CN113286308B

CN113286308B - Switching method between 4G active and passive indoor subsystems based on subway user movement behaviors

Info

Publication number: CN113286308B
Application number: CN202110511453.0A
Authority: CN
Inventors: 华爽; 田宁
Original assignee: China Telecom Corp Ltd Nanjing Branch
Current assignee: China Telecom Corp Ltd Nanjing Branch
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2022-07-22
Anticipated expiration: 2041-05-11
Also published as: CN113286308A

Abstract

The invention discloses a switching method among 4G active passive indoor subsystems based on subway user movement behaviors, which deeply analyzes a 4G network mobility management strategy according to an implementation range to be optimized, and forms a set of 4G dual-system wireless switching optimization method based on user movement behaviors for a subway high telephone traffic platform from three key visual angles of reselection configuration strategy optimization control, dual-system multi-frequency switching strategy optimization control and load balancing configuration strategy optimization control, so that users can perform switching occupation control in an effective cell under a planned path, and the use perception of the users in the moving process is greatly improved; the method has the advantages of excellent precision and efficiency, easy and quick copying, greatly reduced manual workload, and execution time solidification of each sub-link, and is favorable for staged, regional and branch-line scale copying.

Description

Switching method between 4G active and passive indoor subsystems based on subway user movement behaviors

Technical Field

The invention belongs to the field of mobile communication, and relates to a 4G wireless switching optimization method between active and passive dual-chamber subsystems based on user movement behaviors in a subway high telephone traffic platform scene.

Background

The subway platform scene generally comprises a platform area and a rail line area, in the initial stage of 4G network construction, the two areas generally adopt a mode that each operator jointly constructs a passive room subsystem, in the later stage, along with continuous development of services, the telephone traffic of a main line platform is increased rapidly, due to the fact that the original combiner system is difficult to modify and expand, each operator can continuously superpose an independent set of active room subsystems in a high-telephone-traffic platform area, intermodulation interference does not exist, and therefore the telephone traffic absorption capacity is strong, and service perception is good. However, as the scene proportion of the active and passive dual-chamber subsystems is increased, the problem of how users select occupation and switching between the two systems is highlighted increasingly, and the difficulty of cooperation between the two systems is increased continuously.

At present, a common subway dual-system 4G wireless switching configuration method in the industry is the same as a common multi-frequency scene switching configuration method, switching and reselection are carried out among cells based on a coverage comparison threshold, and a terminal is allowed to carry out service in a cell with better coverage quality as much as possible. Because the signal intensity of each frequency point cell between two systems in a subway scene is greatly changed by factors such as rush-hour people flow, platform safety door opening and closing and the like, the signal fluctuation is easy to be unstable, the reconstruction and service perception decline happens when a user enters or leaves a subway too early or too late, and the telephone traffic absorption of the hotspot active room sub-cell is insufficient. Therefore, the 4G wireless parameter configuration needs to combine the moving behavior of the user in the subway and the characteristics of the active and passive dual-system collaborative scene, and is innovative and breakthrough.

The traditional method for optimizing switching between 4G dual systems of the subway is analyzed as follows:

1. the subway station hall platform and the tunnel are located in underground independent spaces, as shown in fig. 1, the subway station hall platform and the tunnel always move in a single direction for a single user, and the user performs switching and reselection in a cell covering each interval according to the signal comparison strength.

The traditional configuration mode is that the switching is triggered when the signal quality of the adjacent cell is better than that of the service cell, when a user moves in the subway, the wireless coverage is carried out on a platform in the cell, an overlapping area of a traditional indoor partition and an active indoor partition exists, the signal strength of a platform dual system is affected by the opening and closing of a subway safety door and the human body loss of a peak in the morning and evening, the fluctuation is large, and the traditional configuration mode is easy to cause the untimely switching and ping-pong switching (the phenomenon that a mobile phone switches back and forth between the service cell and the adjacent cell). At the moment, the wireless signal occupied by the terminal has uncertainty, has the randomness characteristic of selecting between a passive system and an active system, and does not accord with the characteristic of unidirectional movement of most users during the subway taking process, so that the service perception is reduced due to unnecessary switching and residence of the users during the moving process.

2. The traditional subway 4G wireless parameter configuration is the same as the common multifrequency scene pilot frequency switching event, and an A3 event is adopted. The method is similar to the principle of same-frequency configuration, and the terminal is allowed to perform service in a cell with better coverage as much as possible.

As shown in fig. 2, active rooms of a subway high-load platform are divided into 2.1G high-frequency and 1.8G different-frequency networking, and are simultaneously overlaid with traditional passive rooms of 2.1G coverage, the traditional passive rooms of 1.8G which are most seriously affected by intermodulation interference shrink in a platform area (by reducing RS: Reference Signal power), so that a coverage connection effect is achieved in a platform track area, user occupation is reduced, and the coverage capability of each platform, which is mainly three-carrier five-cell, is formed.

For the inter-station mobility scenario, the conventional configuration method is as follows:

when the subway enters a station, a terminal occupies a passive room division signal of a rail running area, when a passive or active signal of a platform area is better than that of the rail running area, the terminal is switched in, after a vehicle door is opened, a user getting off the station and a part of users in the vehicle transfer part of the passive room division signal of the platform, part of the passive room division signal of the platform and part of the passive room division signal of the original rail running area according to signal intensity comparison, and part of the passive room division signal of the platform and part of the active room division signal of the platform are retained;

when the subway is out of the station, under the condition that the terminal occupies the active room of the platform area, the partial terminal keeps switching from the active room of the platform to the rail-bound area after the door is closed, and partial terminal is switched from the active room of the platform to the inactive room of the platform and then is switched to the inactive room of the rail-bound area. Under the condition that the terminal occupies the passive room of the platform area, part of the terminals are switched from the passive room to the rail-mounted area after the vehicle door is closed, and part of the terminals are switched from the passive room to the platform active room and then switched to the rail-mounted area passive room.

Under the scene of active and passive dual system cooperation, the directivity of a switching target is insufficient, a user is switched among different cells along with signal intensity fluctuation, and the switching has randomness.

A method, device and system (granted) for managing mobile handover in a wireless communication network of patent application No. 201210530182.4, wherein a mobile device in the wireless communication network selects a plurality of candidate handover cells to which the trajectories are to be routed in the network according to the predicted motion trajectory of the mobile device, and generates a target handover cell sequence according to the motion speed and direction of the mobile device and the candidate handover cell sequence, where the target handover cell sequence includes a plurality of target handover cells to which the motion path of the mobile device is to be sequentially handed over. However, this method has drawbacks in that: 1. the designed moving path is not specially planned according to the frequency point path which is better perceived by the user after the user occupies; 2. the handover cell sequence is only compared according to the signal strength in the handover sequence, and accurate cell handover control through sufficient mobility policy control is not reflected, and the directivity is insufficient.

In the access switching method disclosed in patent application No. 201110322433.5, mobile access devices detect the signal strength of the access devices along the rail in a subway scene respectively, and select the access device with the largest signal strength, thereby implementing seamless switching between the mobile access devices along the rail. However, this method has the disadvantages that: the designed switching cell is only selected according to the maximum signal intensity, and is not designed according to the specific design of different frequency point paths with better perception according to the occupation of users.

The patent application No. 201711273310.0 discloses a method and apparatus for analyzing network conditions based on subway scene communication records, which obtains position information of subway stations, divides adjacent stations of the subway into more than 1 buffer sections by using a preset communication record reporting period such as position, speed, station, and the like, obtains communication records of the adjacent stations and sequences the communication records according to time, groups the sequenced records according to the preset period, and obtains notification index values of the buffer sections. However, this method has the disadvantages that: the network status is analyzed only based on the communication record, and the switching path is not specifically designed for the user movement behavior, and a control method design that sufficiently embodies the mobility management policy is not provided.

Patent application No. 201911269833.7 is a method for judging whether a user enters or leaves a subway station by using mobile phone signaling data, which can only track and clean mobile phone user signaling, construct a database containing subway user records for grouping and sequencing, and judge the switching type of the signaling record content of the user to obtain whether the user enters or leaves the subway station. However, this method has drawbacks in that: the method is only used for analyzing and judging whether a user enters or leaves a station by using the mobile phone signaling, and cannot effectively design a cell switching occupied path of a specific path of the user.

The prior patent technology mainly focuses on the distinction and judgment of station entering and exiting and signal strength of subway users, and the switching based on the user movement behavior is also only focused on the switching sequence based on the alternative switching cell targets in the large network scene.

Disclosure of Invention

In order to solve the problems in the prior art and fundamentally overcome the difficulty of perception guarantee in the user moving process in the multi-frequency networking scene of the dual system of the subway high telephone traffic platform at present, the invention provides a switching and optimizing method between 4G active passive dual-chamber subsystems in the subway high telephone traffic platform scene based on the user moving behavior.

The invention mainly solves the problems that:

1. planning a moving behavior model of a user in a subway scene, determining the coverage range and the capacity of a dual system of a subway high telephone traffic platform, planning wireless coverage distribution based on the moving behavior of the user, and designing a switching path;

2. based on a one-way movement behavior model of a user in a subway scene, designing a reselection configuration strategy control module, optimizing a resident strategy of the user in an idle state of a subway dual system, and accessing the user to a system with excellent coverage as far as possible;

3. the method solves the problem of multi-frequency switching strategy control optimization between dual systems based on the movement behavior of a user, solves the problems of too late switching and ping-pong switching when the user enters and exits a station of the subway, and ensures smooth switching and smooth experience of the user through the control of various switching events and configuration thresholds;

4. on the basis of the above strategy, the load balancing configuration optimization strategy is superposed, so that the load between the cells with different telephone traffic bearing capacities can be reasonably optimized, the load transfer efficiency is obviously improved, and the user perception reduction caused by unbalanced telephone traffic between the dual-system multi-frequency cells is avoided.

The technical scheme is as follows:

the invention provides a method for wirelessly switching and optimizing 4G dual-system in a subway high telephone traffic platform scene based on user movement behaviors, which comprises the following steps of:

s1, determining the coverage area and the capacity of the dual system of the subway high telephone traffic station, planning wireless coverage distribution based on the movement behavior of the user, and designing a switching path;

s2, determining a target area to be optimized, classifying all cells of the target area according to a system and a scene, dividing the cells into active rooms of a platform area, dividing the passive rooms of the platform area into cells and active rooms of an in-and-out station of a rail area, storing the switching and reselection relations of all the sub-cells in the target area, and counting key performance indexes of the switching of every two adjacent cells, wherein the key performance indexes comprise RRC (Radio Resource Control) connection reconstruction proportion, power switching in the system, the maximum number of users in the cell and the average utilization rate of uplink and downlink PRBs (PHYSICAL Resource BLOCKs);

s3, optimizing reselection parameter configuration among cells in each scene;

s4, optimizing the switching parameter configuration among the cells of each scene;

s5, optimizing the load average parameter configuration among the cells of each scene;

s6, carrying out DT (Drive Test) Test on the optimized subway interval, counting the signal strength and speed before and after switching between the platform and the rail area, and carrying out switching and reselection parameter adjustment on the source cell and the target cell which have serious slippage in the signal strength and speed before and after switching; index monitoring is carried out on the optimized cell, the cells with low power, abnormal MRO (mobile robustness optimization) reasons of two adjacent cell switching and high RRC connection reconstruction ratio are switched into the statistical system, and switching and reselection parameters are adjusted; if the maximum number of users in a certain cell in the target area and the uplink and downlink PRB utilization rate are too high, adjusting load balancing parameters;

s7, counting performance and test indexes of the optimized target interval of the subway, entering the regional network performance and user reporting observation if the performance and the test indexes are normal, and finishing reselection, switching and load balancing parameter configuration and optimization; if abnormal, go back to step S3.

The invention has the advantages of

The invention focuses on the active and passive dual-system 4G wireless switching optimization method based on the user movement behavior in the subway high telephone traffic platform scene, which can not only judge whether the system belongs to the station or the rail line section based on the user occupying the cell, but also carry out the wireless coverage cell switching planning according to the characteristic path of the user moving in one direction, and determines the target area to be optimized according to the planned path, and deeply analyzes the 4G network mobility management strategy, starting from three key perspectives of reselection configuration strategy optimization control, dual-system multi-frequency switching strategy optimization control and load balancing configuration strategy optimization control, the method and the system enable the user to carry out switching occupation control in the effective cell under the set path, fundamentally overcome the key difficult problem of the wireless switching between the 4G dual-system of the current subway high telephone traffic platform based on the user moving behavior, and greatly improve the perception of the user in the moving process. The invention has the advantages of excellent precision and efficiency, easy and quick copying, greatly reduced manual workload, execution time solidification of each sub-link, and contribution to staged, regional and branch line scale copying.

Drawings

FIG. 1 is a schematic diagram of subway user movement behavior and wireless coverage cell

FIG. 2 is a schematic diagram of a dual-system multi-frequency stereo networking architecture of a subway high traffic platform

FIG. 3 is a flowchart of a method for wireless handover and optimization between 4G dual systems based on user mobility

FIG. 4 is a schematic diagram of subway dual system switching based on user movement behavior

FIG. 5 is a block diagram of a reselection configuration policy control module

FIG. 6 is a block diagram of a multi-frequency handover strategy control for dual system

FIG. 7 is a block diagram of a load balancing configuration policy control module

Fig. 8 is a histogram of changes in MRO (mobility robustness optimization) cause values of a typical subway line before and after an experiment

FIG. 9 is a histogram of changes in RRC reestablishment cause values of a typical subway line before and after an experiment

FIG. 10 is a graph showing variation of early peak test RSRP of a typical subway line before and after an experiment

FIG. 11 is a graph showing the variation of DPI (deep packet inspection) before and after an experiment on a typical subway line

Detailed Description

The invention is further illustrated by the following examples, without limiting the scope of the invention:

as shown in fig. 3, the method for wirelessly switching and optimizing the 4G passive and active dual systems of the subway station based on the user movement behavior includes the following steps:

s1, determining the coverage area and the capacity of the dual system of the subway high telephone traffic platform, planning the wireless coverage distribution based on the movement behavior of the user, and designing the switching path, so that the user preferentially uses the active room subsystem signal in the platform area, the user entering the carriage preferentially uses the passive distribution system signal, the user preferentially uses the passive distribution system signal after the subway leaves the station, and the user preferentially uses the active distribution system signal before getting off the train and after getting off the train after the subway enters the station.

S2, determining a target area to be optimized according to user movement behaviors, classifying all cells of the target area according to a system and a scene, respectively dividing the cells into active rooms of a platform area, dividing the passive rooms of the platform area into cells and active rooms of an orbit area into and out of the station, storing the switching and reselection relations of all the sub-cells in the target area according to the user movement behaviors, and counting key performance indexes of the switching between every two adjacent cells, wherein the key performance indexes comprise RRC connection reestablishment proportion, system switching power, the maximum number of users in the cell and the average utilization rate of uplink PRBs and downlink PRBs.

And S3, entering a first key module (reselection configuration strategy control module) to optimize an inter-cell reselection configuration strategy and ensure that the active cell is preferentially selected and resided. And (3) reselecting the active chamber component to the passive chamber component from the method limit, and meanwhile, carrying out fine adjustment subsequently by combining the RSRP (Reference Signal Receiving Power) value of the DT test.

As shown in fig. 5: the reselection parameter configuration is optimized, and the specific method is as follows:

s31, setting reselection priorities of all systems in a subway interval, wherein an active indoor sub-cell is higher than a passive indoor sub-cell;

s32, setting a reselection measurement starting threshold 1 of the active room subsystem, setting a reselection measurement starting threshold 2 of the passive room subsystem, wherein the threshold 2 is higher than the threshold 1, and indicating that the active room subsystem triggers the reselection measurement to the same low priority level later than the passive room subsystem;

s33, setting a reselection threshold 1 of the active indoor subsystem and a reselection threshold 2 of the passive indoor subsystem, and making the reselection thresholds difficult to meet in a reselection scene from an active high reselection priority to a passive low reselection priority; and setting a reselection threshold 3 of the active indoor subsystem, wherein the reselection threshold is equivalent to a set value of a threshold 1, and the reselection threshold is easy to meet in a situation of reselecting from a passive low reselection priority to an active high reselection priority.

And S4, entering a key module II (dual-system multi-frequency switching strategy control module), wherein the key function is to adjust the switching sequence of the users who enter and exit the station through the switching event between the dual-system multi-frequency and the differentiated setting of the threshold. Setting different switching events: distinguishing the cells of the switching target frequency points; setting different switching thresholds: the switching-in requirement of the active chamber is reduced, and the switching-out requirement is improved; setting different frequency offsets and cell offsets: quickening the branch transfer of the user to the active room and reducing ping-pong switching.

As shown in fig. 6: the method for configuring the switching parameters between the two systems of the subway platform comprises the following specific steps:

s41, setting the type of the scenario event

Pilot frequency handover trigger event type 1 scenario: the active chamber is switched to the passive chamber, the active chamber is switched between different frequency cells, and the passive chamber is switched to the active chamber;

pilot frequency handover trigger event type 2 scenario: switching between different frequency cells in a passive room, and switching an active room in a 1.8 frequency-staggered scene from 1.8G to 1.8G in the passive room;

s42, setting a parameter threshold of matching S41 event types based on the movement behaviors of the user

In a subway entrance scene, a user switches from an entrance rail area passive room to a platform active room in a sub-switching mode, a threshold 3 of a pilot frequency switching trigger event type 1 and a threshold 3 of a pilot frequency switching measurement event 1 are set, the thresholds can be accelerated, and the purpose of rapidly switching to a platform active room sub-system is achieved;

in a user platform staying scene, switching between pilot frequency cells of an active indoor distribution system, setting a threshold 1 of a pilot frequency switching measurement event 1 and a threshold 1 of a pilot frequency switching trigger event type 1, wherein the thresholds can be relatively conservative, and unnecessary switching between the pilot frequency cells of the active indoor distribution system is avoided;

in the getting-on scene of a user, switching from the station active room to the station passive room, setting a threshold 1 of a pilot frequency switching trigger event type 1 and a threshold 1 of a pilot frequency switching measurement event 1, wherein the thresholds are moderate, so that the user can reliably occupy the passive room when the intensity of the active room in a carriage is lower than a good level, and the preparation is made for smooth out-going. Based on a platform multi-frequency three-dimensional networking strategy, a passive room is divided into 1.8G to cover and contract, a pilot frequency switching frequency offset threshold 1 is set, the switching from an active room to a passive room is divided into 2.1G, and the impact on the system is relieved;

in a subway outbound scene, a user switches from a station passive room to an outbound rail track area passive room in a sub-switching mode, a threshold 1 of a pilot frequency switching trigger event type 2 and a threshold 1 of a pilot frequency switching measurement event 2 are set, the thresholds are conservative, unnecessary switching between passive pilot frequency cells is avoided, and outbound is smooth in a same-frequency mode as far as possible;

and (3) switching from the station passive room to the station active room in a user getting-off scene, setting a threshold 2 of a pilot frequency switching trigger event type 1 and a threshold 2 of a pilot frequency switching measurement event 1, and accelerating the transfer of the user to the station active room subsystem.

S43, setting 1.8G error frequency scene parameters, setting a threshold 2 of a different frequency switching trigger event type 2 of a source-room-divided 1.8G cell and a threshold 2 of a different frequency switching measurement event 2, enabling measurement and switching between the active-room-divided and passive-room-divided 1.8G error frequency cells to occur as early as possible, and reducing mutual interference between error frequency systems. And setting a pilot frequency switching frequency offset threshold 2, increasing 2.1G switching of the passive room to 1.8G switching of the active room, and slowing down the transfer of 1.8G users of the active room in a 1.8G frequency-staggered scene.

S44, setting a scene ping-pong switching prevention mechanism, setting a threshold 1 for the offset of the platform active room to the adjacent cell of the rail-bound region of the station, and preventing the passive room of the rail-bound region of the station from being switched back from the platform active room after the station is entered; setting a threshold 4 of a different-frequency switching triggering event type 1 of an out-station rail line area passive room and a threshold 4 of a different-frequency switching measuring event 1, and preventing back switching from the out-station rail line area to a platform active room subsystem after the out-station; and a pilot frequency switching frequency offset threshold 3 of a 1.8G error frequency scene is set to prevent ping-pong switching of 1.8G active room and 1.8G passive room of the platform.

And S5, entering a key module III (a load balancing configuration strategy control module), wherein the key module III is mainly used for finely controlling a load balancing strategy based on practice, selecting strategy parameters for a load balancing target for fine optimization on one hand, and reasonably optimizing a load balancing threshold on the other hand, so that load transfer from an active room to a passive room is avoided, and the traffic absorption capacity is improved. Setting different cell capability scaling factors: and the load overflow among the sub-cells of the active room is ensured, so that the load among the hot-spot cells is more balanced.

As shown in fig. 7: the method for configuring the directional load balancing parameters comprises the following specific steps:

s51, setting a double-system load balancing terminal selection strategy

Setting a load balance selection terminal type 1 among the cells of the active room, and allowing terminals in a connection state and an idle state to transfer; setting a load balance selection terminal type 1 among the sub-cells of the passive room, and allowing terminals in a connection state and an idle state to transfer; setting a load balance selection terminal type 2 from the active room to the passive room, and only allowing idle state terminals to transfer;

s52, setting a load balancing mode, and triggering in and among all systems of the subway platform in a user number mode;

s53, setting a connected state pilot frequency load balancing user number threshold 1 and an idle state pilot frequency load balancing user number threshold 2 which are matched with the passive chamber branch of the S52, wherein the threshold 2 is larger than the threshold 1, so that the effective times of connected state load balancing are larger than that of an idle state; the passive indoor sub-system has the same configuration among pilot frequency cells.

S54, setting a user threshold 3 for the idle state pilot frequency load balancing of the active room to the passive room matched with the S52; the active room distribution system pilot frequency inter-cell connection state pilot frequency load balancing user number threshold 4 and idle state pilot frequency load balancing user number threshold 3 are adopted, the threshold 3 is larger than the threshold 4, and therefore the connection state load balancing effective times are larger than the idle state.

S55, setting a scaling factor threshold 1 of 2.1G cell capacity of the active division and a scaling factor threshold 2 of 1.8G cell capacity of the active division, so that the equivalent bandwidth (the product of the scaling factor of the cell capacity and the actual bandwidth) of the active division 1.8G and the active division 2.1G is the same.

And S6, carrying out DT test on the optimized subway interval, counting the signal strength and the speed before and after switching the platform and the rail region, and carrying out switching and reselection parameter adjustment on the source cell and the target cell which have serious downslide of the signal strength and the speed before and after switching. In the station-entering scene, the threshold 3 of the type 1 of the pilot frequency switching trigger event is increased according to 3dB (decibel) as a first order, so that the signal intensity after station-entering switching is not lower than-110 dBm (milliwatt decibel); in the departure scene of the vehicle, the threshold 1 of the pilot frequency switching measurement event 1 is increased according to 2dB (decibel) as a first order, so that the signal intensity before switching after the vehicle is on is not lower than-110 dBm (milliwatt decibel);

and performing index monitoring on the optimized cell, counting the cells switched into the cell with low power, abnormal MRO (handover failure rate) reasons of two adjacent cells and high RRC (radio resource control) connection reconstruction ratio in the system, and adjusting switching and reselection parameters. In the ping-pong switching scenario, when the occupation ratio of reasons for ping-pong switching, too-late switching and too-early switching is high, the RRC connection reestablishment proportion is high, the success rate of system switching is low, and in the station-entering scenario, the offset 1 of the neighboring cell is increased by taking 3dB (decibel) as one order, so that ping-pong switching after station entering is reduced; in the getting-on scene, the threshold 1 of the pilot frequency switching trigger event type 1 is increased according to 2dB (decibel) as a first order, and the switching delay after entering a carriage is reduced; in the outbound scene, the threshold 4 of the pilot frequency switching measurement event 1 is adjusted to be smaller according to-2 dB (decibel) as a first order, and ping-pong switching after the outbound is reduced; in the getting-off scene, the pilot frequency switching frequency offset 3 is increased according to 2dB (decibel) as one order, and the ping-pong switching of the 1.8G error frequency scene is reduced; the threshold 2 of the pilot frequency switching measurement event 1 is adjusted to be small according to-2 dB (decibel) as one step, and premature switching from the platform to the platform is reduced.

And adjusting load balancing parameters when the maximum number of users in a certain type of cell in the target area and the average utilization rate of the downlink PRB are too high. When the maximum number of users in a cell of a traditional indoor distribution system is more than 200 and the average utilization rate of downlink PRBs is more than 40%, a connected state pilot frequency load balancing user number threshold 1 and an idle state pilot frequency load balancing user number threshold 2 are downwards adjusted by taking 5 as one step, and passive indoor distribution load transfer is accelerated; when the maximum number of users in a cell of the active room distribution system is more than 300 and the average utilization rate of downlink PRBs is more than 60%, adjusting an idle state pilot frequency load balancing user number threshold 3 downwards by taking 10 as one order to accelerate the load distribution transfer of the active room; when the load of the active indoor subsystem 1.8G is higher than 2.1G, the cell capacity scaling factor threshold 2 is downwards adjusted by taking 1 time as a first order; when the load of the active indoor subsystem 2.1G is higher than 1.8G, the threshold 1 of the cell capacity scaling factor is adjusted downwards by taking 1 time as a first order, and the load transfer is accelerated. When the single frequency point load of the passive indoor distribution system is too high, the frequency point connection state pilot frequency load balance user number threshold 1 and the idle state pilot frequency load balance user number threshold 2 are adjusted downwards by taking 5 as a first order, so that the load transfer is accelerated.

S7, counting the performance of the cell, entering the regional network performance and user reporting observation if the cell is normal, and ending the configuration and optimization of the wireless parameters; if abnormal, go back to S3.

Effect verification

In order to verify the feasibility of the technical scheme, a series of verification of the method is carried out on the Nanjing subway No. 1 line, the parameter strategy is implemented and then the early peak of the subway is tested, a user can effectively switch and occupy the subway according to a planned route, the uplink test average speed is increased by 5Mbps, the downlink test average speed is increased by 10Mbps, the condition that the RSRP of a platform and a rail running area falls down is reduced, the switching between the platform and the rail is smoother, and the user perception is obviously improved under the cooperative scene of double systems of the subway platform and the subway platform.

Subway typical line application

The method takes Nanjing subway No. 1 line as a typical case, the 4G active and passive dual systems are deployed in 17 high telephone traffic platform scenes, the method is deployed from 6 months in 2020, and the three angles of switching-in are finely controlled according to the switching, reselection and load balancing parameters according to the actual situation of a subway network, so that the coordinated wireless switching and optimization between the 4G dual systems of subway rooms are carried out, and the purposes of 'early entering', 'stable occupying' and 'fast exiting' of the active rooms of the subway platform are achieved.

(1) Parameter configuration of each module in experiment

And (3) reselection parameter setting recommendation:

and switching type parameter setting recommendation:

remarking: the 1.8G error frequency scene is that the active room is divided into 1.8G configuration bandwidth 20M, and the passive room is divided into 1.8G configuration bandwidth 15M.

And (3) recommending the load balancing type parameter setting:

(2) analysis of Experimental Effect

From the experimental effect, the overall uplink sensing rate is improved by about 6%, the downlink sensing rate is improved by about 10%, the user plane time delay is reduced by 5%, the user quantity and the load indexes such as the average utilization rate of uplink and downlink PRBs (physical resource blocks) are kept stable, the key performance indexes such as the RRC connection establishment success rate and the switching power in an LTE (long term evolution) system are improved slightly, the indexes of the switching times to wrong cells, ping-pong switching and early switching times in the system are improved, the improvement of the too-late switching is obvious, and the total reduction reaches 15%. Under the optimized influence of the handover parameters of the station and the tracking area, the class occupancy of the RRC connection reestablishment other (rlf) is reduced by about 3%, as shown in fig. 8 and 9.

The DT test on the experimental subway interval at the early peak indicates that the division ratio of the platform active room is increased by 10%, the uplink low-speed ratio is reduced by 12%, the average uplink ABM test speed is increased by 5Mbps, and the average downlink ABM test speed is increased by 10 Mbps. After optimization, the situation that the station and the track area RSRP falls down is reduced, and the station and track switching is smoother, as shown in FIG. 10.

After the station entering scene is optimized, the passive cells of the rail-bound region carry out pilot frequency measurement in advance, the active cells of the station platform meet the threshold and are switched in, the station entering switching process is simple, and ping-pong switching is not generated by signal fluctuation.

And in the platform residence scene, after optimization, residence can stably occupy the active cell sub-cell between the platform areas.

And in the outbound scene, after optimization, the signals of the sub-cells of the platform active room are weakened and then directly switched to the passive cells of the rail-mounted area, outbound is completed by one-time switching, and the influence on perception is small.

The method provided by the invention aims to ensure that a user can carry out signal occupation and switching on a planned moving path, the residence time on an active room sub-cell is prolonged, the switching smoothness between a platform and a rail line is improved, the indexes of a Deep Packet Inspection (DPI) are observed in continuous early peak periods, and the perception of the core section of the No. 1 line of the Nanjing subway is in an improved trend. As shown in fig. 11.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments, or alternatives may be employed, by those skilled in the art, without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A switching method between 4G active and passive indoor subsystems based on subway user movement behaviors is characterized by comprising the following steps:

s2, determining a target area to be optimized, and dividing the target area into a platform area active room sub-cell, a platform area passive room sub-cell and a rail-driven area in-and-out passive room sub-cell; storing the switching and reselection relations of all sub-cells in a target area, and counting key performance indexes of the switching of every two adjacent cells;

s3, optimizing reselection parameter configuration among cells in each scene;

s5, optimizing load balancing parameter configuration among cells of each scene;

s6, carrying out DT test on the optimized subway interval to obtain signal strength and speed before and after switching between the platform and the rail running area; extracting relevant indexes of the optimized cell from a background network manager for monitoring and analyzing;

s7, counting performance and test indexes of the optimized target interval of the subway, if the performance and the test indexes are normal, finishing the configuration and the optimization of reselection, switching and load balancing parameters, and entering the regional network performance and user reporting observation; and if the abnormal conditions exist, returning to S3-S5 for optimization adjustment.

2. The method according to claim 1, wherein in S2, the key performance indicators include RRC connection re-establishment ratio, intra-system handover power, maximum number of users in a cell, and average uplink and downlink PRB utilization.

3. The method according to claim 1, wherein in S3, the configuration of reselection parameters between cells in each scenario is optimized by the following specific method:

s32, setting a reselection measurement starting threshold of the active room distribution system as a first starting threshold, setting a reselection measurement starting threshold of the passive room distribution system as a second starting threshold, wherein the second starting threshold is higher than the first starting threshold;

s33, setting a reselection threshold of the active indoor distribution system as a first reselection threshold, setting a reselection threshold of the passive indoor distribution system as a second reselection threshold, and setting the threshold to be difficult to meet in a reselection scene from an active high reselection priority to a passive low reselection priority;

and setting a third reselection threshold of the active room subsystem, wherein the third reselection threshold is equivalent to the set value of the first reselection threshold, and the third reselection threshold is easy to meet the situation of reselection from a passive low reselection priority to an active high reselection priority through threshold setting.

4. The method according to claim 1, wherein in S4, the inter-cell handover parameter configuration for each scene is optimized by the following specific method:

s41, setting a scene event type:

inter-frequency handover trigger event scenario 1: the active chamber is switched to the passive chamber, the active chamber is switched between different frequency cells, and the passive chamber is switched to the active chamber;

inter-frequency handover trigger event scenario 2: switching between different frequency cells in a passive room, and switching 1.8G of active room to 1.8G of passive room in a 1.8G frequency-staggered scene;

s42, setting a parameter threshold of matching S41 event types based on the user movement behaviors;

s43, setting 1.8G error frequency scene parameters;

and S44, setting a scene ping-pong prevention switching mechanism.

5. The method according to claim 4, wherein in S42, the user movement behavior is specifically:

in a subway entrance scene, a user is switched from an entrance orbit area passive room to a platform active room in a sub-switching mode, and a threshold 3 of a pilot frequency switching trigger event type 1 and a threshold 3 of a pilot frequency switching measurement event 1 are set;

a user station stay scene, switching between pilot frequency cells of an active indoor subsystem, and setting a threshold 1 of a pilot frequency switching measurement event 1 and a threshold 1 of a pilot frequency switching trigger event type 1;

in a user boarding scene, switching from a station active room to a station passive room, and setting a threshold 1 of a pilot frequency switching trigger event type 1 and a threshold 1 of a pilot frequency switching measurement event 1;

in a subway exit scene, a user switches from a station passive room to an exit rail line area passive room in a sub-switching mode, and a threshold 1 of a pilot frequency switching trigger event type 2 and a threshold 1 of a pilot frequency switching measurement event 2 are set;

and (3) in a getting-off scene of a user, switching from a station passive room to a station active room, and setting a threshold 2 of a pilot frequency switching trigger event type 1 and a threshold 2 of a pilot frequency switching measurement event 1.

6. The method according to claim 4, wherein in S43, the setting of 1.8G error frequency scene parameters specifically includes: a threshold 2 of a pilot frequency switching trigger event type 2 of a 1.8G cell of an active room and a threshold 2 of a pilot frequency switching measurement event 2 are set, so that measurement and switching between 1.8G error frequency cells of the active room and a passive room occur as early as possible, and mutual interference between error frequency systems is reduced; and setting a pilot frequency switching frequency offset threshold 2, increasing 2.1G switching of the passive room to 1.8G switching of the active room, and slowing down the transfer of 1.8G users of the active room in a 1.8G frequency-staggered scene.

7. The method according to claim 4, wherein in S44, the scenario-based anti-ping-pong handover mechanism is specifically set as follows: setting a deviation threshold 1 of adjacent cells of a station active room branch rail-bound region, and preventing the adjacent cells from being switched back from the station active room branch rail-bound region to a passive room branch rail-bound region after station entrance; setting a threshold 4 of a different-frequency switching triggering event type 1 of an out-station rail line area passive room and a threshold 4 of a different-frequency switching measuring event 1, and preventing back switching from the out-station rail line area to a platform active room subsystem after the out-station; and a pilot frequency switching frequency offset threshold 3 of a 1.8G error frequency scene is set to prevent ping-pong switching of 1.8G active room and 1.8G passive room of the platform.

8. The method according to claim 1, wherein in S5, the configuration of the load balancing parameters between cells in each scenario is optimized by the following specific method:

s51, setting a double-system load balancing terminal selection strategy; setting a load balance selection terminal type 1 among the cells of the active room, and allowing terminals in a connection state and an idle state to transfer; setting a load balance selection terminal type 1 among cells of a passive room, and allowing terminals in a connection state and an idle state to transfer; setting a load balance selection terminal type 2 from the active room to the passive room, and only allowing idle state terminals to transfer;

s53, setting a connected state pilot frequency load balancing user number threshold 1 and an idle state pilot frequency load balancing user number threshold 2 which are matched with the passive chamber branch of the S52, wherein the threshold 2 is larger than the threshold 1, so that the effective times of connected state load balancing are larger than that of an idle state; the different frequency cells of the passive indoor distribution system are configured identically;

s54, setting a user threshold 3 for the idle state pilot frequency load balancing of the active room to the passive room matched with the S52; the method comprises the steps that an active room subsystem inter-pilot frequency cell connection state pilot frequency load balancing user number threshold 4 and an idle state pilot frequency load balancing user number threshold 3 are adopted, wherein the threshold 3 is larger than the threshold 4, so that the connection state load balancing effective times are larger than the idle state;

and S55, setting a scaling factor threshold 1 of the 2.1G cell capacity of the active division and a scaling factor threshold 2 of the 1.8G cell capacity of the active division, so that the equivalent bandwidth of the 1.8G active division and the 2.1G active division are the same.

9. The method according to claim 1, wherein in S6, the extracting the relevant index for monitoring and analyzing includes:

-index monitoring is carried out on the optimized cell, switching power in the system, the moving robustness of the switching between every two adjacent cells is calculated, and MRO reasons and RRC connection reconstruction proportion are optimized;

-maximum number of users in a certain type of cell in the target area, uplink and downlink PRB utilization.

10. The method of claim 9, wherein in S7, the back-off to S3-S5 is optimized and adjusted by:

-returning to performing handover and reselection parameter adjustments for source and target cells with severe signal strength and rate downslide before and after handover;

-switching into cells with low power, handover robustness optimization MRO cause anomaly for pairwise neighbor cells and high RRC connection reestablishment proportion in the statistical system, and returning to adjust handover and reselection parameters;

and if the maximum number of users in a certain cell in the target area and the uplink and downlink PRB utilization rate are too high, returning to perform load balancing parameter adjustment.