ComNets Mobile Broadband Internet Access What Comes Next? Bernhard Walke ComNets, RWTH Aachen University Work supported by German.

ComNets Mobile Broadband Internet Access What Comes Next? Bernhard Walke ComNets, RWTH Aachen UniversityWork supported by German Ministry of Research & Education and EU-IST WINNER project 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 5.Conclusions Download URL for papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Fixed Walk Vehicle Bluetooth XDSL, CATV, Fiber High Speed Vehicular Rural Vehicular Urban Pedestrian Nomadic Fixed urban Indoor Personal Area DECT PHS GSM GPRS CDMA-1x EDGE UMTS (W-CDMA) CDMA EV DO Rev. O/A CDMA EV DO Rev. B HSDPA WLAN (IEEE x) HSPA LTE (SAE) UMB IEEE m UMB- Evolution User data rate Mobility / Range Mbps LTE- Advanced EDGE-11 GERAN Evolution IEEE e WiMAX IEEE d 1) non-official name; 2) System Architecture Evolution 1) 2) 1) Source: Takagi/Walke: Spectrum Requirements Planning in Wireless Communications, J. Wiley 2008 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 5.Conclusions Download URL for papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, IMT-Advanced process of ITU-R Source: ITU-R #18#19 #20 #21 #22 #23 #24 #25#26 #27 #28 #29 #30 #31 #32 #33 #34 Principles Resolution Development of a Circular Letter & Evaluation Criteria Proposals First Evaluation Consensus Building (inside & outside of ITU) IMT.GCS Update of IMT.GCS Issue of invitation To IMT-Advanced First release Continued evaluation of potential additional candidate technologies for IMT-Advanced Key meetings for Circular Letter contributions Key meetings for RTT proposal contributions WINNER 3GPP IEEE Tight ITU-R time plan in conjunction with time schedule of regional and global standardisation bodies Strong global competition expected IMT.RADIO WINNER+ GCS: Generic Core Specs RTT: Radio Transmiss. Technology WINNER = Wireless World Initiative New Radio 2008 ComNetsComNets Neubau Einweihung, Nov. 21, ITU-R Systems Generation 3GPP 3GPP2 IEEE 802 1) 2) 2003/42005/62007/82009/102011/12 IMT-2000 IMT-Advanced 3G 4G WCDMA UMTS/FDD/TDD WCDMA HSDPA Rel. 5 OFDM/SC-FDMA LTE Rel. 8 cdma xEV-DO OFDM/SC-FDMA LTE-Advanced cdma 2000 EV-DO Rev A cdma 2000 EV-DO Rev B UMB/OFDM UMB Evolution OFDM.16 Fixed (2004) OFDMA.16e Mobile WiMAX WAVE I OFDMA WAVE II Rel. 1.0 OFDMA.16e,j; WAVE Rel. 1.x WCDMA HSPA EV Rel. 6/7 OFDMA.16m; WAVE Rel. 2.0 B3G 1) Overlay to GSM; 2) Overlay to CDMA-1x; 3) expected, but not specified, so far; 4) non-official name; (currently in question) 3) 4) 3) Source: Takagi/Walke: Spectrum Requirements Planning in Wireless Communications, J. Wiley 2008 Roadmap of IMTAdvanced Candidate Systems 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Bps/Hz Spectral Efficiency Mbps Peak Data Rate 0.01 GPRS CDMA EDGE CDMA xEVDO Rev.0 UMTS 1xEVDO Rev.A HSDPA 1xEVDO Rev.B HSUPA WiMAX UMB LTE WiMAX IMT-Advanced IMT-2000 Narrowband Data Middleband Data Broadband Data 2G2.5G3G B3G4G Multiple Antenna Contribution Source: Takagi/Walke: Spectrum Requirements Planning in Wireless Communications, J. Wiley 2008 Spectral Efficiency and Peak Data Rate Evolution in Time 2008 ComNetsComNets Neubau Einweihung, Nov. 21, IMT-Advanced Candidate Systems 3GPP-LTE II / LTE + / LTE-Advanced Ultra Mobile Broadband (UMB) 3GPP2 / QUALCOMM (possibly: no system proposal) SUPER 3G (Japan) 3G+ (Korea) TD-SCDMA Ev. (China) IEEE m (based on e, j) IEEE n ( ad-hoc component for cellular ) WINNER+ (Europe) LTE-Advanced 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 5.Conclusions Download URL for papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, WRC-07 identified new spectrum for IMT Changed IMT-2000 spectrum identifications to IMT Work has started on spectrum utilization Previous IMT-2000 Identified at WRC07 Bands identified by WRC-07 for IMT Systems Simplified diagram! 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Spectrum Requirements Calculation ITU-R M.1036 Spectrum Estimation Methodology for IMT- Advanced Systems: 450 MHz needed. 464 MHz identified by WRC-07 in Nov April 2008 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 1.MAC protocol proposed by ComNets 2.Layer-2 Relays for IMT-Advanced Systems proposed by ComNets 5.Conclusions Download of papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Main Characteristics of IMT-Advanced Systems Orthogonal Frequency Division Multiplex (OFDM) to share the medium Orthogonal Frequency Division Multiple Access (OFDMA) for medium access Periodic MAC frame (known from RACE Project MBS and BMBF Project ATMmobil) Antenna Arrays at Base and Mobile Terminal Interference Coordination / Cancellation / Avoidance Relay Enhanced Cells (known from Project IST-WINNER Simplified Network Operation (Radio Access Router enhanced by mobility support) 2008 ComNetsComNets Neubau Einweihung, Nov. 21, OFDMA Subchannels and Resource Elements Transmission capacity as a Matrix Allocation of orthogonal Resource Elements possible Multi dimensional REs Time, Frequency Code, Space Constraints Parallel transmission/ reception on different subchannels not possible Medium access control (MAC) is based on REs optimal size of REs? 2-dimensional resource grid (time/frequency) 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 1.MAC protocol proposed by ComNets 2.Layer-2 Relays for IMT-Advanced Systems proposed by ComNets 5.Conclusions Download of papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Medium Access Control (MAC) by central Base Station MAC concept Centralized resource request/grant scheme Used in IEEE (2004), proposed for IEEE n Frame structure Beacon (Broadcast) Announcement of Resource Elements Random Access Channel Association, resource requests, ACKs Resource Element Transmission of data burst (PDU train) 2008 ComNetsComNets Neubau Einweihung, Nov. 21, 2008 BMBF/ATMmobil MAC-Protokoll wurde Std. ETSI/BRAN HiperLAN2 DSA++ Protokoll: ComNets Patent Walke/Petras 1995 Dynamische zentrale Kapazittszuweisung auf Slot Basis Rahmenbasiert, variable MAC Rahmenlnge Untersttzung unterschiedlicher Dienstgteanforderungen 2008 ComNetsComNets Neubau Einweihung, Nov. 21, 2008 WiMAX MAC Protocol is identical to ETSI/BRAN/HiperMAN, that is derived from HiperLAN2 Periodic MAC frame, starting with Frame Control Header (FCH) Contention phase (initial access, bandwidth request) Uplink (UL) and downlink (DL) phase Phases consist of burst Maps describing frame schedule Downlink: Which station should receive the burst Uplink: Which station is allowed to send in the burst 2008 ComNetsComNets Neubau Einweihung, Nov. 21, time time slot (1 OFDMA symbol) 1200 subchannels 100 chunks signaling overhead scheduled resources TTI = 500 s (7 x 66.6 s + 6 x s + 1 x s ) 1/6 for pilots 66.6 s Cyclic prefix 1 chunk = 12x6=72 sub-symbols time f LTE TTI Frame (MAC Frame) Further developed DSA++ protocol for OFDMA systems TTI = transmission time interval 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Link Adaptation: LTE DL PhyModes (MCS) QAM256 is not in the standard proposals High spectral efficiency of LTE (4 to 6 bit/s/Hz) under hight SINR 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Contents 1.Introduction: What Systems are present / expected? 2.Standardization of IMT-Advanced / 4G-Systems 3.Frequency Spectrum for IMT-Advanced 4.Main Characteristics of IMT-Advanced Systems 1.MAC protocol proposed by ComNets 2.Layer-2 Relays for IMT-Advanced Systems proposed by ComNets 5.Conclusions Download of papers referenced: 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Cell Capacity vs. Distance is Inverse to the Needs Range of broadband base station is limited high attenuation at high frequencies limited transmit power (EIRP limits) Unfavourable radio propagation conditions, e.g., in urban area # of BS required increases with increased carrier frequency to cover given area High Capital and Operations Expenses High cost/bit transmitted High data rate available close to AP only Under constant user density: oNumber of users proportional to distance d from Base Station oCell capacity per area element differs from what is requested by users oTechnology trend worsens situation Sources: B. Walke, H. Wijaya, D.C. Schultz: Relays in Infrastructure-based Future Mobile Radio Networks, VTC 2006 Spring, Melbourne, Australia T. Irnich, D.C. Schultz, R. Pabst, P. Wienert: Capacity of a Relaying Infrastructure for Broadband Radio Coverage of Urban Areas. Proc. 10th WWRF meeting, New York, 10/2003 Users at distance d 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Relay Enhanced Cell (REC) A cell complemented by Fixed Relay Nodes (FRN) Layer-2 Relays in REC Save cost for wired backbone access Full flexibility of relays positioning enlarge the coverage area Increase capacity at cell border balance capacity/area element reduce transmission power / co- channel interference Relays Support fast network rollout Allow outdoor to indoor service Serve shadowed areas in REC Exploit macro diversity will be mass products Capacity Optimisation Area Optimisation Coverage of shadowed areas One-hop Cell AP FRN Source: B. Walke, H. Wijaya, D. Schultz: Relays in Infrastructure-based Future Mobile Radio Networks. VTC 2006 Spring, Melbourne, Australia 2008 ComNetsComNets Neubau Einweihung, Nov. 21, 2008 Relaying in Time Domain Subframe Concept ComNets Patent Walke/Esseling 2000 Subframe Concept: Enables multi-hop operation for relaying in time domain Multiple FRSs are served by one BS FRSs MAC frame are embedded to BSs MAC frame Duration of FRS MAC frame may depend on traffic load 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Layer-2 Relays in IMT-Advanced Layer 2 (Decode-and-Forward) relays are part of an IMT-Advanced systems, as specified by WINNER II Relay enhanced RRM technologies Relays and multi-antenna technologies Different modulation and coding schemes on relay and access link Plug and play network roll out Tree topology, self-configuring nodes Self healing: On demand re-organisation of the network topology On demand meshing within REC Cooperative relaying as an option for capacity improvement Cooperative Relaying 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Inter/intra Cell Resource Management Resource Separation in Frequency Domain(OFDMA) full bandwidth Resources used in one cell one TTI frame (500 us) Base station Relay 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Mobile Broadband Networks will base on Relay Enhanced Cells Conclusion IMT-Advanced spectrum allocated IMT-Advanced Systems OFDMA: resources in time, frequency and space Coordination needed: intra- and inter-cell Standardization in progress Relay enhanced cells are part of it (IEEE802.16j) extend cell range increase throughput at cell edge Reduce impact of signal shadowing Relays save Telco infrastructure cost 2008 ComNetsComNets Neubau Einweihung, Nov. 21, Thank you!