1. The document discusses the handover process in mobile networks. It describes the different types of handovers including emergency, normal, and load-based handovers. 2. The handover process involves several steps - measurement report preprocessing, penalty processing of cells, cell ranking and characteristic adjustment, and final handover judgement. Key factors like signal strength, cell load, and layer information are used to select the best candidate cell. 3. An example case study is provided to illustrate layer handover thresholds and parameters for different cell environments like GSM, DCS, and indoor microcells.

1. www.ccsindo.com

2. Contents
1 、 Handover introduction
2 、 Handover process
3 、 Case

3. 1 、 Handover introduction
Handover Purpose
Handover Type

4. Purpose of handover
Page 4
★ Movement → Continuity → Cell
★ Interference → Quality → Channel
★ Traffic → Congestion → Border / Layer

5. Handover Type
Handover Type Handover algorithm
Emergency handover
TA handover
Interference handover
Level rapid decrease handover
Bad quality handover
No downlink measurement report
Normal handover
Edge handover
Layer handover
PBGT
Fast move micro-cell handover
Concentric handover
AMR handover
3G Better cell
Close BCCH handover
Load handover Load handover
Enhanced dual-band network
handover
Enhanced dual-band network handover
Fast handover
Frequency offset handover 、 Fast
PBGT Handover
Synchronous handover ALL
Asynchronous handover ALL

6. Contents
1 、 Handover introduction
2 、 Handover process
3 、 Case

7. 2 、 Handover process
Overall of process
MR preprocessing
Penalty processing
Cell ranking and characteristic adjustment
Handover judgment

8. MR Preprocessing
Penalty processing
Cell ranking
characteristic adjustment
Handover judgment
Emergency ： TA
Emergency ： BQ
Emergency ：
Level rapid decrease
Emergency ： interference
Load handover
Normal ： Edge handover
Normal ：
Layer handover
Normal ： PBGT
Send results
Force handover
Direct retry
Concentric handover
Fast move handover
2.1 Overall of process

9. Step by Step
MR MR
MR MR MR
Measurement
report No. n
Measurement report
No. n+4
Continuous MR
flow
MR
MR MR
MR MR MR
Continuous MR
flow
Page 9
MR preprocessing
Penalty processing
Cell Ranking
Handover Judgment
characteristic adjustment
Interpolate ---- Add MR when missing
Filter----Average several continuous MR
2.2 MR preprocessing
2.2 MR preprocessing

10. Page 10
Step by Step
MR preprocessing
Penalty processing
Cell Ranking
Handover Judgment
characteristic adjustment
2.3 Penalty processing
2.3 Penalty processing
Types of Penalty Process
Penalty on the target cell when a HO fails.
to avoid the MS to select this cell again in next HO
judgment.
Penalty on the original serving cell when an emergency
HO ( base on BQ and TA ) is performed.
Penalty on other high priority layer cells after a fast
moving HO is performed.
to keep MS staying in the umbrella cell and avoid
frequent HO.
A new HO attempt is prohibited within the penalty time
after an overlaid/underlaid HO fails.

11. Page 11
Step by Step
MR preprocessing
Penalty processing
Cell Ranking
Handover Judgment
characteristic adjustment
2.4 Cell ranking and characteristic adjustment
2.4 Cell ranking and characteristic adjustment
M rule —— received signal level → generate candidate cell
list
DL RXLEV >= 【 HOCDCMINDWPWR 】 ＋【 MINOFFSET 】
UL RXLEV >= 【 HOCDCMINUPPWR 】 ＋【 MINOFFSET 】
K rule —— received signal level → rank candidate
cell list
After M rule, sort by level

12. Page 12
Step by Step
MR preprocessing
Penalty processing
Cell Ranking
Handover Judgment
characteristic adjustment
2.4 Cell ranking and characteristic adjustment
2.4 Cell ranking and characteristic adjustment
16 bit ranking —— calculate 16 bit value and rank

13. 2.4 Cell ranking and characteristic adjustment
Page 13
16 Bit
For 16bit algorithm. The value is small, the priority is high.
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8
1-3 bit ： Sort by level 。

14. 4 bit ： Same layer cell handover hysteresis.
Server cell 4 bit always 0 ，
N-Cell RX level ＝ > server cell RX level + Hysteresis ， 4-bit set
to 0 ； N-Cell RX level< server cell RX level + Hysteresis ， 4-
bit set to 1 。
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

15. 9-10 bit: 00 = micro layer = cell layer 1 01 = 1800 layer = cell layer 2
10 = 900 layer = cell layer 3 11 = umbrella layer = cell layer 4
5-8 bit: Cell priority, it’s divided into 16 levels.
0000-1111
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

16. 11 bit ： load adjustment bit
Serving cell ： cell load >= TRIGTHRES ， Set to 1 and 0 Otherwise ；
Neighbor cell ： cell load >= LOADACCTHRES ， Set 1 and 0
Otherwise.
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

17. 12 、 13 bit ： Same BSC/MSC bit
Serving cell ： always 0
Neighbor cell ： Same BSC/MSC with serving cell ， 12/13 set to
0 ， other wise 1
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

18. 14 bit ： layer handover threshold bit
Serving cell: RX level>= INLAYHOTH － LEVHOHYST
， set to 0 。 Otherwise 1 ， and 13 、 12 、 10 ～ 5 bit is
all set to 0.
Neighbor cell ： RX level>= INLAYHOTH ＋
LEVHOHYST ， set to 0 。 Otherwise 1 ， and
13 、 12 、 10 ～ 5 bit is all set to 0.
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

19. 15 bit ： Expansion cell, set to
1.
Normal cell, set to 0.
16 bit ： reserved
2.4 Cell ranking and characteristic adjustment
16 9
10
11
12
13
14
15 1
2
3
4
5
6
7
8

20. MR Preprocessing
Penalty processing
Cell ranking
characteristic adjustment
Handover judgment
Emergency ： TA
Emergency ： BQ
Emergency ：
Level rapid decrease
Emergency ： interference
Load handover
Normal ： Edge handover
Normal ：
Layer handover
Normal ： PBGT
Send results
Force handover
Direct retry
Concentric handover
Fast move handover
2.5 Handover judgment

21.  Class of handover judgment ：
 Class of handover judgment ：
2.5 Handover judgment
 Emergency——TA 、 BQ 、 Rxqckfallho 、 Interference
 Load handover
 Normal——EDGE ， Layer ， PBGT
 Fast move handover
 Concentric handover

22. 2.5 Handover judgment
TA ：
Serving cell of the TA is greater than the emergency
handover TA threshold.
BQ ：
1 、 According to P/N rule

23. 2.5 Handover judgment
Interference handover ：
When the RX-level is greater than a certain value, but the quality is worst
than the quality threshold.

24. 2.5 Handover judgment
Load handover
 Load handover is triggered when three conditions are arrived ：
 System signaling traffic is less than the allowed threshold.
 The load of serving cell is higher than the load threshold.
 The load of target cell is less than the load threshold.
BTS
BSC

25. Edge handover
2.5 Handover judgment
Edge handover ：
1 、 The level of serving less than the EDGE handover threshold.
2 、 P/N rule
3 、 The target cell at the top, the level no need greater than layer
threshold and hysteresis.

26. 2.5 Handover judgment
 Layer handover ：
 1 、 Between the different layers.
 2 、 Neighbor cell level>= layer handover threshold + hysteresis
 3 、 P/N rule

27.  Layer ：
 Layer ：
GSM900
Cell
Micro
Cell
GSM1800 GSM1800
GSM1800
GSM 900
GSM900
GSM900
GSM1800
GSM1800
GSM1800
Cell
2.5 Handover judgment
GSM 900 GSM 900
GSM900
GSM900
GSM1800
GSM1800
Layer handover
Edge
handover
PBGT

28. 2.5 Handover judgment
Neighbor cell loss is less than the serving cell
Neighbor cell in front of serving cell
P/N rule
 PBGT
 PBGT

29. Contents
1 、 Handover introduction
2 、 Handover process
3 、 Case

30. 3.1 Case
 Layer handover case
 Layer handover case
CRO RXMIN HOTHRES LEVHOHYST ULEDGETHRES DLEDGETHRES
GSM 0 6 25 2 12 20
DCS 6 15 18 2 7 15
Indoor 10 25 25 2 10 18

31. 3.1 Case
 Layer handover case
 Layer handover case