BSS Optimization Workshop Presentations

1 © Nokia Siemens Networks
BSS Optimisation Workshop
Denpasar Bali
Oct 21-25, 2013
NSN – TSEL

Idle Parameter Optimization
Power Control Parameter
Handover Control parameter
Radio Resource Administration
Radio resource Management
KPI case
Measurement processing

Radio Resource Administration

TDMA frame
= 8 timeslots
( 0.577ms * 8 = 4.615 ms)
0
1
3
4
5
7
6
0
1
2
3
4
5
7
6
0
1
2
3
4
5
200 kHz
Physical channel
e.g. allocated to one
subscriber with FR voice
and no frequency hopping
frequency
time
TDMA frame
2
2 2 2
Basic TDMA Structure

Base Station
Subsystem
Logical Channels
for transport of specific content
Physical Channels
transport medium
MS
mapping
Physical channel parameters
ARFCN
Time slot number
Frequency hopping algorithm
GSM Channel Organization

SCH
FCCH
PCH
BCCH
AGCH
RACH
SDCCH
SACCH
FACCH
Stand alone Dedicated Control Channel
Frequency Correction Channel
Synchronisation Channel
Broadcast Control Channel
Paging Channel
Slow Associated Control Channel
Fast Associated Control Channel
Paging Channel
Random Access Channel
Access Grant Channel
BCH
CCCH
DCCH
TCH
DL
DL
DL
UL
Common
Channels
Dedicated
Channels
UL/DL
UL/DL
CBCH Cell Broadcast Channel
Logical Channels
FR/HR Full rate / Halft rate TCH
EFR Enhanced Full rate TCH
AMR FR/HR Adaptive multirate TCH (FR/HR)

f s ff s f s
Downlink
51 TDMA frames = 235 ms
-
Uplink
BCCH CCCH
f s f s
CCCH CCCH
r r f r r rr r r r fr r r r r rr r r r fr r r r rr f r r
1 51
CCCH CCCH CCCH CCCH CCCH CCCH
r rr r rr r r r r r r rr r r r r rr rr r r
f = FCCH, s = SCH, r = RACH TDMA frame
- = dummy burst
1 51
Signalling Channel Mapping
(BCCH +CCCH/9)

f s ff s f s
Downlink
-
Uplink
BCCH CCCH
f s f s
CCCH CCCH
SDCCH 0
SDCCH 1
SDCCH 2
SDCCH 3
SACCH
0/2 SACCH
1/3
r r f r r rr r r r fr r r r r rr r r r fr r r r rr f r r
1 51
SACCH
2/0 SACCH
3/1
SDCCH 0
SDCCH 1SDCCH 3
SDCCH 2
f = FCCH, s = SCH, r = RACH TDMA frame
- = dummy burst
1 51
(BCCH + SDCCH/4 + SACCH/C4)

...
1 26
t t tt t t t ft tt t t tt t t tt ft t t ttts i
Full Rate Traffic Channel Configuration (UL & DL)
Half Rate Traffic Channel Configuration (UL & DL)
1 26
t
T T
t t
T
t
f
t t
T T T T
t t
T
t
T
f
T
t
T
tt
T
s
S
t = full rate TCH, s = SACCH/T, i = idle TDMA frame
t = half rate TCH, s = SACCH/T (first user)
T = half rate TCH, S = SACCH/T (second user) TDMA frame
Traffic Channel Mapping

f
f
i = idle TDMA frame
f
iii
iii
SDCCH 0
SDCCH 1
SDCCH 2
SDCCH 3
SDCCH 4
SDCCH 5
SDCCH 6
SDCCH 7
SDCCH 1
SDCCH 2
SDCCH 3
SDCCH 4
SDCCH 5
SDCCH 6
SDCCH 7
SDCCH 0
Downlink
Uplink
SACCH
0/4 SACCH
1/5
SACCH
2/6 SACCH
3/7
SACCH
6/2 SACCH
7/3
SACCH
4/0SACCH
5/1
1 51
1 51
(SDCCH/8 +SACCH/C4)

New improved CCCH features in RG10
•BSS20738 CS Paging Coordination in NMO II
•BSS21538 Extended CCCH
– Extended CCCH can be allocated to timeslot 2,4,6
•BSS101411 Extended BCCH
– For example Uncombined BCCH

Channel configuration defined by parameter channelType
TCHF (0) = full rate traffic channel
TCHH (1) = half rate traffic channel
TCHD (2) = dual rate traffic channel
SDCCH (3) = standalone (SDCCH/8)
MBCCH (4) = broadcast control channel
MBCCHC (5) = BCCH + SDCCH/4
MBCCB (7) = BCCH + SDCCH/3 with CBCH
SDCCB (8) = SDCCH/7 with CBCH
NOTUSED (9) = timeslot has no radio definition or Abis allocation
ERACH (10) = random access channel of extended area
EGTCH (14) = EGPRS packed data traffic channel for extended area
LRTCH (15) = long reach traffic channel
Channel Mapping
Parameter Setting
Note:
• Some values not allowed in certain tsl (e.g. TSL0
can’t have value 8)
• PBCCH is not supported in S13 and onwards
MO Class TR/RTSL
Parameter channelxType (CHx) where x = 0…7

Mobile terminating call -> MSC performs paging
MS identifies paging message with the IMSI/TMSI
MS listens to own paging group only
SEG-BTS parameters
MSC parameters
Repaging Interval (INT) 0.5s…10s Time between consecutive paging
attempts
Repaging Attempts (AT) 0…5 Number of paging repetitions
Buffering
BTS stores up to 8 paging messages of the MSC in page group buffer
BTS sends paging messages to MS according noOfMultiframesBetweenPaging
Paging Channel (PCH) Parameters
MO
Class
Abbreviated
Name
Range
And Step
Description Default
value
BSC - MML
Name
BTS noOfMFramesB
etweenPaging
2...9, step
1
Defines the number of multiframes between
two transmissions of the same paging
message to the MSs of the same paging
group.
4 MFR

Mobile sends channel requests to BTS separated by random time intervals in case of no answer!
Parameters
Random time interval between consecutive retransmissions
t = S + random [0,.. numberOfSlotsSpreadTrans – 1] RACH slots
S depends on numberOfSlotsSpreadTrans
signalling channel mapping (CCCH + SDCCH combined or not in one multi frame)
numberOfSlotsSpreadTrans = 10
signalling channel mapping = not combined  S
= 58
Therefore t = 58..to..67 RACH slots
time channel requests
RACH Parameters
MO
Class
Abbreviated
Name
Range And Step Description Default
value
BSC - MML
Name
BTS maxNumberRetra
nsmission
1,2,4,7 Maximum number of retransmissions on the RACH
that the MS can perform.
4 RET
BTS nbrOfSlotsSpread
Trans
MML Range:
3..12, 14, 16, 20,
25, 32, 50
The number of TDMA frames over which
retransmission is spread on the RACH (random
access channel)
10 SLO

Network gives the MS dedicated resources
Downlink CCCH blocks
• PCH can be used for AGCH messages
• AGCH cannot be used for PCH messages
Reservation of CCCH blocks for AGCH
noOfBlocksForAccessGrant (AG) 0..7 possible number, if CCCH and SDCCH are not combined
1..7 possible number, if CBCH is used in non combined
configuration
0..2 possible number, if CCCH and SDCCH are combined
Preference of AGCH messages on PCH
noOfBlocksForAccessGrant ≠ 0 PCH can be used only, if no paging messages have to be
send
= 0 AGCH messages have higher priority than PCH ones
Number of paging groups
N = (number of CCCH blocks – noOfBlocksForAccessGrant) * noOfMultiframesBetweenPaging
AGCH Parameters

Combined CCCH / SDCCH configuration
noOfBlocksForAccessGrant = 1  2 CCCH blocks for PCH
3 MSs paged per paging message  3 pages per block
2 blocks per multi frame  3 * 2 = 6 pages per multiframe
Number of pages per hour  3600 s / 0.235 s * 6 = 91915
Avg of 2 pages required per MS  91915 / 2 = 45957 MSs per
hour
BTS 3 MS
Paging_Request
BTS 3 MS
Paging_Request
Paging Capacity
Example

Cell with 325 subscribers
1 call per subscriber once in a hour
1 location update (LU) per subscriber once in 2 hours
Duration of call assignment = 4 s  4 s / 3600 s = 1.11 mErl on SDCCH per
subscriber
325 subscribers  325 * 1.11 mErl = 0.3607 Erl on SDCCH
Reservation time for LU = 5s 5 s / 7200 s = 0.69 mErl on SDCCH per subscriber
325 subscribers  0.2242 Erl on SDCCH
Total SDCCH traffic  0.3607 Erl + 0.2242 Erl = 0.5849 Erl
Blocking probability = 1%  4 SDCCHs required  SDCCH combined
with CCCH can be used (MBCCHC)
SDCCH Signalling Capacity
Example with call Establishment & Location Update

Same cell with 325 subscribers
Additional SMS traffic of 1 mErl per subscriber
325 subscribers  325 * 1 mErl = 0.325 Erl on SDCCH
Total SDCCH traffic  0.5849 + 0.325 Erl = 0.9099 Erl
Blocking probability = 1%  5 SDCCHs required  not combined with
CCCH (MBCCH)
SDCCH Signalling Capacity
Example including SMS

Base Station Identity Code BSIC = Network Colour Code NCC + Base Station Colour Code BCC
bsIdentityCode Setting of BSIC
NCC 0..7, distinguishes between PLMNs
BCC 0..7, distinguishes between clusters
BSIC + frequency channel  unique identity of adjacent cell
f1
f2
f3
f1
f1
bcc = 1
bcc = 2
bcc = 3
Base Station Identity Code

200 kHz
890 915 935 960
1 2 3 4 124123 1 2 3 4 124123
duplex distance
Absolute radio frequency carrier number ARFCN
uplink direction downlink direction
Example: GSM 900
Defining Frequency carrier number

Frequency to be used by TRX (must be unique within a BTS)
initialFrequency (FREQ) 1…1023 Setting of ARFCNs
GSM 800: 128 .. 251
GSM 900: 1..124 and 975..1023, 0
GSM 1800: 512..885
GSM 1900: 512..810
f1
f2
f3
f4
f5
f6
f7
f1
f2
f3
f4
f5
f6
f7
f1
f2
f3
f4
f5
f6
f7
Frequency Reuse

Frequency
Time
F1
F2
F3
Call is transmitted through several frequencies to
• average the interference (interference diversity)
• minimise the impact of fading (frequency diversity)
Frequency hopping techniques
hoppingMode (HOP) BB,RF,N
BB = base band hopping (1)
RF = RF hopping (2)
N = no frequency hopping at all (0)
Principle of Frequency Hopping

Baseband Hopping
TRX 1
TRX 2
TRX 3
0 1 72 Timeslot
TRX 4
BC
CH
f 1
f 2
f 3
f 4
HSN1 (BB hopping group 1 and RF hopping)
Timeslot 0 hops over TRXs 2-4 only
BCCH does not hop
HSN2 (BB hopping group 2)
Timeslots 1-7 hop over all TRXs
TRXs do not hop
Physical channels moved from one TRX to another
Hopping sequence
hoppingSequenceNumber (HSN) 0..63
0 = cyclic hopping
1..63 = pseudorandom hopping
Base Band Hopping

RF Hopping
Standard technique
TRX 1
TRX 2
TRX 3
0 1 72 Timeslot
TRX 4
BC
CH f1 – no hopping
f2,f3..fn – hopping according
mobile allocation list
One hopping sequence
number only
All TRXs hop except TRX1 (provides BCCH)
Up to 63 frequencies available defined by mobile allocation list -> better hopping gain
mobileAllocationList Setting of ARFCN values
usedMobileAllocation (MAL) 0,1...2000 0 = BTS detached from any list
1..2000 = indicates list which shall be used

Standard technique
9 hopping hopping frequencies MAI = 0..8
But 3 frequencies available for every TRX only
Freeform hopping
For every sector same
mobile allocation list
hopping sequence number
frame number (frame synchronization)
For every sector different
starting points for hopping sequence
possible by mobile allocation index offset
maioOffset (MO) 0..62
setting of MAIO
9 hopping hopping frequencies MAI = 0..8
9 frequencies available for every TRX
RF Hopping
Freeform Hopping

Freeform hopping
• Not adequate for MA list with consecutive ARFCN
values
• Avoids co-channel interference but not adjacent
channel interference
Flexible MAIO management
MAIO increases with constant step size from one TRX
to the next one
maioStep (MS) 1..62
maioOffset = 0, 6, 12 for sector 1, 2, 3
maioStep = 2
18 frequencies required (2 * number of hopping TRXs)
RF Hopping
Flexible MAIO Management

BCCH
Band allocation:
MA list
Consecutive ARFCN
Only BCCH frequency planning required
Only BCCH frequency planning required
Flexible MAIO management
MAIO Offset + MAIO Step
BCCH
Band allocation:
MA list
Non-adjacent ARFCN
Freeform hopping
MAIO Offset
MA list and BCCH frequency planning required
MA list and BCCH frequency planning required
RF Hopping (Tight Frequency Reuse)

Changing Frequency Plan
BSIC / TSC
Frequencies
Frequency hopping setting
Intelligent underlay overlay TRX settings
• Plan downloaded to BSC/BTSs via MML or GUI
• File-based plan provisioning
• Immediate Plan activation method

Idle Mode Operation

• When the MS is switched ON
• When there is no dedicated connection
When?
• To camp on the best suitable cell
Why?
• For MS to receive system info from the NW on DL
• For MS to be able to initiate a call whenever needed
• For the NW to be able to locate the MS when there is a
MT call/SMS
Why to camp on a specific cell?
• PLMN selection
• Cell selection & re-selection
• Location updates
Idle Mode Tasks
Idle Mode OperationI
MS switched ON
Search RF channels
to find BCCH carrier
Check that the PLMN
& cell is allowed
MS camps on
the best
suitable cell
See slide 10 for detail

Value
LAI (locationAreaId)
• NCC (Network Colour Code) 0 … 7
• BCC (BTS Colour Code) 0 … 7
BSIC (bsIdentityCode)
CI (cell-ID 0 … 65535
Parameter
TSC (trainingSequenceCode) 0 … 7
• MCC (Mobile Country Code) 0 … 999
• MNC (Mobile Network Code) 0 … 99,
0… 999 (optional 3-digit MNC)
• LAC (Location Area Code) 1 … 65533
CGI (Cell Global Identity) MCC + MNC + LAC + CI
ID’s and ID Codes

Any cell
selection
Camped
on
any cell
Choose cell
cell found
no suitable
cell found
suitable cell found
leave
idle
mode
return
to idle
mode
Connected mode
(emergency call
only)
Any
cell re-
selection
trigger
cell
re-selected
no suitable
cell found
go here when no SIM in MS SIM inserted in MS
1
2
cell found
on selected
PLMN
(adopted from TS 43.022 V5.1.0 chap.
States and State Transition for Cell Selection

Camped
normally
(adopted from TS 43.022 V5.1.0 chap. 6
Connected
mode
Normal
cell selection
Stored list
cell selection
Choose cell
Normal
cell re-selection
go here whenever a
new PLMN is selected
BA list stored
for PLMN
no BA list stored
for PLMN
1
no suitable cell found
suitable cell foundsuitable cell found
trigger
Suitable cell
re-selected
no suitable
cell found
suitable cell found
leave
idle
mode
return
to idle
mode
no
suitable
cell
found
no suitable
cell found
• IMSI unknown
• Illegal MS
• PLMN not allowed
2
2
States and State Transition for Cell Selection

Normal Cell Selection
Search all the RF channels, take samples during
3-5 s and calculate averages. And put them in
ascending order with respect to signal level.
Then tune to the strongest RF channel.
Search for the frequency correction burst in that
carrier in order to verify if it is a BCCH carrier
Camp on the cell
Try to synchronize to the carrier and read
the BCCH data
Is it a BCCH
carrier?
Is it a correct
PLMN ?
Is the cell barred?
Is C1>0
Tune to the next highest
RF channel which is not
tried before
No
No
No
No
Yes
Yes
Yes
Yes

I am
outside
I am inside, but
have not enough
power
C1 = A – max(B,0)
= RLA_C – RXLEV_ACCESS_MIN – max(MS_TXPWR_MAX_CCH – P , 0)
RLA_C = avg received RxLev on BCCH
P = MS max output power
max(B,0)
0..63 0..31
Pathloss Criterion C1 for Cell Selection
and Reselection

Cell1
LAC1
C1 ( Cell1) C1 (Cell2)
A B C
A= 4 dB
B= 6 dB
C= 8 dB
Cell2
LAC2
In case the neighbouring cells belong to different Location Area, a hysteresis is
applied with C1 criteria
• minimizing ping-pong cell reselections
• cellReselectHysteresis (HYS)(BTS) (0…14 dB)
Cell Selection with C1

C1 + CELL_RESELECT_OFFSET – (TEMPORARY OFFSET * H(PENALTY_TIME - T))
for PENALTY_TIME ≠ 640 s
< C1 if temporary offset big for PENALTY_TIME = 640 s
C2 =
serving cell:
• C2:
List of 6
strongest
carriers:
• C2:
• C2:
• C2:
• C2:
• C2:
• C2:
0 .. 126 dB
step size: 2 dB
0, 10, 20, 30, 40,
50, 60, ∞ dB
20 .. 640 s
step size: 20 s
PENALTY_TIME
TEMPORARY OFFSET
CELL_RESELECT_OFFSET
C1
C2
T
new candidate
= formerly non-
serving cell
CELL_RESELECT_OFFSET
C1
C2
T
new candidate
= former serving
cell
no TEMPORARY OFFSET
Pathloss Criterion C2

cell 1
cell 2
cell 3
C2
time5 seconds
cell
reselection
5 seconds
CELL_RESELECT_
HYSTERESIS (HYS)
LAC = A LAC = B
cell reselection &
location update
Cell Reselection Based on Pathloss
Criterion C2

Cell "A" Cell "B" Cell "C" Cell "D"
cellReselectOffset 0 dB 20 dB 0 dB 0 dB
temporaryOffset 0 dB 30 dB 0 dB 30 dB
penaltyTime 20 s 20 s 20 s 40 s
Micro 900 "D"
Macro 1800 "B"
Macro 900 "A"
Macro 900 "C"
Road
Parameters
=30 Cell "A" (Serving Cell)
=25 Cell "B"
=5 Cell "C"
=50 Cell "D"
=30 + 0 (H(x)=0, serving cell) Cell "A"
=25 + 20 - 30*H(20 - T) Cell "B"
=5 + 0 - 0*H(20 - T) Cell "C"
=50 + 0 - 30*H(40 - T) Cell "D"
C1
C2 = C1 + cellReselectOffset -
temporaryOffset*H(penaltyTime-T)
C2
Time T: (0 - 19 s)
C2 =30 Cell "A"
C2 =15 Cell "B"
C2 =5 Cell "C"
C2 =20 Cell "D"
Time T: (20 - 39 s)
C2 =30 Cell "A"
C2 =45 Cell "B"
C2 =5 Cell "C"
C2 =20 Cell "D"
Time T: (> 40 s)
C2 =30 Cell "A"
C2 =45 Cell "B"
C2 =5 Cell "C"
C2 =50 Cell "D"
Cell Reselection Based on Pathloss
Criterion C2

When shall I
select a new cell?
C1 ≤ 0 for a period of 5 s
• neighbour‘s C2 value >
current cell‘s C2 value (same LA)
• neighbour‘s C2 value >
current cell‘s C2 value + HYS
(new LA)
for a period of 5 s.
Downlink Signalling Failure
DSC ≤ 0
RACH Failure
MAX RETRANS + 1 times
Authentication Failure
notification by upper layers
Cell has been barred
CELL_BAR_ACCESS & CELL_BAR_QUALIFY
Cell Reselection Events

Location Update Procedure
BSS MSC VLR HLR
REQUEST SUBSCRIBER INFO
ALL OK - HLR UPDATE
MS
LOCATION UPDATE REQUEST
SEND SUBSCRIBER ID
REQUEST SUBSCRIBER ID
SEND SUBSCRIBER INFO
AUTHENTICATION
AUTHENTICATION RESPONSE

Paging
LocUp
# of cells in Loc. area
signalling
traffic
optimum number
of cells in Loc. area
function of user density,
cell size, call arrival rate ...function of
user mobility
Trade-off between Location Update and
Paging Traffic

Location Updates
• MS location & status flag => MSC / VLR
• Mobile Station switched ON mode
– IMSI Attach / Detach
– Same Location Area => No Location Update
– Different Location Area => Location Update
• Change of the Location Area
– Location Area under the same MSC / VLR
– Location Area under another MSC / VLR => HLR will be updated
• Service is rejected (MS unknown in VLR)
• Time-Periodic LU (MS -> MSC/VLR)
MO
Class
Abbreviated
Name
Range And
Step
Description Default
value
BSC -
MML
Name
BTS allowIMSIAtt
achDetach
Yes/No Defines whether IMSI attach/detach is used in the cell. Yes ATT
BTS timerPeriodic
UpdateMs
0...25.5 h,
step 0.1 h
Defines the interval between periodic MS location
updates.
The value 0 means that the periodic location update is
not used.
0.5 h PER

IDLE MODE OPERATION
Idle Mode Controls
Parameter Value
Access
Parameters
notAllowedAccessClasses 0 ... 9, 11 ... 15
emergencyCallRestricted Yes/No
msTxPwrMaxCCH 13 ... 43 (dBm)
rxLevAccessMin -110 ... -47 (dBm)
msMaxDistanceInCallSetup 0 ... 255
radiusExtension 0 ... 67 (Km)
cellBarred Yes/No
plmn-permitted 0 ... 7
cellReselectHysteresis 0 ... 14 (dB)
Mobility
Parameters
cellReselectOffset (REO) 0 ... 126 (dB)
cell reselection parameter index (PI) (N/Y)

IDLE MODE OPERATION
Idle Mode Controls definitions
• RxLevAccessmin :
With this parameter you define the minimum power level an MS has to receive before it is allowed to access the cell.
• MsTxPwrMaxCCH :
With this parameter you define the maximum transmission power an MS may use when accessing a CCH in the cell.
• notAllowedAccessClasses
With this parameter you define the MS access classes that are not allowed to access a cell.
• Emergency Call Restricted
With this parameter you define if an emergency call in the cell is allowed to all MSs or only to the MSs which belong to
one of the classes between 11 to 15. Value ’Y’ means the latter case.
• MsMaxDistancein CallSetup
With this parameter you define the maximum distance between the BTS and the MS in call setup. The maximum distance
is expressed as an access delay. Within the range of 0...62, one step correlates to a distance of 550 meters. If the
access delay of the channel request message exceeds the given maximum, the call attempt is rejected. When the
parameter is given a value from 63 to 255, call attempts are never rejected
• radiusExtention
With this parameter you define the radius extension of an extended cell

Radio Resource management

Channel request (RACH)MS NETWORK
Immediate assignmentImmediate assignment (AGCH)
Service request (SDCCH)
Service request
Authentication request (SDCCH)
Authentication response (SDCCH) Authentication
Ciphering mode command (SDCCH)
Ciphering mode complete (SDCCH) Ciphering mode setting
Setup (SDCCH)
Call initiationCall proceeding (SDCCH)
Assignment command (SDCCH)
Assignment complete (FACCH) Assignment of traffic channel
Alert (FACCH)
Call confirmation
Connect (FACCH)
Connect acknowledged (FACCH) Call accepted
Signalling (Mobile Originating Call)
Idle
parameter
Dedicated
parameter

Page request (PCH)MS NETWORK
Immediate assignmentChannel request (RACH)
Page response (SDCCH)
Service request
Authentication request (SDCCH)
Authentication response (SDCCH) Authentication
Ciphering mode command (SDCCH)
Ciphering mode complete (SDCCH) Ciphering mode setting
Setup (SDCCH)
Call initiationCall confirmation (SDCCH)
Assignment command (SDCCH)
Assignment complete (FACCH) Assignment of traffic channel
Alert (FACCH)
Call confirmation
Connect (FACCH)
Connect acknowledged (FACCH) Call accepted
Immediate assignment (AGCH)
Signalling (Mobile Terminating Call)
Idle
parameter
Dedicated
parameter

DisconnectMS NETWORK
Call clearingRelease
Channel release
Release
Release complete
DisconnectMS NETWORK
Call clearingRelease
Channel release
Release
Release complete
Network initiated
MS initiated
Signalling (Call Release)

MS capabilities
Channel rate : full, half, dual, multi rate
Speech codecs : normal FR, normal HR, EFR, AMR FR, AMR HR, doubleHR(OSC)
MSC demands
A interface circuit allocated for call
BTS demands
Speech codec capabilities
TCH configuration
Current resources
Homogeneous use of TRXs and radio time slots
Large free groups of radio time slots for high loaded HSCSD BTS
Standard TCH Allocation (General Criteria)

TCH Allocation
2 TRX=16 channels
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
12:00:00AM
2:00:00AM
4:00:00AM
6:00:00AM
8:00:00AM
10:00:00AM
12:00:00PM
2:00:00PM
4:00:00PM
6:00:00PM
8:00:00PM
10:00:00PM
RTSL
SDCCH
BCCH
PEAK_PERMANENT_GPRS_CH
AVE_GPRS_CHANNELS
AVE_TCH_BUSY_FULL
0 1 2 3 4 5 6 7
TRX1 BCCH SDCCH SDCCH V/D V/D V/D V/D V/D
TRX2 SDCCH SDCCH V/D V/D V/D V/D D D
TIME
AVE_SDCCH(SDCCH/8)
AVE_BUSY_SDCCH
PEAK_BUSY_SDCCH
AVE_AVAIL_FULL_TCH
AVE_TCH_BUSY_FULL
PEAK_BUSY_TCH
TCH_PEAK_BUSY_FULL
TCH_PEAK_BUSY_HALF
SDCCH_CONG_TIME(sec)
TCH_FR_RADIO_CONGESTION_TIME(sec)
TCH_HR_RADIO_CONGESTION_TIME(sec)
AVE_GPRS_CHANNELS
PEAK_GPRS_CHANNELS
PEAK_PERMANENT_GPRS_CH
12:00:00 AM 32 5.0 18 6.3 4.0 9 9 0 0 8.48 0 4.7 8 2
1:00:00 AM 32 3.1 13 6.8 3.4 9 9 0 0 1.41 0 4.2 9 2
2:00:00 AM 32 1.7 12 5.2 2.9 7 7 0 0 0 0 5.8 9 2
3:00:00 AM 32 1.5 12 6.2 1.4 7 7 0 0 0 0 4.8 9 2
4:00:00 AM 32 1.6 10 8.0 1.7 5 5 0 0 0 0 3.0 9 2
5:00:00 AM 32 8.8 32 5.7 0.8 6 6 0 559 0 0 5.3 9 2
6:00:00 AM 32 5.2 18 4.3 1.1 6 6 0 0 0 0 6.7 9 2
7:00:00 AM 32 6.5 23 8.5 2.6 8 8 0 0 0 0 2.5 6 2
8:00:00 AM 32 4.8 20 6.6 2.2 7 7 0 0 0 0 4.4 9 2
9:00:00 AM 32 4.3 20 6.8 2.4 8 8 0 0 0 0 4.3 9 2
10:00:00 AM 32 5.2 32 7.5 2.6 9 9 0 2 0.21 0 3.5 9 2
11:00:00 AM 32 5.9 18 6.3 2.9 9 9 0 0 8.98 0 4.7 9 2
12:00:00 PM 32 5.9 19 6.8 3.9 9 9 0 0 13.52 0 4.2 8 2
1:00:00 PM 32 7.3 24 6.4 3.4 9 9 0 0 8.96 0 4.6 9 2
2:00:00 PM 32 6.8 30 6.2 3.9 9 9 0 0 44.05 0 4.8 8 2
3:00:00 PM 32 7.1 21 6.7 4.7 9 9 0 0 64.18 0 4.3 9 2
4:00:00 PM 32 7.7 23 6.6 3.9 9 9 0 0 25.61 0 4.4 8 2
5:00:00 PM 32 8.5 23 6.7 3.9 9 9 0 0 34.51 0 4.3 9 2
6:00:00 PM 32 10.7 27 8.3 5.9 9 9 0 0 320.58 0 2.7 7 2
7:00:00 PM 32 11.1 28 8.4 5.6 9 9 0 0 217.77 0 2.6 9 2
8:00:00 PM 32 10.4 30 7.8 5.5 9 9 0 0 284.15 0 3.2 8 2
9:00:00 PM 32 9.3 26 7.5 5.3 9 9 0 0 217.65 0 3.5 8 2
10:00:00 PM 32 8.3 22 7.5 5.2 9 9 0 0 185.36 0 3.5 9 2
11:00:00 PM 32 5.8 21 6.8 4.6 9 9 0 0 89.61 0 4.2 9 2
How can be optimized?

Channel allocation ( For each TS)
Each TRX – have its own Quality both DL and UL and TRX with bad quality
(UL and DL) will result bad KPI on respective TRX
Each TRX – have its own Quality both DL and UL and TRX with bad quality
(UL and DL) will result bad KPI on respective TRX
Placing each Time Slot (BCCH, SDCCH, TCH and PDTCH) properly will result
good KPI (SDSR, DCR, HOSR TBF Completion rate)
Shitting SDCCH, BCCH can improve SDSR and DCRShitting SDCCH, BCCH can improve SDSR and DCR

Measurement of uplink receive level on idle channels = uplink interference
Averaging over interferenceAveragingProcessAverPeriod (AP) = 1..32 SACCH
periods
Classification into interference bands based on interferenceAveragingProcess
(BO1..BO4) = -110..-47 dBm
BSC tries to allocate TCH from best interference band (can be requested by MSC)
If not available,
BSC tries to take TCH from next band
0 71 2 3 4 5 6
rxLevUL = -75 dBm
BO5 –47 (fixed)
BO0 –110 (fixed)
BO4 -90
BO3 -95
BO1 -105
BO2 -100
Standard TCH Allocation
(Interference Bands)

Priority for TCH from BCCH TRX
BCCH transmitted permanently -> no additional interference in network
Planned to be least interfered channels
Priority for TCH from other TRX
BCCH TRX does not hop in case of RF hopping -> hopping gain only for other TRX
Parameter
trxPriorityInTCHAlloc (TRP) 0 = no priority
1 = priority for BCCH TRX
2 = priority for other TRX
3 = priority for BCCH TRX for non-AMR users,
priority for other TRX for AMR users
Prioritized TCH Allocation (TRP)
Whole band , 50 channels 1 ch=200kHz
BCCH, 30 channels TCH, 20 channels
All 50 channels for BCCH and TCH
Case1
Case2

Enables to differentiate Rx level requirement for:
• MS camping to the network /RxLev Access Min
• MS accessing to TCH /RX level based TCH access
RX level based TCH allocation method
• RX Level measured by the MS is used to determine whether the BTS is
acceptable for TCH allocation
• TCH allocation for emergency calls is not restricted due to low RX level
Provides better drop call meters and better performance of MSs
• MSs having too low Rx levels are not allowed to camp the network
By separating camping and TCH access thresholds the operator will be able to
provide the maximum camping footprint
RX level based TCH Allocation (RXP)
Note! RG20 feature – Energy optimized TCH allocation

Allows to define minimum C/N ratios separately for each call type (AMR FR, AMR HR, EFR/FR, HR
and 14.4 data)
Parameter values ‘RX level based TCH access’:
0: RX level based TCH access is not used (C/N definitions not in use)
1: RX level based TCH access is used in call setup
2: RX level based TCH access is used in call setup and in handovers
Downlink RX Level
-> TCH Access
Soft blocking C/N FR: 0…63dB/ def: 12dB
Soft Blocking C/N HR: 0…63dB/ def: 14dB
Soft blocking C/N AMR FR: 0…63dB/ def: 7dB
Soft blocking C/N AMR HR: 0…63dB/ def: 12dB
Soft blocking C/N 14.4 : 0…63dB/ def: 14dB
Soft blocking C/N FR: 0…63dB/ def: 12dB
Soft Blocking C/N HR: 0…63dB/ def: 14dB
Soft blocking C/N AMR FR: 0…63dB/ def: 7dB
Soft blocking C/N AMR HR: 0…63dB/ def: 12dB
Soft blocking C/N 14.4 : 0…63dB/ def: 14dB
RX level based TCH Allocation (RXTA)

Priorities
No TCH available for call set up / handover -> request put into queue
Different kinds of requests can have different priorities
queuePriorityUsed (QPU) Y/N enables use of priorities
queueingPriorityCall (QPC) 1..14 priority for call set up request
queuePriorityNonUrgentHo (QPN) 1..14 priority for non urgent handover (power
budget,
umbrella, slow moving MS, traffic reason)
request
queueingPriorityHandover (QPH) 1..14 priority for urgent handover (all other) request
Queue length and time
maxQueueLength (MQL) 0..100% percentage of number of TCHs handled by
BTS timeLimitCall (TLC) 0..15 s time a call set up request is kept in the queue
0 = queuing is disabled
timeLimitHandover (TLH) 0..10 s time a handover request is kept in the queue
0 = queuing is disabled
Queuing (Parameters)

Conditions
Timers set to values > 0
User of priorities enabled
Queue not full with requests of equal or higher priority than the current one
Queuing of call set up requests
Reservation of SDCCH resources
-> SDCCH easily overbooked
-> blocking of services like SMS or location update
Queuing (Entering the Queue)

Handover request queued by target BTS
Handover timers hoPeriodPBGT and hoPeriodUmbrella stopped
Measurement processing and averaging continues as usual
Intra BSC handover Inter BSC handover
Queuing possibility checked for all
possible target cells Order
according conventional ranking
Target BTS given by MSC by
handover request message
Queuing (Handover)

With TCH allocation
Release of busy TCH
 Check of queue from top to bottom for best matching request
 If TCH allocation possible, request removed from queue
Without TCH allocation
Queuing timer expires
Request of higher priority enters full queue
Queuing (Leaving the Queue)

Directed Retry Timer maxTimeLimitDirectedRetry expires
 call cleared, even if still in queue
Queuing timer expires
 target cell evaluation continues, if directed retry timer is still running
Queuing (Together with Directed Retry)

BTS does not receive measurement report on
SACCH for running call for the first time
Counter initialised with value of radioLinkTimeout
(4,8,..64 SACCH periods)
SACCH not received again
Counter decremented by 1
SACCH received again
Counter incremented by 2
(but not beyond initial value)
Counter has value 0
Call release due to radio link
time out
Example: short tunnel
Dropped Call Control
Radio Link Timeout

• RLT is based on SACCH deletion but SACCH is though not using a
dynamic codec like voice in AMR, which means:
• Using the EFR RLT value an AMR customer can have the call dropped
because RLT = 0 when still the FER is good
• RLT is not anymore reliable with the same value in AMR than in EFR
• Due to the fact that the FER performance is different when comparing AMR
calls to EFR calls, the Radio Link Timeout need to be defined separately for
AMR
• The Radio Link Timeout parameters for AMR are ARLT and AHRLT. The
principle of these is the same than in the RLT but it is used only for the AMR
capable mobile stations. ARLT & AHRLT are not supported in Talk Family
base stations.
Radio Link Timeout

Radio link timeout occurs
callReestablishmentAllowed (RE) set to Y
Receive level of BCCH measured for serving and adjacent cell
Averaged over 5 s
Strongest cell considered
BCCH decoded
C1 cell selection criterion fulfilled
Cell not barred
Cell belongs to selected PLMN
Attempt to re-establish call
Successful within 20s *
 call re-established
Not successful within 20s *
 call released
Example: long tunnel
Call Reestablishment
* MAX WAIT TIME OF RE-ESTAB REQ is a modifiable timer in MSC

NPT parameter related (Idle Parameter)

Measurement Processing

Measurement
Report
Standard
• Rx level
• Rx quality
• Level & BSIC of up
to 6 neighbours
• 3G cells
Enhanced
Standard + following:
• DL frame erasure rate
• DTX bit error probability
• Real time difference serving –
adjacent cell
• 3G cells
• Control over reporting priority
Measurements
Idle mode
• MS listens
to BCCH
Dedicated mode
• MS sends DL
measurement report on
SACCH
• BTS performs UL
measurements
Introduction

P (dBm) P (dBm) LEV
No offset 10 dB offset
-110 -100 0
-109 -99 1
-108 -98 2
. . .
. . .
. . .
-49 -39 61
-48 -38 62
-47 -37 63
Activation of offset to code high levels
scaleOrd (SCO)(SEG)(0,1,2)(0)
0 = no offset used
1 = offset used in general
2 = MS decides automatically about offset
Coding of Rx Level

BER (%) BER (%) QUAL
RANGE MEAN
< 0.2 0.14 0
0.2-0.4 0.28 1
0.4-0.8 0.57 2
0.8-1.6 1.13 3
1.6-3.2 2.26 4
3.2-6.4 4.53 5
6.4-12.8 9.05 6
> 12.8 18.1 7
Coding of Rx Quality
Average window = 4
Quality samples 0,0,7,0
WRONG!!: (0+0+7+0)/4 = 1.75 (wrong!!)
RIGHT: (0.14+0.14.+18.1+0.14)/4 = 4.63 (right!!) => corresponds to Qual5

BEP BER (%) QUAL
VALUE RANGE
22..31 < 0.2 0
19..21 0.2-0.4 1
16..18 0.4-0.8 2
13..15 0.8-1.6 3
10..12 1.6-3.2 4
7..9 3.2-6.3 5
4..6 6.3-12.6 6
0..3 > 12.6 7
Mapping of BEP to RX Quality

X axis: frame erasure rate (< 1%, 1-5 %, 5-10 %, 10-15 %, > 15 %)
Y axis: RX quality (0..7)
Z axis: Percentage of measurements for each FER category
Frame Erasure Rate for Handover / Power Control Decision
fepInPcHoUse (FPHO)(BSC)(Y,N)(N)
Mapping of FER to RX Quality

• Decoding of BCCH
• for serving (camped) cell every 30 s
• for adjacent cells every 5 min
• Pre-synchronization and decoding of BSIC
• for adjacent cells every 30 s
• Adjacent cell list
• Updating every 60 s
• BCCH decoding of new cell in 30 s
MS Measurement Execution
Idle Mode

• Measures RX level and quality for serving cell
• Detects whether DTX is used
26 FRAME MULTIFRAME = 120 ms
TDMA FRAMES
TCH SACCH IDLE
• Measures frequencies of adjacent cells
• BSIC decoding for at least one adjacent cell
• Pre-synchronization on SCH
TDMA FRAMES
4.615 ms
SACCH PERIOD = 480 ms
RX TX RX TX RX TXMEAS MEASMEAS
MS Measurement Execution
Dedicated Mode I

Power Control

• Longer service time of battery
• Realization of power class
• Supported by default on UL
Reduced
interference on
DL/UL
Activation of DL power control
powerCtrlEnabled (PENA) Y,N
Power control independent
• for DL and UL
• for each call
Power Control Motivation

30 dB
Range
Power
class
dependent
range
Attenuations
Power Values
Maximum MS output power
msTxPwrMaxGSM (PMAX1) 5..39 dBm GSM 900 TCH
msTxPwrMaxGSM1x00 0..36/32,33 dBm GSM 1800/1900
TCH (PMAX2)
msTxPwrMaxCCH (TXP1) 5..39 dBm GSM 900 CCH
msTxPwrMaxCCH1x00 0..30 dBm GSM 1800 CCH
(TXP2) 0..32 dBm GSM 1900 CCH
Minimum MS output power
minMSTxPower (PMIN) 5..39 dBm GSM 900
0..36 dBm GSM 1800
0..32 dBm GSM 1900
Maximum BTS output power (by minimum attenuation)
bsTxPwrMax (PMAX1) 0..30 dB GSM 900
bsTxPwrMax1x00 (PMAX2) 0..30 dB GSM 1800/1900
Minimum MS output power (by maximum attenuation)
bsTxPowerMin 0..30 dB
Power Control Parameter
Output Power Limits

Fixed increment step size
• pcIncrStepSize (INC) 2,4,6 dB
Fixed decrement step size
• pcRedStepSize (RED) 2,4,6 dB
Desired power level can be achieved in 1 or 2 commands
Yes
Fixed step size
No
Variable step size
Power Control Parameters
Power Change Step Sizes

UL Level
UL Quality <Av_RXQUAL_UL>
<Av_RXLEV_UL>
DL Level
DL Quality <Av_RXQUAL_DL>
<Av_RXLEV_DL>
POWER CONTROL
UPLINK
POWER CONTROL
UPLINK
THRESHOLD
COMPARISON
POWER CONTROL
DOWNLINK
POWER CONTROL
DOWNLINK
Power control interval
powerCtrlInterval (INT) 0..31 s
Power Control Strategy
Measurement Averaging

threshold
Actual average samples
Nx samples
Less than Px samples exceed threshold
No power change triggered
Nx samples
Px samples are equal to or exceed threshold
Power change triggered
Signal level thresholds
pcUpperThresholdLevelDL/UL (UDR/UUR) -110..-47 dBm
pcLowerThresholdLevelDL/UL (LDR/LUR) -110..-47 dBm
Signal quality thresholds
pcUpperThresholdQualDL/UL (UDR/UUR) 0..7
pcLowerThresholdQualDL/UL (LDR/LUR) 0..7
Number of average samples (for each threshold)
Nx 1..32
Px 1..32
Power change step size estimation
Triggering

Exceeded threshold Action Reason
pcUpperThresholdLevelDL BTS power decrease Signal level
pcLowerThresholdLevelDL BTS power increase Signal level
pcUpperThresholdLevelUL MS power decrease Signal level
pcLowerThresholdLevelUL MS power increase Signal level
pcUpperThresholdQualDL BTS power decrease Signal quality
pcLowerThresholdQualDL BTS power increase Signal quality
pcUpperThresholdQualUL MS power decrease Signal quality
pcLowerThresholdQualUL MS power increase Signal quality
Scenarios

AMR Power Control
Exceeded threshold Action Reason
AMR Power Control FR PC Lower
Threshold DL Rx Qual
BTS power increase Poor DL signal quality
AMR Power Control FR PC Lower
Threshold UL Rx Qual
MS power increase Poor UL signal quality
AMR Power Control FR PC Upper
BTS power decrease Good DL signal quality
AMR Power Control FR PC Upper
MS power decrease Good UL signal quality
AMR Power Control HR PC Lower
BTS power increase Poor DL signal quality
AMR Power Control HR PC Lower
MS power increase Poor UL signal quality
AMR Power Control HR PC Upper
BTS power decrease Good DL signal quality
AMR Power Control HR PC Upper
MS power decrease Good UL signal quality
AMR FR
AMR HR
Details in chapter on AMR

POC
Quality
Signal level
Increase
due to bad
Signal level
Decrease
Due to good
Signal level
Increase due to Bad quality
Decrease due to good quality
Qual 0
Qual 7
-110 dB
-47 dB
Lower
Level(-90)
Upper
Level(-80)
Upper
Quality(1)
Lower
Quality(3)
No action
Ping
pong
effect

POC
Quality
Signal level
Increase
due to level
Decrease
Due to level
Increase due to quality
Decrease due to quality
Qual 0
Qual 7
-110 dB
-47 dB
Lower
Level
Upper
Level
Upper
Quality
Lower
Quality
6dB
No action

POC and HOC (UL)
Quality
Signal levelQual 0
Qual 7
-110 dB
-47 dB
UL Level HO
Threshold
No action
UL Quality HO
Threshold
When UL quality HO is triggered
• Should MS be sent full power?
•What about UL level

Power Control Summary
Lower Level Upper Level
Upper Quality
Lower Quality
No action
Power decrease
due to level
Power increase
due to quality
Power increase
due to level
or quality
Power increase
due to quality
Power decrease
due to level
or quality
Power increase
due to level
Power decrease
due to quality6 dB
Power increase
due to level
Qual 0
Qual 7
-110 dBm -47 dBm

pcLowerThresholdsLevelDL/UL
Power control triggered
UL: Power increase of MS
DL: Power increase of BTS
RXLEV_DL/UL > pcLowerThresholdLevelDL/UL - 2 powerIncrStepSize
Yes
Fixed step size
PWR_INCR_STEP = powerIncrStepSize
No
Variable step size
PWR_INCR_STEP = pcLowerThresholdLevelDL/UL –
RXLEV_UL/DL
Actual receive level RXLEV_DL/UL
Power Increase Due to Signal Level
For MS & BTS

pcUpperThresholdsLevelDL
Power decrease
Yes
Fixed step size
PWR_DECR_STEP = powerDecrStepSize
No
Variable step size
PWR_DECR_STEP = Min (RXLEV_DL –
pcUpperThresholdLevelDL, 10)
Actual received level RXLEV_DL
RXLEV_DL < pcUpperThresholdLevelDL + 2 powerDecrStepSize OR
variableDLStepUse (VDLS) = No
Power Decrease Due to Signal Level
For BTS

pcUpperThresholdsLevelUL
Power decrease
Yes
Fixed step size
PWR_DECR_STEP = powerDecrStepSize
No
Variable step size
PWR_DECR_STEP = RXLEV_UL –
pcUpperThresholdLevelUL
Actual received level RXLEV_UL
RXLEV_UL < pcUpperThresholdLevelUL + 2 powerDecrStepSize
Power Decrease Due to Signal Level
For MS

pcLowerThresholdsQualDL/UL
UL: Power increase of MS
DL: Power increase of BTS
Actual receive quality RXQUAL_DL/UL
Variable step size based on actual quality
PWR_INCR_STEP = (1 + Max (0,QUAL)) * powerIncrStepSize
QUAL = RXQUAL_DL/UL – pcLowerThresholdQualDL/UL
Step size based on actual level
Take algorithm for power increase due to signal level
Take largest step size
Power Increase Due to Signal Quality
For MS & BTS

pcUpperThresholdsQualDL/UL
Actual received quality RXQUAL_DL/UL
Actual RXLEV_DL/UL – pcLowerThresholdLevelDL/UL < 6 dB
Yes No
No power decrease
Avoid ping pong effect
Power decrease
Take algorithm for power decrease due to signal level
(different for MS & BTS power decrease)
Power Decrease Due to Signal Quality
For MS & BTS with No Power Optimization

NPT parameter related (POC Parameter)
Should be greater
than HOC

Handover Control

Intra cell
Only other carrier / timeslot
Inter cell
Intra BSC
Inter BSC
Intra MSC
Inter MSC
Inter PLMN
Global Cell ID required
MCC + MNC + LAC + CI
Germany Czech Republic
Intra PLMN
Simple Cell ID required
LAC + CI
Handover Types

Multi Layer Network Types
Coverage Layer: Gives access to the network
Capacity Layer: Provides additional capacity and allows traffic
distribution
Macro cells
Micro cells
Intelligent Underlay Overlay
Different frequencies for high / low power TRx
Normal
frequency
Super reuse
frequency
GSM 900 cell
GSM 1800 cell

threshold
Actual average samples
Nx samples
Less than Px samples >= threshold
No handover triggered
Nx samples
Px samples are >= threshold
handover triggered
Signal interference thresholds
hoThresholdsInterferenceDL/UL (IDR/IUR) -110..-47 dBm
Signal quality thresholds
hoThresholdsQualDL/UL (QDR/QUR) 0..7
Signal level thresholds
hoThresholdLevelDL/UL (LDR/LUR) -110..-47 dBm
hoThresholdRapidLevelUL (RPD) -110..-47 dBm
MS speed thresholds
upper/lowerSpeedLimit (USL/LSL) 0..255 (unit = 2km/h)
Number of average samples
Nx 1..32
Px 1..32
Target cell selection
Handover Strategy
Triggering
Trigger Point – When the set
threshold has been met or
exceeded Px times of Nx times

More than one handover criterion fulfilled -> process of higher priority performed
Handover and power control criteria fulfilled -> handover performed
1) Interference (uplink or downlink)
2) Intra-segment inter-band because of downlink level (from higher to lower frequency band)
3) Uplink quality
4) Downlink quality
5) AMR unpacking (uplink level and also uplink unpacking quality triggers)
6) Uplink level
7) AMR unpacking (downlink level and also downlink unpacking quality triggers)
8) Downlink level
9) Coverage based inter-system handover to WCDMA RAN
10) IMSI-based inter-system handover to WCDMA RAN
11) IMSI-based handover
12) DTM-based handover to WCDMA RAN
13) Inter-system handover to WCDMA RAN
14) MS-BS distance (maximum or minimum)
15) Turn-around-corner MS
16) Rapid field drop
17) Slow/fast-moving MS
18) Umbrella
19) Power budget
20) DTM-based handover to a GSM DTM cell
21) BSC-initiated TRHO
22) IUO
23) Intra-segment HO based on load
24) AMR packing because of good uplink and downlink quality
25) AMR unpacking because of bad uplink or downlink quality
26) PC because of lower quality thresholds (uplink and downlink)
27) PC because of lower level thresholds (uplink and downlink)
28) PC because of upper quality thresholds (uplink and downlink)
29) PC because of upper level thresholds (uplink and downlink)
Handover Strategy
(Priorities)
Exercise:
Whu UL has many times
higher priority than DL?

HO due to UL/DL Quality
IF
AV_RXQUAL_DL_HO >=
HoThresholdsQualDL
THEN
Handover cause Downlink quality
IF
AV_RXQUAL_UL_HO >=
HoThresholdsQualUL
THEN
Handover cause Uplink quality
Target cells is listed based on below criteria
1. AV_RXLEV_NCELL(n) > RxLevMinCell(n) + MAX(0,Pa)
2.AND IF
EnableHoMarginLevQual(n)= Yes
THEN
AV_RXLEV_NCELL(n) > AV_RXLEV_DL_HO + (BsTxPwrMax - BS_TXPWR)
+ HoMarginQual(n)
3. ELSE
PBGT(n) > HoMarginPBGT(n) (2)
Order of preference of target cells
PRIORITY(n) = HoPriorityLevel(n) - HoLoadFactor(n)
HoLoadFactor value is taken into account when BTSLoadThreshold is
exceeded.
Interval between handovers and handover attempts
Listing set of
target cell
Priority of
target cell
Timer of
source cell

HO due to UL/DL LEVEL
IF
AV_RXLEV_DL_HO<=
HoThresholdsLevDL
THEN
Handover cause Downlink level
IF
AV_RXLEV_UL_HO<=
HoThresholdsLevUL
THEN
Handover cause Uplink level
Target cells is listed based on below criteria
1. AV_RXLEV_NCELL(n) > RxLevMinCell(n) + MAX(0,Pa)
2.AND IF
EnableHoMarginLevQual(n)= Yes
THEN
AV_RXLEV_NCELL(n) > AV_RXLEV_DL_HO + (BsTxPwrMax - BS_TXPWR)
+ HoMarginLev(n)
3. ELSE
HoLoadFactor value is taken into account when BTSLoadThreshold is
exceeded.
GUARD_TIME = 2 * HoPeriodPBGT (Ho Due PBGT)
GUARD_TIME = 2 * HoPeriodUmbrella (HO Due to Umbrella)
Listing set of
target cell
Priority of
target cell
Timer of
source cell

HO due to Fast/Slow moving MS
MS speed in relation to cell size:
IF
MsSpeedDetectionState= 0
AdjCellLayer(n) = Lower
FastMovingThreshold(n)> 0
Measured MS speed:
IF
AV_MS_SPEED <= LowerSpeedLimit
THEN
MS is slow-moving
IF
AV_MS_SPEED >= UpperSpeedLimit
THEN
MS is fast-moving
AV_RXLEV_NCELL(n) >
RxLevMinCell(n) + MAX (0, Pa)
THEN
RXLEV_CNT(n) = RXLEV_CNT(n) + 2
ELSE
RXLEV_CNT(n) = RXLEV_CNT(n) - 1
IF
RXLEV_CNT(n) >=
FastMovingThreshold(n)
THEN
Handover cause Slow-moving MS
Target cell evaluation:
AdjCellLayer(n) = Lower/Upper
AND
AV_RXLEV_NCELL(n) > HoLevelUmbrella(n) (1')
Handover to low layer cell is not possible if maximum power capability of MS exceeds
gsm/dcsMicrocellThreshold
IF
MsSpeedDetectionState= 0
THEN
Handover Cause Fast/Slow-moving MS
ELSE
Scale averaging parameters

HO due to Fast/Slow moving MS (Count)
Target cell evaluation:
AdjCellLayer(n) = Lower/Upper
AND
Handover to low layer cell is not possible if maximum power capability of MS exceeds
gsm/dcsMicrocellThreshold
HoLoadFactor value is taken into account when
BTSLoadThreshold is exceeded

HO due to Umbrella
IF
EnableUmbrellaHO= Yes
HoPeriodUmbrella - interval between the umbrella
handover threshold comparisons
Umbrella handover and target cell evaluation:
AND
( [(P >= macro_thr) AND (pwr(n) >= macro_thr)]
OR
[(P <= micro_thr) AND (pwr(n) <= micro_thr)]
OR
[(P < macro_thr) AND (pwr(n) < macro_thr) AND
(P > micro_thr) AND (pwr(n) > micro_thr)] )
PRIORITY (n) = HoPriorityLevel(n) - HoLoadFactor(n)
BTSLoadThreshold is exceeded.

Umbrella handover
to 1800 cell
Umbrella handover
to 1800 cell
A
B
900 ‘Macro’
hoLevelUmbrella = -85 dBm
gsmMacrocellThreshold = 33 dBm
dcsMacrocellThreshold = 33 dBm
Threshold RX level
handover –95 dBm
Threshold umbrella
handover –85 dBm
PTCH (msTxPwrMax(n)) = 30 dBm -> micro cell
PMAX = 30 dBm -> handover to micro cell only
hoThresholdLevelDL = -95 dBm
1800 ‘Micro’
RX level handover
back to 900 cell
RX level handover
back to 900 cell
Umbrella +FMT Handover
Example
After FMT>1 (example)

HO due to PBGT
IF
EnablePowerBudgetHO= Yes
HoPeriodPBGT - interval between the power budget
threshold comparisons
Power budget and target cell evaluation:
AV_RXLEV_NCELL(n) > RxLevMinCell(n) + MAX(0, Pa) (1)
AND
PBGT(n) = (B - AV_RXLEV_DL_HO -
(BsTxPwrMax - BS_TXPWR)) - (A - AV_RXLEV_NCELL(n))
PRIORITY (n) = HoPriorityLevel(n) - HoLoadFactor(n)
BTSLoadThreshold is exceeded.

Serving cell: A
HO candidate target cells: B, C, D
All cells have the following parameter set:
rxLevMinCell= -99 dBm
msTxPwrMax= 33 dBm
btsTxPwrMax= 42 dBm
hoMarginPBGT= 6 dB
Target cell ‘hoPriorityLevel’:
B priority: 4
C priority: 3
D priority: 3
Target cell ‘HOLoadFactor’:
B load factor: 2
C load factor: 1
D load factor: 1
Target cell B is considered overloaded
BTS
BTS
BTS
BTS
BSC
A B
C
D
Which cell (B/C/D) will be chosen as
target for the Power Budget HO?
Which cell (B/C/D) will be chosen as
target for the Power Budget HO?
AV_RXLEV_NCELL (B)= -80 dBm
AV_RXLEV_NCELL (C)= -83 dBm
AV_RXLEV_NCELL (D)= -85 dBm
Serving cell A:
AV_RXLEV_DL_HO= -92 dBm
BTS_TX_PWR= 42 dBm
Exercise Solution
Power Budget Handover
Exercise

enablePowerBudgetHo = Yes & enableUmbrellaHo = Yes
Power budget handover to cells of the same layer
Umbrella and FMT handover to cells of different layer
Combined Umbrella & Power Budget HO
Overview
macrocells
microcells
RR
PBGT,RR
PBGT,RR
UMBR+FMT
UMBR umbrella HO
RR radio reason HO
PBGT power budget HO

UPPER layer (macro)
SAME layer (serving
layer)
LOWER layer (micro)
Predefinition of layer possible by adjCellLayer (ACL)
Three layers visible relative to serving cell
Used for target cell evaluation
• Combined umbrella and power budget
• Handover based on MS speed
• Fast moving MS handling in macro cell
N (no predefinition)
Combined Umbrella & Power Budget HO
Adjacent Cell Classification

HO due to Directed Retry
IF
DirectedRetryUsed = Yes
Handover from SDCCH of serving cell to TCH of adjacent cell due to congestion
minTimeLimitDR – Target cell evaluation started
MaxTimeLimitDR - Target cell evaluation stopped
Target Cell evaluation
IF
DirectedRetryMethod = 1
THEN
AND
AV_RXLEV_NCELL(n) > DRThreshold
ELSE
AV_RXLEV_NCELL(n) >RxLevMinCell(n) + MAX (0,Pa)

No TCH available during call set up in serving cell -> handover to TCH of other cell
Must be enabled with
drInUse (DR) Y/N
Thresholds to be exceeded by target cell according condition (1a)
drMethod (DRM) 0/1 Defined type of threshold
rxLevMinCell -110..-47 dBm Used if drMethod = 0
drThreshold (DRT) -110..-47 dBm Used if drMethod = 1 and
drThreshold > rxLevMin Cell
Timers (to be counted from TCH assignment)
minTimeLimitDirectedRetry (MIDR) 0..14 s No target cell evaluation
allowed
maxTimeLimitDirectedRetry (MADR) 1..15 s Target cell evaluation allowed
SDCCH
TCH
congested Time
Assignment
Request
minTimeLimitDR
maxTimeLimitDR
DR not allowed
DR allowed
Directed Retry
Parameters

HO due to Rapid Field Drop
IF
HoThresholdsRapidLevUL/Px > 0
IF
Px number of RXLEV_UL measurement < HoThresholdsRapidLevUL
THEN
Handover cause Rapid field drop
Target cell evaluation
IF
ChainedAdjacentCell(n) = Yes
AND
Order of preference of target cells:
The target cells are ranked according to radio link properties
(equation 1).

Chained
Cell
1st
2nd
Serving cell
hoThresholdRapidLevUL = -93 dBm
hoThresholdRapidLevUlN = 2
chainedAdjacentCell = Y
Threshold rapid field drop
handover –93 dBm
Handover
triggered
Serving Cell
Rapid Field Drop Handover
Example

NPT parameter related (HOC Parameter)
Should be lower
than POC

NPT parameter related (ADCE Parameter)

KPI case

Optimization Principle
service
quality
cell coverage cell capacity
Optimization
and Tailoring
Optimization process is a way to do changes in
a network so that those network have maximum
on Capacity, Coverage and Quality
Excessive value RxLevAmi will
improve KPI but coverage and
quality will reduce
Site with height >40m with
total tilt =2 will have wide
coverage but KPI will bad
Site with FRL/FRU = 100% will
have max capacity but have
lower Quality

KPI- Rules, SDCCH Blocking
If SDCCH block high please check:
1.TCH/SDCCH availability
2.LOC design (SDCCH traffic profile)
3.Parameter (CRO, CRH,
RxLevAmi)

KPI- Rules, SDCCH Drop
If SDCCH drop high please check:
1.DL/UL Quality
2.CRO/CRH, TRP setting
3.TA profile – overshooting possibility
4.SDCCH TS location

KPI- Rules, SDCCH Drop due to RF/Abis

KPI- Rules, SDCCH Drop due to Aif

KPI- Rules, SDCCH Drop (A)

KPI- Rules, SDCCH Drop (other)

KPI- Rules, TCH Block

TCH SEIZURES FOR NEW CALL
tch_norm_seiz /c1009
+tch_seiz_due_sdcch_con /c1099 (S5)
+msc_i_sdcch_tch /c4044
+bsc_i_sdcch_tch /c4057
+cell_sdcch_tch /c4074
-tch_succ_seiz_for_dir_acc /c1165 (S7)
-tch_re_est_assign /c57032 (S7)
TCH DROPS AFTER SEIZURE
TCH_RADIO_FAIL /c1013
+TCH_RF_OLD_HO /c1014
+TCH_ABIS_FAIL_CALL /c1084
+TCH_ABIS_FAIL_OLD /c1085
+TCH_A_IF_FAIL_CALL /c1087
+TCH_A_IF_FAIL_OLD /c1088
+TCH_TR_FAIL /c1029
+TCH_TR_FAIL_OLD /c1030
+TCH_LAPD_FAIL /c1046
+TCH_BTS_FAIL /c1047
+TCH_USER_ACT /c1048
+TCH_BCSU_RESET /c1049
+TCH_NETW_ACT /c1050
+TCH_ACT_FAIL_CALL /c1081
-tch_re_est_assign /c57032 (S7)
DROPS
CALLS
100 * %
STARTED CONVERSATIONS
conver_started /c57015
- msc_i_tch_tch /c4043
CONVERSATION DROPS
dropped_calls /c57007
TCH DROPS AFTER ASSIGNMENT
tch_new_call_assign /c57033
+tch_ho_assign /c57034
-tch_norm_release /c57035
-tch_ho_release /c57036
-tch_re_est_assign /c57032
TCH ASSIGNMENTS FOR NEW CALL
tch_new_call_assign /c57033
-tch_re_est_assign /c57032
TCH RELEASE
Disconnect from MS
RF CHN RELEASE
Rf_channel_release_ack
from BTS
CONVERSATION STARTED
conn_ack to BTS
TCH ASSIGNED
Assignment_complete from BTS
TCH SEIZED
BSC allocates a TCH as a response to
TCH request (Channel Activation)
Dcr_8h
Dcr_5a
Dcr_3j
KPI- Rules, TCH Drop Call Ratios

KPI- Rules, TCH Drop due to RF/Abis

KPI- Rules, TCH Drop due to RF Old

How unnecessary HO happened??
GSM
DCS
RxLev = -80dBm
CRO=0
RxLev = -95dBm
CRO=23
HO threshold = 20
On idle mode received level for GSM is
-80 dBm while DCS can be (-95 dBm +
(2 x 23) -49dBm
On dedicated mode user will move
from DCS to GSM due to DCS level
already too low
Unecessary HO can lead to DCR due
to RF Old and HO fail (ex. Due to GSM
blocking)

How unnecessary HO happened??
GSM/DCS A GSM/DCS B
Call establish on cell A, then received
level drop below HO threshold. User
will move from cell A to cell B
After user serve by cell B, cell B will
ask user to do handover as received
level on cell B already below HO
threshold.
RxLev = -95dBm
HO threshold = 20
RxLevmin from A to B = 12
RxLev = -92dBm
HO threshold = 20
RxLevmin from A to B = 12

KPI- Rules, TCH Drop due to Aif

KPI- Rules, TCH Drop due to Transcoder

KPI- Rules, TCH Drop

KPI- Rules, TCH Drop (Other)

KPI- Rules, coverage problems (dlq_2a and ulq_2a)
Here are some examples how different kind of problems can be found
Like Normal distribution HW Problem, TRX/combiner etc is broken
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
CL10 10645 8516 6813 5450 4360 3488 2791 2232 CL10 5323 4258 3406 2725 2180 1744 4563 9765
CL15 47043 37634 30108 24086 9865 7543 5643 2345 CL15 11761 9409 7527 6022 9383 1886 65432 7675
CL20 56204 44963 35971 28776 6574 10324 345 65 CL20 14051 11241 8993 7194 18271 2581 65438 63562
CL30 200863 160690 128552 102842 17654 9876 145 28 CL30 33772 27017 21614 17291 75037 2469 18765 14523
CL40 12785 10228 8182 6546 456 112 24 23 CL40 3196 2557 2046 1636 4938 28 3659 2648
CL63 4583 1123 583 452 261 76 26 2 CL63 1146 281 146 113 3378 19 100 174
HW problem, Q4 amount of samples is strange Interference problem
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
CL10 5323 4258 3406 2725 2180 1744 1395 1116 CL10 5323 4258 3406 2725 2180 1744 1395 1116
CL15 23522 18817 15054 12043 18765 3772 2822 1173 CL15 23522 13234 10588 8470 13234 10588 8470 6776
CL20 28102 22482 17985 14388 36542 5162 173 33 CL20 28102 2123 1699 1359 2123 1699 1359 1087
CL30 67544 54035 43228 34582 150073 4938 73 14 CL30 67544 3634 2908 2326 3634 2908 2326 1861
CL40 6393 5114 4091 3273 9876 56 12 12 CL40 6393 4091 3273 2618 4091 3273 2618 4532
CL63 2292 562 292 226 6756 38 13 1 CL63 9987 7543 4323 3454 2275 1187 876 654
HW Problem, TRX/combiner etc is broken
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
CL10 200863 160690 128552 102842 17654 9876 7865 6543
CL15 16543 13234 10588 8470 6776 2822 1173 234
CL20 2654 2123 1699 1359 1087 173 33 65
CL30 4543 3634 2908 2326 1861 73 14 28
CL40 5114 4091 3273 2618 2095 12 12 23
CL63 24 54 8 87 7 0 0 0
1
2
3
1. Lots of Q4 samples. Distribution is not OK  HW problem. Site reset will help
2. Lots of bad signal level samples. TRX/Combiner is broken. If no HW problem 
Site is totally in wrong place, site is like transferring traffic to another cell ( cause
level HO). Typically a HW problem
3. Lots of Q6 and Q7 samples. Distribution is not OK, no Q5 samples  HW
problems. Site reset or broken TRX
4. Typical normal interference problem.
Here are some examples how different kind of HW problems can be found
4

KPI- Rules, Interference analysis DL /UL
Rx Quality x Rx Level
CoverageProblem:
Bad qualityand
LowRxLevel
InterferenceProblem:
Bad qualityand
High RxLevel
Good Quality
High RvLevel
HW Problem:
Bad Quality
forall RxLevels
NWDreport 204model
HW Problem
All samples below
-100dBm
CL10  <-100dBm
Same level – quality distribution
for both UL and DL

KPI- Rules, Interference, UL
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 1234 987 790 632 505 404 323 259
-47dBm 24 19 15 12 10 8 6 5
MS power control can be seen here.
If Power is reduced → no bad UL
problems. BSC border is increasing
good level samples
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 1234 987 790 632 505 404 323 259
-47dBm 24 19 15 12 10 8 6 5
Bad interference problems. By POC
parameter interference can be
decreased, how power is adjusted
etc. Also optimum MS power feature
improves UL interference, no full
power is sent after HO.
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 1234 987 790 632 505 404 323 259
-47dBm 24 19 15 12 10 8 6 5
Bad quality sample due to signal
level problems. Diversity should be
checked, also possibilities to use
LNA to improve UL signal level.
Antenna place should be also
checked if there are some obstacles
near the antenna.

KPI- Rules, Interference, UL, examples
UL_q0 UL_q1 UL_q2 UL_q3 UL_q4 UL_q5 UL_q6 UL_q7 DL_q0 DL_q1 DL_q2 DL_q3 DL_q4 DL_q5 DL_q6 DL_q7
-100dBm 251992 30668 20552 18417 18156 18286 16983 12478 27862 5537 5529 6069 6109 6107 5389 4119
-95dBm 123653 1151 403 692 519 351 221 72 89094 4236 3853 3576 2893 2264 1372 584
-90dBm 62938 247 144 288 353 129 62 29 142228 2732 2550 2356 1510 1114 774 404
-80dBm 27005 51 65 149 177 82 40 16 222462 1523 1355 1552 716 812 1081 343
-70dBm 2831 3 9 28 87 10 6 0 44504 91 123 151 81 101 191 88
-47dBm 751 0 4 10 25 1 0 0 5994 49 17 17 12 29 65 10
Huge amount of UL bad samples. Cells is not working properly, it is like transferring traffic, UL quality/ UL level HO’s are
triggering immediately. These kind of cells must be investigated.
UL_q0 UL_q1 UL_q2 UL_q3 UL_q4 UL_q5 UL_q6 UL_q7
-100dBm 490 137 368 605 1014 1378 1830 2586
-95dBm 8410 3768 3225 3023 2767 2304 1561 1859
-90dBm 38512 5249 3066 2323 1692 1570 1191 1268
-80dBm 219137 4600 2453 2311 1470 1724 1864 1221
-70dBm 509591 2504 1812 3050 1271 1465 1649 337
-47dBm 244302 582 711 1363 1713 873 671 87
UL_q0 UL_q1 UL_q2 UL_q3 UL_q4 UL_q5 UL_q6 UL_q7
-100dBm 70004 5020 3500 2564 2232 1946 2190 2579
-95dBm 80339 392 286 461 328 250 275 92
-90dBm 106883 233 318 602 199 146 234 64
-80dBm 246892 227 314 860 298 338 395 60
-70dBm 254875 155 298 935 203 135 166 15
-47dBm 23288 21 27 103 109 11 41 0
Some UL interference in good signal
level. UL power control is not
working properly. Ul power control is
good indicator, if power is adjusted,
there are no big problems in UL
direction
There is no UL interference, or just a
little. MS is adjusting power properly,
there are only little samples in good
UL signal level.

q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 12785 10228 8182 6546 456 112 24 23
-47dBm 4583 1123 583 452 261 76 26 2
KPI- Rules, Interference, DL
Bad interference problem → signal level good (<-80dBm)
and sometimes no better cell available. If better cell
available and quality samples are 4 or worse → HO (reason
quality or interference, depends on the parameter)
Interference is causing drops.
Really bad interference problem → signal level is really
good (<-70dBm) and usually no better cell available → no
HO → samples can be seen in the table. Interference is
causing drops.
Situation is “network is working properly” If there are quality
4 or worse samples → quality HO. Most of the samples are
q4 samples. If lots of q5..q7 samples → interference
problem and interference must be analyzed / removed. If
quality HOs but no q5..q7 samples → better cell is available
→ no interference problems. In these signal levels
overlapping exists and if handover reason is no PBGT, it will
be quality HO. By parameter amount of quality HOs can be
adjusted
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 12785 10228 8182 6546 456 112 24 23
-47dBm 4583 1123 583 452 261 76 26 2
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 12785 10228 8182 6546 456 112 24 23
-47dBm 4583 1123 583 452 261 76 26 2
q0 q1 q2 q3 q4 q5 q6 q7
-100dBm 10645 8516 6813 5450 4360 3488 2791 2232
-95dBm 47043 37634 30108 24086 9865 7543 5643 2345
-90dBm 56204 44963 35971 28776 16574 5676 845 65
-80dBm 200863 160690 128552 102842 17654 3653 145 28
-70dBm 12785 10228 8182 6546 456 112 24 23
-47dBm 4583 1123 583 452 261 76 26 2
Bad quality samples due to signal level problems. If PBGT
overlapping is not existing → lots of quality HOs + level HOs
(margin are lower than in PBGT).
Not interference problem, more signal level problem.
Check how much samples vs. HOs → are
better cells available or not.

KPI- Rules, Interference, DL, examples
DL_q0 DL_q1 DL_q2 DL_q3 DL_q4 DL_q5 DL_q6 DL_q7
-100dBm 12057 2827 3108 3952 4783 6200 7013 8156
-95dBm 44818 4811 5041 5866 6587 7223 7259 6781
-90dBm 98587 7107 7400 8334 8470 8781 7825 6162
-80dBm 225919 7450 7731 8445 7726 7441 5695 3369
-70dBm 88708 1014 971 998 751 688 689 367
-47dBm 15881 84 109 122 104 167 199 184
-100dBm 8006 1636 1681 2197 2379 2510 2025 1290
-95dBm 24951 1636 1627 1767 1037 431 175 53
-90dBm 57559 2171 1884 1651 781 330 161 47
-80dBm 200602 5771 4686 4130 1736 566 254 97
-70dBm 304206 5464 4310 3796 1315 350 153 105
-47dBm 108047 2134 1908 1623 689 230 129 64
There are almost as much samples Q5 and Q7 samples as
Q 4 samples → even interference is really bad or there is
no better cell available ( no ho’s after bad quality samples).
These kind of interference cells should be optimized,
otherwise there are lots of drops etc
There are no as much Q5…Q7 samples as Q4 samples →
after interference samples Quality HO is done or the
interference situation is not so bad, for example sampling is
Q0,Q2,Q4,Q2,Q5,Q0,Q2,Q3,Q4,Q2 → quality HO is not
triggering
-100dBm 7055 1398 1374 1906 2163 2003 1468 832
-95dBm 20109 1307 1274 1161 694 332 211 84
-90dBm 34531 1053 745 587 273 131 94 41
-80dBm 107539 875 518 630 161 98 113 47
-70dBm 177614 283 316 663 61 32 29 9
-47dBm 58718 78 91 198 54 40 54 32
There are bad quality samples only due to signal level
problems.

KPI- Rules, Interference (internal / external)
•Internal Interference
– Interference can be seen from stats or can be measured by scanner.
– Neighbor cells (DL) or mobiles (UL) are causing interference.
– By frequency / network planning interference can be decreased.
•External Interference
– Interference can be seen from stats or can be measured by scanner.
– External radio frequencies are causing interference
 Military use
 In the border area, interference is coming from other country.
 Some external wireless system (for example some wireless industry system)
is causing interference
 Increased I level can be also due to external interference

KPI- Rules, HOSR

KPI- Rules, HO fail
sum(msc_o_succ_ho + bsc_o_succ_ho + cell_succ_ho)
Total HO success ratio = 100 * (-------------------------------------------------------------------------------- ) (ho_65)
sum(msc_o_ho_cmd + bsc_o_ho_cmd_assgn + bts_ho_assgn)
sum(a.msc_o_succ_ho + a.bsc_o_succ_ho + a.cell_succ_ho +
a.msc_to_wcdma_ran_succ_tch_ho)
Total HO failure ratio = 100 * (1- -------------------------------------------------------------------------------------) (hfr_2b)
sum(b.msc_o_ho_cmd + b.bsc_o_ho_cmd_assgn +
b.bts_ho_assgn+a.msc_gen_sys_wcdma_ran_ho_com)
/* handovers failing due to blocking */
sum(a.msc_o_fail_lack + a.bsc_o_fail_lack + a.cell_fail_lack
+ a.msc_to_wcdma_ran_fail_lack)
HO failure ratio due to RF blocking = 100 * ---------------------------------------------------------------------------------------
/* all HO attempts */
sum(b.msc_o_ho_cmd + b.bsc_o_ho_cmd_assgn +
b.bts_ho_assgn + a.msc_gen_sys_wcdma_ran_ho_com)
(hfr_55a)

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