFY :

805

BCCH 1800 _QUALIFY = 0 CELL _ BAR

20

BCCH 900 CELL _ BAR _QUALIFY = 1

=> selection of the 1800 cell


MCD/CO/OC

Idle



mode parameters (4)

Re-selection, use of C2 : 

criterion only used by phase 2 MS



two formulas according to the parameter PE NALTY _ TIME : 

if PE NALTY _ TIME { 31 :

C2

= C1 + CELL _ RESELECT _OFFSET - TEMPOR AR Y _OFFSET*H(PE NALTY _ TIME - T) with H(x) = 0 for the serving cell and if x <0 and H(x) = 1 otherwise 

if PE NALTY _ TIME = 31 : C2



T

= C1 - CELL _ RESELECT _OFFSET

is a timer incremented from 0 when the neighbouring cell enters in the list of the

neighbouring cells.

T

strongest

is put back to 0 when the neighbouring cell does not belong to this list any

longer Mobile Communication Division

6

MCD/CO/OC

Idle



mode parameters (5)

Re-selection, use of C2 : 

Parameters :  CELL _ RESELECT _OFFSET  TEMPOR AR Y _OFFSET





: 0 to 126 dB, 2 dB steps

: 0, 10, 20, 30, 40, 50, 60, infinite dB

PE NALTY _ TIME : 20 to 620 s, 20 s steps parameters broadcasted on the BCCH if CELL _ RESELECT _ PAR AM _ I ND = 1, otherwise C2 = C1


MCD/CO/OC

Idle



mode parameters ( 6)

Re-selection, use of C2 :

805

BCCH 1800 CELL _ RESELECT _OFFSET = 60 dB TEMPOR AR Y _OFFSET = 0 dB PE NALTY _ TIME = 20 s

20

BCCH 900 CELL _ RESELECT _OFFSET = 0 dB TEMPOR AR Y _OFFSET = 0 dB PE NALTY _ TIME = 20 s C2(1800) = C1(1800) + 60 C2(900) = C1(900)

=> the re-selection of the 1800 cell is favoured Mobile Communication Division

MCD/CO/OC

Call

 SDCCH-TCH

set-up (1)

handover only possible if the serving cell is completely congested (queuing)

 Internal

and external Directed Retry are possible

 SDCCH-TCH  

handover on :

better condition or emergency causes = Directed Retry cause 20 = Forced Directed Retry


MCD/CO/OC

Call



set-up (2)

Directed Retry : 

enabled /disabled on a per cell basis with the parameter E N_ DR



all handover causes are available except causes 10, 11 and 13 (concentric cells) and causes 15 and 16 (intracell HO)



candidate cell evaluation process : same than for TCH-TCH HO


MCD/CO/OC

Call



set-up (3)

Forced Directed Retry : 

enabled/disabled on a per cell basis with the parameter E N_FOR CED _ DR which is relevant only when E N_ DR = E NABLE



detection = cause 20 : AV _ RXLEV _NCELL _ DR(n) > L _ RXLEV _NCELL _ DR(n)



AV _ RXLEV _NCELL _ DR(n)



if less than A _ PBGT _ DR samples are available, the average value is calculated with the available samples and the averaging window is filled in with 0 (-110 dBm)


is calculated with A _ PBGT _ DR samples

MCD/CO/OC

Call



set-up (4)

Forced Directed Retry : 

Candidate

cell evaluation process :



PREF_ LAYER, PR IOR ITY(0,n), frequency



no filtering process



neighbouring cells sorted according to their PBGT _ DR : ±

AV _ RXLEV _NCELL _ DR(n)

±

t(n) > FREElevel _ DR(n)

±

PBGT _ DR(n) = AV _ RXLEV _NCELL _ DR(n) - AV _ RXLEV _ PBGT _ DR - (BS _ TXPWR _ MAX - BS _ TXPWR) - (MS _ TXPWR _ MAX(n) - MS _ TXPWR _ MAX)


> RXLEVmin(n) + max(0, MS _ TXPWR _ MAX(n) - P)

MCD/CO/OC

Better condition handovers (1) 



Five better condition handover causes : 

causes 21, 14 and 12



cause 13 for concentric cells



cause 20

Each time a measurement result is received, handover causes are checked with the following priority order : cause 21, 14, 12, 13 and 20

 If

a handover cause is triggered, handover causes with lower priority are not checked


MCD/CO/OC

Better condition handovers (2)  Cause

21 : Preferred band H O



handovers from cells working in the non-preferred band to cells working in the preferred band



preferred band indicated on a per BSS basis by the parameter PREFERRED _ BA ND



detection : 

AV _ LOAD(0)

> MULTIBA ND _ LOAD _ LEVEL AV _ LOAD(0) is the average percentage of busy TCH over a given period and is calculated independently



AV _ RXLEV _NCELL(n)



E N_ PREFERRED _ BA ND _ HO = E NABLE

> L _ RXLEV _ CPT _ HO(n) + max(0, MS _ TXPWR _ MAX(n) - P) AV _ RXLEV _NCELL(n) is calculated with A _ PBGT _ HO samples


MCD/CO/OC


14 : Capture for slow mobiles



handovers from cells of the upper layer (umbrella cells) to cells of a lower layer (micro and mini cells)



detection : 

AV _ RXLEV _NCELL(n)

> L _ RXLEV _ CPT _ HO(n) AV _ RXLEV _NCELL(n) is calculated with A _ PBGT _ HO samples



MS _ SPEED = slow the speed of the mobile is determined independently by the speed discrimination process



E N_ MCHO_NCELL = E NABLE


MCD/CO/OC

Better condition handovers (4) 

MS speed discrimination process : 

C _ DWELL(n)

is a counter measuring the number of SACCH periods of monitoring neighbour n over the threshold L _ RXLEV _ CPT _ HO(n)



C _ DWELL(n)



if for one neighbour n, C _ DWELL(n) >= 2*MI N_ DWELL _ TIME then MS _ SPEED is set to slow



if E N_ SPEED _ DISC = DISABLE, C _ DWELL(n) is initialized with the value 2*(MI N_ DWELL _ TIME - L _ MI N_ DWELL _ TIME). In this case, there is no regulation according to the load of the serving umbrella cell

is compared to the threshold (variable according to the load of the serving umbrella cell) 2*MI N_ DWELL _ TIME in order to determine MS speed


MCD/CO/OC


12 : Power budget



only possible between cells belonging to the same layer and working in the same band



detection : 

PBGT(n) > HO_ MAR GI N(0,n) with PBGT(n) = AV _ RXLEV _NCELL(n) - AV _ RXLEV _ PBGT _ HO - (BS _ TXPWR _ MAX - BS _ TXPWR) - (MS _ TXPWR _ MAX(n) - MS _ TXPWR _ MAX) - PI NG _ PONG _ MAR GI N(n, call _ ref) AV _ RXLEV _NCELL(n) and AV _ RXLEV _ PBGT _ HO are calculated with A _ PBGT _ HO samples



E N_ PBGT _ HO = E NABLE


MCD/CO/OC

Better condition handovers ( 6)  Anti 



ping-pong mechanism :

PI NG _ PONG _ MAR GI N is a penalty put on the neighbouring cell n if : 

it is the immediately precedent cell on which the call has been



this cell belongs to the same BSC than the serving cell



the call has not performed a Forced DR towards the serving cell



less the T _ HCP seconds have elapsed since the last handover

the penalty is PI NG _ PONG _ HCP


MCD/CO/OC

Emergency handovers (1) 

12 emergency handover causes : 

cause 7 : consecutive bad SACCH frames (micro cells only)



causes 17 and 18 : level UL/DL high threshold (micro cells only)



causes 2 and 4 : quality UL/DL



causes 3 and 5 : level UL/DL



cause 6 : distance



causes 10 and 11 : inner zone level UL/DL (concentric cells only)



causes 15 and 16 : intracell HO


MCD/CO/OC

Emergency handovers (2) 

Priority order : 

7, 17, 18, 2, 4, 3, 5, 6, 10, 11, 15 and 16

 Averaging

windows :



causes 2, 3, 4 and 5 : A _ LEV _ HO and A _QUAL _ HO



cause 6 : A _ R A NGE _ HO



causes 17 and 18 : A _ LEV _ MCHO


MCD/CO/OC

Candidate

cell evaluation process (1)

 The

HO detection process gives to the H O evaluation process 

the HO cause value



the preferred layer for the target cell indicated by the variable PREF_ LAYER



the list of potential candidates


MCD/CO/OC

Candidate

 List








of candidates :

emergency cause : all neighbouring cells better condition cause : the neighbouring cells which verify the cause special case of hierarchical network : if the serving CELL _ LAYER _ TYPE = lower, the HO cause = 12 and MS _ SPEED = fast, addition of the whole set of internal neighbouring umbrella cells not loaded ( AV _ LOAD(n) < L _ LOAD _OBJ(n) )


MCD/CO/OC

Candidate




Preferred layer : 

in a non hierarchical network : upper + single



in a hierarchical network : 



in case of emergency alarm : ±

upper if CELL _ LAYER _ TYPE = lower and E N_ RESCUE _ UM = E NABLE (used generally for micro cells)

±

lower if CELL _ LAYER _ TYPE = lower and E N_ RESCUE _ UM = DISABLE (used generally for mini cells)

±

none if CELL _ LAYER _ TYPE = lower and E N_ RESCUE _ UM = I NDEFI NITE

±

upper + single if CELL _ LAYER _ TYPE = upper

in case of better condition alarm : ±

upper if the serving MS _ SPEED = fast

±

none otherwise


_ TYPE CELL _ LAYER

MCD/CO/OC

= lower, the handover cause = 12 and

Candidate




Ordering of candidate cells : 

the improved cell evaluation process is the default process in B5 release



layer



PR IOR ITY(0,n) :





four values : 0, 1, 2, 3



from highest priority (0) to lowest one (3)

frequency band : 

serving cell frequency band



non serving cell frequency band


MCD/CO/OC

Candidate




Ordering of candidate cells : Frequency band = serving cell

Priority(0,n) = 0 _ type Cell _ layer

= Pref _ layer

Priority(0,n) = 1 Priority(0,n) = 2

List

of candidate cells n

Cell _ layer _ type


{

Priority(0,n) = 3

Pref _ layer

MCD/CO/OC

Frequency band { serving cell

Candidate



cell evaluation process ( 6)

Filtering process : 

a filtering process is possible before the ORDER or GR ADE evaluation process



enabled or disabled on E N_ PBGT _FILTER I NG

a

per

cell

basis

by

the

parameter



neighbouring cells n which do not fulfil the following condition are rejected from the list sent to the Order or Grade evaluation process : PBGT(n) > HO_ MAR GI N_ X X(0,n) + Cause _ Margin _ P _ X with HO_ MAR GI N_ XX(0,n) = HO_ MAR GI N_QUAL(0,n) if cause = 2, 4 or 7 = HO_ MAR GI N_ LEV(0,n) if cause = 3, 5, 6, 17 or 18 = HO_ MAR GI N(0,n) if cause = 12, 14 or 21



the filtering process does not take place in case of Forced Directed Retry


MCD/CO/OC

Classmark

handling (1)



Power capabilities of a dual band MS in each frequency band are contained in the Classmark 3



When the NSS supports dual band feature, the BSS has to forward CM2 without processing and CM3


MCD/CO/OC

Classmark



handling (2)

Parameters : 





BSS _ SE ND _ CM _ E NQUIR Y 

BSS



management of the Classmark Enquiry procedure in case of Location U pdating

E N_ SE ND _ CM3 

BSS



control of MS CM2 and MS CM3 sent to the MSC

STR IP _O5 _ CM2 

BSS



control of MS CM2 and MS CM3 sent to the MSC


MCD/CO/OC

Parameters and configurations


MCD/CO/OC

Neighbouring cells reporting and description

Cell

Classmark handling

Cell

selection

reselection

Few parameters are used to manage a dual band network Better condition handovers

Candidate


MCD/CO/OC

cell evaluation process

Dual band parameters (1) 

Neighbouring cells reporting and description : 

TI NG MULTIBA ND _ REP REPOR TI 



default value : 3

E N_ I NTERBA ND _NEIGH 

default value : enable


MCD/CO/OC

Dual band parameters (2)  Classmark 

BSS _ SE ND _ CM _ E NQUIR Y 



default value value : 1 = Classmark Enquiry in case of a Location U pdating Request message with ES I ND = 0

E N_ SE ND _ CM3 



handling :

default value : enable (assumption : the MSC fully supports MAP version 2. CM3 is sent by the BSC)

STR IP _O5 _ CM2 

default value : disable (assumption (assum ption : the MSC fully supports suppo rts MAP version 2. No stripping of byte 5 of MS CM2)


MCD/CO/OC

Dual band parameters (3)  Cell 

selection :

CELL _ BAR _QUALIFY 

 Cell 

re-selection :

CELL _ RESELECT _ PAR AM _ I ND 



default value : 0 (it seems that some MS are disturbed by C _ B _Q = 1)

default value : 1

CELL _ RESELECT _OFFSET, TEMPOR AR Y _OFFSET,

PE NALTY _ TIME 

default value : configuration dependent


MCD/CO/OC

Dual band parameters (4) 

Better condition handovers : 

PREFERRED _ BA ND 



E N_ PREFERRED _ BA ND _ HO 




MULTIBA ND _ LOAD _ LEVEL 



default value : new frequency band


L _ RXLEV _ CPT _ HO(n) 



MCD/CO/OC

Dual band parameters (5)  Candidate 

E N_ PBGT _FILTER I NG 



default value : enable

PR IOR ITY(0,n) 




default value : 0

HO_ MAR GI N_ LEV(0,n), HO_ MAR GI N_QUAL(0,n) 



MCD/CO/OC

Configurations



(1)

Possible configurations :

New dual band network

+ micro 900 + micro 1800 + micro 900 and 1800

1800 MHz Existing network

Macro 1800 not co-located 900 MHz

Hot spot Macro 1800 co-located Continuous


MCD/CO/OC

coverage

Configurations



(2)

Preliminary remarks : 



the speed discrimination process is always disable hereafter : 

this process is complicated : variable threshold MI N_ DWELL _ TIME according to the load of the umbrella cell



it is easier to use of fixed time threshold to have the same behaviour than in R3



it is possible to enable it in lower layer cells in order to send fast mobiles to upper layer cells

the improved cell evaluation process is the default process in B5 release


MCD/CO/OC

Configurations



(3)

Preliminary remarks : 

use of cause 21 or 14 : 

assumption : preferred band = 1800



cause 21 is used to go from 900 cells to 1800 cells



cause 14 is used to go from umbrella cells (900 or 1800) to micro or mini cells (900 or 1800)



cause 21 is checked before cause 14



if cause 21 is verified, cause 14 is not checked



it is mandatory to enable cause 14 if it is necessary to take the speed of the mobiles into account : case of micro cells or little mini cells



if there is a micro layer in the network : enable cause 14 on umbrella cells


MCD/CO/OC

Configurations



(4)

We will study hereafter two examples

 Aim

of these examples : show the use of the algorithms and parameters

 Values

: only given as examples


MCD/CO/OC

First example : 2 layers

macro 900 + macro 1800


MCD/CO/OC

Existing 900 MHz network + macro 1800 (1)  Idle 

mode :

Cell

selection : higher priority for macro 1800 cells CELL _ BAR _QUALIFY

1800

=0 900

CELL _ BAR _QUALIFY

=1

=> a dual band MS tries to select first a macro 1800 cell


MCD/CO/OC

Existing 900 MHz network + macro 1800 (2)  Idle 

mode :

Cell

re-selection : higher priority for macro 1800 cells CELL _ RESELECT _OFFSET =

126 dB

1800 900

CELL _ RESELECT _OFFSET =

C2(1800) = C1(1800)

+ 126

C2(900) = C1(900)

=> a dual band MS re-selects a macro 1800 cell Mobile Communication Division

MCD/CO/OC

0 dB

Existing 900 MHz network + macro 1800 (3)  Call

set-up :

macro 900

Cause

E N_ DR = Enable E N_FOR CED _ DR = Enable L _ RXLEV _NCELL _ DR(n) = -85 dBm FREElevel _ DR(n) = 4

20

macro 1800 E N_ DR = Enable E N_FOR CED _ DR = Enable L _ RXLEV _NCELL _ DR(n) = -85 dBm FREElevel _ DR(n) = 2 

Directed and Forced Directed Retry are enabled



cause 20 is triggered when the average level from a neighbouring cell is higher than -85 dBm


MCD/CO/OC

Existing 900 MHz network + macro 1800 (4)  Cell 



administration :

first solution : 

macro 900 = umbrella or single



macro 1800 = umbrella or single



absolutely possible to manage the network with this configuration but less flexibility : not possible to have a distinct behaviour in case of emergency HO and Forced DR

second solution : 

macro 900 = umbrella



macro 1800 = mini



distinct behaviour in case of Forced DR and emergency HO


MCD/CO/OC

Existing 900 MHz network + macro 1800 (5)  Umbrella

or single 900/1800 versus umbrella 900 + mini

1800 : 



umbrella 900/1800 or single 900/1800 : 

Forced DR : the traffic distribution is driven by the parameter PR IOR ITY(0,n) because Pref layer = none



emergency alarm : the traffic distribution is driven by the parameter PR IOR ITY(0,n) because Pref layer = upper + single

umbrella 900 + mini 1800 : 

Forced DR : the traffic distribution is driven by the parameter PR IOR ITY(0,n) because Pref layer = none



emergency alarm : the traffic distribution is first driven by the layer because Pref layer = upper + single for umbrella 900 cells and none or lower (according to the parameter E N_ RESCUE _ UM) for mini 1800 cells


MCD/CO/OC

Existing 900 MHz network + macro 1800 ( 6) 

Better condition handovers Cause

12

macro 900 umbrella

HO_ MAR GI N(0,n) = 5dB Cause

21

Cause Cause

14

12

macro 1800 mini

HO_ MAR GI N(0,n) = 5dB BSS parameters : PREFERRED _ BA ND = 1800 L _ MI N_ DWELL _ TIME = ? s


MULTIBA ND _ LOAD _ LEVEL = 0% E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 12

MCD/CO/OC

L _ RXLEV _ CPT _ HO(n)

= -85 dBm E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 10

Existing 900 MHz network + macro 1800 (7) 

Better condition handovers : 

cause 21 is triggered when a macro 1800 cell is received with an average level higher than -85 dBm and whatever the load of the macro 900 serving cell (MULTIBA ND _ LOAD _ LEVEL = 0%)



it is necessary to choose between causes 21 and 14 : cause 14 only in case of a hot spot macro 1800 + problems with fast mobiles



if cause 14 is used, it is triggered when a macro 1800 cell is received with an average level higher than -85 dBm during L _ MI N_ DWELL _ TIME seconds (E N_ SPEED _ DISC = Disable)



cause 12 is used to make intra-layer handovers (PBGT(n) > 5dB)


MCD/CO/OC

Existing 900 MHz network + macro 1800 (8)  Candidate

cell evaluation process PR IOR ITY(0,n) = 1 HO_ MAR GI N(0,n) = 5dB HO_ MAR GI N_ LEV(0,n) = 5dB HO_ MAR GI N_QUAL(0,n) = 5dB

PR IOR ITY(0,n) = 0 HO_ MAR GI N(0,n) = -127 dB HO_ MAR GI N_ LEV(0,n) = -127 dB HO_ MAR GI N_QUAL(0,n) = -127 dB

PR IOR ITY(0,n) = 0 HO_ MAR GI N(0,n) = 5dB HO_ MAR GI N_ LEV(0,n) = 5dB HO_ MAR GI N_QUAL(0,n) = 5dB

macro 900 umbrella E N_ PBGT _FILTER I NG = Enable CELL _ EV = GR ADE RXLEVmin(n) = -100 dBm

macro 1800 mini

PR IOR ITY(0,n) = 1 HO_ MAR GI N(0,n) = 5dB HO_ MAR GI N_ LEV(0,n) = 5dB HO_ MAR GI N_QUAL(0,n) = 5dB


MCD/CO/OC

E N_ RESCUE _ UM = Indefinite E N_ PBGT _FILTER I NG = Enable CELL _ EV = GR ADE RXLEVmin(n) = -100 dBm

Existing 900 MHz network + macro 1800 ( 9)  Candidate 




Forced DR : 

macro 1800 -> macro 900




emergency handover : 






MCD/CO/OC

Second

example : 3 layers

macro 900 + micro 900 + macro 1800


MCD/CO/OC

Macro 900 + micro 900 + macro 1800 (1)  Idle 

mode :

Cell

selection : higher priority for macro 1800 cells

CELL _ BAR _QUALIFY

1800

=0

_QUALIFY CELL _ BAR

=1

µ 900 900

_QUALIFY CELL _ BAR

=> a dual band MS tries to select first a macro 1800 cell Mobile Communication Division

MCD/CO/OC

=1


mode :

Cell

re-selection :



higher priority for macro 1800 or micro 900 cells



higher priority for a corporate micro 900 cell = indoor coverage


MCD/CO/OC


mode :

Cell

re-selection : micro 900 (slow mobiles) > macro 1800 > macro 900 CELL _ RESELECT _OFFSET =

20 dB TEMPOR AR Y _OFFSET = 0 dB PE NALTY _ TIME = 20 s

1800

µ 900

CELL _ RESELECT _OFFSET =

40 dB TEMPOR AR Y _OFFSET = 60 dB PE NALTY _ TIME = 20 s 900 CELL _ RESELECT _OFFSET =


C2(1800) = C1(1800) + 20 C2(900) = C1(900) C2(µ 900)

= C1(µ 900) + 40 dB µ 900 serving cell or after 20 s of monitoring = C1 - 20 dB otherwise


MCD/CO/OC


mode :

Cell

re-selection : macro 1800 > micro 900 (slow mobiles) > macro 900 CELL _ RESELECT _OFFSET = 60

1800

TEMPOR AR Y _OFFSET =

dB

µ 900

0 dB

PE NALTY _ TIME = 20 s CELL _ RESELECT _OFFSET =

30 dB TEMPOR AR Y _OFFSET = 60 dB PE NALTY _ TIME = 20 s 900 CELL _ RESELECT _OFFSET =


C2(1800) = C1(1800) + 60 C2(900) = C1(900) C2(µ 900)

= C1(µ 900) + 30 dB µ 900 serving cell or after 20 s of monitoring = C1 - 30 dB otherwise


MCD/CO/OC

Macro 900 + micro 900 + macro 1800 (5)  Cell

administration :



macro 900 and 1800 cells = umbrella



micro 900 = micro



with umbrella and micro cells cause 14 is available


MCD/CO/OC

Macro 900 + micro 900 + macro 1800 (6)  Call

set-up Macro 900 Cause

20

Cause

E N_ DR = Enable E N_FOR CED _ DR = Enable L _ RXLEV _NCELL _ DR(n) = -85 dBm FREElevel _ DR(n) = 4 Macro 1800

20

Cause

20

E N_ DR = Enable E N_FOR CED _ DR = Enable L _ RXLEV _NCELL _ DR(n) = -85 dBm FREElevel _ DR(n) = 2 Micro 900

Avoid

to send fast mobiles towards the micro 900 layer on cause 20 : L _ RXLEV _NCELL _ DR(n) = -47 dBm


MCD/CO/OC

E N_ DR = Enable E N_FOR CED _ DR = Enable L _ RXLEV _NCELL _ DR(n) = -47 dBm FREElevel _ DR(n) = 16

Macro 900 + micro 900 + macro 1800 (7) 

Better condition handovers : corporate micro 900 > macro 1800 > macro 900 Cause

Macro 900 Cell _ dimension _ type = macro Cell _ layer _ type = upper MULTIBA ND _ LOAD _ LEVEL = 0% E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 12

12


21 Cause Cause

12



12

BSS parameters : PREFERRED _ BA ND = 1800 L _ MI N_ DWELL _ TIME = 8 s


14

Macro 1800 Cell _ dimension _ type = macro _ type = upper Cell _ layer = -85 dBm E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 10 Micro 900 Cell _ dimension _ type = micro _ type = lower Cell _ layer

HO_ MAR GI N(0,n) = 5dB L _ RXLEV _ CPT _ HO(n)


MCD/CO/OC


Better condition handovers : corporate micro 900 > macro 1800 > macro 900 : 

if a macro 1800 cell and a micro 900 cell are available, a dual band MS is sent to the micro 900 cell after 2 handovers : 

first HO on cause 21 between the macro 900 cell and the macro 1800 cell



second HO on cause 14 between the macro 1800 cell and the micro 900 cell



a dual band MS is sent directly (1 HO) to the micro 900 cell only if cause 21 is not triggered



cause 12 is used for intra-layer handovers


MCD/CO/OC


Better condition handovers : macro 1800 > public micro 900 > macro 900 Cause

Macro 900 Cell _ dimension _ type = macro _ type = upper Cell _ layer

12 Macro 1800 Cell _ dimension _ type = macro _ type = upper Cell _ layer

HO_ MAR GI N(0,n) = 5dB

MULTIBA ND _ LOAD _ LEVEL = 0% E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 12

Cause

21 Cause

12

Cause

14




21 Cause

12

BSS parameters : PREFERRED _ BA ND = 1800 L _ MI N_ DWELL _ TIME = 8 s



MCD/CO/OC

Micro 900 Cell _ dimension _ type = micro _ type = lower Cell _ layer MULTIBA ND _ LOAD _ LEVEL = 0% L _ RXLEV _ CPT _ HO(n) = -85 dBm E N_ SPEED _ DISC = Disable A _ PBGT _ HO = 6


Better condition handovers : macro 1800 > public micro 900 > macro 900 : 

if a macro 1800 cell and a micro 900 cell are available, a dual band MS is sent to the macro 1800 cell on cause 21 and then stays on this layer



a dual band MS is sent to the micro 900 cell only if cause 21 is not triggered. Then it is sent to the macro 1800 layer (higher priority) on cause 21



cause 12 is used for intra-layer handovers


MCD/CO/OC

Macro 900 + micro 900 + macro 1800 (11)  Candidate

cell evaluation process PR IOR ITY(0,n) = 0 HO_ MAR GI N_ XX(0,n) = 5 dB

Macro 900 E N_ PBGT _FILTER I N G = Enable CELL _ EV = GR ADE RXLEVmin(n) = -100 dBm

PR IOR ITY(0,n) = 1 HO_ MAR GI N_ XX(0,n) = 5 dB


PR IOR ITY(0,n) = 0 HO_ MAR GI N_ XX(0,n) = -127 dB



Macro 1800 E N_ PBGT _FILTER I N G = Enable CELL _ EV = GR ADE RXLEVmin(n) = -100 dBm



Micro 900 PR IOR ITY(0,n) = 0 HO_ MAR GI N_ XX(0,n) = 5 dB


MCD/CO/OC

E N_ RESCUE _ UM = Enable E N_ PBGT _FILTER I N G = Disable CELL _ EV = ORDER RXLEVmin(n) = -100 dBm

Macro 900 + micro 900 + macro 1800 (12)  Candidate




the values are only given for example



with these values : 

serving cell = micro 900 : ±



serving cell = macro 900 : ±



FDR and emergency alarm : macro 900 > macro 1800

serving cell = macro 1800 : ±





HO_ MAR GI N_ XX(0,n) = -127 dB between a macro 1800 cell and a macro 900 cell : no PBGT filtering because the macro 900 layer is seen as a rescue layer


MCD/CO/OC

Other aspects (1) 

Hot spot and continuous coverage : 

2 differences : 

behaviour in case of emergency HO : ±



if the coverage provided by the macro 1800 layer is good enough, it is possible to give a higher priority to this layer (use of E N_ RESCUE _ UM or PR IOR ITY(0,n))

way to exit a macro 1800 cell : ±

continuous coverage and cell at the center of the 1800 area : cause 12 (PBGT)

±

hot spot : emergency alarm on level or quality with the risk to stay a long time on the macro 1800 cell and to be unable to find a macro 900 neighbouring cell


MCD/CO/OC

Other aspects (2)  Continuous

coverage :



it is necessary to distinguish inner cells located at the center of the 1800 area from outer cells located at the border of the 1800 area



difference : the way to exit the macro 1800 cell



outer cell : use same set of parameters than for a hot spot (zone exit)


MCD/CO/OC


1800 cells co-located or not with 900 cells : 

1800 cells co-located with 900 cells : levels are correlated. It is sensible to take into account the difference in propagation losses with an offset of 10-12 dB



1800 cells not co-located with 900 cells : levels are not correlated. No offset


MCD/CO/OC


Multi vendor environment : 

macro 900 = one vendor, macro 1800 = another vendor



not the best technical solution



no change in parameters



inter-band HO = inter-BSC HO : the operator has less possibilities to manage its network (example : traffic load in the other band not known)



external Directed Retry only available with Alcatel and Ericsson MSC


MCD/CO/OC


Existing 1800 MHz network : 

case identical to the case of an existing 900 MHz network



2 differences : 

because propagation losses are lower in the 900 band, it is a good idea to give a higher priority to this band in case of emergency alarm



the 1800 operator may use the new frequency band to cover rural areas


MCD/CO/OC


Existing 1800 MHz network Urban

area = 1800 area Cause

12

Rural area = 900 area Cause

21

Cause

12 BSS parameters :




Macro 900 Cell _ dimension _ type = macro _ type = single Cell _ layer

MULTIBA ND _ LOAD _ LEVEL = 0% A _ PBGT _ HO = 10



A _ PBGT _ HO

MCD/CO/OC

= 12

= -85 dBm

PREFERRED _ BA ND = 900

S pecial


sets of parameters

MCD/CO/OC

Zone

exit on preventive handover

 The

risk with the default parameters is to stay a long time connected to a macro 1800 cell when leaving the 1800 area.



New set of parameters in order to anticipate the zone exit : 

L _ RXLEV _ DL _ H

= normal value + 10 dB



use of the filtering process macro 900

HO_ MAR GI N_ LEV(0,n) = 20 dB

HO_ MAR GI N_ LEV(0,n) = -127 dB

macro 1800

Exit of the macro 1800 area HO_ MAR GI N_ LEV(0,n) = 8 dB Use


of a high L _ RXLEV _ DL _ H

MCD/CO/OC

Capture



threshold set on a per cell basis (1)

Example : a real network is made up of public and corporate micro cells Macro 900 Cell _ dimension _ type = macro _ type = upper Cell _ layer Cause Cause

14

21 Cause

14

Macro 1800 Cell _ dimension _ type = macro Cell _ layer _ type = upper Cause

Micro 900 Cell _ dimension _ type = micro _ type = lower Cell _ layer


public

MCD/CO/OC

14

corporate

Capture

 Solution

threshold set on a per cell basis (2)

:



modify the parameter Cause _ Margin _ P _ 14 on macro 1800 cells (= 60 dB)



use of the filtering process : 

HO_ MAR GI N(0,n) = 5 dB between a macro 1800 cell and a public micro 900 cell



HO_ MAR GI N(0,n) = -127 dB between a macro 1800 cell and a corporate micro 900 cell


MCD/CO/OC

Tuning


MCD/CO/OC

Idle



mode

Re-selection : 



in the tuning of the parameters CELL _ RESELECT _OFFSET and TEMPOR AR Y _OFFSET it is necessary to take into account : 

the difference of propagation losses between 900 and 1800 MHz if 900 and 1800 cells are co-located



the value of RXLEV _ ACCESS _ MI N

a good choice of re-selection parameters is necessary to avoid emergency handovers


MCD/CO/OC

Connected

 Call 

set-up :

FDR : tune L _ RXLEV _NCELL _ DR(n) to avoid quality problems in the target cell

 Capture 



mode

handover :

use the parameter MULTI _ BA ND _ LOAD _ LEVEL in order to reduce the number of inter-band HO (cause 21) be careful with the value of the capture thresholds to avoid emergency handovers and ping-pong HO


MCD/CO/OC

Other aspects 

Neighbouring cells : 

number limited to 32 BCCH



limit easily reached in a network with 3 or 4 layers



special care must be taken when defining the list of neighbouring cells


MCD/CO/OC

Problems of B5 release


MCD/CO/OC

Detection of better condition H O causes (1) 

Description of the problem : 

when a handover cause is verified, handover causes with a lower level of priority are not checked



behaviour problematic in a multi-layer, multi-band network : 

if the neighbouring cell which has triggered the handover cause with the level of priority n is not accessible (congestion for example) it is not possible to make a handover towards a neighbouring cell using a handover cause of priority n-1 or n-2



it is much more complicated to manage the priority between the different layers. Indeed, the use of the parameter PR IOR ITY(0,n) is limited to a group of neighbouring cells (lower layer cells, preferred band cells, «)


MCD/CO/OC


Example : 

cause 21 triggered but macro 1800 cell congested



micro 900 cell not accessible Cause

12

Macro 900 Cell _ dimension _ type = macro _ type = upper Cell _ layer Cause


Cause

12

Cause



Cause

MCD/CO/OC

21

12

14

Cause

21


Example : 

high priority for the micro 900 layer but cause 21 triggered : 2 HO to reach the micro 900 layer Macro 900 Cell _ dimension _ type = macro _ type = upper Cell _ layer

Cause

12

Cause


Cause

12

Cause



Cause

MCD/CO/OC

12

14

21

Cause



Description of the problem : 



21 and micro 1800 cells (1)

avoid cause 21 towards a micro 1800 cell (no speed discrimination)

Example :

Cause

12

Macro 900 Cell _ dimension _ type = macro _ type = upper Cell _ layer Cause

21 Cause

Macro 1800 Cell _ dimension _ type = macro Cell _ layer _ type = upper

12

Cause Cause



MCD/CO/OC

12

14

Alcatel's Parameter

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