November 2005 doc.: IEEE 802.22-05/0092r0 Nextwave Broadband WRAN Proposal IEEE P802.22 Wireless RANs Date: 2005-11-07 Authors: Name Company Address Phone email Ramon Khalona Nextwave Broadband 2075 Las Palmas Drive 760-710-2063 email@example.com Carlsbad, CA 92009 U.S.A. Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at firstname.lastname@example.org. > Submission Slide 1 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Abstract Nextwave Broadband intends to submit a WRAN proposal that • Is based on 802.16e OFDMA PHY/MAC (5MHz profile) • Is compliant with the 802.22 FRD document • Addresses coexistence concerns with incumbent services • Incorporates additional features to achieve maximum spectral efficiency and coverage Submission Slide 2 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 802.22 Protocol Reference Model Scope of Standard CS SAP Convergence Sublayer Management Entity (CS) Convergence Sublayer Network Management System MAC SAP MAC MAC Common Part Sublayer Management Entity (MAC CPS) MAC Common Part Sublayer Security Sublayer Security Sublayer PHY SAP PHY Physucak Layer (PHY) Management Entity PHY Layer Data/Control Plane Management Plane Submission Slide 3 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY/MAC Summary • The proposed PHY/MAC = a subset of 802.16 PHY/MAC + enhancements required • The subset of 802.16 PHY/MAC = the subnet that supports the S-OFDMA PHY/MAC, as specified in the following references: • IEEE Std 802.16-2004 • IEEE P802.16-2004/Cor1/D5 • IEEE P802.16e/D12 Submission Slide 4 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY Summary (based on 802.16e OFDMA 5 MHz Profile) Channel Bandwidth 5 MHz Modulation QPSK/16-QAM/64-QAM Coding Conv./Conv. Turbo (r = 1/2, 2/3, 3/4) Duplex Method TDD FFT Size 512 OFDMA Symbol Time 100.8 µs (11.2 µs guard) Frame size(s) 5 ms, 10 ms (49, 98 OFDM symbols, respectively) Diversity Scheme Space Time Coding (STC) + Beamforming (for enhanced coverage and range) Submission Slide 5 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY Summary (Cont.) Time MAC MAC MAC MAC frame ……. Frame n-1 frame n frame n+1 n+2 TDD MAC Frame TTG RTG TDD Frame structure with multiple DL Subframe UL Subframe zones in DL and UL subframes Submission Slide 6 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 OFDMA Frame Structure (with only mandatory Zone) Submission Slide 7 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY Summary (Cont.) DL distributed subcarrier permutation BW = 5 MHz, NFFT = 512 FUSC PUSC Number of Guard subcarriers 86 91 Number of clusters/subchannels -- 30/15 Number of used subcarriers 426 421 Number of data subcarriers 384 360 Number of pilot subcarriers 42 60 Number of subchannels 8 15 Subcarrier Permutation Type 1 Type 1 (802.16-2004) (802.16-2004) Cluster renumbering -- Activated Submission Slide 8 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY Summary (Cont.) UL distributed subcarrier permutation BW = 5 MHz, NFFT = 512 PUSC OPUSC Number of guard subcarriers 103 79 Number of tiles 102 144 Number of used subcarriers 409 433 Number of subchannels 17 24 Tile permutation Type 2 -- Subcarrier permutation Type 3 Type 4 Submission Slide 9 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 PHY Summary (Cont.) DL/UL adjacent subcarrier permutation BW = 5 MHz, NFFT = 512 Subcarriers Number of Guard 79 subcarriers Number of used subcarriers 433 Number of data subcarriers 384 Number of pilot subcarriers 48 (Npilots) Number of data subcarriers Number of bands 12 Number of bins per band 4 Number of subcarriers per 9 bin (8 data +1 pilot) Number of subchannels 8 Subcarrier Permutation None Pilot subcarrier index 9k+3m+1, for k=0,1,……, Npilots and m=[symbol index] mod 3 Submission Slide 10 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Proposed MAC -- Highlights • Designed for Broadband Wireless Access systems; • Topologies: Point-to-point, Point-to-Multipoint • Connection-oriented • Multiple Access: TDM, TDMA, and OFDMA • Duplex modes: TDD • Adaptive burst profiles (Modulation and FEC) on both DL and UL • Upper layer Protocol-independent core (ATM, IP, Ethernet, ……) • Flexible QoS offering (CBR, rt-VBR, nrt-VBR, BE, and ERT-VR) • Strong security support (Privacy Key management, Authorization, data encryption, message authentication) • Robust link layer error control: ARQ and HARQ • Flexible and efficient MAC PDU and MAC management message encodings • Procedures for Shared Frequency Band Usage Combined benefits from ATM + DOCSIS Submission Slide 11 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 IEEE 802.16 MAC – Three SubLayers • Convergence Sublayer (CS) – Mapping upper-layer data into MAC SDUs – upper-layer data traffic classifications, i.e., mapping to proper connection. – Payload header suppression (PHS) • MAC Common Part Sublayer (MAC CPS) – access control – MAC PDU encoding and decoding – Bandwidth management – MAC connection management – QoS provision • Security Sublayer – Functions: • Secures over-the-air transmissions • Protects from theft of service – component protocols: • Message authentication • Authorization policy • Data encryption protocol • A client/server model based Key management protocol (Privacy Key Management, or PKM) Submission Slide 12 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 IEEE 802.16 MAC – Access Control Mechanisms • Contention-Free Access – the major access mechanism; – used for all data transmissions and most of the control message transmissions; – BS centralized scheduling: use the DL-MAPs/and UL-MAPs to specify who, when, how, and how long to access the air link; – TDM, TDMA, and OFDMA. • Contention-based Access – the supporting access mechanism; – only used for some special control signaling, e.g., initial ranging, bandwidth request, etc. – Collision Detection and Resolution • Detection: SS does not get the expected response in a given time • Resolution: a truncated binary exponential backoff window Submission Slide 13 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 802.16 MAC Connections • 802.16MAC is connection-oriented!! • 802.16 MAC Connection – Unidirectional; – 16-bit connection ID (i.e., CID), used in MAC PDU Header; – Unique CID on per direction basis; – Associated with Service flow to define QoS parameters; – Associated with Security association to define the security paramters; – Connection creation and termination are triggered by higher layers; – For each direction, two mandatory management connections: • Basic connection • Primary management connection – For each direction, one optional management connection: • Secondary management connection Submission Slide 14 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 MAC PDU Format msb lsb Generic MAC CRC MAC PDU Header payload (optional) (optional) (6 bytes) Generic MAC Header Format Signalling Header Format (Header Type (HT) = 0) (Header Type (HT) =1) E LEN H E Type (6 bits) S C EKS rs msb H E Type Header Content T C I (2) v T C (3 bits) msb (11) F (3) LEN lsb (8) CID msb (8) Header Content (8) CID msb (8) CID lsb (8) HCS (8) CID lsb (8) HCS (8) Submission Slide 15 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 MAC Management Messages and TLV Encoding Mechanism • MAC management message format: 8 bits mgmt msg MAC mgmt msg payload HD • MAC management messages can only be sent on the management connections; • MAC management messages have two type of information fields: • Fixed field • TLV: a triplet (type, length, value), e.g. in UCD message, the TLV for uplink center frequency is (5, 4, f), where f is the frequency in KHz, 5 is type, and 4 is the length of f in bytes. Submission Slide 16 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 802.16 MAC QoS Supports • Three basic components: – Service flow QoS scheduling – Dynamic service establishment – Two-phase activation model (i.e., admit first, then activate) • QoS related concepts/mechanisms – QoS Parameters – Scheduling Services, i.e., Service Types: • Unsolicited Grant Service (UGS), • Real-time Variable Rate (rt-VR), • Extended Real-time Variable Rate (Ert-VR), • Non-real-time Variable Rate (nrt-VR), and • Best Effort (BE). – 16MAC Connections / 16MAC Service Flows – Traffic classification (in MAC Convergence sublayer) – Bandwidth Allocation – BS scheduler and SS scheduler (not standardized, i.e., out of scope of 802.16 standard) Submission Slide 17 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 802.16 MAC QoS Parameters • Minimum Reserved Traffic Rate • Minimum Tolerable Traffic Rate • Maximum Sustained Traffic Rate • Maximum Traffic Burst • Max Latency • Tolerated Jitter • Traffic Priority • Request/Transmission Policy Submission Slide 18 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Bandwidth Allocation • Bandwidth is allocated to SS/SS by the BS scheduler in the form of scheduled transmissions; • Each scheduled transmission is defined by: – Who to Tx – When to Tx – How long to Tx – How to Tx • Service flow QoS based scheduling/bandwidth allocation; • DL and UL bandwidth partition – FDD: determined by regulatory rules and network planning; – TDD: adaptive DL/UL bandwidth partition; • Different schemes to collect DL and UL bandwidth requirements. Submission Slide 19 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 UL Bandwidth Request • UL BW requests per connection tell the BS the SS/MS’s traffic composition; • Two types of BW requests: – Incremental: add the new req. to the perception of the BW needs; – Aggregate: replace its perception of the BW needs with the new requested quantity. • Self correcting for BW request, i.e., – No acknowledgement for BW req. – All BW req. errors are handled by periodically using “aggregate” BW req. • UL Bandwidth Request Transmission: – Contention-free – Contention-based Submission Slide 20 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 UL Bandwidth Grant • BW grants are per Subscriber Station (GPSS): – Allows real-time reaction to QoS need, i.e., SS may re-distribute bandwidth among its connections, maintaining QoS and service- level agreements – Lower overhead, i.e., less UL-MAP IE entries compare to grant per connection; – off- loading base station’s work – requires intelligent subscriber station, i.e, SS/MS scheduler Submission Slide 21 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 RF Link Management • Ranging – Ranging is a process of acquiring the correct timing offset, and PHY parameters, such as, Tx power level, frequency offset, etc. so that the SS can communicate with the BS correctly; – BS performs measurements and feedback; – SS performs necessary adjustments; – Two types of Ranging for Fixed Applications: • Initial ranging: for a new SS to join the system • Periodic ranging (also called maintenance ranging): dynamically maintain a good RF link; • DL burst profile management – SS monitors the DL RF link quality; – SS reports DL link quality measurements to the BS; – Either BS or SS can initiate the process of changing DL burst profile (modulation, coding, etc.) for the SS. Submission Slide 22 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 MAC ARQ • MAC ARQ, i.e., part of the MAC layer; • ARQ can be enabled / disabled on a per-connection basis by using DSA/DSC messages; • A connection cannot have a mixture of ARQ and non- ARQ traffic; • CRC-32 shall be used in all MAC PDUs on an ARQ- enabled connection. Submission Slide 23 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 IEEE 802.16 Hybrid ARQ (HARQ) • HARQ can be enabled and disabled on per connection basis • Two basic HARQ variants: – CC: Chase Combining • One version of the encoded HARQ packet • No SPID (subpacket ID) – IR: Incremental redundancy • Several versions of the encoded HARQ subpackets • Use SPID to identify each subpacket • Per allocation (burst) usages – Cannot mix HARQ and non-HARQ traffic on the same burst, allocated by one MAP-IE – Can mix HARQ bursts and non-HARQ bursts in the same MAC frame Submission Slide 24 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Coexistence Procedures for Shared Frequency Band Usage • Purposes of the procedures: – Reduction of interference to/from other systems or services; and/or – Facilitate coexistence of systems; and/or – Compliant with the regulatory requirements. • The defined Procedures include: – Testing channels for other users including specific spectrum users – Discontinuing operations after detecting other users including specific spectrum users – Detecting other users including specific spectrum users – Scheduling for channel testing – Requesting and reporting of measurements – Selecting and advertising a new channel Submission Slide 25 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Performance Summary • Spectral Efficiency: up to 3 bps/Hz Achieved through the use of spatial and time diversity techniques (MIMO/H-ARQ) • Data rates: 15 Mbps (peak) in both directions (5 MHz) Achieved through the use of high order modulation in moderate-to- good channel conditions (w. diversity). Key goal of proposal will be to achieve graceful degradation towards cell edge • Range Extension through Beamforming and Repeaters Typical cell radii (in the order of < 10 Km) can be extended through the use of beamforming techniques and/or distributed repeater architecture Submission Slide 26 Ramon Khalona/Nextwave Broadband, Inc. November 2005 doc.: IEEE 802.22-05/0092r0 Performance Improvement with Diversity Techniques (802.16d/3GPP frequency selective channel model) Percentage of cell area with data rates less than Maximum throughput of Space-Time Coding/Spatial 1.5 Mbps Multiplexing techniques with precoding (A. Ghosh et al., “Broadband Wireless Access with WiMax/8O2.16: Current Performance Benchmarks and Future Potential,” IEEE Communications Magazine, February 2005, pp. 129-136) Submission Slide 27 Ramon Khalona/Nextwave Broadband, Inc.
Pages to are hidden for
"November 2005 doc IEEE 802 22 05 0092r0 Nextwave Broadband WRAN Proposal"Please download to view full document