WO2013024349A2 - Method and apparatus for user equipment mobility state estimation in a wireless communication network - Google Patents
Method and apparatus for user equipment mobility state estimation in a wireless communication network Download PDFInfo
- Publication number
- WO2013024349A2 WO2013024349A2 PCT/IB2012/001887 IB2012001887W WO2013024349A2 WO 2013024349 A2 WO2013024349 A2 WO 2013024349A2 IB 2012001887 W IB2012001887 W IB 2012001887W WO 2013024349 A2 WO2013024349 A2 WO 2013024349A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mobility state
- state estimation
- cell
- estimation parameter
- user equipment
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000004891 communication Methods 0.000 title claims abstract description 13
- 230000005540 biological transmission Effects 0.000 claims description 12
- 230000003993 interaction Effects 0.000 claims description 6
- 238000012423 maintenance Methods 0.000 claims description 6
- 230000007246 mechanism Effects 0.000 abstract description 5
- 230000011664 signaling Effects 0.000 description 7
- 238000013507 mapping Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000000593 degrading effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000013146 percutaneous coronary intervention Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/32—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data
- H04W36/324—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data by mobility data, e.g. speed data
Definitions
- F F + a - l F reselections will be increased by the following equation: " " _1 , where " is the calibrated number of handovers or cell reselections in current serving cell, and " _1 is the number of handovers or cell selections in the last serving cell.
- a range split of PCI values is performed corresponding to cell radius or cell type.
- the base station obtaining a mobility state estimation parameter comprises obtaining the mobility state estimation parameter from interactions with neighboring base stations or obtaining the mobility state estimation parameter from Operation and Maintenance Control Node OMC.
- the present invention further proposes a base station for assisting handover of a user equipment within coverage of cells in a wireless communication network, the base station comprising: mobility state estimation parameter obtaining module configured to obtain a mobility state estimation parameter, and sending module configured to send to the user equipment a message including the mobility state estimation parameter, wherein the mobility state estimation parameter will be used by the user equipment to determine mobility state and adapt to actual mobile speed.
- the present invention further proposes a user equipment for handover by means of a base station within the coverage of cells in a wireless communication network, the user equipment comprising: adjusting module configured to adjust the number of handovers or cell reselections according to a mobility state estimation parameter provided by the base station, and determining module configured to determine mobility state and adapt to actual mobile speed.
- Figure 1 shows an example in HetNet, where UE goes through many small cells
- Figure 2 is a flowchart of the UE improving UE mobility state estimation according to a mobility state estimation factor according to an embodiment of the present invention
- Figure 3 is an instance of PCI range split according to the embodiment of the present invention.
- the UE When the UE receives the mobility factor, it shall calibrate the mobility state estimation accordingly. For example, the UE shall increase the number of handovers or cell reselections by the estimation factor when performing mobility state estimation as in the following equation.
- the UE If the UE does not receive the mobility factor, it shall follow normal mobility state estimation procedure, i.e. increase the number of handovers or cell reselections by 1.
- the estimation factor can be indicated to the UE through either a cells-common or UE-dedicated message.
- the UE shall follow normal estimation procedure in step 202, i.e. increase the number of handovers or cell reselections by 1 according to the above equation (2).
- the UE If the UE receives the cell-specific mobility state estimation parameter, supposing that mobility state factor a is received in the example, proceed to step 207, then proceeding to step 207, the UE shall increase the number of handovers or cell reselections by the calibrated number according to the above equation (1) to improve mobility state estimation.
- the serving cell may notify the cell size or cell power to the UE. Based on this information, the UE can autonomously calibrate the number of handovers or cell reselections in its way.
- the serving cell may explicitly send its cell size indicator to the UE for the mobility state estimation, and the cell size may be one of ⁇ large, medium, small, and very small ⁇ .
- the UE When the UE receives this notification, it shall scale a factor or add an offset to the number of handovers or cell reselections.
- the scaling rule can be left to the UE as an appropriate algorithm.
- Table 1 shows a mapping table of cell size and scale value. In this table, the scale value is selected from 1, 0.5, 0.25 and 0.125. Those skilled in the art can easily appreciate that less or more scale values may be used in other cases.
- the serving cell shall send its cell transmission power to the UE for mobility state estimation, which provides a more accurate but indirect measurement of cell size. For example, larger cell transmission power corresponds to the larger cell size.
- the UE may calibrate its mobility state estimation as a proprietary algorithm. Similar to Table 1, one possible implementation is that a function (or a table) with the cell transmission power variables is defined to derive a scale value similar to a as in the mobility state estimation factor method.
- the UE When the UE is informed of the cell transmission power, it shall perform scaling according to an appropriate algorithm. For example, in the above table, instead of cell size, the mapping relationship between the cell transmission power and scale values within the range of (0,1] can be used to calibrate the speed of the UE.
- the operation procedure of the cell size/cell power method is similar to the mobility state estimation factor method shown in Figure 2, with the difference being that the parameter received by the UE is the cell size/cell power rather than the mobility state estimation factor. Therefore, the flow of Figure 2 proceeds to step 205, i.e., the UE shall perform the operation of mapping from the cell radius or cell transmission power to a scale value.
- the UE shall increase the number of handovers or cell reselections by the calibrated number in a way similar to the above equation (1) to improve mobility state estimation.
- the scale value is selected from ⁇ 0.125, 0.25, 0.5, 1 ⁇
- the UE determines it is in which state ⁇ high, medium, normal ⁇ and adjusts mobility parameters to adapt to UE speed.
- the UE can regulate its mobility parameters in the following ways, for example, adding an offset to a hysteresis value for idle UE or scale TimeToTrigger by a factor for connected UE to adapt to real mobile speed, of course, the UE can also regulate any other mobility parameter that may adapt to actual mobile speed to achieve the purpose of the present invention.
- PCI Physical Cell ID
- 504 PCIs are defined in current LTE, requiring to be used separately in a large enough space so that the UE does not receive information from a cell with the same PCI.
- the PCI value has no association with the cell size.
- a range of PCI values is exclusively reserved by the network for use by cells.
- the split of PCI range can be dependent on different cell sizes. For example, large coverage cells can use a range of high PCI values whereas small coverage cells can use a range of low PCI values.
- the PCI range split information is sent to the UE. For example, PCI 0-199 are allocated to cells with the radius larger than 5 km, and PCI 200-399 are allocated to cells with the radius of 1-5 km.
- FIG. 4 is a functional block diagram of a base station (e.g. eNB, NB, etc.) and user equipment UE according to the embodiment of the present invention.
- the base station and user equipment UE according to the embodiment of the present invention can be simply modified in terms of functionality based on the prior art.
- Signaling delivery for the base station and user equipment UE can take advantage of the existing signaling or add new message elements on the existing signaling, whereby based on the disclosure of the present invention, it is not very difficult for those skilled in the art to implement the base station and user equipment UE of the present invention.
- the base station 401 may comprise mobility state estimation parameter obtaining module 11 configured to obtain the mobility state estimation parameter, and sending module 12 configured to send to the user equipment a message including the mobility state estimation parameter, wherein the mobility state estimation parameter will be used by the user equipment to determine mobility state and adapt to actual mobile speed.
- the mobility state estimation parameter obtaining module 11 may be configured to obtain the mobility state estimation parameter from interactions with neighboring base stations or to obtain the mobility state estimation parameter from Operation and Maintenance Control node OMC.
- the mobility state estimation parameter is such as the mobility state estimation factor, the cell radius, the cell power and the PCI value and the like mentioned above.
- Module 12, which is configured to send to the user equipment a message including the mobility state estimation parameter may use an existing signaling or add new message elements to an existing signaling, and include the mobility state estimation parameter mentioned above in the message sent.
- the user equipment may comprise adjusting module 21 configured to adjust the number of handovers or cell reselections according to the mobility state estimation parameter provided by the base station, and determining module 22 configured to determine mobility state and adapt to actual mobile speed.
- the module 21 shall increase the number of handovers or cell reselections directly or indirectly according to the
- F F + a - l mobility state estimation parameter, for example, by the following equation: " " _1 , F
- the mobility state estimation parameter is the cell radius, cell power or PCI value, then the mobility state estimation parameter is mapped to a scale value, and the number of handovers or cell reselections is increased according to the scale value.
- the module 22 shall determine the actual mobile speed according to the calibrated value of the number of handovers or cell reselections and adjust the mobility parameters to adapt to actual mobile speed.
- the method and relevant apparatus according to the invention address the UE mobility state estimation for robust mobility state estimation in the HetNet.
- the unique benefits thereof are as follows.
- PCI range split may be used to allocate PCI based on the cell size/cell type.
- This mechanism proposes some signalling between eNB and UE for robust mobility in the HetNet.
- the signaling can be easily detected.
Abstract
The present invention relates to a method for assisting handover of a user equipment within coverage of cells in a wireless communication network. The method comprises: a base station obtaining a mobility state estimation parameter, and the base station sending to the user equipment a message including the mobility state estimation parameter, in order to determine mobility state by the user equipment according to the mobility state estimation parameter and adapt to actual mobile speed. Compared with UE autonomous estimation method, the enhanced UE mobility state estimation mechanism proposed by the present invention has high reliability and robust mobility.
Description
Method and Apparatus for User Equipment Mobility State Estimation in a Wireless
Communication Network
Technical Field
The present invention relates to a wireless communication network, and specifically, to handover or cell reselection in the wireless communication network.
Description of the Related Art
In order to meet the rapid requirement of data services, besides macro cells deployed by operators, so called "low-transmitted power nodes" including pico nodes, femto nodes, relay nodes, and RRHs (Remote Radio Head), etc are introduced to augment the network coverage and system capacity. In such heterogeneous network (HetNet), the chance of handover or cell reselection becomes much higher due to the small coverage of these "low-transmitted power nodes". This is especially true for high-speed user equipments (UEs). Hence in this HetNet scenario it is more challenging to configure the optimal mobility parameters since the improper configuration may lead to handover failure, ping-pong effect, etc, thus degrading the user experience and wasting the radio resources.
In order to meet the rapid requirement of data services, besides the macro cells deployed by operators, so called "low-transmitted power nodes" including pico nodes, femto nodes, relay nodes, and RRHs, etc are introduced to augment the network coverage and system capacity. In such heterogeneous network (HetNet), the chance of handover or cell reselection becomes much higher due to the small coverage of these "low-transmitted power nodes". This is especially true for high-speed UEs. Hence in this HetNet scenario it is more challenging to configure the optimal mobility parameters since the improper configuration may lead to handover failure, ping-pong effect, etc, thus degrading the user experience and wasting the radio resources.
Before the cell reselection (for UE in RRC-Idle state) or handover (for UE in RRC-Connected state), UE shall estimate its mobility state first, which may be expressed as the number of cells crossed within a certain predetermined duration. The normal method is described as follows. Each time the cell changes, UE may increase the number of cell reselections or handovers by one.
If the counter number exceeds a high threshold within the predetermined duration, UE determines it is in high-mobility state. If the counter number exceeds a medium threshold but
does not exceed the high threshold within the predetermined duration, UE determines it is in medium-mobility state. Otherwise, UE determines it is in normal-mobility state.
Based on the mobility state estimation, UE may adjust its mobility parameters, e.g. adding an offset to hysteresis value for idle UE or scale TimeToTrigger by a factor for connected UE to adapt to real mobile speed.
The offset here is a parameter adjusted for adapting to different mobility. For example, at a conventional mobile speed, if a neighboring cell with Received Signal Strength -90dBm can be used as a suitable cell for UE selection or handover, but the time selective fading of the UE under high mobility will worsen the UE's receiving performance, and to this end, it is required to provide some compensation mechanism, for example, the offset is set to 6dB; in other words, when the UE knows itself in fast movement, only when the send strength of an neighboring cell reaches -84dBm (-90dBm +6 dB) or more, it will select or be handed over to this candidate cell. Hysteresis value is a parameter set for overcoming the ping-pong effect, or uninstalling throughput and the like, for example, the send strength of the current cell is -90dBm while that of the neighboring cell being -85dBm, if the Hysteresis value is set to lOdB, only when the neighboring cell reaches -80dBm, the handover will be initiated; TimeToTrigger means only when specific conditions (such as handover conditions) are satisfied within designated time, the UE will trigger and deliver the measurement report to eNB; if high-speed UE moves in a cell with a small coverage radius, it is necessary to reduce the trigger time indicated by TimeToTrigger; otherwise before the handover is completed, the UE will detach from the serving cell, thereby causing a handover failure.
The normal method works fine in homogeneous network for the relatively small difference of cell size across cells. However in HetNet with dense deployment of "low-transmitted power nodes", the cell size may vary significantly. When the UE just counts the number of cell changes to determine its mobility state and adjusts its mobility parameters based on this estimation, the mobility performance becomes unreliable and even lots of radio link failure happens. Fig. 1 gives a UE mobility example in HetNet, where the UE goes through many small cells. The UE may incorrectly estimate it is in high-mobility state. And it shall scale down its mobility parameters to adapt to the high mobility state, e.g. shorter TimeToTrigger to enable the handover process faster. However this incorrect estimation may result in handover failure due to the too early handover and the UE has to perform radio link recovery with the source cell. During this process, even some ping-pong handover happens unexpectedly.
There are no existing solutions to address the reliable UE mobility state estimation problem in the HetNet yet. One straightforward solution is based on cellular network positioning method at UE side. Based on the varying positions, UE can estimate its mobility state and calibrate its mobility state accordingly. However, the positioning method may involve a lot of sending transmission over radio interface and core network. And it may cost the UE battery consumption if the positioning method is associated with UE. Finally the positioning method to estimate the UE speed may be not applied to idle UEs.
Because of the significantly varied cell size in the HetNet, it is unreliable to estimate mobility state by purely counting the number of handovers or cell selections. An enhanced mechanism with high reliability will be proposed below to enable mobility robust performance.
Summary of the Invention
The basic idea of the invention is that under the assistance of serving cell, UE takes the varying cell size into account for the mobility state estimation. Specifically, the serving cell may notify cell size and/or cell type related information to UE. Based on this, UE can calibrate its mobility state estimation and tune its mobility parameters to adapt to actual mobility state.
There are several ways for the serving cell to notify cell size or cell type related information to UE for mobility state estimation.
Based on the above understanding, the present invention proposes a method for assisting handover of a user equipment within coverage of cells in a wireless communication network, the method comprising: a base station obtaining a mobility state estimation parameter, and the base station sending to the user equipment a message including the mobility state estimation parameter, in order to determine mobility state by the user equipment according to the mobility state estimation parameter and adapt to actual mobile speed.
According to a preferred embodiment of the present invention, the mobility state estimation parameter is one of a mobility state estimation factor CI , CI = (0, 1] , cell radius, cell transmission power, and physical ID of the cell, i.e., PCI value.
According to the embodiment of the present invention, if the mobility state estimation parameter is the mobility state estimation factor CI , the number of handovers or cell
F = F + a - l F reselections will be increased by the following equation: " "_1 , where " is the
calibrated number of handovers or cell reselections in current serving cell, and "_1 is the number of handovers or cell selections in the last serving cell.
According to the embodiment of the present invention, a range split of PCI values is performed corresponding to cell radius or cell type.
According to the embodiment of the present invention, if the mobility state estimation parameter is the cell radius, cell transmission power or PCI value, the mobility state estimation parameter is mapped to a scale value, and the number of handovers or cell reselections is increased by the scale value.
According to the embodiment of the present invention, the base station obtaining a mobility state estimation parameter comprises obtaining the mobility state estimation parameter from interactions with neighboring base stations or obtaining the mobility state estimation parameter from Operation and Maintenance Control Node OMC.
The present invention further proposes a base station for assisting handover of a user equipment within coverage of cells in a wireless communication network, the base station comprising: mobility state estimation parameter obtaining module configured to obtain a mobility state estimation parameter, and sending module configured to send to the user equipment a message including the mobility state estimation parameter, wherein the mobility state estimation parameter will be used by the user equipment to determine mobility state and adapt to actual mobile speed.
According to the embodiment of the present invention, the mobility state estimation parameter obtaining module is further configured to obtain the mobility state estimation parameter from interactions with neighboring base stations or to obtain the mobility state estimation parameter from Operation and Maintenance Control node OMC.
According to the embodiment of the present invention, the wireless communication network is one of GSM, WCDMA, LTE, CDMA, CDMA2000, WiMAX network.
The present invention further proposes a user equipment for handover by means of a base station within the coverage of cells in a wireless communication network, the user equipment comprising: adjusting module configured to adjust the number of handovers or cell reselections according to a mobility state estimation parameter provided by the base station, and determining module configured to determine mobility state and adapt to actual mobile speed.
Compared with UE autonomous estimation method, this solution proposed by the present invention has the following advantages:
High reliability: the serving cell notifies the cell type/cell size related information for reliable mobility state estimation.
Robust mobility: handover failure or handover ping-pong is much avoided.
Brief Description of the Drawings
Exemplary embodiments of the present invention will be described below with reference to the drawings. In the drawings, same reference signs refer to the same or similar technical features.
Figure 1 shows an example in HetNet, where UE goes through many small cells;
Figure 2 is a flowchart of the UE improving UE mobility state estimation according to a mobility state estimation factor according to an embodiment of the present invention;
Figure 3 is an instance of PCI range split according to the embodiment of the present invention; and
Figure 4 is a functional block diagram of a base station and user equipment according to the embodiment of the present invention.
Detailed Description of the Preferred Embodiment
Embodiments to which the basic idea of the present invention is applied to improve UE mobility state estimation are given below. It is worth noting that although the method and apparatus of the present invention are described by example of a base station eNB and user equipment UE in LTE networks, they are not limiting. For those skilled in the art, on the basis of the disclosure of the present invention, application of the basic idea and spirit of the present invention to GSMAVCDMA, CDMA/CDMA2000 and WiMAX networks and the like can likewise implement enhanced mobility state estimation to improve cell handover within the corresponding networks. Therefore, the present invention is generally applicable in GSM/W CDMA/LTE, CDMA/CDMA2000 and WiMAX networks and the like.
1. Mobility State Estimation Factor
In this method, the serving cell sends a mobility state estimation factor a to assist the UE mobility state estimation. This factor can implicitly identify the serving cell size or cell type. The value range for fl is (0,1], typically obtained by the current serving cell from network entities such as Operation and Maintenance Control OMC node or obtained in interactions with other cells.
When the UE receives the mobility factor, it shall calibrate the mobility state estimation
accordingly. For example, the UE shall increase the number of handovers or cell reselections by the estimation factor when performing mobility state estimation as in the following equation.
F = F , + a · 1
p
where " is the calibrated number of handovers or cell reselections in current serving p
cell, "_1 is the number of handovers or cell selections in the last serving cell, and a is the sent estimation factor.
If the UE does not receive the mobility factor, it shall follow normal mobility state estimation procedure, i.e. increase the number of handovers or cell reselections by 1.
= Fn-^ (2)
Based on the counted number, the UE determines in which state (high, medium, normal) it is and adjusts the mobility parameters depending on the UE speed.
The estimation factor can be indicated to the UE through either a cells-common or UE-dedicated message.
As shown in the flowchart in Error! Reference source not found., in step 201, it is determined whether the UE receives cell- specific mobility state estimation parameter.
If the UE does not receive the cell-specific mobility state estimation parameter, i.e., the No branch of step 201, the UE shall follow normal estimation procedure in step 202, i.e. increase the number of handovers or cell reselections by 1 according to the above equation (2).
If the UE receives the cell-specific mobility state estimation parameter, supposing that mobility state factor a is received in the example, proceed to step 207, then proceeding to step 207, the UE shall increase the number of handovers or cell reselections by the calibrated number according to the above equation (1) to improve mobility state estimation.
Based on the counted number, in step 211, the UE determines it is in which state (high, medium, normal) and adjusts mobility parameters to adapt to UE speed. Wherein, the UE can regulate its mobility parameters in the following ways, for example, adding an offset to a hysteresis value for idle UE or scale TimeToTrigger by a factor for connected UE to adapt to real mobile speed, of course, the UE can also regulate any other mobility parameter that may adapt to actual mobile speed to achieve the purpose of the present invention.
2. Cell Size/Power Notification
In this method, the serving cell may notify the cell size or cell power to the UE. Based on
this information, the UE can autonomously calibrate the number of handovers or cell reselections in its way.
(1) Cell size method
The serving cell may explicitly send its cell size indicator to the UE for the mobility state estimation, and the cell size may be one of {large, medium, small, and very small}. When the UE receives this notification, it shall scale a factor or add an offset to the number of handovers or cell reselections. The scaling rule can be left to the UE as an appropriate algorithm. Table 1 shows a mapping table of cell size and scale value. In this table, the scale value is selected from 1, 0.5, 0.25 and 0.125. Those skilled in the art can easily appreciate that less or more scale values may be used in other cases.
Table 1
(2) Cell power method
The serving cell shall send its cell transmission power to the UE for mobility state estimation, which provides a more accurate but indirect measurement of cell size. For example, larger cell transmission power corresponds to the larger cell size. Based on this message, the UE may calibrate its mobility state estimation as a proprietary algorithm. Similar to Table 1, one possible implementation is that a function (or a table) with the cell transmission power variables is defined to derive a scale value similar to a as in the mobility state estimation factor method.
When the UE is informed of the cell transmission power, it shall perform scaling according to an appropriate algorithm. For example, in the above table, instead of cell size, the mapping relationship between the cell transmission power and scale values within the range of (0,1] can be used to calibrate the speed of the UE.
The operation procedure of the cell size/cell power method is similar to the mobility state estimation factor method shown in Figure 2, with the difference being that the parameter received by the UE is the cell size/cell power rather than the mobility state estimation factor. Therefore, the flow of Figure 2 proceeds to step 205, i.e., the UE shall perform the operation of mapping from the cell radius or cell transmission power to a scale value.
In the following step 209, the UE shall increase the number of handovers or cell reselections by the calibrated number in a way similar to the above equation (1) to improve mobility state estimation. In this example, the scale value is selected from {0.125, 0.25, 0.5, 1 }·
Based on the counted number, in step 211, the UE determines it is in which state {high, medium, normal} and adjusts mobility parameters to adapt to UE speed. Wherein, the UE can regulate its mobility parameters in the following ways, for example, adding an offset to a hysteresis value for idle UE or scale TimeToTrigger by a factor for connected UE to adapt to real mobile speed, of course, the UE can also regulate any other mobility parameter that may adapt to actual mobile speed to achieve the purpose of the present invention.
3. PCI Range Split
PCI (Physical Cell ID) is to mark different cells on the physical layer, and 504 PCIs are defined in current LTE, requiring to be used separately in a large enough space so that the UE does not receive information from a cell with the same PCI. Currently the PCI value has no association with the cell size.
In this PCI range split method proposed by the present invention, a range of PCI values is exclusively reserved by the network for use by cells. The split of PCI range can be dependent on different cell sizes. For example, large coverage cells can use a range of high PCI values whereas small coverage cells can use a range of low PCI values. The PCI range split information is sent to the UE. For example, PCI 0-199 are allocated to cells with the radius larger than 5 km, and PCI 200-399 are allocated to cells with the radius of 1-5 km.
Figure 3 shows one instance of PCI range split, where low PCI values are allocated to very small coverage cells whereas high values are allocated to large coverage cells. Based on this information, the UE can identify its serving cell size, type and calibrate its number of handovers or cell reselections accordingly. When the UE synchronizes with the serving cell and identifies the PCI value, it can identify the cell size or cell type of the serving cell directly based on or from the PCI range split information, and calibrate the UE mobility state accordingly.
The operation procedure of the PCI range split method is similar to the cell size/cell power method, with the difference being that the mobility state estimation parameter provided by the base station (e.g. eNB) is the PCI value rather than the cell size/cell power. Therefore, in step 205, it is required to perform the operation of mapping the PCI value to the scale value.
Figure 4 is a functional block diagram of a base station (e.g. eNB, NB, etc.) and user equipment UE according to the embodiment of the present invention.
The base station and user equipment UE according to the embodiment of the present invention can be simply modified in terms of functionality based on the prior art. Signaling delivery for the base station and user equipment UE can take advantage of the existing signaling or add new message elements on the existing signaling, whereby based on the disclosure of the present invention, it is not very difficult for those skilled in the art to implement the base station and user equipment UE of the present invention.
According to the embodiment of the present invention, the base station 401 may comprise mobility state estimation parameter obtaining module 11 configured to obtain the mobility state estimation parameter, and sending module 12 configured to send to the user equipment a message including the mobility state estimation parameter, wherein the mobility state estimation parameter will be used by the user equipment to determine mobility state and adapt to actual mobile speed. The mobility state estimation parameter obtaining module 11 may be configured to obtain the mobility state estimation parameter from interactions with neighboring base stations or to obtain the mobility state estimation parameter from Operation and Maintenance Control node OMC. The mobility state estimation parameter is such as the mobility state estimation factor, the cell radius, the cell power and the PCI value and the like mentioned above. Module 12, which is configured to send to the user equipment a message including the mobility state estimation parameter may use an existing signaling or add new message elements to an existing signaling, and include the mobility state estimation parameter mentioned above in the message sent.
According to the embodiment of the present invention, the user equipment may comprise adjusting module 21 configured to adjust the number of handovers or cell reselections according to the mobility state estimation parameter provided by the base station, and determining module 22 configured to determine mobility state and adapt to actual mobile speed. In a case of receiving the mobility state estimation parameter, the module 21 shall increase the number of handovers or cell reselections directly or indirectly according to the
F = F + a - l mobility state estimation parameter, for example, by the following equation: " "_1 , F
where " is the calibrated number of handovers or cell reselections in current serving cell, F
"-1 is the number of handovers or cell selections in the last serving cell, and in this equation a is the mobility state estimation factor. In other cases, the scale value within the range of
(0,1] obtained through the mapping operation is likewise applicable to this equation. For example, the mobility state estimation parameter is the cell radius, cell power or PCI value, then the mobility state estimation parameter is mapped to a scale value, and the number of handovers or cell reselections is increased according to the scale value. The module 22 shall determine the actual mobile speed according to the calibrated value of the number of handovers or cell reselections and adjust the mobility parameters to adapt to actual mobile speed.
The method and relevant apparatus according to the invention address the UE mobility state estimation for robust mobility state estimation in the HetNet. The unique benefits thereof are as follows.
- The cell type/cell size information is taken into account to enhance the UE mobility state estimation, and potential solutions are given to address this problem.
- PCI range split may be used to allocate PCI based on the cell size/cell type.
- This mechanism proposes some signalling between eNB and UE for robust mobility in the HetNet. The signaling can be easily detected.
- In this invention an enhanced UE mobility state estimation mechanism is proposed, which is essential for the reliability and efficiency of mobility management in the HetNet. Those skilled in the art should appreciate that the above description with reference to the drawings is illustrative, rather than to limit the scope of this invention. Those skilled in the art can devise various modifications and variants within the spirit and scope of the present invention limited by the claims.
Claims
1. A method for assisting handover of a user equipment within coverage of cells in a wireless communication network, the method comprising:
a base station obtaining a mobility state estimation parameter, and
the base station sending to the user equipment a message including the mobility state estimation parameter, in order to determine mobility state by the user equipment according to the mobility state estimation parameter and adapt to actual mobile speed.
2. The method according to claim 1, wherein the mobility state estimation parameter is one of:
a mobility state estimation factor CI , CI = (0, 1] ,
cell radius,
cell transmission power, and
physical ID of the cell, i.e., PCI value.
3. The method according to claim 2, if the mobility state estimation parameter is the mobility state estimation factor CI , the number of handovers or cell reselections will be
F = F + a - l F
increased by the following equation: " "_1 , where " is the calibrated number of
F
handovers or cell reselections in current serving cell, and "_1 is the number of handovers or cell selections in the last serving cell.
4. The method according to claim 2, wherein a range split of PCI values is performed corresponding to cell radius or cell type.
5. The method according to claim 2, if the mobility state estimation parameter is the cell radius, cell transmission power or PCI value, the mobility state estimation parameter is mapped to a scale value, and the number of handovers or cell reselections is increased by the scale value.
6. The method according to any one of claims 1 to 5, wherein the base station obtaining a mobility state estimation parameter comprises obtaining the mobility state estimation parameter from interactions with neighboring base stations or obtaining the mobility state estimation parameter from Operation and Maintenance Control Node OMC.
7. The method according to any one of claims 1 to 5, wherein the wireless communication network is one of GSM, WCDMA, LTE, CDMA, CDMA2000, WiMAX network.
8. A base station for assisting handover of a user equipment within the coverage of cells in a wireless communication network, the base station comprising:
mobility state estimation parameter obtaining module for obtaining a mobility state estimation parameter, and
sending module for sending to the user equipment a message including the mobility state estimation parameter, wherein the mobility state estimation parameter will be used by the user equipment to determine mobility state and adapt to actual mobile speed.
9. The base station according to claim 7, wherein the mobility state estimation parameter is one of:
a mobility state estimation factor CI , CI = (0, 1] ,
cell radius,
cell transmission power, and
physical ID of the cell, i.e., PCI value.
10. The base station according to claim 8 or 9, wherein the mobility state estimation parameter obtaining module is further configured to obtain the mobility state estimation parameter from interactions with neighboring base stations or to obtain the mobility state estimation parameter from Operation and Maintenance Control node OMC.
11. A user equipment for handover by means of a base station within coverage of cells in a wireless communication network, the user equipment comprising: adjusting module configured to adjust the number of handovers or cell reselections according to a mobility state estimation parameter provided by the base station, and determining module configured to determine mobility state and adapt to actual mobile speed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110230786.2A CN102932865B (en) | 2011-08-12 | The mobile status appraisal procedure of subscriber equipment and equipment in cordless communication network | |
| CN201110230786.2 | 2011-08-12 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2013024349A2 true WO2013024349A2 (en) | 2013-02-21 |
| WO2013024349A3 WO2013024349A3 (en) | 2013-05-02 |
Family
ID=47647534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/IB2012/001887 WO2013024349A2 (en) | 2011-08-12 | 2012-08-13 | Method and apparatus for user equipment mobility state estimation in a wireless communication network |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2013024349A2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013140026A1 (en) * | 2012-03-19 | 2013-09-26 | Nokia Corporation | User equipment mobility in networks including small cells |
| EP3005779A4 (en) * | 2013-06-03 | 2016-11-02 | Sony Corp | Device and method in wireless communication system |
| CN106304172A (en) * | 2015-05-18 | 2017-01-04 | 中国移动通信集团公司 | A kind of method and apparatus determining moving velocity of terminal |
| US11632271B1 (en) | 2022-02-24 | 2023-04-18 | T-Mobile Usa, Inc. | Location-based channel estimation in wireless communication systems |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101453770A (en) * | 2007-12-07 | 2009-06-10 | 华为技术有限公司 | Measurement control method and apparatus |
| WO2011013967A2 (en) * | 2009-07-27 | 2011-02-03 | Lg Electronics Inc. | Apparatus and method for determining mobility state in wireless communication system |
| CN102026309A (en) * | 2009-09-10 | 2011-04-20 | 大唐移动通信设备有限公司 | Method, system and device for detecting mobile state of terminal |
-
2012
- 2012-08-13 WO PCT/IB2012/001887 patent/WO2013024349A2/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101453770A (en) * | 2007-12-07 | 2009-06-10 | 华为技术有限公司 | Measurement control method and apparatus |
| WO2011013967A2 (en) * | 2009-07-27 | 2011-02-03 | Lg Electronics Inc. | Apparatus and method for determining mobility state in wireless communication system |
| CN102026309A (en) * | 2009-09-10 | 2011-04-20 | 大唐移动通信设备有限公司 | Method, system and device for detecting mobile state of terminal |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013140026A1 (en) * | 2012-03-19 | 2013-09-26 | Nokia Corporation | User equipment mobility in networks including small cells |
| US9503946B2 (en) | 2012-03-19 | 2016-11-22 | Nokia Corporation | User equipment mobility in networks including small cells |
| EP3005779A4 (en) * | 2013-06-03 | 2016-11-02 | Sony Corp | Device and method in wireless communication system |
| CN106304172A (en) * | 2015-05-18 | 2017-01-04 | 中国移动通信集团公司 | A kind of method and apparatus determining moving velocity of terminal |
| US11632271B1 (en) | 2022-02-24 | 2023-04-18 | T-Mobile Usa, Inc. | Location-based channel estimation in wireless communication systems |
| US11881966B2 (en) | 2022-02-24 | 2024-01-23 | T-Mobile Usa, Inc. | Location-based channel estimation in wireless communication systems |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102932865A (en) | 2013-02-13 |
| WO2013024349A3 (en) | 2013-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10834648B2 (en) | Handover method, base station, and terminal device | |
| US9973915B2 (en) | Handover with ping pong avoidance in a wireless network | |
| CN104272777B (en) | Terminal, base station, and method thereof in mobile communication system | |
| JP6551236B2 (en) | Machine-to-machine (M2M) terminal, base station, method, and program | |
| EP3285520B1 (en) | Determining, by a user equipment (ue), a time-to-trigger parameter for handover execution in a heterogeneous network | |
| US9860815B2 (en) | Method and apparatus for carrying out cooperative cell clustering-based cooperative communication and handover | |
| RU2634704C1 (en) | Method for transmisting service between cells, base station and system | |
| US9432930B2 (en) | Method and apparatus for transmitting list of bearers in wireless communication system | |
| CN112584456A (en) | Method and apparatus for controlling latency in determining radio link failure | |
| WO2014025907A1 (en) | User mobility control for heterogeneous wireless networks | |
| WO2013131553A1 (en) | Handover method in a cellular wireless communication system | |
| KR20140085475A (en) | Mobility enhancement for fast moving user equipment in a heterogenous network environment | |
| WO2013048096A1 (en) | Method and apparatus for selecting cell in wireless communication system | |
| WO2013180447A1 (en) | Method for reporting mobility information in wireless communication system and device for supporting same | |
| US9288799B2 (en) | Method and apparatus for selecting carrier in wireless communication system | |
| WO2013024349A2 (en) | Method and apparatus for user equipment mobility state estimation in a wireless communication network | |
| US9131406B2 (en) | Method and apparatus for reporting short stay in wireless communication system | |
| CN104113874A (en) | Method of measurement report, and device of measurement report | |
| US9900819B2 (en) | Method and apparatus for transmitting information on user equipments according to type in wireless communication system | |
| Zhou et al. | Evaluation of mobility performance in 3GPP heterogeneous networks | |
| WO2013012294A1 (en) | Method and apparatus for selecting carrier in wireless communication system | |
| EP2991401A1 (en) | Mobility management method, device and system | |
| KR101680478B1 (en) | Method and apparatus for handover control and handover blacklist management in a mobile communication system | |
| WO2015149856A1 (en) | Cell change in communications | |
| KR20160052975A (en) | Method and apparatus for measuring signal strength at mobile station |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12823773 Country of ref document: EP Kind code of ref document: A2 |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 12823773 Country of ref document: EP Kind code of ref document: A2 |