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Huawei eRAN 3.0 ANR Feature Introduction

Huawei eRAN 3.0 ANR Feature Introduction. Objectives. Upon completion of this course, you will be able to: Describe the basic conceptions of ANR Describe the principle of intra-RAT ANR Describe the principle of inter-RAT ANR Performance manual neighbor relation management. Contents.

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Huawei eRAN 3.0 ANR Feature Introduction

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  1. Huawei eRAN3.0ANR Feature Introduction

  2. Objectives • Upon completion of this course, you will be able to: • Describe the basic conceptions of ANR • Describe the principle of intra-RAT ANR • Describe the principle of inter-RAT ANR • Performance manual neighbor relation management

  3. Contents • ANR Overview • Intra-RAT ANR Management • Inter-RAT ANR Management

  4. Contents • ANR Overview • Intra-RAT ANR Management • Inter-RAT ANR Management

  5. 36.300 • The Automatic Neighbour Relation (ANR) function resides in the eNB and manages the conceptual Neighbour Relation Table (NRT). Located within ANR, the Neighbour Detection Function finds new neighbours and adds them to the NRT. ANR also contains the Neighbour Removal Function which removes outdated NRs.

  6. What is ANR? Missing Neighboring Cells Optimized by ANR • ANR ( Automatic Neighbor Relation) • ANR is a self-optimization function that belong to SON • It automatically maintains the integrity and effectiveness of neighbor cell lists to increase handover success rates and improve network performance • ANR automatically detects missing neighboring cells, PCI collisions, abnormal neighboring cell coverage and analyzes neighbor relations. PCI collision Abnormal Neighboring Cell Coverage

  7. ANR Classification • Based on neighbor relations, ANR is classified into intra-RAT ANR and inter-RAT ANR. • Based on the methods of measuring neighboring cells, ANR is classified into event-triggered ANR and fast ANR (also known as periodic ANR).

  8. Basic Conceptions - NCL • NCL(Neighbor Cell List) contains the information about the external neighboring cells of a serving cell. NCLs are classified into intra-RAT NCLs, inter-RAT NCLs. Each eNodeB has an intra-RAT NCL and inter-RAT NCLs. • NCL includes the E-UTRAN Cell Global Identifiers(or CGIs for inter-RAT), PLMN,PCIs, TAC, eNodeB ID and E-UTRA Absolute Radio Frequency Channel Numbers (EARFCNs) of the neighboring cells.

  9. Basic Conceptions - NRT • NRT(Neighbor Relations Table) contains the information about the neighbor relations between the source cell and its neighboring cells. NRTs are classified into intra-RAT NRTs and inter-RAT NRTs. Each cell has an intra-RAT NRT, inter-RAT NRTs.

  10. Basic Conceptions - NRT • The NRT contains the following information, which can be updated automatically or manually: • SN: denotes the serial number of a neighbor relation. • LCI: Local cell ID, identifies the source cell of a neighbor relation. • Local Cell PLMN:The Public Land Mobile Network which Local Cell belongs to. • TCI: identifies the target cell of a neighbor relation. This attribute is defined by the ECGI of the target cell. • Target Cell PLMN:The Public Land Mobile Network which Target Cell belongs to. • NO Remove: indicates whether a neighbor relation can be removed from the NRT by ANR. By default, the NO Remove attribute of a neighbor relation is set to FALSE. • If the NO Remove attribute of a neighbor relation is TRUE, this neighbor relation cannot be removed from the NRT. • If the NO Remove attribute of a neighbor relation is FALSE, this neighbor relation can be removed from the NRT. • NO HO: indicates whether this neighbor relation can be used for a handover. By default, the NO HO attribute of a neighbor relation is set to FALSE. • If the NO HO attribute of a neighbor relation is TRUE, this neighbor relation cannot be used for a handover. • If the NO HO attribute of a neighbor relation is FALSE, this neighbor relation can be used for a handover.

  11. HO Black List and HO White List • No remove: cannot be removed automatically from the NRT by ANR HO Black list HO White list No remove = True No HO= True No remove = True No HO= False

  12. Abnormal Neighbor Cell • The coverage of neighboring cells may be abnormal in any of the following scenarios: • The antenna tilt or orientation changes because of improper installation or a natural phenomenon such as strong wind • In mountains, the signals of the umbrella cell cover lower cells Deteced by ANR Cell1 Cell2 Actual coverage Expected coverage

  13. Contents • ANR Overview • Intra-RAT ANR Management • Inter-RAT ANR Management

  14. Contents • Intra-RAT ANR Management 2.1 Event- Triggered ANR 2.2 Fast ANR

  15. Event-Triggered ANR Overview • Main function of event-triggered ANR • Missing neighbor detection • Neighbor relations maintenance • Abnormal neighbor coverage detection Detecting missing neighbor Neighbor relations maintenance Detecting Abnormal Neighbor Coverage NRT Result output

  16. MML to Switch on the Intra-RAT ANR Intra-RAT event-triggered ANR is controlled by the IntraRatEventAnrSwitch check box under the AnrSwitch parameter. The intra-RAT event-triggered ANR function is activated when the IntraRatEventAnrSwitch check box is selected.

  17. Missing Neighbor Detection – By UE Measurement

  18. Missing Neighbor Detection – By UE Measurement • The procedure is described as follows: • The source eNodeB delivers the inter-frequency measurement configuration to the UE and requests the UE to measure inter-frequency neighboring cells that meet the measurement configuration. Note: The UE performs intra-frequency neighbor cell measurements by default. And inter-frequency neighbor cell measurement is triggered by A2 event. • The UE detects that the PCI of cell B that meets the measurement configuration and reports it to the source eNodeB. Then, the source eNodeB checks whether the intra-RAT NCL of cell A includes the EARFCN-PCI combination of cell B. If yes, the procedure ends. If no, the following steps continue. • The source eNodeB instructs the UE, using the newly discovered PCI as a parameter, to read the ECGI, Tracking Area Code (TAC), and Public Land Mobile Network (PLMN) ID list of cell B. • The source eNodeB schedules appropriate idle periods to allow the UE to read the ECGI, TAC, and PLMN ID list of cell B over the broadcast channel (BCH). • The UE reports the detected ECGI, TAC, and PLMN ID list of cell B to the source eNodeB.

  19. Missing Neighbor Detection – By UE History Information Source Cell (Cell A) Target Cell (Cell B) M2000 1.Handover request 2.Handover response 3.Report cell A ECGI 4.Send info to cell B Information query In this case, Cell B exist in the NCL/NRT of Cell A, but there is no Cell A info in NCL/NRT of Cell B

  20. Missing Neighbor Detection – By UE History Information • UE history information is containing the previous cell information. This information is contained in handover request message. Following is the contents of information • ECGI of last visit cell • Type of last visit cell • Duration of UE for camping on the cell • The above flow shows how to detect missing neighbor cell by using UE history information • The source eNodeB sends a Handover Request message to the target eNodeB including UE history information • The target eNodeB obtains the UE history information from the message. If the target eNodeB detects that the ECGI of the last visited cell (that is, cell A, the source cell) does not exist in the NCL of the target cell (cell B), cell A is considered as a new neighboring cell of cell B. • The target eNodeB reports the ECGI of cell A to the M2000. • The M2000 queries the PCI, TAC, and PLMN ID list of cell A based on the reported ECGI and sends the parameters to the target eNodeB. The target eNodeB adds cell A to the intra-RAT NCL of cell B and adds the neighbor relation to the intra-RAT NRT.

  21. Neighbor Relations Maintenance—NRT Maintenance Period calculation Result analysis Is removed from NRT Adjust the list of NRT Remaining in NRT

  22. Neighbor Relations Maintenance—NCL Maintenance Period calculation Result analysis Is removed from the NCL Adjust the list of NCL Is kept in NCL

  23. Contents • Intra-RAT ANR Management 2.1 Event- Triggered ANR 2.2 Fast ANR

  24. Fast ANR • In order to reduces the impact of event-triggered UE measurements on handover performance, system supports period measurement. Period measurement report

  25. Fast ANR Restriction When current UE number involved in fast ANR achieve the threshold, eNodeB stop selecting new UE for fast ANR • Periodic UE measurements have a negative impact on the uplink throughput of the network. Therefore, intra-RAT fast ANR restricts the number of concurrent UEs involved in periodic measurements by several mechanisms. When the specific UE measurements achieve the threshold, the UE stop fast ANR report When the total Ue number involved in fast ANR achieve the threshold in the certain period, the eNodeB will get into the state of monitoring or start a new FastAnr Period .

  26. Related Parameters

  27. Contents • ANR Overview • Intra-RAT ANR Management • Inter-RAT ANR Management

  28. Event-Triggered ANR • Inter-RAT event-triggered ANR support GERAN and UTRAN system, controlled by the GeranEventAnrSwitch and UtranEventAnrSwitch check boxes under the AnrSwitch parameter • CDMA doesn’t support event-triggered ANR

  29. Flow of Event-Triggered ANR

  30. Flow of Event-Triggered ANR • The procedure is described as follows: • The source eNodeB delivers the inter-RAT measurement configuration (including target RATs and Frequencys) to the UE, activates the measurement gap mode, and instructs the UE to measure the neighboring cells that meet the measurement configuration. It is triggered by A2 event. • The UE detects that the PCI of cell B meets the measurement configuration and reports it to cell A. If the source eNodeB detects that its NCL does not include the Frequency-PCI combination of cell B, it proceeds to the following step. • The source eNodeB instructs the UE, using the newly discovered PSC(For UTRAN) as a parameter, to read other parameters of cell B. • The source eNodeB schedules appropriate measurement gaps to allow the UE to read the CGI and other parameters of cell B over the BCH. • The UE reports the source eNodeB the CGI and other parameters of cell B. The source eNodeB adds the newly detected neighboring cell to its inter-RAT NCL and adds the neighbor relation to the inter-RAT NRT.

  31. Fast ANR • Inter-RAT fast ANR has similar processing as intra-RAT fast ANR. • It is controlled by the GeranFastAnrSwitch, UtranFastAnrSwitch, and CdmaFastAnrSwitch check boxes under the AnrSwitch parameter.

  32. Related Parameters

  33. Summary • ANR is a self-optimization function that belong to SON. Based on neighbor relations, ANR is classified into intra-RAT ANR and inter-RAT ANR. Based on the methods of measuring neighboring cells, ANR is classified into event-triggered ANR and fast ANR (also known as periodic ANR). • ANR function includes automatic missing neighboring cells detection, PCI conflict detection, abnormal neighboring cell coverage query and analyzes neighbor relations. With these functions, ANR automatically maintains the integrity and effectiveness of neighbor cell lists to increase handover success rates and improve network performance.

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