Mobile Network Evolution - From GSM to LTE

Transcription

1 Mobile Network Evolution - From GSM to LTE Andreas Mitschele-Thiel Mobile Network Evolution Andreas Mitschele-Thiel 1

2 Outline Evolution from GSM to UMTS Architecture Packet handling Resource management Comparison with LTE + SAE = EPS Features and requirements Architecture Protocols Packet handling and resource management Mobility management and HO Self-organization Conclusions References Abbreviations Mobile Network Evolution Andreas Mitschele-Thiel 2

3 From GSM to UMTS: Architecture Base station Base station PSTN Base station +EDGE GSM RAN Base station controller MSC GSM Core (Circuit switched) GMSC HLR AuC EIR node B node B +HSPA node B UTRAN Radio network controller SGSN GPRS Core (Packet Switched) IMS GGSN Internet Mobile Network Evolution Andreas Mitschele-Thiel 3

4 From Circuit Switched to Packet Switched Communication Connection (e.g. voice, CS data) => principle for GSM & UMTS RAN clearly defined start and end times no burstiness => dedicated channels connection setup connection release Packet session => supported by GPRS core, IMS, SAE, HSPA, LTE packet arrival times are typically unknown to the system traffic is highly bursty => shared channels & packet scheduling minutes hours seconds Mobile Network Evolution Andreas Mitschele-Thiel 4

5 UMTS RAN Resource Management When to free resources? After short or long breaks? hours cell_dch cell_fach URA_PCH idle fast release seconds slow release Mobile Network Evolution Andreas Mitschele-Thiel 5

6 UMTS RAN Resource Management When to free resources? After short or long breaks? latency idle setup delay T 3 URA_PCH T 2 transient resource usage cell_fach resource consumption T 1 cell_dch radio resources channel codes HW resources Mobile Network Evolution Andreas Mitschele-Thiel 6

7 UMTS RAN Resource Management When to free resources? After short or long breaks? fast release idle T 3 + reduced fixed cost increase of transitive cost URA_PCH T 2 slow release cell_fach T 1 cell_dch increase of fixed cost + decrease of transitive cost + decrease of mean call setup times Mobile Network Evolution Andreas Mitschele-Thiel 7

8 UMTS Resource Management (control plane) A sophisticated QoS architecture TE Local Service Control Transl. MT UMTS BS Manager Adm./Cap. Control UTRAN Adm./Cap. Control RAB Manager Adm./Cap. Control CN EDGE UMTS BS Manager Subscr. Control Gateway Adm./Cap. Control UMTS BS Manager Transl. Ext. Netw. Ext. Service Control Local BS Manager Radio BS Manager UTRA ph. BS M Radio BS Manager UTRA ph. BS M Adm. Iu BS Iu BS Contr Manager Manager. Adm. Contr Iu NS Adm.. Iu NS Manager Contr Manager Adm.. Contr service primitive interface Adm.. protocol interface Contr. CN BS Manager BB NS Manager CN BS Manager BB NS Manager Ext. BS Manager Mobile Network Evolution Andreas Mitschele-Thiel 8

9 UMTS Resource Management (user plane) TE MT UTRAN CN EDGE Gateway Ext. Netw. Class if. Class if. Cond. Cond. Cond. Mapper Mapper Mapper Local BS Resource Manager Resource Manager Resource Manager Resource Manager Resource Manager Resource Manager External BS UTRA phys. BS Iu network service BB network service data flow with indication of direction Mobile Network Evolution Andreas Mitschele-Thiel 9

10 Compare to Resource Management Distributed Coordination Function (DCF) with Exponential Backoff DIFS DIFS bo e bo r DIFS bo e bo r DIFS bo e busy station 1 bo e busy station 2 station 3 busy bo e busy bo e bo r station 4 bo e bo r bo e busy bo e bo r station 5 t busy medium not idle (frame, ack etc.) bo e elapsed backoff time packet arrival at MAC bo r residual backoff time Mobile Network Evolution Andreas Mitschele-Thiel 10

11 Compare to e Resource Management (EDCA) Enhancement of access during Contention Period (CP) Multiple backoff instances for data streams => different priorities Priority over legacy stations (ensured for CW min [TC]<15) Parameters per Traffic Category (TC): AFIS Arbitration Inter Frame Space CW Contention Window (min & max values) PF Persitency Factor (parameter for calculation of CW after unsuccessful transmission attempt) Mobile Network Evolution Andreas Mitschele-Thiel 11

12 Compare to e Resource Management (EDCA) Up to 8 transmission queues per station Mobile Network Evolution Andreas Mitschele-Thiel 12

13 UMTS vs system operation UMTS: pros: full control of radio spectrum wide-area coverage full fledged and individual QoS control (similar to IntServ) cons: high initial overhead to set up business high equipment cost licence cost and spectrum availability limited bandwidth high administrative overhead to establish as a operator acquisition of antenna locations : pros: small cost to set up a business (in very dense areas) no license needed ample spectrum widely available handsets (though not very mobile) simple authentication and accounting (credit cards) no long-term contracting with users cons: no control of radio spectrum (risk of investments in public areas) limited coverage limited QoS support (similar to DiffServ) high installation cost (backhaul) in case of small traffic per area (use of mesh networks to minimize backhaul cost) no long-term binding of users to provider Mobile Network Evolution Andreas Mitschele-Thiel 14

14 From GSM to LTE/SAE: Protocols and Channels GSM: voice-dominated, dedicated channels, heavy states GPRS: add support for packet data on shared channels; add IPbased core network EDGE: increased packet data capacity for GSM systems UMTS: separate voice and packet data support; focus on dedicated channels and heavy states, complicated RAN architecture and protocols due to macro diversity and QoS requirements HSPA: improved support for packet data; emphasis on shared channels IMS: support for IP-based services, e.g. voice (VoIP) LTE: strong packet data support (latency, throughput, control overhead), limited state; simplified protocols; PS only, i.e. no CS core network Mobile Network Evolution Andreas Mitschele-Thiel 15

15 3GPP Evolution towards LTE/SAE Background (1/3) Discussion started in December 2004 State of the art then: The HSPA extension for UMTS provides very efficient packet data transmission capabilities, but UMTS should continue to be evolved to meet the ever increasing demand of new applications and user expectations 10 years have passed since the initiation of the 3G program and it is time to initiate a new program to evolve 3G which will lead to a 4G technology Mobile Network Evolution Andreas Mitschele-Thiel 16

16 3GPP Evolution towards LTE/SAE Background (2/3) From the application/user perspectives, the UMTS evolution should target at significantly higher data rates and throughput, lower network latency and support of always-on connectivity From the operator perspectives, an evolved UMTS will make business sense if it: provides significantly improved power and bandwidth efficiencies facilitates the convergence with other networks/technologies reduces transport network cost limits additional complexity Mobile Network Evolution Andreas Mitschele-Thiel 17

17 3GPP Evolution towards LTE/SAE Background (3/3) Evolved-UTRA is a packet only network - there is no support for circuit-switched services (no MSC) Evolved-UTRA starts on a clean state - everything is up for discussion including the system architecture and the split of functionality between RAN and CN Led to 3GPP Study Item (Study Phase: Q2006) 3G Long-term Evolution (LTE) for new Radio Access and System Architecture Evolution (SAE) for Evolved Network Mobile Network Evolution Andreas Mitschele-Thiel 18

18 Economic Drivers for Network Evolution Decouple network cost from traffic volume! Traffic volume Network cost (existing technologies) Revenue Profit Network cost (LTE) Time Voice dominated Data dominated Mobile Network Evolution Andreas Mitschele-Thiel 19

19 LTE Requirements and Performance Targets Mobile Network Evolution Andreas Mitschele-Thiel 20

20 Key Features of LTE to Meet Requirements Selection of Orthogonal Frequency Division Multiplexing (OFDM) for the air interface Less receiver complexity Robust to frequency selective fading and inter-symbol interference (ISI) Access to both time and frequency domain allows additional flexibility in scheduling (including interference coordination) Scalable OFDM makes it straightforward to extend to different transmission bandwidths Integration of Multiple-Input Multiple-Output (MIMO) techniques Pilot structure to support 1, 2, or 4 Tx antennas in the Downlink (DL) and Multi-user MIMO (MU-MIMO) in the Uplink (UL) Simplified network architecture Reduction in number of logical nodes à flatter architecture Clean separation of user and control plane No direct backward compatibility with UMTS/HSPA! Mobile Network Evolution Andreas Mitschele-Thiel 21

21 Transition to LTE/SAE: Architecture Base station Base station PSTN Base station GSM RAN Base station controller MSC GSM Core (Circuit switched) GMSC HLR AuC EIR e- node B e- node B e- node B S-GW SGSN Radio network controller E- UTRAN EPC GPRS Core (Packet Switched) P-GW IMS GGSN Internet Mobile Network Evolution Andreas Mitschele-Thiel 22

22 Network Simplification: From 3GPP to 3GPP LTE &'()*+,%$3;A63B342(3*0C%D+*;%EFGG%(*%EFGG%H#I 3GPP architecture EFGG%2+453('4(J+' 4 functional entities on the K%BJ04(3*026%'0(3(3'-%*0%(5'% control plane and user plane 4*0(+*6%A620'%201%J-'+%A620' 3 standardized user plane E%-( L'1%J-'+%A620'%M% and control plane interfaces Control plane GGSN SGSN RNC NodeB User plane Control plane MME MMF ASGW S-GW enodeb User plane $7FOC%$'+<30Q%F2(')2P S-GW: Access Server Gateway ""IC%"*U363(P%"202Q';'0(%I0(3(P MME: Mobility Management '&*1'NC%I<*6<'1%&*1'N Entity enodeb: Evolved NodeB 4*0(+*6%A620'%30('+B24'- 3GPP LTE architecture EFGG%H#I%2+453('4(J+' 2 functional entities on the user >%BJ04(3*026%'0(3(3'-%*0%(5'% plane: enodeb and S-GW J-'+%A620'C%'&*1'N%201%$7FO SGSN control plane functions => $F$&%4*0(+*6%A620'%BJ04(3*0-% S-GW & MME $7FO%M%""I Less interfaces, some functions H'--%30('+B24'-8%-*;'% BJ04(3*0-%)366%13-2AA'2+ will disappear K%62P'+-%30(*%>%62P'+- 4 layers into 2 layers I<*6<'%FF$&% 30('Q+2('1% $7FO% Evolve GGSN à integrated S- "*<30Q%$F$&%BJ04(3*0263(3'-%(*% GW $7FO=% Moving SGSN functionalities to R&S%'<*6J(3*0-%(*%RR"%*0%2% S-GW TG%13-(+3UJ('1%0'()*+,%B*+% ' Q%;*U363(P% RNC evolutions to RRM on a IP ;202Q';'0(= distributed network for enhancing G2+(%*B%R&S%;*U363(P%BJ04(3*0% mobility management U'30Q%;*<'1%(*%$7FO%M% Part of RNC mobility function '&*1'N being moved to S-GW & enodeb!"#$%&'()*+,- /01+'2-%"3(-45'6'7#53'68%9'0-%":4,'05'3;% &*<=%>?@@. Mobile Network Evolution Andreas Mitschele-Thiel 23

23 Evolved Packet System (EPS) Architecture Key elements of network architecture MME/S-GW MME/S-GW No more RNC RNC layers/functionalities moves in enb X2 interface for seamless mobility (i.e. data/context forwarding) and interference management Note: Standard only defines logical structure! enb S1 X2 S1 S1 S1 S1 X2 enb S1 X2 enb EPC E-UTRAN EPC = Evolved Packet Core Mobile Network Evolution Andreas Mitschele-Thiel 24

24 EPS Architecture - Functional Description of the Nodes Mobile Network Evolution Andreas Mitschele-Thiel 25

25 EPS Architecture - Control Plane Layout over S1 UE enb NAS sub-layer performs: Authentication Security control Idle mode mobility handling Idle mode paging origination MME NAS RRC PDCP RLC PDCP sub-layer performs: Integrity protection MAC & ciphering PHY RRC PDCP RLC MAC PHY NAS RRC sub-layer performs: Broadcasting Paging Connection Mgt Radio bearer control Mobility functions UE measurement reporting & control UE enode-b MME Mobile Network Evolution Andreas Mitschele-Thiel 26

26 EPS Architecture - User Plane Layout over S1 Physical sub-layer performs: DL: OFDMA, UL: SC-FDMA Forward Error Correction (FEC) UL power control Multi-stream transmission & reception (i.e. MIMO) UE PDCP RLC MAC PHY enb PDCP RLC MAC PHY PDCP sub-layer performs: Header compression Ciphering S-Gateway RLC sub-layer performs: Transferring upper layer PDUs In-sequence delivery of PDUs Error correction through ARQ Duplicate detection Flow control Concatenation/Concatenation of SDUs MAC sub-layer performs: Scheduling Error correction through HARQ Priority handling across UEs & logical channels Multiplexing/de-multiplexing of RLC radio bearers into/from PhCHs on TrCHs UE enode-b MME Mobile Network Evolution Andreas Mitschele-Thiel 27

27 LTE Key Features (Release 8) Multiple access scheme DL: OFDMA with Cyclic Prefix (CP) UL: Single Carrier FDMA (SC-FDMA) with CP Adaptive modulation and coding DL modulations: QPSK, 16QAM, and 64QAM UL modulations: QPSK and 16QAM (optional for UE) Rel. 6 Turbo code: Coding rate of 1/3, two 8-state constituent encoders, and a contention-free internal interleaver ARQ within RLC sublayer and Hybrid ARQ within MAC sublayer Advanced MIMO spatial multiplexing techniques (2 or 4) x (2 or 4) downlink and uplink supported Multi-layer transmission with up to four streams Multi-user MIMO also supported Implicit support for interference coordination Support for both FDD and TDD Mobile Network Evolution Andreas Mitschele-Thiel 28

28 PARKVALL LAYOUT 3/25/09 2:17 PM Page 48 Multi-antenna Solutions Diversity for improved system performance Spatial-division multiple access ( MU-MIMO ) for improved capacity (more users per cell) Beam-forming for improved coverage (less cells to cover a given area) Multi-layer transmission ( SU-MIMO ) for higher data rates in a given bandwidth as the bea to a limit (precoder) In add forming as tiplexing, non-codeb codebook non-codeb must mak formed ch the possibi ment (UE ted using data, and the overall Figure 5. Multiple-antenna techniques in LTE. Mobile Network Evolution Andreas Mitschele-Thiel 29 INTER-C

29 Interference Coordination Mobile Network Evolution Andreas Mitschele-Thiel 30

30 Downlink Peak Rates Assumptions: 64QAM, code rate =1, 1OFDM symbol for L1/L2, ignores subframes with P-BCH, SCH Mobile Network Evolution Andreas Mitschele-Thiel 31

31 Uplink Peak Rates Assumptions: code rate =1, 2PRBs reserved for PUCCH (1 for 1.4MHz), no SRS, ignores subframes with PRACH, takes into account highest prime-factor restriction Mobile Network Evolution Andreas Mitschele-Thiel 32

32 Scheduling and Resource Allocation (1/2) LTE uses a scheduled, shared channel on both the uplink (UL- SCH) and the downlink (DL-SCH) Normally, there is no concept of an autonomous transmission; all transmissions in both uplink and downlink must be explicitly scheduled LTE allows "semi-persistent" (periodical) allocation of resources, e.g. for VoIP Mobile Network Evolution Andreas Mitschele-Thiel 33

33 Scheduling and Resource Allocation (2/2) Basic unit of allocation is called a Resource Block (RB) 12 subcarriers in frequency (= 180 khz) 1 sub-frame in time (= 1 ms, = 14 OFDM symbols) Multiple resource blocks can be allocated to a user in a given subframe The total number of RBs available depends on the operating bandwidth Mobile Network Evolution Andreas Mitschele-Thiel 34

34 LTE Handover (1/2) LTE uses UE-assisted network controlled handover UE reports measurements; network decides when to handover and to which cell Relies on UE to detect neighbor cells à no need to maintain and broadcast neighbor lists Allows "plug-and-play" capability; saves BCH resources For search and measurement of inter-frequency neighboring cells only carrier frequency need to be indicated X2 interface used for handover preparation and data forwarding Target enb prepares handover by sending required information to UE transparently through source enb as part of the Handover Request Acknowledge message New configuration information needed from system broadcast Accelerates handover as UE does not need to read BCH on target cell Buffered and new data is transferred from source to target enb until path switch à prevents data loss UE uses contention-free random access to accelerate handover Mobile Network Evolution Andreas Mitschele-Thiel 35

35 LTE Handover (2/2) Characteristics No soft handover Handover latency (2. 11.) ~ 55 msec Handover Interruption (7. 11.) ~ 35 msec Synchronization (9.) on RACH Mobile Network Evolution Andreas Mitschele-Thiel 36

36 Tracking Area Tracking Area Identifier (TAI) sent over Broadcast Channel BCH Tracking Areas can be shared by multiple MMEs Mobile Network Evolution Andreas Mitschele-Thiel 37

37 EPS Bearer Service Architecture Mobile Network Evolution Andreas Mitschele-Thiel 38

38 LTE RRC States No RRC connection, no context in enodeb (but EPS bearers are retained) UE controls mobility through cell selection UE-specific paging DRX cycle controlled by upper layers UE acquires system information from BCH UE monitors paging channel to detect incoming calls RRC connection and context in enodeb Network controlled mobility Transfer of unicast and broadcast data to and from UE UE monitors control channels associated with the shared data channels UE provides channel quality and feedback information Connected mode DRX can be configured by enodeb according to UE activity level Mobile Network Evolution Andreas Mitschele-Thiel 39

39 EPS Connection Management States No signaling connection between UE and core network (no S1-U/ S1-MME) No RRC connection (i.e. RRC_IDLE) UE performs cell selection and tracking area updates Signaling connection established between UE and MME, consists of two components RRC connection S1-MME connection UE location is known to accuracy of Cell-ID Mobile Network Evolution Andreas Mitschele-Thiel 40

40 EPS Mobility Management States EMM context holds no valid location or routing information for UE UE is not reachable by MME as UE location is not known UE successfully registers with MME with Attach procedure or Tracking Area Update UE location known within tracking area MME can page to UE UE always has at least one PDN connection Mobile Network Evolution Andreas Mitschele-Thiel 41

41 Broadcast/Multicast Support Mobile Network Evolution Andreas Mitschele-Thiel 42

42 LTE vs. WiMax vs. 3GPP2 WiMAX IMS 3GPP/LTE PCRF IMS 3GPP2/UMB PCRF IMS AAA HA HSS PDN GW AAA HA Authenticator Paging Controller Page buffering Handover Control Radio Resource Management ARQ/MAC/PHY L2 Ciphering Classification/ ROHC CAP-C FA/Router Access Point Local mobility Session setup Bearer mapping Authenticator Paging Controller Session setup MME Handover Control Radio Resource Management ARQ/MAC/PHY E-Node B L2 Ciphering ROHC Bearer mapping Serv GW Local mobility Page buffering Authenticator Paging Controller SRNC Handover Control Radio Resource Management ARQ/MAC/PHY L2 Ciphering ROHC ebts Access GW Local mobility Session setup Bearer mapping IETF-centric architecture IETF-friendly, but still some flavor of UMTS/ GPRS GTP, etc IETF-centric architecture Mobile Network Evolution Andreas Mitschele-Thiel 43

43 Self-Organizing Systems General Definitions Local system control C S 1 C S 2 Local interactions (environment, neighborhood) C S 3 C S 4 C S 5 Simple local behavior C S 6 Mobile Network Evolution Andreas Mitschele-Thiel 44

44 Self-Organizing Systems General Properties Property No central control Emerging structures Description No global control system No global information Subsystems perform completely autonomous Global behavior or functioning of the system emerges in form of observable pattern or structures Resulting complexity High scalability Even if the individual subsystems can be simple as well as their basic rules, the resulting overall system becomes complex and often unpredictable No performance degradation if more subsystems are added to the system System performs as requested regardless of the number of subsystems Mobile Network Evolution Andreas Mitschele-Thiel 45

45 Self-organization in LTE Motivation and drivers Multitude of re-configurable parameters, e.g. transmit powers, control channel powers, handover parameters etc. Huge number of enbs expected with the introduction of Home enb concept Home enb Small Coverage Area Small number of users per cell May be switched off by user Not physically accessible for operators Self-organization (SO) is driven by operators to reduce Operational Expenses (OPEX) Main push of Self-Optimizing Networks (SON) by NGMN alliance ( Mobile Network Evolution Andreas Mitschele-Thiel 46

46 SO Functionality in LTE (1/5) SO functionality includes Self-configuration Self-optimization Self-healing and self-repair Mobile Network Evolution Andreas Mitschele-Thiel 47

47 SO Functionality in LTE (2/5) Self-Configuration Objective is to have plug-n-play enabled nodes Works in pre-operational state, which starts when the node is powered up and has backbone connectivity until the RF transmitter is switched on Automatic installation procedures for newly deployed nodes Automatic creation of the logical associations (interfaces) with the network and establishment of the necessary security contexts Download of configuration files from a configuration server Performing a self-test to determine if everything is working as intended Finally, switching to active service Mobile Network Evolution Andreas Mitschele-Thiel 48

48 SO Functionality in LTE (3/5) Self-optimization Uses UE & enb measurements and performance statistics to auto-tune the network Works in operational state, which starts when the RF interface is switched on Mobile Network Evolution Andreas Mitschele-Thiel 49

49 SO Functionality in LTE (4/5) Self-optimization process includes Neighbor list optimization Reconfigures the neighbor list to have the minimum set of cells necessary for handover Coverage and capacity optimization Maximizes the system capacity while ensuring an appropriate overlapping area between the adjacent cells Mobility robustness optimization Adjusts the handover thresholds to avoid unnecessary handovers Mobility load balancing optimization Automatically handover some UEs at the edge of a congested cell to neighboring less congested cells Energy Saving Autonomously switching off some of the resources or the complete node during the times of low network demand Mobile Network Evolution Andreas Mitschele-Thiel 50

50 SO Functionality in LTE (5/5) Self-healing and self-repair Detects equipment faults, identifies the root causes and takes recovery actions such as Reducing transmit power in case of temperature alarm Fallback to the previous software version Switching to backup units If the fault can not be resolved locally by the above measures, the affected cell and the neighboring cells take cooperative actions to minimize QoS degradation Results in a reduced failure recovery time and a more efficient allocation of maintenance personnel Mobile Network Evolution Andreas Mitschele-Thiel 51

51 SON Architecture (1/4) Based on the location of SO functionality three architectural approaches are possible Centralized Distributed Hybrid Mobile Network Evolution Andreas Mitschele-Thiel 52

52 SON Architecture (2/4) Centralized Architecture SO functionality resides in the OAM system at higher level of network architecture Easy to deploy due to fewer number of installation sites OAM is vendor specific, so no support for multi-vendor optimization Existing interface N (Itf-N) between Network Manager (NM) and Element Manager (EM) or Network Element (NE) needs to be extended Mobile Network Evolution Andreas Mitschele-Thiel 53

53 SON Architecture (3/4) Distributed Architecture SO functionality resides in the enb at the lower level of network architecture Difficult to deploy because of large number of installation sites Difficult to perform complex optimizations involving large number of enbs Better performance for less complex optimizations involving a small number of enbs X2 interface between the enbs needs to be extended Mobile Network Evolution Andreas Mitschele-Thiel 54

54 SON Architecture (4/4) Hybrid Architecture SO functionality resides both at the OAM and enb level Difficult to deploy because of large number of installation sites involved Optimization problems can be categorized depending upon their complexity level and can be performed either locally at enb or at OAM center Requires multiple interfaces extension Mobile Network Evolution Andreas Mitschele-Thiel 55

55 Conclusions LTE is a new air interface with no backward compatibility to WCDMA Combination of OFDM, MIMO and Higher-Order Modulation SAE/EPS realizes a flatter IP-based network architecture with less complexity enodeb, S-GW, P-GW Some procedures/protocols are being reused from UMTS Protocol stack Concept of Logical, Transport and Physical Channels Complexity is significantly reduced Reduced UE state space Most transmission uses shared channels LTE standard (Rel. 8) is stable Enhancements are discussed for Rel. 10 under LTE+ Support of wider spectrum bandwidth (up to 100 MHz) Spatial multiplexing in UL and DL Beamforming and Higher-order MIMO in DL Coordinated multipoint transmission and reception Repeater (L1) and relaying (L3) functionality Mobile Network Evolution Andreas Mitschele-Thiel 56

56 References LTE/SAE A. Toskala et al, UTRAN Long-Term Evolution, Chapter 16 in Holma/ Toskala: WCDMA for UMTS, Wiley 2007 E. Dahlman et al, 3G Evolution, HSPA and LTE for Mobile Broadband, Elsevier Journal, 2007 Special Issue on LTE/ WIMAX, Nachrichtentechnische Zeitung, pp , 1/2007 3rd Generation Partnership Project Long Term Evolution (LTE), official website: Technical Paper, UTRA-UTRAN Long Term Evolution (LTE) and 3GPP System Architecture Evolution (SAE), last update October 2006, available at: ftp://ftp.3gpp.org/inbox/2008_web_files/lta_paper.pdf Standards TS 36.xxx series, RAN Aspects TS , E-UTRAN; Overall description; Stage 2 TR , Feasibility study for evolved Universal Terrestrial Radio Access (UTRA) and Universal Terrestrial Radio Access Network (UTRAN) TR , Physical layer aspect for evolved UTRA TR , 3GPP System Architecture Evolution: Report on Technical Options and Conclusions Self-organizing networks and LTE Self-organizing networks and LTE, NGMN Recommendation on SON and O&M Requirements, Dec. 5, 2008, NGMN, uploads/media/ngmn_recommendation_on_son_and_o_m_requirements.pdf Mobile Network Evolution Andreas Mitschele-Thiel 57

57 Abbreviations CP DFT DRX ECMEPS Cyclic Prefix Discrete Fourier Transformation Discontinuous Reception Connection Management EMM EPS Mobility Management enodeb Evolved NodeB enb Evolved NodeB EPC Evolved Packet Core EPS volved Packet System E-UTRAN Evolved UTRAN FDD Frequency-Division Duplex FDM Frequency-Division Multiplexing FFT Fast Fourier Transformation HD-FDD Half-Duplex FDD HO Handover HOM Higher Order Modulation IFFT Inverse FFT ISI Inter-Symbol Interference LTE Long Term Evolution MIMO Multiple-Input Multiple-Output MME Mobility Management Entity OAM Operation, Administration and Management OFDM Orthogonal Frequency-Division Multiplexing OFDMA Orthogonal Frequency-Division Multiple- Access PDN Packet Data Network P-GW PDN Gateway RA Random Access RB Resource Block RRC Radio Resource Control SAE System Architecture Evolution SCH Shared Channel S-GW Serving Gateway SC-FDMA Single Carrier FDMA TDD Time-Division Duplex TA Timing Advance/ Tracking Area TAI Tracking Area Indicator TAU Tracking Area Update UE User Equipment Mobile Network Evolution Andreas Mitschele-Thiel 58