Cellular telecommunications network
By deploying nodes that can identify and manage PCI conflicts in cellular telecommunications networks, the management difficulties of PCI conflicts in the case of increased cellular network density are solved, improving user experience and reducing operator burden.
Patent Information
- Application Number
- CN202380066532.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-09-30
- Filing Date
- 2023-08-09
- Publication Date
- 2025-04-25
AI Technical Summary
As cellular network density increases, PCI conflicts become more common and difficult to manage, especially in ad hoc network environments in small cells.
By deploying a node in a cellular telecommunications network, the node can identify PCI conflicts, prioritize conflict solutions based on the energy-saving state of neighboring cells, and implement solutions through reconfiguration.
Effectively manage and resolve PCI conflicts, improve user experience, reduce interference and handover failures, and reduce the PCI allocation burden of mobile network operators.
Smart Images
Figure CN119895922A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to cellular telecommunication networks. Background Art
[0002] A Physical Cell Identifier (PCI) is an identifier of a cell of a base station in a cellular telecommunications network. The PCI is broadcast in a physical layer transmission so that any user in the cellular network receiving the physical layer transmission can determine the PCI of the cell (even if the user is connected to another cell).
[0003] PCIs are assigned to cells in a cellular network from a limited range (504 in LTE and 1008 in 5G). PCIs must be assigned carefully to avoid PCI conflicts. One form of PCI conflict is called PCI collision, where two cells with overlapping coverage areas have the same PCI, so that users in the overlapping coverage area cannot distinguish between the two cells. Another form of PCI conflict is called PCI confusion, where a cell includes two adjacent cells with the same PCI. PCI conflicts are known to result in poor user experience, such as increased interference or failed handovers.
[0004] Typically, PCI assignments are performed manually to avoid these PCI conflicts. However, as the density of cellular networks increases due to increased deployment of small cells (eg, femto cells), PCI conflicts may become more common and difficult to manage by manually assigning PCIs by mobile network operators.
[0005] In particular, the introduction of the Self-Organizing-Network (SON) capability in small cells enables the cell to allocate its own PCI. This is usually achieved by the cell discovering the PCI of its neighboring cells through the Automatic Neighbour Relation (ANR) process, for example, by obtaining data from the user in the measurement report identifying the neighboring cells, or by using Radio Environment Monitoring (REM) scanning to detect neighboring cells and allocate their PCIs based on the PCIs of their neighboring cells. SON PCI allocation technology facilitates the large-scale deployment of small cells without increasing the PCI allocation burden on mobile network operators.
[0006] Another feature related to PCI selection is PCI pooling. This is a technique for assigning PCIs to cells in a specific PCI set based on cell category (e.g., macro cell, pico cell, femto cell, etc.). This allows a cell to identify the category of a neighboring cell from its PCI and assign itself a PCI that avoids collisions with PCIs of neighboring cells of different categories.
[0007] The trend towards network densification due to large-scale deployment of small cells, the use of SON-based PCI allocation and PCI pooling from a limited PCI range means that PCI conflicts are more likely to occur. Summary of the invention
[0008] According to a first aspect of the present invention, there is provided a node for a cellular telecommunication network, the cellular telecommunication network comprising a plurality of transceivers, the node comprising: a transceiver configured to obtain data comprising a physical cell identifier PCI of each of the plurality of transceivers; and a processor configured to: based on the obtained data, identify a first PCI conflict between a first pair of transceivers among the plurality of transceivers and a second PCI conflict between a second pair of transceivers among the plurality of transceivers; determine that a priority of a solution to the first PCI conflict is greater than a priority of a solution to the second PCI conflict, wherein the priority of a solution to the first PCI conflict and the priority of a solution to the second PCI conflict are based on respective energy saving states of the respective first pair of transceivers and the second pair of transceivers, the energy saving state being one of a normal mode, an energy saving mode and a compensation mode; identify a solution to the first PCI conflict; and enable reconfiguration in the cellular telecommunication network to implement the identified solution.
[0009] The power saving state of the first pair of transceivers may be based on at least one of the group consisting of: a current power saving state of a first transceiver in the first pair of transceivers, a current power saving state of a second transceiver in the first pair of transceivers, a power saving state capability of the first transceiver in the first pair of transceivers, and a power saving state capability of the second transceiver in the first pair of transceivers.
[0010] The power saving state of the second pair of transceivers may be based on at least one of the group consisting of: a current power saving state of a first transceiver in the second pair of transceivers, a current power saving state of a second transceiver in the second first pair of transceivers, a power saving state capability of the first transceiver in the second pair of transceivers, and a power saving state capability of the second first transceiver in the second pair of transceivers.
[0011] The solution may be one or more of a group including: changing a PCI of one or more transceivers among the plurality of transceivers, limiting a power saving state operation mode of one or more transceivers among the plurality of transceivers, wherein the power saving state operation mode is one of a power saving mode, a normal mode, and a compensation mode, limiting a transmission power of one or more transceivers among the plurality of transceivers, and disabling one or more transceivers among the plurality of transceivers.
[0012] The node may be one of the group consisting of: a controller, and a transceiver of a plurality of transceivers.
[0013] According to a second aspect of the present invention, a method in a cellular telecommunication network is provided, the cellular telecommunication network comprising a plurality of transceivers, the method comprising the following steps: obtaining data comprising a physical cell identifier PCI of each of the plurality of transceivers; identifying, based on the obtained data, a first PCI conflict between a first pair of transceivers in the plurality of transceivers and a second PCI conflict between a second pair of transceivers in the plurality of transceivers; determining that a priority of a solution to the first PCI conflict is greater than a priority of a solution to the second PCI conflict, wherein the priority of a solution to the first PCI conflict and the priority of a solution to the second PCI conflict are based on respective energy saving states of the respective first pair of transceivers and the second pair of transceivers, wherein the energy saving state is one of a normal mode, an energy saving mode and a compensation mode; identifying a solution to the first PCI conflict; and enabling reconfiguration in the cellular telecommunication network to implement the identified solution.
[0014] According to a third aspect of the present invention, there is provided a computer program, the computer program comprising instructions for causing the node of the first aspect of the present invention to execute the steps of the method of the second aspect of the present invention. The computer program may be stored on a computer readable medium. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to better understand the present invention, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0016] Figure 1 is a schematic diagram of a cellular telecommunications network;
[0017] Figure 2 yes Figure 1 A schematic diagram of a base station of a network;
[0018] Figure 3 yes Figure 1 A schematic diagram of a controller of a network;
[0019] Figure 4 is a flow chart showing a first process;
[0020] Figure 5 is a flow chart showing the second process;
[0021] Figure 6 is a flow chart showing a third process;
[0022] Figure 7 is a schematic diagram of a cellular telecommunications network;
[0023] Figure 8 is a flowchart showing a fourth process; and
[0024] Fig. 9 is a flowchart showing the fifth process. DETAILED DESCRIPTION
[0025] Figure 1 A cellular telecommunication network 100 is shown. The cellular telecommunication network 100 comprises a first base station 110, a second base station 120, a third base station 130 and a fourth base station 140. The first base station 110, the second base station 120, the third base station 130 and the fourth base station 140 each have a single respective transceiver configured to communicate in a respective coverage area (in other words, each base station is a single cell base station). The first base station 110, the second base station 120, the third base station 130 and the fourth base station 140 communicate using the same frequency.
[0026] As shown in the figure, the first base station 110 and the second base station 120 have partially overlapping coverage areas, the second base station 120 and the third base station 130 have partially overlapping coverage areas, and the third base station 130 and the fourth base station 140 have partially overlapping coverage areas. Note the following terms regarding the neighboring relationships between these base stations. From the perspective of the first base station 110, the second base station 120 is a "first-order neighbor" because it has a partially overlapping coverage area with the first base station 110; the third base station 130 is a "second-order neighbor" because it is a first-order neighbor of the first-order neighbor of the first base station 110 (i.e., the second base station 120), and it itself is not a first-order neighbor of the first base station 110; and the fourth base station 140 is a "third-order neighbor" because it is a first-order neighbor of the second-order neighbor of the first base station 110 (i.e., the third base station 130), and it itself is not a first-order neighbor or a second-order neighbor of the first base station 110. For completeness, the following table indicates Figure 1 The neighbor relationship of the base station shown in:
[0027]
[0028] Each of the first base station 110 , the second base station 120 , the third base station 130 , and the fourth base station 140 may be connected to one or more user equipments (UE) (not shown).
[0029] Figure 1 A controller 150 is further shown. The controller 150 is shown as part of the core network, but in other implementations, the controller 150 may be part of a radio access network (e.g., in an Open Radio Access Network (Open RAN) architecture). The controller 150 is connected (directly or indirectly) to each of the first base station 110, the second base station 120, the third base station 130, and the fourth base station 140.
[0030] exist Figure 2 1. The first base station 110 is shown in more detail in FIG. The first base station 110 comprises a first communication interface 111, a memory module 113, a processing module 115 and a second communication interface 117, all connected via a communication bus 119. The first communication interface 111 is connected to a transceiver for wireless communication with a UE. The second communication interface 117 is a wired (e.g., optical fiber) connection to a core network including a controller 150 of the cellular telecommunication network 100.
[0031] The first base station 110 is identified by (at least) a physical cell identifier (PCI). The PCI is sent by the first base station 110 in a physical layer broadcast transmission so that it can be decoded by any UE in the cellular telecommunication network 100 (including UEs connected to the first base station 110 and UEs not connected to the first base station 110).
[0032] The memory module 113 stores a Neighbour Relations Table (NRT) identifying one or more other base stations in the cellular telecommunication network 100. The first base station 110 is configured to populate the NRT in the following manner:
[0033] 1. receiving a measurement report identifying another base station in the cellular telecommunication network 100 from a UE connected to the first base station 110, and adding the other base station to the NRT; and / or
[0034] 2. Perform a Radio Environment Monitoring (REM) scan (via the first communication interface 111) to detect another base station in the cellular telecommunication network 100 and add the other base station to the NRT.
[0035] These measurement reports and REM scans may identify PCIs that have not yet been recorded in the NRT. In this case, it is assumed that the PCI is sent by a neighboring cell that has not yet been identified in the NRT. In response, the first base station 110 creates a new record for the neighboring cell in the NRT and determines its unique identifier (global cell ID).
[0036] The first base station 110 is also configured to transmit its NRT to the controller 150. This may be performed periodically or in response to a trigger (eg, the NRT is updated).
[0037] The second base station 120, the third base station 130, and the fourth base station 140 operate in a similar manner to send their respective PCIs, fill their respective NRTs, and transmit their respective NRTs to the controller 150. Figure 1As shown, the first base station 110 uses PCI 7, the second base station 120 uses PCI 8, the third base station 130 uses PCI 9, and the fourth base station 140 uses PCI 7.
[0038] Figure 3 150 is shown in more detail in FIG. The controller includes a first communication interface 151, a memory module 153, and a processing module 155, all of which are connected via a communication bus 157. The first communication interface 151 is a wired (e.g., optical fiber) connection (directly or indirectly) connected to each of the first base station 110, the second base station 120, the third base station 130, and the fourth base station 140. The first communication interface 151 can also enable the controller 150 to communicate with other networked nodes including other controllers in the case of performing a process (described below) in a distributed environment. The memory module 153 stores a combined NRT filled with data from the NRT received by each of the first base station 110, the second base station 120, the third base station 130, and the fourth base station 140. Therefore, the combined NRT can identify the first-order neighboring area, the second-order neighboring area, and the third-order neighboring area of each base station for each base station. The processing module 155 is configured to perform the first process and / or the second process described below.
[0039] We will now describe Figure 4 The first process is shown in the flowchart of FIG. This process is executed by the controller 150 and involves the following steps: Figure 1 The cellular network 100 shown. In the first step (S101), the controller 150 triggers the PCI (re) allocation process. The trigger can be in response to an event (for example, the controller 150 receives a message indicating a change in the PCI of any base station in the network 100 or a change in the neighbor relationship between the base stations from one or more of the first base station 110, the second base station 120, the third base station 130 and the fourth base station 140, or a PCI (re) allocation event triggered within the controller 150 or the core network, or the trigger can be time-based (such as the expiration of a timer)). If there is a change in PCI or neighbor relationship between base stations, the combined NRT is updated to incorporate these changes.
[0040] In step S103, the controller 150 analyzes the current PCI allocations for each base station in the network 100 and the current neighbor relations between each pair of base stations in the network 100. This is achieved by entering an iterative loop, wherein, in each iteration, the current PCI allocations and the current neighbor relations are analyzed to identify one or more base station pairs having a particular combination of PCI allocations and neighbor relations. Each iteration is associated with a particular combination of PCI allocations and neighbor relations, which is ranked by the severity of the actual (or potential) degradation of network performance by that combination of PCI allocations and neighbor relations. These severity levels are listed in the following table:
[0041] Severity relation 1 First-order neighbors with the same PCI value ("PCI collision") 2 Second-order neighbors with the same PCI value ("PCI confusion") 3 Third-order neighboring cells with the same PCI value 4 First-order neighboring cells with the same PCI modulo 3 value 5 First-order neighboring cells with the same PCI modulo 4 value 6 First-order neighbors with the same PCI modulo 30 value 7 Second-order neighboring cells with the same PCI modulo 3 value 8 Second-order neighboring cells with the same PCI modulo 4 value 9 Second-order neighbors with the same PCI modulo 30 value 10 Fourth-order neighboring areas with the same PCI value 11 Third-order neighboring cells with the same PCI modulo 3 value 12 Third-order neighboring cells with the same PCI modulo 4 value 13 Third-order neighboring cells with the same PCI modulo 30 value 14 Fourth-order neighboring regions with the same PCI modulo 3 value 15 Fourth-order neighboring cells with the same PCI modulo 4 value 16 Fourth-order neighboring cells with the same PCI modulo 30 value
[0042] These PCI relationships include those current PCI conflicts that are known to result in degraded network performance (e.g., Severity Level 1, Severity Level 2, Severity Level 4, Severity Level 5, and Severity Level 6 relationships), and those potential PCI conflicts that would achieve degraded network performance if a higher-order neighbor is reconfigured to a lower-order neighbor (e.g., Severity Level 3 and Severity Level 7 to Severity Level 16 PCI conflict types). In the first example, the reconfiguration may be due to a higher-order neighbor transmitting at a different transmission power in order to change its coverage area to a lower-order neighbor (such as when a base station compensates a base station to enter a power-saving mode), or in the second example, the higher-order neighbor is a mobile base station that moves to another location in order to change its coverage area to a lower-order neighbor. Thus, these potential PCI conflict types cover scenarios in which two base stations with the same PCI value (or related PCI values) have satisfactory performance within their current respective coverage areas, but would have unsatisfactory performance if the two base stations were reconfigured to lower-order neighbors.
[0043] Apply this step to Figure 1 In the cellular network 100 of FIG. 1 , in a first iteration loop, the controller 150 determines whether there is a relationship of severity level 1 in the network 100. Since there are no first-order neighbors with the same PCI value, the determination is negative. Therefore, the controller 150 enters a second iteration loop and determines whether there is a relationship of severity level 2 in the network 100. There are also no second-order neighbors with the same PCI value, so the determination is negative. Therefore, the controller 150 enters a third iteration loop and determines whether there is a relationship of severity level 3 in the network 100. Since the first base station 110 and the fourth base station 140 are third-order neighbors and have the same PCI value, the determination is positive.
[0044] In response to the affirmative determination of step S103, the controller 150 identifies a suitable solution (step S105). Since the relationship identified in step S103 is a relationship with a potential PCI conflict, the PCI reallocation is a preferred solution to the PCI conflict that will occur if one or both base stations in the identified base station pair (the first base station 110 and the fourth base station 140) are reconfigured so that the base station pair has a lower-order neighbor relationship. The preferred solution may be one or more of the following:
[0045] · reallocating one or more PCIs in the cellular network 100; and
[0046] • Ensure that one or both base stations in the identified pair cannot be reconfigured as a lower order neighbor.
[0047] Any preemptive solution to reallocating one or more PCIs in the cellular network 100 may be to reallocate the PCI of one or both base stations in the identified base station pair and / or one or more other base stations. The reallocated PCIs should not create a relationship with a higher severity level, but may create a relationship with a lower severity level. In this example, the PCIs of the first base station 110 and / or the fourth base station 140 may be changed so that the first base station 110 and the fourth base station 140 no longer have the same PCI, without causing one or both of the first base station 110 and the fourth base station 140 to use PCI 8 or PCI 9 (such as would create a PCI relationship of severity level 1 or 2). After this reconfiguration, one or both base stations in the identified base station pair may be reconfigured as a lower order neighbor.
[0048] A preemptive solution to ensure that one or both base stations in the identified base station pair cannot be reconfigured as a lower order neighbor may include one or more of the following:
[0049] · shutting down one or both base stations in the identified base station pair or instructing one or both base stations in the identified base station pair to enter a power saving mode;
[0050] · limiting the transmission power of one or both base stations in the identified base station pair so that they cannot become lower-order neighbors; and
[0051] • Preventing one or both base stations in the identified pair of base stations from entering backoff mode.
[0052] These preemptive solutions ensure that one or both base stations cannot be reconfigured to a lower order neighbor (and may involve the base stations continuing to use their current PCIs). These restrictions may also identify acceptable states for each base station in the network based on other base stations in the network (e.g., a base station may enter backoff mode only if another base station is not in backoff mode) to avoid PCI conflicts that would otherwise occur.
[0053] After identifying a suitable solution in step S105, the controller 150 determines whether there are further relationship severity levels to be analyzed. Since severity levels 4 to 16 have not yet been analyzed, the controller 150 iteratively analyzes each severity level and, if there are relationships at a severity level, identifies a suitable solution that does not create a relationship at a higher severity level. In this example, no further relationships are identified and the controller 150 proceeds to step S107, in which the controller 150 instructs one or more base stations in the network 100 to implement the identified solution. This can be achieved by sending corresponding messages to each base station involved in the identified solution, which messages cause each corresponding base station to implement the identified part of their solution.
[0054] Figure 4 The process enables the network 100 to proactively resolve one or more PCI conflicts that would degrade network performance in the event of a change in neighbor relations in the network. Conventional PCI allocation processes typically allocate PCIs to base stations such that there are no PCI conflicts for the current corresponding coverage area of each base station. However, because the cellular network 100 implements technology that enables one or more base stations to change their respective coverage areas (such as mobile base stations or compensation base stations that are energy-saving base stations), these allocated PCIs may still result in PCI conflicts when one or more base stations change their respective coverage areas. Although this can be resolved by detecting PCI conflicts and reallocating PCIs in response, Figure 4 The process provides a preemptive solution so that potential PCI conflicts do not occur when one or more base stations change their respective coverage areas.
[0055] also, Figure 4 The process of prioritizing solutions for relationships based on the actual or potential performance degradation of each relationship. That is, the solutions are sorted by severity level such that solutions for relationships with greater actual or potential performance degradation are prioritized.
[0056] We will now describe Figure 5 The second process is also executed by the controller 150 and also involves Figure 1The cellular network 100 shown. In this second process, the controller 150 additionally stores data related to the energy-saving state of each base station in the network 100. Each base station in the network 100 can operate in normal mode, energy-saving mode (in which it enters an energy-saving state), or compensation mode (in which it compensates for another base station entering an energy-saving mode). Conventionally, base stations are configured to switch between normal mode and energy-saving mode, or between normal mode and compensation mode. One or more base stations in the network 100 may be configured to operate only in normal mode. The data stored by the controller 150 identifies, for each base station, its current energy-saving state (normal mode, energy-saving mode, or compensation mode) and its potential energy-saving state (normal mode, energy-saving mode, or compensation mode). The data can be transmitted from each base station to the controller 150 (e.g., as part of an NRT update message).
[0057] In a first step of this second process (S201), the controller 150 triggers a PCI (re)assignment process. The trigger may be in response to an event or may be time-based.
[0058] In step S203, the controller 150 analyzes the current PCI allocation of each base station in the network 100, the current neighbor relationship between each pair of base stations in the network 100, and the energy-saving state of each base station in the network 100. This second process introduces the concept of energy-saving priority groups. Energy-saving priority groups refer to the energy-saving state of a base station, such as its current energy-saving state and its potential energy-saving state (i.e., the energy-saving state of the base station when the demand in the network is low). Energy-saving priority groups are defined as follows:
[0059] Energy saving priority group Potential energy saving state Current energy saving status 1 Compensation Mode Compensation Mode 2 Compensation Mode Normal Mode 3 Normal Mode Normal Mode 4 Energy saving mode Normal Mode 5 Energy saving mode Energy saving mode
[0060] exist Figure 1 In the example shown, the first base station 110 and the fourth base station 140 are in energy saving priority group 2 (they are currently in normal mode, but can operate in compensation mode when network demand is low), and the second base station 120 and the third base station 130 are in energy saving priority group 4 (they are currently in normal mode, but can operate in energy saving mode when network demand is low).
[0061] In the following analysis, the concept of "maximum energy saving priority group" is also defined to indicate the maximum energy saving priority group of base station pairs identified as having a specific combination of PCI allocation and neighbor relationship. Figure 1 In the example shown, the first base station 110 and the fourth base station 140 are third-order neighboring cells with the same PCI, and the maximum energy saving priority group of the base station pair is 2.
[0062] Back to Figure 5In step S203, the controller 150 enters an iterative loop, wherein in each iteration, the controller 150 analyzes the current PCI allocation and the current neighbor relationship to identify one or more base station pairs having a specific combination of PCI allocation and neighbor relationship, and further determines whether the maximum energy saving priority group of any identified base station pair is equal to a specific value. These iterations are again sorted by the severity of the actual (or potential) degradation of network performance by the combination of PCI allocation, neighbor relationship, and maximum energy saving priority group. These severity levels are listed in the following table:
[0063]
[0064] For the sake of brevity, further severity levels and corresponding relations are not shown (and may additionally cover severity levels for each maximum energy saving priority group, each combination of PCI relations and neighbor relations for the first process in the table, or a subset thereof).
[0065] Will Figure 5 The process is applied to Figure 1 In the network shown, the controller 150 does not identify any base station pairs having a combination of PCI allocation, neighbor relationship and maximum energy saving priority group with severity levels 1 to 5, but instead identifies base station pairs having a combination of PCI allocation, neighbor relationship and maximum energy saving priority group with severity level 6 (i.e., the first base station 110 and the fourth base station 140 are third-order neighboring cells with the same PCI value, and the maximum energy saving priority group of the first base station 110 and the fourth base station 140 is 2).
[0066] The process then proceeds to step S205, in which a suitable solution is identified to preemptively resolve the potential PCI conflict. The controller 150 may identify a solution involving one or more of the following: reallocating one or more PCIs in the cellular network 100, and ensuring that one or both base stations in the identified base station pair cannot be reconfigured as a lower-order neighbor. The solution may be based on the energy-saving state of the base stations, so that the base stations in the identified base station pair with a relatively low energy-saving priority group are primarily subject to any performance degradation caused by the solution (for example, if the first base station in the identified base station pair has energy-saving priority group 1 and the second base station in the identified base station pair has energy-saving priority group 2, then the solution will primarily sacrifice the performance of the second base station, such as by limiting the transmission power of the second base station or reallocating the PCIs in the network so that the PCI conflict of the second base station is more severe than any PCI conflict of the first base station). In other words, any performance change as a result of the solution ensures that the performance of the base stations of the identified base station pair with a relatively high energy-saving priority group is better than the performance of the base stations of the identified base station pair with a relatively low energy-saving priority group.
[0067] In step S207 , the controller 105 instructs one or more base stations in the network 100 to implement the identified solution.
[0068] Therefore, by considering the current energy-saving state and the potential energy-saving state of the base stations involved in the identified relationship, the second process can prioritize solutions that favor the performance of base stations that contribute more to the overall network performance. That is, other base stations that are currently in compensation mode or configured to compensate for entering energy-saving mode contribute more to the overall network performance (e.g., in terms of the number of users served and throughput) than base stations that are in energy-saving mode or configured to enter energy-saving mode. Therefore, any solution to a potential PCI conflict that preemptively resolves a performance degradation of one of the base stations involved in the potential PCI conflict should prioritize the performance of base stations that are more likely to compensate for one or more other base stations.
[0069] Now refer to Figure 7 The network 200 shown describes Figure 6 The third process shown. Figure 7 A network 200 is shown with a controller 250, a first base station 210, a second base station 220, a third base station 230, a fourth base station 240, and a fifth base station 250. As shown, the first base station 210 and the second base station 220 have partially overlapping coverage areas, the second base station 220 and the third base station 230 have partially overlapping coverage areas, the third base station 230 and the fourth base station 240 have partially overlapping coverage areas, and the fourth base station 240 and the fifth base station 250 have partially overlapping coverage areas. The third process may be performed by the controller 250.
[0070] In this third process, the controller 250 stores data about the PCI allocation and energy saving state of each base station in the network 200. The energy saving state data stored by the controller 250 identifies, for each base station, its current energy saving state (normal mode, energy saving mode, or compensation mode) and its potential energy saving state (normal mode, energy saving mode, or compensation mode). This data can be transmitted from each base station to the controller 250. The controller 250 can identify an energy saving priority group for each base station in the network 200. As described above, the energy saving priority group relates to the energy saving state of the base station, such as its current energy saving state and its potential energy saving state. The energy saving priority groups are defined in the following table:
[0071] Energy saving priority group Potential energy saving state Current energy saving status 1 Compensation Mode Compensation Mode 2 Compensation Mode Normal Mode 3 Normal Mode Normal Mode 4 Energy saving mode Normal Mode 5 Energy saving mode Energy saving mode
[0072] exist Figure 7In the network, the first base station 210 uses PCI 7 and is in energy saving priority group 4, the second base station 220 uses PCI 8 and is in energy saving priority group 3, the third base station 230 uses PCI 7 and is in energy saving priority group 3, the fourth base station 240 uses PCI 9 and is in energy saving priority group 3, and the fifth base station 250 uses PCI 7 and is in energy saving priority group 2.
[0073] In the first step of the third process (S301), the controller 250 triggers the PCI (re)assignment process. The trigger may be in response to an event (such as a change in the PCI or energy saving state of a base station in the network 200) or may be time-based.
[0074] In step S303, the controller 250 analyzes the current PCI allocations in the network to identify multiple PCI conflicts. Figure 7 In the network shown, the controller 150 identifies a first PCI conflict between the first base station 210 and the third base station 230 (second-order neighbor cells with the same PCI), and further identifies a second PCI conflict between the third base station 230 and the fifth base station 250 (again, second-order neighbor cells with the same PCI). Note that the PCI conflict between the first base station 210 and the fifth base station 250 is ignored because, in this example, the controller 250 only identifies PCI conflicts between first-order neighbor cells, second-order neighbor cells, and third-order neighbor cells.
[0075] In step S305, the controller 250 identifies a solution to the multiple PCI conflicts identified in step S303. The solution is based on the maximum (ie, highest priority) energy saving priority group of each base station pair for each PCI conflict. Figure 7In the example, the maximum energy-saving priority group of the base station pair of the first PCI conflict is 3, and the maximum energy-saving priority group of the base station pair of the second PCI conflict is 2. This solution makes any network performance degradation as a result of the solution more likely for the base station pair with a relatively high maximum priority energy-saving priority group value, and therefore more likely to enter the energy-saving mode. In other words, the scheme ensures that the performance of the base station pair with a relatively low maximum energy-saving priority group (i.e., the base station pair that is more likely to compensate for other base stations) is better than the performance of the base station pair with a relatively high maximum energy-saving priority group (i.e., the base station pair that is more likely to enter the energy-saving mode). In the example where the multiple PCI conflicts include the first PCI conflict (wherein the maximum energy-saving priority group of the base station involved in the first PCI conflict is 3) and also include the second PCI conflict (wherein the maximum energy-saving priority group of the base station involved in the second PCI conflict is 2), the controller identifies a solution that prioritizes the performance of the second PCI conflict over the first PCI conflict. In other words, the identified solution is a solution in which the base station involved in the first PCI conflict (at least primarily) suffers any network performance degradation.
[0076] The identified solution may involve reallocating PCIs to base stations in the network 200. In this case, the reallocated PCIs should resolve the second PCI conflict, and the base stations involved in the first PCI conflict should suffer any network performance degradation from the reallocation. For example, the PCI allocation may involve reallocation of a PCI for the third base station 230 so that the third base station 230 and the fifth base station 250 no longer have the same PCI, even if the change causes the first base station 210 and the third base station 230 to have another form of PCI conflict.
[0077] In step S307 , the controller 250 instructs each base station to implement its corresponding part of the identified solution.
[0078] Similar to the second process detailed above, this third process also considers the current energy-saving state and potential energy-saving state of the base stations involved in the identified PCI conflict in order to prioritize solutions that favor the performance of base stations that contribute more to the overall network performance. That is, base stations that are currently in compensation mode or configured to compensate for other base stations entering energy-saving mode contribute more to the overall network performance (e.g., in terms of the number of users served and throughput) than base stations that are in energy-saving mode or configured to enter energy-saving mode. Therefore, solutions to PCI conflicts involving performance degradation of one of the base stations involved in the PCI conflict should prioritize the performance of base stations configured to compensate for one or more other base stations over the performance of base stations configured to enter energy-saving mode.
[0079] As mentioned above, Figure 1The controller 150 is configured to perform the first process and the second process, and Figure 7 The controller 250 is configured to perform the third process. However, this is not necessary, and the first process, the second process, and the third process may be performed by one or more base stations. That is, the base station may exchange necessary data (such as NRT data and energy-saving status data) in inter-base station messaging so that the remaining steps of each process may be performed locally. The base station may identify the neighbor relationship between base stations by comparing the NRT data. For example, if a first base station receives an NRT that can be detected by the first base station from a first neighboring base station (so that the first neighboring base station is a first-order neighbor of the first base station) and the NRT includes data on a second neighboring base station that cannot be detected by the first base station, the second neighboring base station is a second-order neighbor. The NRT may include the neighbor order of each base station (from the perspective of the base station that fills the NRT) to reduce calculations.
[0080] In the second and third processes detailed above, the energy saving priority group is used to define multiple energy saving states of the base station (including its current energy saving state and potential energy saving state). Each base station may have multiple potential energy saving states, in which case the energy saving priority group should reflect the energy saving state with the largest coverage. In addition, a single energy saving state (current or potential) may be used instead.
[0081] Instead of identifying the maximum energy-saving priority group of the base station involved in the PCI conflict, the minimum energy-saving priority group can be used. A combined energy-saving priority group representing the corresponding energy-saving priority group of each base station involved in the PCI conflict can also be used. The combination can be achieved by averaging or adding the corresponding energy-saving priority groups.
[0082] In the above process, one of the solutions to the PCI conflict is to configure the coverage area of the base stations involved so that the PCI conflict cannot occur (such as by limiting the transmission power of one or more base stations). Those skilled in the art will understand that these solutions may not remove the PCI conflict, but only reduce the performance degradation caused by the PCI conflict to below a threshold amount. For example, the solution may be to reduce the transmission power of one of the base stations involved in the conflict so that the conflict still exists in a smaller geographical area.
[0083] The above procedures are described in the context of a conventional radio access network. However, these procedures may also be applied to a disaggregated radio access network having remote units and centralized units (e.g., disaggregated units and / or central units). In this case, when a PCI conflict is found between two remote units, a check may be made to determine whether they have a common centralized unit. If the two remote units have a common centralized unit, the threshold amount of acceptable performance degradation may be relatively high.
[0084] Figure 8 An example can be Figure 1 A fourth process implemented in a node of a network of. In step S401, the node obtains data indicating corresponding physical cell identifiers PCIs of a first transceiver and a second transceiver among a plurality of transceivers, and also indicates a current neighbor relation between the first transceiver and the second transceiver, the current neighbor relation between the first transceiver and the second transceiver having a specific order. In step S403, in the case where the order of the current neighbor relation between the first transceiver and the second transceiver is reduced, the node identifies a first potential PCI conflict between the first transceiver and the second transceiver among the plurality of transceivers from the obtained data. In step S405, the node identifies a solution to the first potential PCI conflict. In step S407, the node causes a reconfiguration in the cellular telecommunication network to implement the identified solution.
[0085] Fig. 9 An example can be Figure 7 A fifth process implemented in a node of a network of. In step S501, the node obtains data including a physical cell identifier PCI of each transceiver in a plurality of transceivers. In step S503, the node identifies a first PCI conflict between a first pair of transceivers in the plurality of transceivers and a second PCI conflict between a second pair of transceivers in the plurality of transceivers based on the obtained data. In step S505, the node determines that a solution priority of the first PCI conflict is greater than a solution priority of the second PCI conflict, wherein the solution priority of the first PCI conflict and the solution priority of the second PCI conflict are based on respective energy-saving characteristics of the respective first pair of transceivers and the second pair of transceivers. In step S507, the node identifies a solution to the first PCI conflict. In step S509, the node causes a reconfiguration in the cellular telecommunication network to implement the identified solution.
[0086] A person skilled in the art will understand that any combination of features is possible within the scope of the claimed invention.
Claims
1. A node for a cellular telecommunication network, the cellular telecommunication network comprising a plurality of transceivers, the node comprising: a transceiver configured to obtain data including a physical cell identifier (PCI) of each of the plurality of transceivers; as well as A processor, the processor being configured to: identifying, based on the obtained data, a first PCI conflict between a first pair of transceivers in the plurality of transceivers and a second PCI conflict between a second pair of transceivers in the plurality of transceivers, determining that a resolution priority of the first PCI conflict is greater than a resolution priority of the second PCI conflict, wherein the resolution priority of the first conflict and the resolution priority of the second PCI conflict are based on respective power saving states of the respective first pair of transceivers and the second pair of transceivers, the power saving state being one of a normal mode, a power saving mode, and a compensation mode, Identifying a solution to the first PCI conflict, and Reconfiguration in the cellular telecommunication network is enabled to implement the identified solution.
2. The node according to claim 1, wherein: The power saving state of the first pair of transceivers is based on at least one of the group consisting of: a current power saving state of a first transceiver of the first pair of transceivers, a current power saving state of a second transceiver of the first pair of transceivers, power saving state capability of a first transceiver of the first pair of transceivers, and A power saving state capability of a second first transceiver of the first pair of transceivers.
3. A node according to claim 1 or claim 2, wherein: The power saving state of the second pair of transceivers is based on at least one of the group consisting of: a current power saving state of a first transceiver of the second pair of transceivers, a current power saving state of a second transceiver of the second first pair of transceivers, power saving state capability of a first transceiver of the second pair of transceivers, and The power saving state capability of the second first transceiver of the second pair of transceivers.
4. A node according to any one of the preceding claims, wherein: The solution is one or more of the group consisting of: changing a PCI of one or more transceivers of the plurality of transceivers, limiting a power saving state operating mode of one or more of the plurality of transceivers, limiting a transmission power of one or more of the plurality of transceivers, and One or more transceivers of the plurality of transceivers are disabled.
5. The node according to any one of the preceding claims, the node being one of the group consisting of: a controller; and a transceiver of the plurality of transceivers.
6. A method in a cellular telecommunication network, the cellular telecommunication network comprising a plurality of transceivers, the method comprising the steps of: obtaining data including a physical cell identifier (PCI) of each transceiver of the plurality of transceivers; Based on the obtained data, identifying a first PCI conflict between a first pair of transceivers in the plurality of transceivers and a second PCI conflict between a second pair of transceivers in the plurality of transceivers; determining that a resolution priority of the first PCI conflict is greater than a resolution priority of the second PCI conflict, wherein the resolution priority of the first PCI conflict and the resolution priority of the second PCI conflict are based on respective power saving states of the respective first pair of transceivers and the second pair of transceivers, wherein the power saving state is one of a normal mode, a power saving mode, and a compensation mode; identifying a solution to the first PCI conflict; and Reconfiguration in the cellular telecommunication network is enabled to implement the identified solution.
7. A computer program, comprising instructions for causing the node of any one of claims 1 to 5 to execute the steps of claim 6.
8. A computer-readable medium having the computer program according to claim 7 stored thereon.