1、 ETSI TR 136 902 V9.3.1 (2011-05)Technical Report LTE;Evolved Universal Terrestrial RadioAccess Network (E-UTRAN);Self-configuring and self-optimizing network (SON)use cases and solutions (3GPP TR 36.902 version 9.3.1 Release 9)ETSI ETSI TR 136 902 V9.3.1 (2011-05) 13GPP TR 36.902 version 9.3.1 Rele
2、ase 9Reference RTR/TSGR-0336902v931 Keywords LTE ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notic
3、e Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable
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6、reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2011. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTM, TIPHONTM, the TIPHON logo and the ETSI logo are Trade Marks
7、of ETSI registered for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. LTE is a Trade Mark of ETSI currently being registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and
8、the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TR 136 902 V9.3.1 (2011-05) 23GPP TR 36.902 version 9.3.1 Release 9Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaini
9、ng to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretaria
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11、updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or reports using their 3GPP iden
12、tities, UMTS identities or GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. ETSI ETSI TR 136 902 V9.3.1 (2011-05) 33GPP T
13、R 36.902 version 9.3.1 Release 9Contents Intellectual Property Rights 2g3Foreword . 2g3Foreword . 5g3Introduction 5g31 Scope 6g32 References 6g33 Definitions, symbols and abbreviations . 6g33.1 Definitions 6g33.2 Symbols 6g33.3 Abbreviations . 7g34 Description of envisioned self configuring and self
14、 optimizing functionality, Use cases 7g34.1 Coverage and capacity optimization. 7g34.1.1 Use Case description . 7g34.2 Energy Savings . 7g34.2.1 Use Case description . 8g34.2.2 Solution Description . 8g34.2.2.1 Input data, definition of Measurements or Performance data . 8g34.2.2.2 Output, influence
15、d entities and parameter . 8g34.2.2.3 Impacted specifications, procedure interactions and interfaces 8g34.3 Interference Reduction . 8g34.3.1 Use Case description . 8g34.4 Automated Configuration of Physical Cell Identity . 8g34.4.1 Use Case description . 8g34.4.2 Solution Description . 9g34.4.2.1 I
16、nput data, definition of Measurements or Performance data . 9g34.4.2.2 Output, influenced entities and parameter . 9g34.4.2.3 Impacted specifications and interfaces 10g34.5 Mobility robustness optimisation . 10g34.5.1 Use Case description . 10g34.5.2 Required Functionality . 10g34.5.2.1 Detection of
17、 Too Late HO . 10g34.5.2.2 Detection of Too Early HO . 10g34.5.2.3 Detection of HO to a Wrong Cell 11g34.5.2.4 Reducing inefficient use of network resources due to unnecessary HOs 11g34.5.2.5 Optimization of cell reselection parameters 11g34.5.3 Evaluation scenarios and expected results 11g34.5.4 O
18、2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third digit is incremented when editorial only changes have been incorpora
19、ted in the document. Introduction Reduction of operational efforts and complexity are key drivers for RAN Long Term Evolution. One of the important aspects to this is that the system operability is improved under multi vendor environment. It is of importance that measurements and performance data of
20、 different vendors share the same “language.” Such alignment is easing ease network performance analyses and problem finding, and reduces efforts in maintaining the network at a properly working state. It is also of interest to minimise operational effort by introducing self configuring and self opt
21、imising mechanisms. A self optimising function shall increase network performance and quality reacting to dynamic processes in the network. Especially in the early deployment phase, the efforts to set up and optimise are significant and traditionally lead to lengthy periods of getting an optimum and
22、 stable system setup. It is thus essential to have the necessary set of self configuration and self optimisation mechanisms already available when initial deployment starts. As such, standardisation is asked to define the necessary measurements, procedures and open interfaces to support better opera
23、bility under multi vendor environment. Such standardised functions shall also facilitate self configuration and self optimisation under multi vendor environment. Especially the interaction between self configuring/optimizing networks and O Overall description; Stage 2“. 3 3GPP TS 36.211: “Radio Acce
24、ss (E-UTRA); Physical Channels and Modulation“ 4 3GPP TS 36.304: “Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode“. 5 3GPP TS 36.331: “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification“. 6 3GPP T
25、S 36.321: “Radio Access (E-UTRA); Medium Access Control (MAC) Protocol Specification“. 7 3GPP TS 36.423: “X2 application protocol (X2AP) “. 8 3GPP TS 36.213: “Radio Access (E-UTRA); Physical Layer Procedures“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present d
26、ocument, the terms and definitions given in TR 21.905 1 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 1. 3.2 Symbols For the purposes of the present document, the following symbols apply: ETSI ETSI TR 136 9
27、02 V9.3.1 (2011-05) 73GPP TR 36.902 version 9.3.1 Release 93.3 Abbreviations For the purposes of the present document, the abbreviations given in TR 21.905 1 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any
28、, in TR 21.905 1. CP Contention Probability DMP Detection Miss Probability DRX Discontinuous Reception ICIC Inter-cell Interference Coordination OFDM Orthogonal Frequency Division Multiplexing PRB Physical Resource Block RACH Random Access CHannel RAT Radio Access Technology RRM Radio Resource Manag
29、ement SC-FDMA Single Carrier Frequency Division Multiple Access 4 Description of envisioned self configuring and self optimizing functionality, Use cases 4.1 Coverage and capacity optimization A typical operational task is to optimize the network according to coverage and capacity. Planning tools su
30、pport this task based on theoretical models but for both problems measurements must be derived in the network. Call drop rates give a first indication for areas with insufficient coverage, traffic counters identify capacity problems. 4.1.1 Use Case description The use case will have two main objecti
31、ves: Providing optimal coverage This objective requires that in the area, where LTE system is offered, users can establish and maintain connections with acceptable or default service quality, according to operators requirements. It implies therefore that the coverage is continuous and users are unaw
32、are of cell borders. The coverage must be therefore provided in both, idle and active mode for both, UL and DL. Providing optimal capacity While coverage optimization has higher priority than capacity optimization in Rel-9, the coverage optimization algorithms must take the impact on capacity into a
33、ccount. Since coverage and capacity are linked, a trade-off between the two of them may also be a subject of optimisation. This use case is not completed in rel-9. 4.2 Energy Savings A typical critical cost for the operator is the energy expenses. Cuts on energy expenses could be realized if the cap
34、acity offered by the network would match the needed traffic demand at any point of time as close as possible. ETSI ETSI TR 136 902 V9.3.1 (2011-05) 83GPP TR 36.902 version 9.3.1 Release 94.2.1 Use Case description Objective: Energy savings based on enabling the possibility, for a cell providing addi
35、tional capacity in a deployment where capacity boosters can be distinguished from cells providing basic coverage, to be switched off when its capacity is no longer needed and to be re-activated on a need basis. Expected outcome: Cuts on operational expenses through energy savings. 4.2.2 Solution Des
36、cription 4.2.2.1 Input data, definition of Measurements or Performance data See TS 36.300 2. 4.2.2.2 Output, influenced entities and parameter See TS 36.300 2. 4.2.2.3 Impacted specifications, procedure interactions and interfaces See TS 36.300 2. 4.3 Interference Reduction Capacity could be improve
37、d through interference reduction by switching off those cells which are not needed for traffic at some point of time, in particular home eNodeBs when the user is not at home. 4.3.1 Use Case description Objective: Interference reduction based on cell switch on/off. Expected outcome: square4 Increased
38、 capacity through interference reduction. square4 Increased quality through interference reduction. This use case is not completed in rel-9. 4.4 Automated Configuration of Physical Cell Identity 4.4.1 Use Case description Objective: Automatic configuration of the Physical ID of an eNBs radio cell Th
39、e proposed SON use case provides an automated configuration of a newly introduced cells physical ID (L1 cell identifier TS 36.300 2). ETSI ETSI TR 136 902 V9.3.1 (2011-05) 93GPP TR 36.902 version 9.3.1 Release 9Figure 4.4.1: Deployment Illustration The physical cell identity, or L1 identity (Phy_ID
40、in this document), is an essential configuration parameter of a radio cell, it corresponds to a unique combination of one orthogonal sequence and one pseudo-random sequence, and 504 unique Phy_IDs are supported leading to unavoidable reuse of the Phy_ID in different cells (TS 36.211 3). When a new e
41、NodeB is brought into the field, a Phy_ID needs to be selected for each of its supported cells, avoiding collision with respective neighbouring cells (the use of identical Phy_ID by two cells results in interference conditions hindering the identification and use of any of them where otherwise both
42、would have coverage). Traditionally, the proper Phy_ID is derived from radio network planning and is part of the initial configuration of the node. The Phy_ID assignment shall fulfil following conditions, “collision-free”: the Phy_ID is unique in the area that the cell covers “confusion-free”: a cel
43、l shall not have neighbouring cells with identical Phy_ID 4.4.2 Solution Description Self-configuration case applied during initial cell configuration Functionality: selection of a Physical ID for a newly deployed radio cell Actions: FFS Expected outcome: Selection of Phy_ID without conflicts. 4.4.2
44、.1 Input data, definition of Measurements or Performance data (FFS) 4.4.2.2 Output, influenced entities and parameter Output parameters from the SON function are: ETSI ETSI TR 136 902 V9.3.1 (2011-05) 103GPP TR 36.902 version 9.3.1 Release 9Self-configuration of Phy_ID 4.4.2.3 Impacted specification
45、s and interfaces There may be an impact related to the method to be used for obtaining existing configuration at neighbours that is FFS. 4.5 Mobility robustness optimisation 4.5.1 Use Case description Manual setting of HO parameters in current 2G/3G systems is a time consuming task. In many cases, i
46、t is considered too costly to update the mobility parameters after the initial deployment. For some cases, RRM in one eNB can detect problems and adjust the mobility parameters, but there are also examples where RRM in one eNB can not resolve problems: Incorrect HO parameter settings can negatively
47、affect user experience and wasted network resources by causing HO ping-pongs, HO failures and radio link failures (RLF). While HO failures that do not lead to RLFs are often recoverable and invisible to the user, RLFs caused by incorrect HO parameter settings have a combined impact on user experienc
48、e and network resources. Therefore, the main objective of mobility robustness optimization should be reducing the number of HO-related radio link failures. Furthermore, non-optimal configuration of handover parameters, even if it does not result in RLFs, may lead to serious degradation of the servic
49、e performance. Example of such a situation is incorrect setting of the HO hysteresis, which may be the reason for either ping-pong effect or prolonged connection to non-optimal cell. Thus the secondary objective will be reduction of the inefficient use of network resources due to unecessary or missed handovers. HO-related failures can be categorized as follows: square4 Failures due to too late HO triggering square4 Failures due to too early HO triggering square4 Failures due to HO to a wrong cell Additionally cell-reselection parameters not a
