Method and system for harmonizing an operation area for a mobile device in a cellular radio network
View Patent ↗The invention relates to a method and a system for harmonising an operational area for a mobile device on a cell-by-cell-basis in a cellular radio network, like a GSM network, wherein, in idle mode, the mobile device compares field strength levels of different base stations with each other in order to set up a power budget, and selects the most appropriate base station in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget. The invention is characterized in that in connection mode, the mobile device compares the power received from different base stations with each other in order to set up a power budget, and selects the most appropriate base station in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget, and both offset terms are set so as to be similar to each other or the same.
1. A method, comprising:
in idle mode, comparing, by a mobile device, field strength levels of different base stations with each other in order to set up a power budget, and selecting the most appropriate base station in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget, the method being for harmonizing an operational area for a mobile device on a cell-by-cell-basis in a cellular radio network; and
in connection mode, comparing, by the mobile device, the power received from different base stations with each other in order to set up a power budget, and selecting the most appropriate base station in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget,
wherein both offset terms are set so as to be similar to each other or the same.
2. The method according to claim 1 , wherein idle mode parameters relate to the size of cells of adjacent base stations.
3. The method according to claim 2 , wherein the idle mode parameters affect to the size of cells of adjacent base stations in a non-directional way.
4. The method according to claim 1 , wherein connection mode parameters take into account differences between cells of adjacent base stations.
5. The method according to claim 1 , wherein said offset terms are biasing margin terms.
6. The method according to claim 5 ,
wherein the power budget PBGT serv (adj) is calculated by using the equation
PBGT serv ( adj ) =RxLev adj −RxLev serv −HoMarginPBGT serv ( adj ),
where RxLev adj is the received downlink level from an adjacent base station, RxLev serv is the received downlink level from the currently serving base station, and
HoMarginPBGT serv (adj) is a handover margin power budget parameter to artificially change priority of the adjacent base station for handover from the serving base station;
characterized in that
the handover margin power budget parameter is averaged by using the equation
HoMarginPBGT
_
adj
[
dB
]
=
HoMarginPBGT
serv
(
adj
)
+
HoMarginPBGT
adj
(
serv
)
2
where HoMarginPBGT adi (serv) is a handover margin power budget parameter to artificially change priority of the currently serving base station.
7. The method according to claim 6 , characterized in that the priority difference Adj PriorDifference adj between the cell of the currently serving base station and the cell of an adjacent base station is calculated by using the equation
AdjPriorDifference
adj
[
dB
]
=
(
HoMarginPBGT
serv
(
adj
)
-
HoMarginPBGT
_
)
=
(
HoMarginPBGT
adj
(
serv
)
-
HoMarginPBGT
_
)
.
8. The method according to claim 7 , characterized in that the averaged offset term X is calculated by using the equation
X
=
Average
adj
[
(
Incom
+
Outg
.
HOTraffic
adj
↔
serv
∑
adj
Incom
+
Outg
.
HOTraffic
adj
↔
serv
)
·
AdjPriorDifference
adj
]
,
wherein Incom+Outg.HOTraffic adj⇄cell reflects the sum of incoming and outgoing handovers between adjacent and serving cells.
9. The method according to claim 1 , characterized in that in connection mode the additional offset term is created by averaging terms for both directions between a cell of a currently serving base station and a cell of an adjacent base station.
10. The method according to claim 1 , wherein in connection mode for prioritizing a plurality of base stations a corresponding plurality of individual additional offset terms are provided; characterized in that the offset terms are averaged so as to create an averaged offset term.
11. The method according to claim 10 ,
wherein in idle mode a basis C2 cell reselection is calculated by using the equation
C2 serv =( RxLev serv −RxLevAccesMin serv )+CellReselectOffset serv ,
where RxLev serv is the received downlink level from the currently serving base station,
RxLevAccessMin serv is the minimum downlink level threshold received by the mobile device to camp in, a cell, and
CellReselectOffset serv is the biasing term to artificially change the priority of the currently serving base station;
characterized in that, if the averaged offset term is positive, it is taken as the parameter CellReselectOffset serv .
12. A system, comprising:
an idle mode unit configured to compare field strength levels of different base stations with each other in order to set up a power budget and to select the most appropriate base station for a mobile device in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget, the system being used for harmonizing an operational area for a mobile device on a cell-by-cell-basis in a cellular radio network; and
a connection mode unit configured to compare the power received from different base stations with each other in order to set up a power budget, and to select the most appropriate base station for the mobile device in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget,
wherein both offset terms are set so as to be similar to each other or the same.
13. The system according to claim 12 , wherein idle mode parameters relate to the size of cells of adjacent base stations.
14. The system according to claim 13 , wherein the idle mode parameters affect to the size of cells of adjacent base stations in a non-directional way.
15. The system according to claim 12 , wherein connection mode parameters take into account differences between cells of adjacent base stations.
16. The system according to claim 12 , wherein said offset terms are biasing margin terms.
17. The system according to claim 16 ,
wherein the power budget PBGT serv (adj) is calculated by using the equation
PBGT serv ( adj ) =RxLev adj −RxLev serv −HoMarginPBGT serv ( adj ),
where RxLev adj is the received downlink level from an adjacent base station,
RxLev serv is the received downlink level from the currently serving base station, and
HoMarginPBGT serv (adj) is a handover margin power budget parameter to artificially change priority of the adjacent base station for handover from the serving base station;
characterized in that
said averaging means averages
the handover margin power budget parameter by using the equation
HoMarginPBGT
_
adj
[
dB
]
=
HoMarginPBHGT
serv
(
adj
)
+
HoMarginPBGT
adj
(
serv
)
2
where HoMarginPBGT adi (serv) is a handover margin power budget parameter to artificially change priority of the currently serving base station.
18. The system according to claim 17 ,
characterized by means for calculating the priority difference Adj PriorDifference adi between the cell of the currently serving base station and the cell of an adjacent base station by using the equation
AdjPrior
Difference
adj
[
dB
]
=
(
HoMarginPBGT
serv
(
adj
)
-
HoMarginPBGT
_
)
=
(
HoMarginPBGT
adj
(
serv
)
-
HoMarginPBGT
_
)
.
19. The system according to claim 18 ,
characterized in that said averaging means calculates the averaged offset term X by using the equation
X
=
Average
adj
[
(
Incom
+
Outg
.
HOTraffic
adj
↔
serv
∑
adj
Incom
+
Outg
.
HOTraffic
adj
↔
serv
)
·
AdjPrior
Difference
adj
]
,
wherein Incom+Outg.HOTraffic adj⇄cell reflects the sum of incoming and outgoing
handovers between adjacent and serving cells.
20. The system according to claim 12 , characterized by an averaging unit for averaging terms for both directions between a cell of a currently serving base station and a cell of an adjacent base station in the connection mode.
21. The system according to claim 12 ,
wherein in connection mode for prioritizing a plurality of base stations a corresponding plurality of individual additional offset terms are provided; characterized by averaging means for averaging said offset terms so as to create an averaged offset term.
22. The system according to claim 21 ,
wherein said idle mode means calculates a basis C2 cell reselection by using the equation
C2 serv =(RxLev ser −RxLevAccesMin serv )+CellReselectOffset serv ,
where RxLev serv is the received downlink level from the currently serving base station,
RxLevAccesMin serv is the minimum downlink level threshold received by the mobile device to camp in a cell, and
CellReselectOffset serv , is the biasing term to artificially change the priority of the currently serving base station;
characterized by means for taking the averaged offset term as the parameter CellReselectOffset serv if the averaged offset term is positive.
23. An apparatus, comprising:
idle mode means for comparing field strength levels of different base stations with each other in order to set up a power budget and selecting the most appropriate base station for a mobile device in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget; and
connection mode means for comparing the power received from different base stations with each other in order to set up a power budget, and selecting the most appropriate base station for the mobile device in accordance with said power budget, wherein for prioritizing a predetermined base station an individual additional offset term is applied in the power budget,
wherein both offset terms are set so as to be similar to each other or the same.