CN101873566B

CN101873566B - Mobility management method and system of user terminal along given line

Info

Publication number: CN101873566B
Application number: CN200910083021.3A
Authority: CN
Inventors: 朱昀; 王曼
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2009-04-24
Filing date: 2009-04-24
Publication date: 2014-04-09
Anticipated expiration: 2029-04-24
Also published as: WO2010121549A1; CN101873566A

Abstract

The invention discloses a mobility management method and a system of a user terminal along a given line. The invention reduces unnecessary measurement, avoids the disordered reselection or switching of a side cell and improves the efficiency of UE mobility management by setting a proper adjacent cells list and decides the reselected or switched target cell according to the UE movement direction and improves the accuracy of the UE mobility management. At the same time, the invention separates a private network covered by the given line from a common public network, enlarges the coverage range of each private network cell by adopting RRU and the RRU cell merging technology of different types and makes the cell coverage thereof accord with the linear shape of scenes along the given line in order to reduce the times of the cell reselection and switching.

Description

Mobility management method and system for user terminal along established line

Technical Field

The present invention relates to the field of mobile communication, and in particular, to a method and a system for mobility management along a given line (such as a high-speed railway and a highway) by a third generation mobile communication technology, wherein the mobility management comprises a method and a system for cell reselection and cell handover.

Background

The development of personal mobile communication has greatly enriched the lives of people, so that people can conveniently access a communication network at any place, at any time and under any condition to enjoy voice or data communication services. While relying on wireless "full coverage" and mobility management mechanisms of mobile communication networks behind the achievement of this goal. Taking the third generation mobile communication system as an example, the radio access network is composed of a plurality of cell-shaped cells covering the whole terrestrial land system (PLMN). Each cell is covered by radio signals transmitted by a base station node (NodeB) of the cell, and user terminals (UE) and NodeB in several cells are controlled and managed by a Radio Network Controller (RNC). When the UE moves between different cells, the geographical information of the UE is known by the RNC, and the RNC allocates radio resources to the NodeB and each UE according to the known information of the cell under control and the information of the UEs in the cell, and the NodeB and each UE establish a radio channel by using the radio resources and receive/transmit data on the radio channel.

For mobility management, a further understanding is: cell reselection (or handover) is initiated when a UE moves from one cell to another, and in the prior art, cell reselection is implemented following S-criteria and H-criteria: that is, the UE firstly determines the received signal quality of the cells according to the S criterion, sorts the cell quality of the cells satisfying the S criterion according to the H criterion, and if the first best cell is not the current serving cell, the UE leaves the current cell and camps on the best cell. The handover is implemented by that the UE continuously measures the received signal quality of the (current) serving cell and the neighboring cell, and when it is found that the signal quality of a certain cell meets the preset trigger condition (the trigger condition is preset by the RNC and issued to the UE), the UE sends a measurement report to the RNC, and then the RNC decides handover according to the received measurement report, and the UE executes the handover.

There are major obstacles to setting up a wireless coverage network and performing mobility management on a UE moving at a high speed in a high-speed railway environment according to the prior art: one is that the traditional wireless coverage area is in a honeycomb hexagon shape, while the shape of the high-speed railway is in a linear shape, and the geometric shape of the traditional wireless coverage area and the high-speed railway is greatly different. Secondly, when cell reselection or handover is realized, the UE initiates measurement, signal averaging, decision and execution of these procedures, and a certain time is required for completing these procedures, so that no problem will occur in the ordinary situation. This is like a "relay" race, where the athlete often cannot smoothly meet/receive the baton while running at high speeds. There is therefore a need to modify and optimize existing network coverage and mobility management.

Disclosure of Invention

It is therefore a primary objective of the claimed invention to provide a method and system for radio coverage and UE mobility management (including reselection and handover) along a given line. The method is used for solving the technical problems that when a traditional wireless coverage cell is adopted along a given line (such as a high-speed railway and a highway), the coverage area is small, the resource waste is large, and when a user terminal is in a high-speed motion state, the mobility management is difficult, the call completing rate is low, the call dropping rate is high, the user terminal is easy to generate disordered reselection and ping-pong effect, and the like.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a mobility management method for user terminals along a given line,

when cell reselection is executed, a user terminal UE calculates cell rank values of adjacent cells and a current service cell, reselection is executed according to the cell rank values, and the UE preferentially reselects the adjacent cells in the UE movement direction;

when cell switching is executed, UE reports a measurement report of the received signal quality of an adjacent cell to a radio network controller RNC, and the RNC switches to the adjacent cell in the UE movement direction preferentially according to the movement direction of the UE.

Based on the technical scheme, further, a coverage mode of separating a private network from a public network is adopted for wireless coverage along a given line;

in a private network, an RNC configures two private network cells connected with a current private network cell in front of and behind a set line as adjacent cells of the current private network cell; in a public network, an RNC configures all cells which are adjacent to a current public network cell in geography into adjacent cells of the current public network cell; the private network coverage area is a chain-shaped area along a given line.

Further, a radio remote technology and different types of remote radio unit combination technologies are adopted in a private network to realize the chain-shaped coverage of the private network cells;

the radio frequency remote technology is characterized in that a large-capacity baseband processing unit in a base station is intensively placed in a central machine room, and a radio frequency module in the base station is remotely arranged to two sides along a set line by adopting optical fiber connection;

the different types of remote radio frequency unit combination technology refers to that areas covered by a plurality of remote radio frequency modules which are different in type and are geographically connected are classified into a logic cell in a baseband processing mode, and the combined logic cell covers an area along a section of a given line.

Further, a method for the UE to perform cell reselection of the present invention is:

a1, UE continuously measures the quality of the received signal of the current service cell, when the UE finds that the quality of the received signal of the current service cell is less than a set threshold, the UE measures the quality of the received signal of the adjacent cell;

a2, UE judges the movement direction of the UE, excludes the cell with the reverse movement direction from the reselected target cell range, and calculates the cell grade only for the current service cell and the adjacent cell in the movement direction of the UE;

the cell rank value of the current serving cell is: the value Qmeas of the quality of the signal received by the current serving cell is subtracted by the reselection hysteresis parameter Qhcs of the current serving cell_s；

The cell rank values of the neighboring cells are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n；

A3, UE reselects to set time T_reselcetThe adjacent cells with the highest cell rank value can be always kept.

Further, another method for the UE to perform cell reselection of the present invention is:

b1, UE continuously measures the quality of the received signal of the current service cell, when the UE finds that the quality of the received signal of the current service cell is less than the set threshold, the UE measures the quality of the received signal of the adjacent cell;

b2, RNC judges the movement direction of UE, and informs the movement direction to UE, UE calculates the cell grade of the current service cell and the adjacent cell by the following method:

The cell rank values of the neighboring cells in the UE movement direction are: the neighbor cell received signal quality value Qmeas, n plus the reselection hysteresis parameter Qhcs of the neighbor cell_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n；

The cell rank values of the adjacent cells against the UE movement direction are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is also needed TO be subtracted_n；

And B3, the UE reselects the adjacent cell which can always keep the cell grade value to be the highest in the set time.

The method for UE to execute cell switching comprises the following steps:

c1, UE judges its own moving direction, when UE finds out through measurement that the quality of the received signal of the current service cell and/or the adjacent cell meets the preset reporting trigger condition, only reporting the quality of the received signal of the current service cell and the adjacent cell in the moving direction to RNC;

c2, RNC decides whether UE switches according to the cell received signal quality measurement report reported by UE, and if deciding switching, decides which adjacent cell UE switches to at the same time; or,

another method for executing cell switching by the UE of the present invention is:

d1, when the UE finds that the quality of the received signals of the current serving cell and/or the adjacent cells meets the preset reporting trigger condition through measurement, reporting the quality of the received signals of the current serving cell and all the adjacent cells to the RNC;

d2, RNC judges UE movement direction and eliminates the adjacent cell in reverse movement direction outside the switched selection cell, RNC judges whether UE switches according to the signal quality of the remaining adjacent cell and the current service cell, if judging switching, then judges which adjacent cell UE switches to at the same time.

Another object of the present invention is to provide a system for mobility management of a ue along a given line, and to achieve the object, the present invention adopts the following technical solutions:

a system for mobility management of user terminals along a given line, comprising:

the UE movement direction judging module is used for judging the current movement direction of the UE;

the cell reselection module is used for executing cell reselection with priority of the adjacent cell in the UE movement direction according to the cell rank values of the adjacent cell and the current service cell and the UE movement direction output by the UE movement direction judgment module;

and the cell switching module is used for executing the cell switching with priority of the adjacent cells in the UE moving direction according to the measurement report of the received signal quality of the adjacent cells reported by the UE and the UE moving direction output by the UE moving direction judging module.

Further, an implementation manner of the cell reselection module of the present invention includes:

the first cell measurement module is used for measuring the received signal quality of an adjacent cell when the UE finds that the received signal quality of the current serving cell is less than a set threshold;

the reverse motion direction cell exclusion module is used for excluding the adjacent cell in the reverse UE motion direction out of the reselected target cell range according to the UE motion direction output by the UE motion direction judgment module;

the first cell grade calculating module is used for calculating the cell grade of a reselection target cell after excluding the adjacent cell against the movement direction of the UE;

and the first reselection module is used for reselecting the adjacent cell which can always keep the cell grade value to be the highest in the set time.

Further, another implementation manner of the cell reselection module of the present invention includes:

the second cell measurement module is used for measuring the received signal quality of the adjacent cell when the UE finds that the received signal quality of the current service cell is smaller than a set threshold;

a cell grade correction calculation module for calculating the cell grades of the current service cell and the adjacent cells and correcting the grade of the adjacent cell according to the UE movement direction output by the UE movement direction judgment module, wherein the correction is favorable for preferentially reselecting the adjacent cell in the UE movement direction;

and the second reselection module is used for reselecting the adjacent cell which can always keep the cell grade value to be the highest in the set time according to the result calculated by the cell grade correction calculation module.

One implementation manner of the cell switching module of the present invention includes:

the first measurement report reporting module is used for reporting the received signal quality of the current serving cell and/or the adjacent cell in the UE moving direction to the first switching module when the UE finds that the received signal quality of the current serving cell and/or the adjacent cell meets the preset reporting trigger condition through measurement;

the first switching module is used for judging whether the UE is switched according to a measurement report of the cell received signal quality reported by the UE, and simultaneously judging which adjacent cell the UE is switched to if the UE is judged to be switched; or,

another implementation manner of the cell switching module of the present invention includes:

a second measurement report reporting module, configured to report, when the UE finds, through measurement, that the received signal quality of the current serving cell and/or the neighboring cell meets a preset reporting trigger condition, the received signal quality of the current serving cell and all neighboring cells to the RNC;

and the second switching module is used for excluding the adjacent cell in the reverse motion direction from the selected cell to be switched according to the motion direction of the UE judged by the UE motion direction judging module, judging whether the UE is switched according to the signal quality of the remaining adjacent cells and the current service cell, and simultaneously judging which adjacent cell the UE is switched to if the UE is judged to be switched.

Furthermore, the UE movement direction judgment module is positioned at the UE end or the RNC end;

the invention separates the private network covered along the high-speed railway from the common public network, and the private network coverage adopts Radio Remote Unit (RRU) cell merging technology of different types to enlarge the coverage area of each cell and enable the cell coverage to be suitable for the linear shape in the railway scene so as to reduce the times of cell reselection and switching.

By setting a proper adjacent cell list, unnecessary measurement is reduced, disordered reselection (and switching) of lateral cells is avoided, and the efficiency of UE mobility management is improved; and the target cell for reselection (or handover) is determined according to the movement direction of the UE, so that the accuracy of the UE mobility management is improved.

The invention utilizes the Doppler frequency shift value generated when the UE moves to set Qhcs_s、Qhcs_nAnd the parameters are equal, so that the UE can more easily reside in a private network cell in a high-speed motion state, and the accuracy and efficiency of cell reselection and handover are further improved.

Drawings

FIG. 1 is a schematic view of wireless coverage along a high speed railway;

fig. 2 is a schematic structural diagram of a system for implementing radio remote according to the present invention;

FIG. 3 is a flow chart of a cell reselection implementation of the present invention;

FIG. 4 is a flow chart of the present invention for implementing cell handover;

fig. 5 is a logic structure diagram of a first cell reselection module according to the present invention;

fig. 6 is a logic structure diagram of a second cell reselection module according to the present invention;

FIG. 7 is a logic structure diagram of a first cell switching module according to the present invention;

fig. 8 is a logic structure diagram of a second cell switching module according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below by taking a high-speed railway as an example and referring to the accompanying drawings.

Fig. 1 shows an example of different level cells covering a hierarchical network (HCS) along a high speed railway. Layer a cell (in)

Shaded portion) and layer B cells are at two different levels. The two levels are geographically overlapped with each other along the high-speed railway and in the vicinity thereof; but the difference between the two is: the level B is a common (public network) cell level, the target service object of the level B is the UE which does not move in the carriage at high speed and is only located in the area along the railway geographically, and the cell of the level B is a common honeycomb hexagonal cell. Level A is covering the high speed ironIn the private network cell level along the route, the target service object is UE moving in a carriage, the coverage of the cell is chain-shaped coverage (namely, a single cell covers one section along the railway, the cells and the cells are buckled with each other like a chain ring to cover the whole area along the railway), and the coverage can be realized by adopting Radio Remote Unit (RRU) combination technology of different types.

For the remote radio technology finger: a large-capacity baseband processing unit (BBU) in a base station is centrally placed in a certain central machine room, radio frequency modules in the base station are pulled to a far end by adopting optical fiber connection, and each far end module is called as a far-end radio frequency unit (RRU). Referring to fig. 2, the internal structure and the operation principle of the RRU are as follows: the baseband signal downlink is sent to an antenna feeder line after frequency conversion, filtering, radio frequency filtering and a linear power amplifier. The uplink performs filtering, low noise amplification, radio frequency small signal amplification filtering and down conversion on the received UE uplink signal, then completes analog-to-digital conversion, digital intermediate frequency processing and the like, and sends the processed signal to the baseband unit. The connection between the RRU and the BBU may be a Common Public Radio Interface (CPRI) or an open base station architecture (OBASI). Referring to fig. 1 again, the remote RRU units along the high-speed railway are arranged at two sides of the railway line, so that the wireless signals of the remote RRU units intensively cover the railway line and the two sides; meanwhile, a plurality of RRU cells (an RRU cell refers to an area wirelessly covered by one RRU unit) with different types but connected geographically are classified into one logical cell (a logical cell refers to a set of baseband resources corresponding to one carrier frequency and a coverage area thereof in a base station node) by a baseband processing manner. Different geographical scenes can exist in different types of RRU cells, such as common plain environment, tunnel environment, and complex scenes of a tunnel entrance part of a high-speed rail, a rail bend part and the like. The number of the combined RRUs can be within the range of the number of the baseband resources supported on the BBU baseband board, and the combination modes are combined randomly. Therefore, the combined logic cells cover a section of railway line, and the cells are linked with each other, so that linear coverage is realized.

As described above, the areas along and near the high-speed railway are overlappingly and wirelessly covered by hierarchical cells of two different levels (private network level a and public network level B). Since the focus of attention is the moving UE on the high-speed railway, the technical problems to be solved by the invention are as follows: how to make the UEs camp on the private network cell as much as possible; and how to perform more efficient mobility management for these UEs, and in particular, how to enable these UEs to perform accurate and efficient cell reselection or handover.

In the preferred embodiment of the invention, the cell list is optimized by the RNC as follows so that the UE is resided in the private network cell as much as possible:

the method for setting the adjacent cell list by the RNC comprises the following steps: for the cell with the geographical position being the platform, when the RNC configures the adjacent cell list, the cells of the private network and the public network are mutually configured into the adjacent cell; for a cell at a non-platform position, when configuring an adjacent cell list of a private network cell, an RNC (radio network controller) configures the two private network cells linked front and back of the cell along a railway line into adjacent cells; when the RNC configures a list of neighbouring cells of a public network cell, all geographically neighbouring cells are added to the list according to the prior art. Further, after configuring the neighbor cell list of each cell, the RNC sends the neighbor cell list to all UEs in the cell through a system message (SIB) on a Broadcast Channel (BCH) of the cell.

The optimized setting of the adjacent cell list aims to narrow the cell range to be reselected by the UE in the non-platform private network cell, reduce the times of reselection measurement, and avoid possible disordered reselection (and switching) of lateral cells, and the excluded cells are geographically adjacent public network cells and other adjacent private network cells such as rail intersections or rail junctions, and the UE in a high-speed train can be resided in the private network as much as possible through the setting.

The cell reselection process is shown in fig. 3, and the specific contents are as follows:

in step 301, the UE periodically, or event-triggered, measures the received signal quality of the current serving cell.

Step 302, if the UE finds that the received signal quality value of the current serving cell is lower than a certain set threshold, that is, whether the value meets the S criterion, if the value meets the S criterion, the UE starts to measure the received signal quality of the neighboring cell, and step 303 is executed; otherwise, executing step 301;

step 303, calculating the cell level H values of the neighboring cells and the current serving cell whose received signal quality value of the cell in the neighboring cells is greater than the set threshold, sorting the obtained H values, and finding out the cell with the highest level (referred to as H criterion);

in order to narrow the reselected target cell range, in a preferred embodiment of the present invention, the UE determines its own moving direction, excludes a cell in the reverse moving direction from the reselected target cell range, and calculates the cell rank H only for the current serving cell and an adjacent cell in the moving direction of the UE, in the following manner:

for the current serving cell: Hs-Qmeas, s-Qhcs_s

For the neighboring cells: Hn-Qmeas, n-Qhcs_n-TO_n*Ln

Where the subscript s denotes the current serving cell and n denotes the neighboring cell. Qmeas represents the received signal quality value obtained by the measurement (the implementation of which is not relevant to the present invention). TO_nFor the offset parameter of the cells between different hierarchies, Ln is 1 if the neighboring cell and the current serving cell are not in the same hierarchy, and Ln is 0 if in the same hierarchy.

There are various techniques disclosed for determining the movement direction of the UE: for example, the UE may determine whether the doppler frequency offset (fd) is positive or negative, that is: if the Doppler frequency offset is positive, the UE moves towards the node B, and if the Doppler frequency offset is negative, the UE moves away from the node B. The method for determining the UE moving direction may also be that the UE determines by measuring a change of a Timing Advance (TA) of the corresponding cell base station, that is, when the TA decreases, the UE moves closer to the NodeB, that is, when the TA increases, the UE moves farther from the NodeB.

In another preferred embodiment of the present invention, the RNC determines the moving directions of a plurality of UEs in a cell, in which case, the NodeB needs to report the doppler shift values or TA values of the UEs to the RNC first, and then the RNC determines the moving direction of each UE, and the RNC informs the UE of the moving direction. In this way, the RNC can obtain samples of the motion directions of a plurality of UEs, and can consider that the UEs in the same cell are all in the same train, so that the RNC can use the motion directions of most of the UEs determined as the motion directions of all the UEs, thereby improving the accuracy of the determination. The UE calculates the cell grades of the current serving cell and the adjacent cells by the following modes:

the cell rank value of the current serving cell is: Hs-Qmeas, s-Qhcs_s

The cell rank values of the neighboring cells in the UE movement direction are: Hn-Qmeas, n + Qhcs_n-TO_n*Ln

The cell rank values of the adjacent cells against the UE movement direction are: Hn-Qmeas, n-Qhcs_n-TO_n*Ln

Obviously, the neighboring cell rank in the direction of motion is likely to be higher than the neighboring cell in the opposite direction of motion, and the UE will reselect to the correct cell.

Step 304, determining a certain cell is in a fixed time (T)_reselect) Whether the cell rank value can be always kept to be the highest, if so, executing step 305; otherwise, go to step 303;

step 305, the UE reselects to the fixed time (T)_reselect) The cell with the highest cell rank value is always kept in the cell.

In view of the above implementation manners of cell reselection, the present invention provides the implementation structure diagrams of two cell reselection modules as shown in fig. 5 and fig. 6, in fig. 5, a first cell measurement module measures the quality of a cell received signal and outputs the measured quality to an inverse moving direction cell exclusion module, the inverse moving direction cell exclusion module excludes an adjacent cell in the inverse UE moving direction from a selected cell according to a UE moving direction determination result output by a UE moving direction determination module located at a UE end, then a first cell grade calculation module performs grade calculation on the selected cell, and the first reselection module reselects a cell with the highest grade according to a result of the first cell grade calculation module. The structure shown in fig. 6 is different from the embodiment corresponding to fig. 5 in that the UE movement direction determining module is located at the RNC end, and the RNC performs comprehensive determination according to data reported by each UE to obtain an accurate value of the UE movement direction and notify the accurate value of the UE movement direction to the UE.

The cell handover process is shown in fig. 4, and includes the following specific steps:

step 401, NodeB measures Doppler frequency shift value of each UE and reports it to RNC, RNC sets the trigger condition for UE to report measurement report, and sends it to UE;

step 402, UE continuously measures the received signal quality of the current service cell and the adjacent cell;

step 403, when the UE finds that the signal quality of a certain cell meets a preset trigger condition, the UE executes step 404; otherwise, executing step 402;

step 404, reporting the measurement result of the quality value of the received signal of the current serving cell and/or the adjacent cell to the RNC as a measurement report;

in order to reduce the range of the switchable target cell, in a preferred embodiment of the present invention, the UE determines its own moving direction, and only reports the received signal quality of the current serving cell and/or the neighboring cell in the moving direction to the RNC when the UE finds, through measurement, that the received signal quality of the current serving cell and/or the neighboring cell meets a preset cell received signal quality reporting trigger condition;

the triggering condition is similar to an S criterion in cell reselection, namely, the RNC presets and issues some thresholds and timer parameters to the UE, and if the signal quality of a certain cell exceeds the threshold or the signal quality of an adjacent cell is superior to that of the current service cell in the timing time according to the measurement result of the UE, the signal quality of the cell is reported to the RNC;

step 405, the RNC decides whether the UE performs handover or not and which neighboring cell to handover to according to the measurement report reported by the UE.

In order to reduce the range of the switchable target cell, in another preferred embodiment of the present invention, the RNC determines the motion direction of the UE, because a single UE may have a motion direction determination error, and the RNC may obtain the motion direction information of a plurality of UEs in the same train, thereby reducing the possibility of such determination error as a whole. Correspondingly, in step 404, the UE reports the received signal quality values of all cells meeting the preset trigger condition to the RNC, the RNC excludes the cells adjacent to the reverse motion direction from the target cell to be switched, and the RNC determines whether the UE is to be switched according to the received signal quality of the target cell to be switched.

The above cell switching implementation manners correspond to the implementation result diagrams of the cell switching modules shown in fig. 7 and fig. 8, respectively. In fig. 7, the first measurement report reporting module at the UE end only reports the measurement report of the received signal quality of the neighboring cell in the UE moving direction according to the determination result of the UE moving direction determining module at the UE end, so that the first handover module at the RNC end can preferentially handover to the neighboring cell in the UE moving direction. The difference between the embodiment shown in fig. 8 and the embodiment corresponding to fig. 7 is that the UE movement direction determining module is located at the RNC end, the second measurement report reporting module located at the UE end does not perform an excluding operation on the reverse movement direction cell, as long as the adjacent cells meeting the trigger condition are reported to the second handover module, and the second handover module excludes the reverse movement direction adjacent cell from the target cell to be handed over according to the determination result of the UE movement direction determining module, so as to exert the advantage that the RNC determines the UE movement direction more accurately.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. A method of performing cell reselection along a given line,

wherein, the preferentially reselecting the adjacent cell in the UE moving direction by the UE comprises:

the UE judges the motion direction of the UE;

for cells in the same direction of motion, calculatingWhen the cell rank value is obtained, the cell rank value of the adjacent cell in the UE moving direction is as follows: the neighbor cell received signal quality value Qmeas, n plus the reselection hysteresis parameter Qhcs of the neighbor cell_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n(ii) a The cell rank values of the adjacent cells against the UE movement direction are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is also needed TO be subtracted_n。

2. The method of claim 1, wherein the step of the UE performing cell reselection comprises:

3. The method of claim 1, wherein the step of the UE performing cell reselection comprises:

4. The method of claim 1,

a covering mode of separating a private network and a public network is adopted for wireless covering along a given line;

5. The method of claim 4, wherein a radio remote technology and a combination of different types of remote radio units are used in a private network to achieve the chain coverage of the private network cells;

6. A method for performing cell switching for a user equipment along a predetermined line,

when cell switching is executed, UE reports a measurement report of the received signal quality of an adjacent cell to a radio network controller RNC, and the RNC is switched to the adjacent cell in the UE movement direction preferentially according to the movement direction of the UE;

the step of UE executing cell switching is as follows:

d2, RNC judges the movement direction of UE and excludes the adjacent cell against the movement direction from the switched selection cell, RNC judges whether UE switches according to the signal quality of the remaining adjacent cell and the current service cell, if judging switching, then judging which adjacent cell the UE switches to;

when the UE is switched,for the cells in the same moving direction, when the cell rank value is calculated, the cell rank values of the adjacent cells in the moving direction of the UE are as follows: the neighbor cell received signal quality value Qmeas, n plus the reselection hysteresis parameter Qhcs of the neighbor cell_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n(ii) a The cell rank values of the adjacent cells against the UE movement direction are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is also needed TO be subtracted_n。

7. The method of claim 6,

8. The method of claim 7, wherein a radio remote technology and a combination of different types of remote radio units are used in a private network to achieve the chain coverage of the private network cells;

9. A system for performing cell reselection by a user terminal along a given line, comprising:

the cell reselection module is used for executing cell reselection with priority of the adjacent cell in the UE movement direction according to the cell rank values of the adjacent cell and the current service cell and the UE movement direction output by the UE movement direction judgment module; and, when performing the cell reselection, for: for the cells in the same moving direction, when the cell rank value is calculated, the cell rank values of the adjacent cells in the moving direction of the UE are as follows: the neighbor cell received signal quality value Qmeas, n plus the reselection hysteresis parameter Qhcs of the neighbor cell_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n(ii) a The cell rank values of the adjacent cells against the UE movement direction are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is also needed TO be subtracted_n；

The UE movement direction judging module is positioned at the UE end or the RNC end.

10. The system of claim 9, wherein the cell reselection module comprises:

11. The system of claim 9, wherein the cell reselection module comprises:

12. The system of claim 9,

13. The system of claim 12, wherein a radio remote technology and a combination of different types of remote radio units are used in a private network to achieve the chain coverage of the private network cells;

14. A system for performing a cell handover for a user terminal along a given line, comprising:

the cell switching module is used for executing the cell switching with priority of the adjacent cells in the UE moving direction according to the measurement report of the received signal quality of the adjacent cells reported by the UE and the UE moving direction output by the UE moving direction judging module; and, when performing the cell handover, for: for the cells in the same moving direction, when the cell rank value is calculated, the cell rank values of the adjacent cells in the moving direction of the UE are as follows: the neighbor cell received signal quality value Qmeas, n plus the reselection hysteresis parameter Qhcs of the neighbor cell_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is subtracted_n(ii) a The cell rank values of the adjacent cells against the UE movement direction are: the neighbor cell received signal quality value Qmeas, n minus the neighbor cell reselection hysteresis parameter Qhcs_nWhen the adjacent cell and the current service cell are not in the same hierarchy, the offset parameter TO of the cells in different hierarchies is also needed TO be subtracted_n；

The UE movement direction judging module is positioned at a UE end or an RNC end;

wherein the cell switching module comprises:

the first switching module is used for judging whether the UE is switched according to a measurement report of the cell received signal quality reported by the UE, and simultaneously judging which adjacent cell the UE is switched to if the UE is judged to be switched;

or,

the cell switching module includes:

15. The system of claim 14,

16. The system of claim 15, wherein a radio remote technology and a combination of different types of remote radio units are used in a private network to achieve the chain coverage of the private network cells;