Background technology
Along with development of Communication Technique, reduce the complexity of operational administrative work and reduce operation maintenance cost, become an urgent demand of common carrier.Mobile communication system in future, LTE (Long TermEvolution for example, Long Term Evolution) in the system, by introducing the mechanism of network self-organization, by network based statistic Automatic Optimal parameter, can reduce the artificial participation of the network planning and Operation and Maintenance, reduce the construction and the operation cost of network.
Based on above-mentioned background, 3GPP (3rd Generation Partnership Project, the 3rd generation partner program) with E-UTRAN (Evolved UMTS Terrestrial Radio Access Network, the universal mobile telecommunications system terrestrial wireless access of evolution) SON (the Self Organizing Networks in the system, self-organizing network) technology is studied as the work subject under discussion, and the SON technology comprises self-configuring, self-optimizing and cures certainly.Wherein, self-optimizing is a key property wherein, need some networks of monitoring and system performance parameter as input, as the statistics of network performance index, fault warning, notice etc., after the input data were analyzed, optimized Algorithm made a policy, the last adjustment operation that triggers relevant network node automatically, if necessary, also can be by manual activation.Load at this sub-district and adjacent area carries out intra-LTE and inter-RAT (Radio Access Technology, the self-optimizing of mobility parameter wireless access technology), compare and be not optimized, can improve the capacity of system effectively, also can reduce the workload of manual intervention network management and optimization.
MLB (Mobility Load Balancing, the moving load equilibrium) is important research use-case in the SON self-optimization function, its basic target is: mean allocation load in the LTE minizone and between different RAT, by the reselecting parameters of optimization sub-district and the load balancing between the handoff parameter realization sub-district, minimize the quantity of switching and being redirected by load balancing, improving the capacity of whole network, and improve user's experience.Therefore, load balancing should not have a negative impact to user's QoS (Quality of Service, service quality), and this influence can not surpass in the user experience that does not have under the normal mobility situation of load balancing.In the load balancing of Inter-RAT, adopt RIM (RAN Information Management, wireless access network information management) mechanism to carry out the mutual of message, relevant message is placed in the container, with convenient follow-up expansion.In the MLB of intra-LTE, parameter negotiation mainly adopts normalized parameter, the position of the handoff boundary band of this parametric representation sub-district, and the variation of being with can relevant parameter be switched according to algorithm adjustment separately in each sub-district with realization.
All relate to the inter-RAT sub-district gravity treatment of E-UTRAN and all carry out based on the mode of priority, for E-UTRAN and UTRAN (UMTS Terrestrial Radio Access Network, the universal mobile telecommunications system terrestrial wireless inserts), each frequency can have independent priority; For GERAN (GSM/EDGE Radio Access Network, global system for mobile communications/enhanced data rates global system for mobile communications evolution technology wireless access network), each group of frequencies can have independent priority.
Particularly, the gravity treatment of LTE sub-district comprises to the condition of UTRAN sub-district:
(1) for the frequency that frequency priority is higher than current use frequency, need to satisfy following relation:
S
noservingcell,x>Thresh
x,high(UtranInLTE)
Wherein, S
Noservingcell, xSignal strength signal intensity for the current non-resident sub-district of the UE that defines in the TS36.304 agreement (being the Target cell of gravity treatment); Thresh
X, highBe the triggering thresholding that resides in the high priority frequency that defines in the TS36.304 agreement; Thresh
X, high (UtranInLTE)In the LTE system, when the frequency priority of UTRAN is higher than the frequency of LTE sub-district of current service, the thresholding of triggering cell gravity treatment.
(2) for the frequency that frequency priority is lower than current use frequency, need to satisfy following relation:
S
serving<S
non?int?rasearch
And, S
Serving<Thresh
Serving, low (lte)
And, S
Nonservingcell, x>Thresh
X, low (utranInLTE)
Wherein, S
ServingSignal strength signal intensity for the resident sub-district of current UE; S
Non int rasearchThresholding for the measurement of the triggering different frequency/different system that stipulates in the TS36.304 agreement when signal strength signal intensity of current service cell is lower than this thresholding, triggers the measurement of different frequency/different system; Thresh
Serving, lowTriggering thresholding for the sub-district gravity treatment of the low priority that defines in the TS36.304 agreement; Thresh
Serving, low (lte)In the LTE system, the triggering thresholding of the sub-district gravity treatment of low priority; Thresh
X, lowBe the triggering thresholding that resides in the low priority frequency that defines in the TS36.304 agreement; Thresh
X, low (UtranInLTE)In the expression LTE system, when the frequency priority of UTRAN is lower than the frequency of LTE sub-district of current service, the thresholding of triggering cell gravity treatment.The signal strength signal intensity of current frequency is lower than Thresh
Serving, low (lte)And the frequency of Target cell is higher than Thresh
X, low (UtranInLTE)The time, trigger the sub-district gravity treatment of low priority.
UE is resident after at least 1 second, could gravity treatment to arrive other sub-districts to the LTE sub-district.
The incident that LTE switches the sub-district comprises B1 incident and B2 incident.
Wherein, the Rule of judgment of B1 incident is:
Mn+Ofn-Hys>Thresh
The Rule of judgment of B2 incident is:
Ms+Hys<Thresh1
And, Mn+Ofn-Hys>Thresh2
Wherein, Mn is the signal strength signal intensity of adjacent area, and OFn is the skew of the frequency of adjacent area use, and Hys is sluggish parameter, and Thresh is the threshold parameter of incident, and Ms is the signal strength signal intensity of this sub-district.
The gravity treatment of UTRAN sub-district is as follows to the condition of LTE sub-district:
(1) for the frequency that frequency priority is higher than current use frequency, need to satisfy following relation:
S
noservingcell,x>Thresh
x,high(UtranInLTE)
Wherein, S
Noservingcell, xSignal strength signal intensity for the current non-resident sub-district of the UE that defines in the TS25.304 agreement (being the Target cell of gravity treatment); Thresh
X, highBe the triggering thresholding that resides in the high priority frequency that defines in the TS25.304 agreement; Thresh
X, high (UtranInLTE)In the UTRAN system, when the frequency priority of LTE is higher than the frequency of UTRAN sub-district of current service, the thresholding of triggering cell gravity treatment.
(2) for the frequency that frequency priority is lower than current use frequency, need to satisfy following relation:
Be lower than current use frequency for frequency priority, following relation arranged:
S
serving<S
prioritysearch
And, S
Serving<Thresh
Serving, low (Utran)
And, S
Nonservingcell, x>Thresh
X, low (LTEinUtran)
Wherein, S
ServingSignal strength signal intensity for the resident sub-district of current UE; S
PrioritysearchThresholding for the measurement of the triggering different frequency/different system that stipulates in the TS25.304 agreement when signal strength signal intensity of current service cell is lower than this thresholding, triggers the measurement of different frequency/different system; Thresh
Serving, lowTriggering thresholding for the sub-district gravity treatment of the low priority that defines in the TS25.304 agreement; Thresh
Serving, low (Utran)In the UTRAN system, the triggering thresholding of the sub-district gravity treatment of low priority; Thresh
X, lowBe the triggering thresholding that resides in the low priority frequency that defines in the TS25.304 agreement; Thresh
X, low (LTEInUtran)In the UTRAN system, when the frequency priority of LTE is lower than the frequency of UTRAN sub-district of current service, the thresholding of triggering cell gravity treatment.The signal strength signal intensity of current frequency is lower than Thresh
Serving, low (Utran)And the frequency of Target cell is higher than Thresh
X, low (LTEInUtran)The time, trigger the sub-district gravity treatment of low priority.
The inventor is in realizing process of the present invention, and there are the following problems at least to find prior art:
(1) parameter negotiation among the 3GPP R9 has only been consulted and has been switched relevant parameter, and according to the variation adjustment reselecting parameters of switching band, but in the inter-RAT scene, reselection modes and switching mode be difference to some extent, if continue to adopt the negotiation mode of R9 intra-LTE, will make the base station can't adjust reselecting parameters.
(2), in some scene, can not occur switching, but adopt the switching of side Network Based to finish the transfer of load by the different system of Event triggered because the network configuration of inter-RAT is the layering scene.In addition, the switching between a large amount of systems can increase the load of core net, and for the switching between the homologous ray, the switching time between system is longer, can cause user's experience to descend.
(3) in the prior protocols process, before parameter negotiation, the measurement event that disposes between parameter relevant with gravity treatment and the different system can't be known in the sub-district of two different systems, can't determine the gravity treatment of being correlated with and switch band.When parameter adjustment makes mistakes, can cause mobility problems such as ping-pong reselection, table tennis switching, cause terminal to be difficult to normally be linked in any one network, influence terminal normally to use, reduce user's experience.
Embodiment
The embodiment of the invention provides a kind of adjustment scheme of mobility parameter, in this scheme, source base station carries out parameter evaluation according to the mobility parameter and the configuration parameter of target BS, obtains the parameter adjustment advisory information, and this parameter adjustment advisory information is sent to target BS.Target BS carries out parameter evaluation to the parameter adjustment advisory information that receives, and when parameter evaluation passes through, sends confirmation to source base station.Source base station sends the parameter update notice according to the affirmation information that receives to target BS, and carry out the adjustment of mobility parameter constantly according to the parameter update that carries in the parameter update notice with target BS, thereby avoided mobility problems such as the ping-pong reselection that causes, the switching of rattling, improved the success rate of parameter negotiation because parameter does not match.
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.
In the embodiment of the invention, the exchange of mobility parameter and configuration parameter can be carried out in the adjacent each other base station of source base station and target BS.Wherein, the mobility parameter can be including but not limited to one of following and combination: the gravity treatment of the frequency re-selections priority list of the handover configurations of different system, current area and current area configuration in the current area; Configuration parameter can be including but not limited to one of following and combination: the target coverage radius of the geographical position of current area, current area and the transmitting power of current area.In addition, can also exchange the parameter type that the request target side provides between source base station and the target BS.
Source base station and target base station exchange mobility parameter and relevant configuration parameter can be periodic, also can be the modes of Event triggered, and this trigger event can be moving load balance optimizing, mobile robustness optimization or the congested control of loading.Source base station and target BS obtain the mode of the other side's mobility parameter and relevant configuration parameter can be for being undertaken by dedicated signaling alternately or obtaining from the OAM system, when the mode that adopts dedicated signaling is mutual, can be undertaken alternately by handoff procedure, also can relevant parameter be placed in the container, be undertaken alternately by RIM mechanism.
As shown in Figure 1, the method for adjustment flow chart for the mobility parameter in the embodiment of the invention may further comprise the steps:
Step 101, source base station carries out parameter evaluation according to the mobility parameter and the configuration parameter of target BS, obtains the parameter adjustment advisory information.
Particularly, source base station can be according to self and the mobility parameter of target BS and the covering scene that configuration parameter is determined source base station and target BS, select the mobility parameter of needs adjustment and obtain adjusted mobility parameter according to described covering scene, obtain comprising the parameter adjustment advisory information of this adjusted mobility parameter.Wherein, when determining covering scene, can judge the relative position relation of two sub-districts, for follow-up parameter is selected and the decision-making of other MLB provides the basis according to the configuration of OAM system or by the relevant parameter of exchange; When selecting to adjust parameter, can be in conjunction with concrete MLB algorithm and covering scene, and select suitable adjustment parameter according to the information on load of cell-of-origin and Target cell, obtain comprising the parameter adjustment advisory information of the adjustment parameter of selection, and the adjustment parameter of selecting need satisfy principles such as not producing table tennis switching, ping-pong reselection.
Step 102, source base station sends the parameter adjustment advisory information to target BS.
Particularly, source base station utilizes the RIM process to send the parameter adjustment advisory information to Target cell, and the parameter adjustment advisory information can comprise one or more scheme, and each scheme is including but not limited to one of following information or combination:
A. the relevant parameter of handover configurations is adjusted in this sub-district, for example, and the thresholding in B1 and the B2 incident (parameters such as Ofn and Thresh);
B. the relevant parameter of gravity treatment configuration is adjusted in this sub-district, and for example, the gravity treatment of low priority frequency triggers thresholding Thresh
X, low
C. the frequency priority list adjusted of this sub-district;
D. the relevant parameter of the switching that need adjust of Target cell, for example, the dependent threshold of 3a incident;
E. the gravity treatment relevant parameter that need adjust of Target cell, for example, the gravity treatment of low priority frequency triggers thresholding Thresh
X, low
F. the frequency priority list adjusted of Target cell.
Step 103, target BS carries out parameter evaluation to the parameter adjustment advisory information, if parameter evaluation passes through, then execution in step 104; Otherwise, execution in step 107.
Particularly, target BS can combining target sub-district and the Load distribution of all adjacent areas and the parameter adjustment advice message that relevant strategy provides source base station, judge whether the adjustment parameter of carrying in the parameter adjustment advisory information satisfies the principle that does not produce table tennis switching and ping-pong reselection, to determine whether the accepting adjustment parameter that the parameter adjustment advice message comprises, prevent the appearance of mobility problems such as unnecessary ping-pong reselection that wrong parameter adjustment causes, table tennis switching.In addition, for the relevant parameter of adjusting based on frequency, target BS also this parameter of needs assessment adopts the influence that the adjacent area produced of same frequency to other, and estimates the variation of load.
Step 104, target BS returns confirmation to source base station.
Particularly, if target BS is accepted the parameter adjustment advice message from source base station, then to source base station feedback acknowledgment information, comprise the ID of acceptable scheme in time that the Target cell parameter can upgrade and the parameter adjustment advice message in this confirmation.Wherein, the time that the Target cell parameter can be upgraded can be a time point, also can be an effective time period.
Step 105, source base station sends the parameter update notice to target BS.
Wherein, can comprise the moment that parameter update is prepared to carry out in the cell-of-origin, the time that can upgrade that this needs the reference target sub-district to provide constantly in the parameter update notice in confirmation.
Step 106, source base station and target BS carry out the adjustment of mobility parameter constantly according to the parameter update that carries in the parameter update notice.
Wherein, the mobility parameter of adjustment can comprise the handover configurations of different system in the current area, the frequency re-selections priority list of current area and the gravity treatment configuration of current area.
Step 107, target BS returns refusal information to source base station.
Particularly, if the scheme of all recommendations can not be accepted by Target cell in the parameter adjustment advice message, then target BS returns refusal information to source base station, can comprise one group or organize suggested design in this refusal information more.
Step 108, source base station is assessed the parameter adjustment scheme of carrying in the refusal information, obtains the parameter adjustment advisory information.
Particularly, when source base station receives refusal information, and when carrying the parameter adjustment scheme in the refusal information, source base station is assessed the parameter adjustment scheme, initiates new parameter-negotiation procedure.Source base station can judge whether the parameter adjustment scheme satisfies the principle that does not produce table tennis switching and ping-pong reselection, if satisfy the principle that does not produce table tennis switching and ping-pong reselection, be the parameter adjustment scheme evaluation by the time, source base station generates the parameter adjustment advisory information of carrying this parameter adjustment scheme; If do not satisfy the principle that does not produce table tennis switching and ping-pong reselection, when promptly the parameter adjustment scheme evaluation passed through, source base station carried out parameter evaluation according to the mobility parameter and the configuration parameter of target BS, obtains the parameter adjustment advisory information.
Wherein, source base station is judged when whether the parameter adjustment scheme satisfies the principle that does not produce table tennis switching and ping-pong reselection, can be according to the covering scene of source base station and target BS and handoff parameter and the reselecting parameters in the parameter adjustment scheme, obtain the switching scope and the gravity treatment scope of cell-of-origin and Target cell, and judge whether to produce table tennis and switch according to whether the switching scope of the switching scope of cell-of-origin and Target cell overlapping, judge whether to produce ping-pong reselection according to the gravity treatment scope of the gravity treatment scope of cell-of-origin and Target cell is whether overlapping.
Need to prove, execute this step after, can continue execution in step 102.
In the step 103 of above-mentioned flow process shown in Figure 1, target BS is judged when whether the adjustment parameter of carrying in the parameter adjustment advisory information satisfies the principle that does not produce table tennis switching and ping-pong reselection, can be according to the covering scene of source base station and target BS and handoff parameter and the reselecting parameters in the parameter adjustment advisory information, obtain the switching scope and the gravity treatment scope of cell-of-origin and Target cell, and judge whether to produce table tennis and switch according to whether the switching scope of the switching scope of cell-of-origin and Target cell overlapping, judge whether to produce ping-pong reselection according to the gravity treatment scope of the gravity treatment scope of cell-of-origin and Target cell is whether overlapping.If do not have overlappingly, then parameter adjustment advisory information satisfies the demands, and parameter evaluation passes through; When not satisfying above-mentioned condition, then parameter adjustment advisory information does not satisfy the demands, and parameter evaluation does not pass through.
Below according to the different frequency priority plans of establishment, the parameter adjustment advisory information is satisfied when not producing the principle of ping-pong reselection, the condition that needs to satisfy is described in detail:
(1) in the cell-of-origin, the frequency priority of the frequency that use the cell-of-origin is higher than the frequency priority of the frequency of Target cell use; In Target cell, the frequency priority of the frequency that Target cell uses is higher than the frequency priority of the frequency that uses the cell-of-origin;
The parameter adjustment advisory information satisfies when not producing the principle of ping-pong reselection, and the reselecting parameters in the parameter adjustment advisory information need one of meet the following conditions at least:
1.r′
t?arget-r′
source≥d
(2) in the cell-of-origin, the frequency priority of the frequency that use the cell-of-origin is higher than the frequency priority of the frequency of Target cell use; In Target cell, the frequency priority of the frequency that Target cell uses is lower than the frequency priority of the frequency that uses the cell-of-origin;
The parameter adjustment advisory information satisfies when not producing the principle of ping-pong reselection, and the reselecting parameters in the parameter adjustment advisory information need one of meet the following conditions at least:
1.Thresh
x,high(sourceIntarget)≥TH
source
2.r′
target+r′
source>d>r′
targ?et-r′
source,r
t?arg?et+r′
source≤d
(3) in the cell-of-origin, the frequency priority of the frequency that use the cell-of-origin is lower than the frequency priority of the frequency of Target cell use; In Target cell, the frequency priority of the frequency that Target cell uses is higher than the frequency priority of the frequency that uses the cell-of-origin;
The parameter adjustment advisory information satisfies when not producing the principle of ping-pong reselection, and the reselecting parameters in the parameter adjustment advisory information need one of meet the following conditions at least:
1.r′
t?arg?et-r′
source≥d
2.r′
target+r′
source>d>r′
t?arg?et-r′
source,TH
target<Thresh
x,high(targetInsource)
(4) in the cell-of-origin, the frequency priority of the frequency that use the cell-of-origin is lower than the frequency priority of the frequency of Target cell use; In Target cell, the frequency priority of the frequency that Target cell uses is lower than the frequency priority of the frequency that uses the cell-of-origin;
The parameter adjustment advisory information satisfies when not producing the principle of ping-pong reselection, and the reselecting parameters in the parameter adjustment advisory information need meet the following conditions:
r
target+r′
source≤d
Wherein, r '
SourceIn Target cell, the covering radius of the frequency that use the cell-of-origin; R '
T arg etIn Target cell, the covering radius of the frequency that Target cell uses; D is the distance of source base station to target BS; TH
SourceThe gravity treatment thresholding of the frequency that uses for the cell-of-origin; TH
T arg etThe gravity treatment thresholding of the frequency that uses for Target cell; r
SourceIn the cell-of-origin, the covering radius of the frequency that use the cell-of-origin; r
T arg etIn the cell-of-origin, the covering radius of the frequency that Target cell uses; Thresh
X, low (sourceInt arg et)In Target cell, the thresholding of triggering cell gravity treatment; Thresh
X, low (targetInsource)In the cell-of-origin, the thresholding of triggering cell gravity treatment.
Below be example with LTE sub-district and UTRAN sub-district, the judgment criterion that prevents ping-pong reselection is carried out detailed, concrete description.The scene that can exist a plurality of sub-districts to overlap in real network, the situation that this scene can be reduced to two sub-districts is analyzed.
For ease of describing, can carry out the definition of following form:
TH
LTE=min(S
non?int?rasearch,Thresh
serving,low(LTE),Th
int?ra)
TH
Utran=min(S
prioritysearch,Thresh
serving,low(utran),Th
int?ra)
The propagation model of LTE base station is P
1(dis)=Pathloss
The propagation model of UTRAN base station is P
2(dis)=Pathloss
Wherein, TH
LTEGravity treatment thresholding for the LTE frequency; S
Nonint rasearchThresholding for the measurement of the triggering different frequency/different system that stipulates in the TS36.304 agreement when signal strength signal intensity of current service cell is lower than this thresholding, triggers the measurement of different frequency/different system; Thresh
Serving, low (LTE)In the LTE system, the triggering thresholding of the sub-district gravity treatment of low priority; Th
Int raFor triggering the thresholding of selecting with frequently; TH
UtranGravity treatment thresholding for the UTRAN frequency; S
Priorityse archThresholding for the measurement of the triggering different frequency/different system that stipulates in the TS25.304 agreement when signal strength signal intensity of current service cell is lower than this thresholding, triggers the measurement of different frequency/different system; Thresh
Serving, low (utran)In the UTRAN system, the triggering thresholding of the sub-district gravity treatment of low priority; Dis is the distance of UE to the base station, and Pathloss is the path loss of UE to the base station.
In the LTE sub-district, the covering radius of LTE signal strength threshold Thresh is
The covering radius of UTRAN signal strength threshold Thresh2 is
In the UTRAN sub-district, the covering radius of LTE signal strength threshold Thresh3 is
The covering radius of UTRAN signal strength threshold Thresh4 is
Wherein, Tx_LTE is the transmitting power of LTE sub-district, and Tx_Utran is the transmitting power of UTRAN sub-district.
What in addition, can also define a closure is that the zone of the gravity treatment coverage of r is S with the radius
r, this extra-regional scope is
The LTE base station is d to the distance of UTRAN base station.
According to UTRAN sub-district and LTE sub-district medium priority be provided with different, can be divided into following several situation and describe the judgment criterion that prevents ping-pong reselection:
Situation 1:
In the LTE sub-district, the frequency priority that current LTE sub-district is set is higher than the frequency of adjacent UTRAN sub-district; In the UTRAN sub-district, the frequency priority that current UTRAN sub-district is set is higher than the frequency of adjacent LTE sub-district.
Then the gravity treatment of LTE sub-district to the zone of UTRAN sub-district is:
The gravity treatment of UTRAN sub-district to the zone of LTE sub-district is:
For avoiding ping-pong reselection, can not there be overlapping in then above-mentioned two gravity treatment zones, and adjusting parameter need one of meet the following conditions at least:
1.r′
Utran-r′
Lte≥d
Situation 2:
In the LTE sub-district, the frequency priority that current LTE sub-district is set is higher than the frequency of adjacent UTRAN sub-district; In the UTRAN sub-district, the frequency priority that the LTE sub-district is set is higher than the frequency of current UTRAN sub-district.
Then the gravity treatment of LTE sub-district is identical with the content described in the situation 1 to the zone of UTRAN sub-district, and the gravity treatment of UTRAN sub-district to the zone of LTE sub-district is:
For avoiding the generation of ping-pong reselection phenomenon, then above-mentioned two gravity treatments zone coverage can not have overlapping, and adjusting parameter need one of meet the following conditions at least:
1.Thresh
x,high(LTEinUtran)≥TH
LTE
2.r′
Utran+r′
LTE>d>r′
utran-r′
LTE,r
Utran+r′
Lte≤d
Situation 3:
In the LTE sub-district, the frequency priority that the UTRAN sub-district is set is higher than the frequency of current LTE sub-district; In the UTRAN sub-district, the frequency priority that the UTRAN sub-district is set is higher than the frequency of LTE sub-district.
Then the gravity treatment of UTRAN sub-district is identical with the content described in the situation 1 to the zone of LTE sub-district, and the gravity treatment of LTE sub-district to the zone of UTRAN sub-district is:
For avoiding the generation of ping-pong reselection phenomenon, then above-mentioned two gravity treatments zone coverage can not have overlapping, and adjusting parameter need one of meet the following conditions at least:
1.r′
Utran-r′
Lte≥d
2.r′
Utran+r′
LTE>d>r′
utran-r′
LTE,TH
Utran<Thresh
x,high(UtraninLTE)
Situation 4:
In the LTE sub-district, the frequency priority that the UTRAN sub-district is set is higher than the frequency of LTE sub-district; In the UTRAN sub-district, the frequency priority that the LTE sub-district is set is higher than the frequency of UTRAN sub-district.
Then the gravity treatment of UTRAN sub-district to the zone of LTE sub-district is:
The gravity treatment of LTE sub-district is to the zone of UTRAN sub-district:
For avoiding the generation of ping-pong reselection phenomenon, then above-mentioned two gravity treatments zone coverage can not have overlapping, and adjusting parameter need meet the following conditions:
r
utran+r′
LTE≤d
In addition, also can utilize the local area that UE reports and the signal strength signal intensity of adjacent area to calculate relevant propagation model, the related content of its method in can grid of reference planning.
For simplicity, when the frequency range of UTRAN base station and LTE base station and site height near the time, can be similar to and think that the propagation model of two base stations is identical, and make Δ P=P
1(d), represent the path loss between two base stations, this value can be obtained by the signal strength signal intensity of measuring the adjacent area by the UE that is positioned at center of housing estate, also can estimate to obtain according to the distance or the propagation model of two sub-districts.
When the propagation model of UTRAN base station and LTE base station was identical, the judgment criterion that prevents ping-pong reselection can be reduced to:
During situation 1, adjusting parameter need one of meet the following conditions at least:
1.Thresh
x,low(LTEinUtran)-TH
Utran≥ΔP+Tx_LTE-Tx_Utran
2.TH
Utran+ Thresh
X, low (LTEinUtran)During≤Tx_Utran+Tx_LTE+ Δ P, need satisfy one of following condition:
TH
LTE<Thresh
x,low(LTEinUtran)
TH
Utran+Thresh
x,low(UtraninLTE)≤ΔP+Tx_LTE+Tx_Utran
3.Tx_Utran-TH
Utran+Tx_LTE-Thresh
x,low(LTEinUtran)>ΔP
Δ P>Tx_Utran-TH
Utran-Tx_LTE+Thresh
X, low (LteInUtran)The time, need satisfy one of following two conditions:
TH
Utran<Thresh
x,low(UtraninLTE)
TH
LTE-TH
Utran≥ΔP+Tx_LTE-Tx_Utran
During situation 2, adjusting parameter need one of meet the following conditions at least:
1.Thresh
x,high(LTEinUtran)≥TH
LTE
2.Tx_Utran-TH
Utran+Tx_LTE-Thresh
x,low(LTEinUtran)>ΔP
And, Δ P>Tx_Utran-TH
Utran-Tx_LTE+Thresh
X, low (LteInUtran)
And, Tx_Utran+Tx_LTE-Δ P≤Thresh
X, low (UtraninLTE)+ Thresh
X, high (LTEinUtran)
During situation 3, adjusting parameter need one of meet the following conditions at least:
1.Tx_Utran-Tx_LTE≥ΔP+TH
Utran-Thresh
x,low(LTEinUtran)
2.Tx_Utran-TH
Utran+Tx_LTE-Thresh
x,low(LTEinUtran)>ΔP
And, Δ P>Tx_Utran-TH
Utran-Tx_LTE+Thresh
X, low (LteInUtran)
And, TH
Utran<Thresh
X, high (UtraninLTE)
During situation 4, adjusting parameter need meet the following conditions:
Tx_Utran+Tx_LTE-ΔP≥TH
Utran+Thresh
x,high(LTEinUtran)
By above description as can be seen, because the information on load that the target BS of load balancing provides for source base station can reflect the load condition around the target BS better, make source base station obtain more cell information indirectly, and the appearance of minimizing concussion adjustment, revise less to the existing protocol process simultaneously, the equipment realization of equipment manufacturers and the enforcement of operator have been made things convenient for, in addition, method in the embodiment of the invention is not only applicable in the load balancing Automatic Optimal of SON scope, also go in LTE and the follow-up evolvement network (as LTE+) thereof during traditional load balancing manually optimizes, can be used as a kind of scheme implementation of simple and easy to do load balancing parameter coordination.
Respectively with under focus covering scene shown in Figure 2, common covering scene shown in Figure 4 and the adjacent scene shown in Figure 6, the specific implementation process of the embodiment of the invention is that example describes below.
As shown in Figure 2, be the focus covering scene schematic diagram in the embodiment of the invention, wherein, the LTE sub-district covers less zone, and the TD-SCDMA sub-district covers bigger zone.The frequency range that adopt LTE sub-district and TD-SCDMA sub-district all is the 2G frequency range, and the ground level of standing is approaching, therefore, approximate think that the LTE sub-district is identical with the propagation model of TD-SCDMA sub-district, and the priority that current frequency is set respectively in LTE sub-district and the TD-SCDMA sub-district is higher than the priority of other RAT.
As shown in Figure 3, the method for adjustment flow chart for the mobility parameter in the focus covering scene may further comprise the steps:
Step 301, the information on load of its following sub-district of LTE base station periodic statistics knows that the load of self is too high, triggers the exchange of information on load and parameter configuration, by mutual information on load of RIM process and TD-SCDMA base station and parameter configuration.
Step 302, LTE base station are known the coverage of self in the coverage of TD-SCDMA according to interactive information, decision reduces the handoff parameter Thresh1 and the reselecting parameters Thresh of this sub-district
Serving, low
Particularly,, therefore, judge the situation 1 that belongs to, obtain following information by the relation of the reselecting parameters between two sub-districts because the frequency priority of current two sub-districts all is that the frequency that current service frequency is higher than other technologies is set:
The gravity treatment of LTE sub-district to the zone of TD-SCDMA sub-district is:
The gravity treatment of TD-SCDMA sub-district does not exist to the zone of LTE sub-district, is sky.
Equally, the trigger event that the LTE sub-district switches to the TD-SCDMA cell configuration is the B2 incident, and the zone that switches to the TD-SCDMA sub-district is consistent with the gravity treatment scope:
The TD-SCDMA sub-district is owing to the reason of signal strength signal intensity switches to the zone of LTE sub-district for empty.
By with co-relation as can be known, the decision of LTE base station reduces the handoff parameter Thresh1 and the reselecting parameters Thre of this sub-district
Shserving, low, its adjusting range can be determined by the step-length of OAM system configuration or the implementation algorithm of MLB.
Step 303, LTE base station are utilized RIM message on the S1 interface, the parameter of needs adjustment is sent to the TD-SCDMA base station with the form of parameter recommendation information.
Wherein, the RIM message content of carrying comprises: the variable quantity of the handoff parameter Thresh1 of LTE sub-district and the reselecting parameters Thresh of LTE sub-district
Serving, lowVariable quantity.
Step 304, the TD-SCDMA base station is assessed parameter recommendation information, knows that parameter satisfies the criterion that does not produce table tennis switching, ping-pong reselection respectively, accepts the parameter recommendation information of LTE base station.
Step 305, TD-SCDMA base station are passed through the Iu interface to LTE base station feedback confirmation.
Wherein, can comprise the zero-time that parameter can be upgraded in the confirmation.
Step 306, LTE base station utilize the S1 interface to send the parameter update notice to the TD-SCDMA base station.
Wherein, comprise the time T that LTE sub-district and TD-SCDMA sub-district begin undated parameter simultaneously in the parameter update notice.
Step 307, when time T, LTE sub-district and TD-SCDMA sub-district are upgraded relevant parameter simultaneously.
Carry out the mobility parameter of two different system cell intercorrelations of parameter adjustment in the embodiment of the invention, realize parameter negotiation and parameter evaluation in the load balancing, and carry out parameter adjustment in conjunction with the information on load of two different system cells, current mobility parameter, distribution situation with change of load, reduce mobility problems such as the ping-pong reselection that causes, the switching of rattling because parameter does not match, improve the success rate of parameter negotiation and the convergence of load balancing, and guarantee user's QoS.
As shown in Figure 4, be the common covering scene schematic diagram in the embodiment of the invention, wherein, sub-district A is the LTE sub-district, and sub-district B is the TD-SCDMA sub-district.TD-SCDMA base station and LTE base station are deployed on the site jointly, and the overlay area is a small-sized square, and covering radius is 500 meters.The priority that current frequency is set respectively in LTE and the TD-SCDMA sub-district is higher than the priority of other RAT.
As shown in Figure 5, for being total to the method for adjustment flow chart of the mobility parameter in the covering scene, may further comprise the steps:
Step 501, the information on load of its following sub-district of LTE base station periodic statistics knows that the load of self is too high, triggers the exchange of information on load and parameter configuration, by mutual information on load of RIM process and TD-SCDMA base station and parameter configuration.
Step 502, LTE base station are known with the TD-SCDMA base station according to interactive information and are belonged to common covering scene, and determine to adjust parameter.
Particularly,, therefore, judge the situation 1 that belongs to, can obtain following information by the gravity treatment between two sub-districts, handoff parameter relation because the frequency priority of current two sub-districts all is that the frequency that current service frequency is higher than other technologies is set:
Switching and gravity treatment scope between two sub-districts do not exist, promptly under the parameter current configuring condition, connected state UE and Idle state UE can not independently switch or gravity treatment in the sub-district of location altogether.
The LTE base station is carried out user's redistribution according to the moving load equalization algorithm by adjusting gravity treatment carrier wave priority and relevant parameter.For the connected state user, the LTE base station adopts the switching of network side to carry out user's transfer.In LTE, improve the carrier wave priority of TD-SCDMA, make its priority be higher than the frequency that LTE uses.Because variation has taken place in frequency priority, need recomputate reselecting parameters Thresh
X, high (UtraninLTE), its computational methods are that the load of current LTE sub-district is S, and the load that expectation is shifted is Δ S, and the target coverage radius is r
N, and approximate think that the user belongs to even distribution, initial parameter is distributed can be according to following computing formula:
Carry out.
Step 503, LTE base station are utilized RIM message on the S1 interface, the parameter of needs adjustment is sent to the TD-SCDMA base station with the form of parameter recommendation information.
Wherein, the RIM message content of carrying comprises: the reselecting parameters Thresh that upgrades in the new gravity treatment frequency priority list of LTE sub-district and the LTE sub-district
X, high (UtraninLTE)
Step 504, the TD-SCDMA base station is assessed parameter recommendation information, knows that parameter satisfies the criterion that does not produce table tennis switching, ping-pong reselection respectively, accepts the parameter recommendation information of LTE base station.
Step 505, TD-SCDMA base station are passed through the Iu interface to LTE base station feedback confirmation.
Wherein, can comprise the zero-time that parameter can be upgraded in the confirmation.
Step 506, LTE base station utilize the S1 interface to send the parameter update notice to the TD-SCDMA base station.
Wherein, comprise the time T that LTE sub-district and TD-SCDMA sub-district begin undated parameter simultaneously in the parameter update notice.
Step 507, when time T, LTE sub-district and TD-SCDMA sub-district are upgraded relevant parameter simultaneously.
Carry out the mobility parameter of two different system cell intercorrelations of parameter adjustment in the embodiment of the invention, realize parameter negotiation and parameter evaluation in the load balancing, and carry out parameter adjustment in conjunction with the information on load of two different system cells, current mobility parameter, distribution situation with change of load, reduce mobility problems such as the ping-pong reselection that causes, the switching of rattling because parameter does not match, improve the success rate of parameter negotiation and the convergence of load balancing, and guarantee user's QoS.
As shown in Figure 6, be the adjacent scene schematic diagram in the embodiment of the invention, have three TD-SCDMA base stations around the LTE sub-district, three TD-SCDMA base stations are adopted N frequency technology respectively, and dominant frequency point is inequality.
As shown in Figure 7, the method for adjustment flow chart for the mobility parameter in the adjacent scene may further comprise the steps:
Step 701, the information on load of its following sub-district of LTE base station periodic statistics knows that the load of self is too high, triggers the exchange of information on load and parameter configuration, by mutual information on load of RIM process and TD-SCDMA base station and parameter configuration.
Particularly, LTE eNodebB1 sub-district disposes relevant information by the RIM process to TD NodeB1,2,3 sub-districts difference required parameter.
Step 702, LTE base station are known with the TD-SCDMA base station according to interactive information and are belonged to adjacent covering scene, and determine to adjust parameter.
Particularly,, therefore judge the situation 1 that belongs to, can obtain following information by the gravity treatment between two sub-districts, handoff parameter relation because the frequency priority of current two sub-districts all is that the frequency that current service frequency is higher than other technologies is set:
The LTE gravity treatment is empty to the zone of TD-SCDMA, and then UE can not trigger the gravity treatment of LTE to TD-SCDMA because of the problem of signal strength signal intensity; The trigger event that LTE switches to the TD-SCDMA configuration is the B2 incident, and it is Zone switched to be empty.
At this moment, the decision of LTE base station improves the frequency priority of three TD-SCDMA sub-districts and the reselecting parameters Thresh that revises each frequency
Serving, high,, carry out user's transfer for the switching that existing connected state adopts network side to trigger to change the resident distribution of UE.
Step 703, LTE base station are utilized RIM message on the S1 interface, the parameter of needs adjustment is sent to TD NodeB1,2,3 with the form of parameter recommendation information.
Wherein, the RIM message content of carrying comprises: the reselecting parameters Thresh that upgrades in the new gravity treatment frequency priority list of LTE sub-district and the LTE sub-district
X, high (UtraninLTE)
Step 704, the TD-SCDMA base station is assessed parameter recommendation information, knows that parameter satisfies the criterion that does not produce table tennis switching, ping-pong reselection respectively, accepts the parameter recommendation information of LTE base station.
Step 705, TD-SCDMA base station are passed through the Iu interface to LTE base station feedback confirmation.
Wherein, can comprise the zero-time that parameter can be upgraded in the confirmation.
After step 706, LTE base station receive the affirmation message of three TD-SCDMA base stations, utilize the S1 interface to send a parameter update notice respectively to three TD-SCDMA base stations.
Wherein, can comprise the time T that LTE sub-district and TD-SCDMA sub-district begin undated parameter simultaneously in the parameter update notice.
Step 707, when time T, LTE sub-district and three TD-SCDMA sub-districts are upgraded relevant parameter simultaneously.
Carry out the mobility parameter of two different system cell intercorrelations of parameter adjustment in the embodiment of the invention, realize parameter negotiation and parameter evaluation in the load balancing, and carry out parameter adjustment in conjunction with the information on load of two different system cells, current mobility parameter, distribution situation with change of load, reduce mobility problems such as the ping-pong reselection that causes, the switching of rattling because parameter does not match, improve the success rate of parameter negotiation and the convergence of load balancing, and guarantee user's QoS.
As shown in Figure 8, the source base station structural representation in the embodiment of the invention comprises:
First evaluation module 810 is used for carrying out parameter evaluation according to the mobility parameter and the configuration parameter of target BS, obtains the parameter adjustment advisory information.
Particularly, first evaluation module 810, be used for covering scene according to mobility parameter and configuration parameter judgement source base station and target BS, select the mobility parameter of needs adjustment and obtain adjusted mobility parameter according to this covering scene, obtain comprising the parameter adjustment advisory information of this adjusted mobility parameter.
First transceiver module 820 is used for sending the parameter adjustment advisory information to target BS, after the affirmation information that receives from target BS, sends the parameter update notice to target BS.
First adjusting module 830 is used to carry out the adjustment of mobility parameter.
Particularly, first adjusting module 830 is used for carrying out the adjustment of mobility parameter constantly according to the parameter update that the parameter update notice that first transceiver module 820 sends is carried.
Above-mentioned first transceiver module 820 also is used for receiving the refuse information from target BS when target BS does not pass through the assessment of parameter adjustment advisory information; When the parameter adjustment scheme evaluation that carries in 810 pairs of refusal information of first evaluation module passes through, send the parameter adjustment advisory information of carrying the parameter adjustment scheme to target BS; Correspondingly, first evaluation module 810, the parameter adjustment scheme that also is used for refusal information is carried is carried out parameter evaluation.
Particularly, first evaluation module 810 judges whether the parameter adjustment scheme satisfies the principle that does not produce table tennis switching and ping-pong reselection, if satisfy, then the parameter adjustment scheme evaluation passes through; Otherwise the parameter adjustment scheme evaluation does not pass through.First evaluation module 810 is according to the covering scene of source base station and target BS and handoff parameter and the reselecting parameters in the parameter adjustment scheme, obtain the switching scope and the gravity treatment scope of cell-of-origin and Target cell, and judge whether to produce table tennis and switch according to whether the switching scope of the switching scope of cell-of-origin and Target cell overlapping, judge whether to produce ping-pong reselection according to the gravity treatment scope of the gravity treatment scope of cell-of-origin and Target cell is whether overlapping.
Carry out the mobility parameter of two different system cell intercorrelations of parameter adjustment in the embodiment of the invention, realize parameter negotiation and parameter evaluation in the load balancing, and carry out parameter adjustment in conjunction with the information on load of two different system cells, current mobility parameter, distribution situation with change of load, reduce mobility problems such as the ping-pong reselection that causes, the switching of rattling because parameter does not match, improve the success rate of parameter negotiation and the convergence of load balancing, and guarantee user's QoS.
As shown in Figure 9, the target BS structural representation in the embodiment of the invention comprises:
Second transceiver module 910 is used to receive the parameter adjustment advisory information from source base station, when 920 pairs of parameter adjustment advisory information assessments of second evaluation module are passed through, sends confirmation to source base station, and receives the parameter update notice from source base station.
Second evaluation module 920 is used for the parameter adjustment advisory information that second transceiver module 910 receives is carried out parameter evaluation.
Particularly, above-mentioned second evaluation module 920 is used to judge whether the parameter adjustment advisory information satisfies the principle that does not produce table tennis switching and ping-pong reselection, if satisfy, the assessment of then parameter adjustment advisory information is passed through; Otherwise the assessment of parameter adjustment advisory information is not passed through.Second evaluation module 920 is according to the covering scene of source base station and target BS and handoff parameter and the reselecting parameters in the parameter adjustment advisory information, obtain the switching scope and the gravity treatment scope of cell-of-origin and Target cell, and judge whether to produce table tennis and switch according to whether the switching scope of the switching scope of cell-of-origin and Target cell overlapping, judge whether to produce ping-pong reselection according to the gravity treatment scope of the gravity treatment scope of cell-of-origin and described Target cell is whether overlapping.
Second adjusting module 930 is used to carry out the adjustment of mobility parameter.
Particularly, second adjusting module 930, the parameter update that the parameter update notice that is used for receiving according to second transceiver module 910 is carried carries out the adjustment of mobility parameter constantly.
Above-mentioned second transceiver module 910 also is used for sending refuse information to source base station when 920 pairs of parameter adjustment advisory information assessments of second evaluation module are not passed through, and carries the parameter adjustment scheme in this refuse information; When source base station passes through the parameter adjustment scheme evaluation, receive parameter adjustment advisory information from the parameter adjustment scheme of carrying of source base station.
Carry out the mobility parameter of two different system cell intercorrelations of parameter adjustment in the embodiment of the invention, realize parameter negotiation and parameter evaluation in the load balancing, and carry out parameter adjustment in conjunction with the information on load of two different system cells, current mobility parameter, distribution situation with change of load, reduce mobility problems such as the ping-pong reselection that causes, the switching of rattling because parameter does not match, improve the success rate of parameter negotiation and the convergence of load balancing, and guarantee user's QoS.
Through the above description of the embodiments, those skilled in the art can be well understood to the present invention and can realize by the mode that software adds essential general hardware platform, can certainly pass through hardware, but the former is better execution mode under a lot of situation.Based on such understanding, the part that technical scheme of the present invention contributes to prior art in essence in other words can embody with the form of software product, this computer software product is stored in the storage medium, comprise that some instructions are with so that a station terminal equipment (can be mobile phone, personal computer, server, the perhaps network equipment etc.) carry out the described method of each embodiment of the present invention.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be looked protection scope of the present invention.
It will be appreciated by those skilled in the art that the module in the device among the embodiment can be distributed in the device of embodiment according to the embodiment description, also can carry out respective change and be arranged in the one or more devices that are different from present embodiment.The module of the foregoing description can be integrated in one, and also can separate deployment, can merge into a module, also can further split into a plurality of submodules.
The invention described above embodiment sequence number is not represented the quality of embodiment just to description.
More than disclosed only be several specific embodiment of the present invention, still, the present invention is not limited thereto, any those skilled in the art can think variation all should fall into protection scope of the present invention.