802.16 Architecture - cgu.edu.tw

802.16 Architecture - cgu.edu.tw

IEEE 802.16 MAC and PHY Specifications for Broadband WMAN Tel : (03) 211-8800 ext. 5990 E-mail: [email protected] CGU NDSL WMAN - 1 Resources Part Source : Roger B. Marks, National Institute of Standards and Technology Boulder, Colorado, USA Chair, IEEE 802.16 Working Group http://WirelessMAN.org CGU NDSL WMAN - 2

Broadband Access to Buildings Metro Ethernet 802.11 Wireless Ethernet First/Last mile access Fast local connection to network Target Applications (similar as DSL and CableModem) Data Voice Video distribution

Real-time videoconferencing High-capacity cable/fiber to every user is expensive Network operators demand it Business and residential customers demand it CGU NDSL WMAN - 3 Wireless Metropolitan Area Network CGU NDSL WMAN - 4 Application CGU NDSL WMAN - 5

Features (1/2) Broad bandwidth Up to 134.4 Mbit/s in 28 MHz channel (in 10-66 GHz) GHz (UWB ?) 32Mb/s - 134.4Mb/s 20/25/28MHz per channel line of sight is required and multipath is negligible (short waveleng th). Supports multiple services simultaneously with full QoS Efficiently transport IPv4, IPv6, ATM, Ethernet, etc. Wireless transportation system. system Bandwidth on demand (frame by frame)

Similar to HIPERLAN Type II (frame-based protocol) Centralized control MAC designed for efficient used of spectrum Comprehensive, modern, and extensible security ()tensio ns to mobility are coming next. CGU NDSL WMAN - 6 Features (2/2) Supports multiple frequency allocations from 2-66 GHz in 802.16 (10-66GHz) and 802.16a (2-11GHz) Single carrier (SC) for line-of-sight situations OFDM and OFDMA for non-line-of-sight situations OFDMA : orthogonal frequency division multiple access Access schemes:

TDD (time division duplex) and FDD (frequency division duplex) Link adaptation: Adaptive modulation and coding Point-to-multipoint (star) topology and mesh network extension Support for adaptive antennas and space-time coding (in 802.16a) Extensions to mobility. mobility (IEEE 802.16e started from Jan. 2003) ()tensions to mobility are coming next. CGU NDSL WMAN - 7 IEEE 802.16 Standard and amendments Fixed Broadband Wireless Access (FBWA) Systems Air Interface (MAC and PHY) Band 10-66GHz (ranges 1/2/3 : 10-23.5GHz/23.5-43.5GHz/43.5-66GHz) 25/28M

Hz per channel line-of-sight (LOS) requirement One PHY WirelessMAN-SC (Single Carrier) Point-to-Multipoint Topology (Star) TDD/FDD with burst profile option (depending on SNR) Completed in October 2001 Published in April 2002 Followup interoperability projects

802.16c (Profiles): published in Jan 2003 802.16.1 (PICS): in ballot; completion expected Mar 2003 PICS : Protocol Implementation Conformance Statement 802.16.2 (10-66GHz Coexistence of FBWA Systems) Focus on 23.5 to 43.5 GHz (local multipoint distribution service (LMDS), millimet er wave, etc.,) WiMAX submitted proposal in Jan 2003 CGU NDSL WMAN - 8 IEEE 802.16a Standard Medium Access Control Modifications and Additional Physical Layer Specifi cations for 211 GHz Band 2-11GHz Non-line-of-sight (NLOS) requirement and Multi-path issue

Near-LOS License-exempt band 5-6 GHz (802.11a and HIPERLAN II) Three PHYs WirelessMAN-SC2 (single carrier) WirelessMAN-OFDM (multiple carriers with 256-point transform) is mandatory for license exempt bands WirelessMAN-OFDMA (multiple carriers with 2048-point transform) Multiple access is provided by addressing a subset of the multiple carriers to in dividual receivers. Advanced Antenna Systems (AAS) is optional Add mesh network topology (MAC) provide automatic repeat request (ARQ) retransmission (MAC) Completed in November 2002 and Approved April 2003 IEEE 802.16e (mobility) first meeting in 2004 D5

IEEE 802.16.2a (coexistence including 2-11GHz) CGU NDSL WMAN - 9 IEEE 802.16a Standard license-exempt bands below 11 GHz The PHY and MAC introduce mechanisms such as dynamic frequency selection (DFS) to detect and avoid interference. CGU NDSL WMAN - 10 IEEE 802.16-2004 Standard IEEE Std 802.16-2004 Air Interface for Fixed Broadband Wireless Access Syst ems - IEEE 802.16d Approved 24 June 2004

This standard revises and consolidates IEEE Std 802.16-200 1, IEEE Std 802.16a-2003, and IEEE Std 802.16c-2002. IEEE Std 802.16f MIB (Management Information Base) IEEE Std 802.16g System/resource/handover Management Interoperability CGU NDSL WMAN - 11 IEEE 802.16e Enhance IEEE 802.16-2004 PHY is similar to 802.16-2004 Focus on 2-6GHz

1.75-20MHZ per channel Enhance OFDMA PHY Supports 2048-point, 1024-point, 512-point and 128-point FFT Data rate 10Mhz/channel, OFDM-64QAM provides 30Mbps Max. moving speed : 120km/h Range : several Kms Chip appears in 2006 vs. IEEE 802.20

Below 3.5GHz Max. moving speed : 250Km/h (high-speed train) vs. 3G CGU NDSL WMAN - 12 802.16 Air Interface CGU NDSL WMAN - 13 WiMAX Evolution Source : Siemens, 2004 CGU NDSL WMAN - 14 WiMAX Forum WiMAX (Worldwide Interoperability for Microwave

Access) Like WECA in IEEE 802.11 WLAN Mission: To promote deployment of BWA by using a global standard and certifying interoperability of products and technologies. Principles: Support IEEE 802.16x 2-66 GHz (16a : 2-11 GHz and 16 : 10-66GHz)

Propose access profiles for the IEEE 802.16 standard Guarantee known interoperability level Open for everyone to participate Developing & submitting baseline test specs CGU NDSL WMAN - 15 Point-to-Multipoint configuration Two components Subscriber Stations (SSs) SS typically serves a building (business or residence) Base Station (BS) connected to public networks BS serves Subscriber Stations provide SS with first-mile(or last mile) access to public networks

Compared to a Wireless LAN Multimedia QoS not only contention-based connection-oriented Many more users Much higher data rates Much longer distances CGU NDSL WMAN - 16

Mesh Topology (defined in 802.16a) Dynamic topology Self-organizing network More complicated CGU NDSL WMAN - 17 IEEE 802.16 vs. ETSI Frequent communications between 802.16 WG and ETSI (European Telecom Standards Institute) ETSI HIPERACCESS Above 11 GHz (outdoor , 11- 40GHz, 5Km, 25Mb/s) ETSI began first, but IEEE finished first 802.16 has encouraged harmonization

ETSI HIPERMAN Below 11 GHz (outdoor) IEEE began first Healthy cooperation Harmonized with 802.16a OFDM ETSI HIPERLAN HIPERMAN ETSI HIPERLINK

5GHz (indoor/outdoor) 6-54Mb/s 17GHz (150m, point-2-point) 155Mb/s (OC3) Irrelative with 802.16 Irrelative with 802.16 CGU NDSL WMAN - 18 IEEE 802.16 Working Group

Below 11GHz MAC 802.16e Mobility Enhancem ents (scability) PHY SOFDMA 10-66 GHz

802.16-2001 TDMA TDD/FDD 802.16a SCa OFDM-256 OFDM-2048 802.16c System Profile 802.16-2004 (802.16REVd) 802.16f: MIB for 802.16-2004

NetMAN 802.16g: Mgmt. Plane Procedures and Services Conf.-01: PICS ProFo. Conformance Conf.-02: Test Suites Conf.-03: Radio Tests Coexistence 802.16.2-2001 Coexistence 802.16.2 REVa

CGU NDSL WMAN - 19 MAC Overview Connection-oriented Supports difficult user environments High bandwidth, hundreds of users per channel For variable Continuous and burst traffic Very efficient use of spectrum

Protocol-Independent core (ATM, IP, Ethernet, ) Balances between stability of contentionless and efficien cy of contention-based operation Negotiate the burst profile between sender and receiver Flexible QoS offerings CBR, rt-VBR, nrt-VBR, BE, with granularity within classes Supports multiple 802.16 PHYs CGU NDSL WMAN - 20 Protocol Stack ATM packet SSCS

Packet convergence Sublayer (PCS) (security sublayer 16-2004) CGU NDSL WMAN - 21 802.16 MAC Reference Model Convergence Sublayer (CS) Mapping external network data into MAC SDU Classifying external network SDU Associating to MAC connection ID Payload header suppression Common Part Sublayer (CPS)

Core MAC functionality System access Bandwidth allocation Connection establishment Connection maintenance Security Sublayer Authentication Security key exchange Encryption

PHY Multiple sections Each appropriate to a frequency range and application CGU NDSL WMAN - 22 Service Specific Convergence Sublayer (SSCS) The CS performs the following functions: accepting higher-layer PDUs from the higher layer performing classification of higher-layer PDUs processing (if required) the higher-layer PDUs based on the classification delivering CS PDUs to the appropriate MAC SAP receiving CS PDUs from the peer entity Currently, two CS specifications are provided Asyncronous Transfer Mode (ATM) CS

Packet CS Such as IP, PPP, Ethernet, etc., Other CSs may be specified in the future. CGU NDSL WMAN - 23 Packet Convergence Sublayer (PCS) Packet convergence sublayer (PCS) The packet CS resides on top of the Common Part Sublayer (CPS) The PCS performs the following functions, utilizing th e services of the MAC sublayer: a) Classification of the higher-layer protocol PDU into the app ropriate connection

b) Suppression of payload header information (optional) c) Delivery of the resulting CS PDU to the MAC SAP associat ed with the service flow for transport to the peer MAC SAP d) Receipt of the CS PDU from the peer MAC SAP e) Rebuilding of any suppressed payload header information ( optional) CGU NDSL WMAN - 24 Packet Process Procedure A classifier is a set of matching criteria applied to each packet It consists of some protocol-specific packet matching criteria (destin ation IP address, for example), a classifier priority, and a reference t o a CID. The service flow characteristics of the connection provide the Q

oS for that packet Several classifiers may each refer to the same service flow. Downlink classifiers are applied by the BS to packets it is transm itting and uplink classifiers are applied at the SS. a packet fails to match the set of defined classifiers. CS/SS shall discard the packet. Packet Classifier(s) CID CID/SFID PHSI mapper

SFID SFID/QoS mapper PHS ruler SFID/PHSI (sender) CID/PHSI (receiver) QoS Parameters (used in scheduler) CGU NDSL WMAN - 25

Common Part Sublayer (CPS) The MAC CPS provides the core MAC functionality of system access, bandwidth allocation, connection esta blishment, and connection maintenance: a) System Access b) Bandwidth Request/Allocation c) Connection Establishment/Maintenance e) Quality of Service (QoS) CGU NDSL WMAN - 26 Security Sublayer The security sublayer providing

a) authentication, b) secure key exchange, and c) Encryption Two component protocols Encapsulation protocol Cryptographic suites Key management protocol (PKM) Create and exchange traffic encryption key (TEK) CGU NDSL WMAN - 27 Classifications

A MAC SDU is mapped onto a particular connection for transmission between MAC peers According to protocol-specific packet matching criteria (e.g. destination IP address), classifier priority and a reference to a CID (connection ID) creates an association with the service flow ID (SFID) 32 bits service flow ID (SFID) Conn. ID (CID) PHS PHS CID+PHSI

CGU NDSL WMAN - 28 Classifications PHS service flow ID (SFID) Conn. ID (CID) CGU NDSL WMAN - 29 Classifications A MAC SDU is mapped onto a particular connection for transmission between MAC peers

according to protocol-specific packet matching criteria (e.g. IP address), classifier priority and a reference to a CID. SS and BS use multiple classifiers. classifiers Each classifier contains a priority field which determines the search order for the classifier. Searching algorithm is similar to policy-based search algorithm (e.g. Firewall) Firewall Classifiers can be added by dynamic signaling. Simple Network Management Protocol (SNMP)(SNMP) based operations can only view Classifiers, no add/delete CGU NDSL WMAN - 30

Payload Header Suppression (PHS) For some payload protocols, each payload consists of an 8-bit payload header suppression index (PHSI) followed by the actual payload. A value of zero in the PHSI indicates no payload header suppression has been applied to the PDU. Otherwise, the value in the index identifies the rules for suppression. 8-bit MAC header PHSI refer the payload header suppression field (PHSF) CGU NDSL WMAN - 31

Payload Header Suppression (PHS) If PHS is enabled at MAC connection, each MAC SDU is prefixed with a PHSI, which references the Payload Header Suppression Field (PHSF). The classifier uniquely maps packets to its associated PHS Rule. The receiving entity uses the CID and the PHSI to restore the PHSF. (CID+PHSI PHSF/PHSM/PHSS) When a classifier is deleted, any associated PHS rule shall also be deleted. CGU NDSL WMAN - 32 PHS

operation CGU NDSL WMAN - 33 Payload Header Suppression (PHS) Rule Payload header suppression valid (PHSV) : option to verify or not verify the payload header before suppressing it Payload header suppression mask (PHSM) option to allow sel ect bytes not to be suppressed. Such as IP sequence numbers should not be supressed

Payload header suppression size (PHSS) Payload header suppression field (PHSF) Payload header suppression index (PHSI) Service flow ID (SFID). (SFID) PHS rules are indexed by the combination of (SFID, PHSI) Preconfigured header format or higher-level signaling protocols are outside the scope of specification CGU NDSL WMAN - 34 PHS with masking A,C,E are compressed Only sends B and E

CGU NDSL WMAN - 35 PHS Rules The BS shall define the PHSI when the PHS Rule is c reated The SS or BS may define the PHSS and PHSF. To change the value of a PHSF on a service flow, a n ew PHS rule shall be defined It is possible to partially specify a PHS rule (in particul ar the size of the rule) at the time a service flow is cre ated Values of some fields [for example: IP addresses, User Data gram Protocol (UDP) port numbers, etc.] may be unknown a nd would be provided in a subsequent DSC as part of the act ivation of the service flow

using the Set PHS Rule DSC Action CGU NDSL WMAN - 36 PHS Signaling PHS requires the creation of the following three obje cts: a) Dynamic Service Flow (DSA/DSC/DSD) Addition/Change/Deletion b) Classifier c) PHS rule (PHSI is assigned by BS since BS has many SSs) CGU NDSL WMAN - 37

Connection ID (CID) A unidirectional mapping between BS and SS MAC p eers for the purpose of transporting a service flows tr affic Connections are identified by a connection identifier ( CID) All traffic is carried on a connection, even for service f lows that implement connectionless protocols CID maps to a service flow identifier (SFID), which defines the Quality of Service (QoS) parameters of the service flow associated with that connection. Security associations (SAs) also exist between keyi ng material and CIDs. CGU NDSL WMAN - 38

Connection ID (CID) Connections are identified by a 16-bit CID At SS initialization, three management connections in each direction (uplink and downlink) shall be establish ed between the SS and the BS. The Basic Connection is used for exchanging short, time-ur gent management messages. such as DBPC-REQ/RSP : Downlink Burst Profile Change Req /Rsp, RNG-REQ/RSP : Ranging Req/Rsp The Primary Management Connection is used for exchang ing longer, more delay tolerant MAC management messages . Such as DSA/DSC/DSD_REQ/RSP/ACK, REG_REQ/RSP The Secondary Management Connection is used for transf

erring delay tolerant, tolerant standards based DHCP, TFTP, SNMP, etc., management messages. CGU NDSL WMAN - 39 Connection ID (CID) BS returns Basic CID and Primary CID to SS via RNG-RSP messages. BS returns Secondary CID to SS via REG-RSP messages (optional). The same CID value is assigned to both members (uplink and downlink) of each connection pair. Many higher-layer sessions may operate over the same wireless CID. CGU NDSL WMAN - 40

Connection ID (CID) CGU NDSL WMAN - 41 MAC Protocol CGU NDSL WMAN - 42 MAC overview Wireless link operates with sectorized antenna is capable of handling multiple independent sectors simultaneously (chan nel reuse) Subscriber stations share the uplink to the BS on a demand basis. Four different types of uplink scheduling mechanisms

unsolicited bandwidth grants (CBR) Polling (unicast polling) guarantees applications receive service on a deterministic basis (delay t olerant services) contention procedures contention may be used to avoid individual polling of SSs that have bee n inactive for a long period (multicast/broadcast polling) Bandwidth stealing a portion of the bandwidth allocated in response to a bandwidth request for a connection to send another bandwidth request rather than sending data Piggyback (via grant subheader ; w/o scheduling) CGU NDSL WMAN - 43

MAC overview Service flows provide a mechanism for uplink and do wnlink QoS management. In particular, they are integral to the bandwidth allocation pro cess. An SS requests uplink bandwidth on a per connection basis ( implicitly identifying the service flow). Bandwidth is granted by the BS to an SS as an aggregate of grants in response to per connection requests from the SS. CGU NDSL WMAN - 44 OFDM Frame Structure with TDD Time Frame n-1

Frame n Frame n+1 DL Subframe Premble FCH DLFP DL Burst#1 UL Subframe

DL Burst#2 MPDU ... T DL T Burst#3 G UL-Trans. from SS #1

R UL-Trans. T from SS #2 G RNG-REQ BW-REQ Slots Slots Preamble UL burst MPDU Pad DL-MAP, UL-MAP, MPDUs DCD, UCD

DLFP: Downlink Frame Prefix FCH: Frame Control Header TTG: Transmission Transition Gap RTG: Receive Transition Gap MPDU MAC header ... Payload MPDU Pad

CRC-32 CGU NDSL WMAN - 45 OFDM frame structure with FDD (download) CGU NDSL WMAN - 46 OFDM frame structure with FDD (upload) CGU NDSL WMAN - 47 MPDU format CRC capability is mandatory for SCa, OFDM and OFDMA PHY layers

6 octets HT=0 Generic MAC PDU formats HT=1 Bandwidth Request Connections are identified by a 16-bit CID. CGU NDSL WMAN - 48

Generic MAC Header CGU NDSL WMAN - 49 Type encodings (in Generic Header) Type bits Bit mapping CGU NDSL WMAN - 50 Bandwidth Request MAC Header 000 : incremental (BS adds the needed quantity of CID) 001 : aggregate (BS replaces the needed quantity of CID) CGU NDSL WMAN - 51

Bandwidth Request The Bandwidth Request shall have the following prop erties: a) length of the header = 6 bytes b) EC field = 0 (indicating no encryption) c) CID (Basic) indicates the connection for which uplink bandwi dth is requested. d) Bandwidth Request (BR) field indicates the number of bytes requested. e) The allowed types for bandwidth requests are 000 for incre mental and 001 for aggregate. CGU NDSL WMAN - 52 Subheader Types

Five types of subheaders Mesh Grant Management Fragmentation Packing FAST-FEEDBACK_Allocation (MIMO) The subheaders are inserted in MAC PDUs immediately foll owing the Generic MAC header Sequence

Grant -> Fragmentation Mesh -> others others -> Fast-Feedback_allocation The Packing and Fragmentation subheaders are mutually exclusive and shall not both be present within the same MAC PDU The only per-SDU subheader is the Packing subheader CGU NDSL WMAN - 53 MPDU Transmission long Ethernet packet Short ATM cells CGU NDSL WMAN - 54 Concatenation

Mandatory capability Multiple MAC PDUs may be concatenated into a sing le transmission in either the uplink or downlink direct ions. each MAC PDU is identified by a unique CID CGU NDSL WMAN - 55 Packing The capability of unpacking is mandatory. mandatory pack multiple MAC SDUs into a single MAC PDU. PDU Differs from concatenation Packing makes use of the connection attribute indicati

ng whether the connection carries fixed-length or va riable-length packets. The construction of PDUs varies for ARQ and non-AR Q connections with respect to packing and fragmentat ion syntax CGU NDSL WMAN - 56 Packing for non-ARQ connections Packing fixed-length MAC SDUs (Generic MAC Header T ype = 000000) the Request/Transmission Policy shall be set to allow packing and prohibit fragmentation, and the SDU size shall be included in DSAREQ message when establishing the connection If the MAC SDU size is n bytes, the receiver unpacks simply by kno wing that the length field in the MAC header will be nk+j, where k i s the number of MAC SDUs packed into the MAC PDU and j is the

size of the MAC header and any prepended MAC subheaders. no added overhead CGU NDSL WMAN - 57 Packing for non-ARQ connections Packing variable-length MAC SDUs indication of where one MAC SDU ends and another begins. the MAC attaches a Packing subheader (PSH) to each MA C SDU unfragmented MAC SDUs and MAC SDU fragments may bot h be present in the same MAC PDU CGU NDSL WMAN - 58 Packing for non-ARQ connections

Simultaneous fragmentation and packing allows effici ent use of the airlink when a Packing subheader (PSH) is present, the frag mentation information for individual MAC SDUs or MA C SDU fragments is contained in the corresponding P acking subheader. Else (If no PSH is present), the fragmentation informa tion for individual MAC SDU fragments is contained in the corresponding Fragmentation subheader (FSH) CGU NDSL WMAN - 59 Packing for non-ARQ connections PSH

FSH PSH CGU NDSL WMAN - 60 Packing for ARQ-enabled connections Each of the packed MAC SDU or MAC SDU fragments o r ARQ feedback payload requires its own Packing subhe ader A MAC SDU may be partitioned into multiple fragments th at are then packed into the same MAC PDU for the first tra nsmission. MAC PDUs may have fragments from the same or differen t SDUs, including a mix of first transmissions and retransm issions. The 11-bit BSN and 2-bit FC fields uniquely identify each f

ragment or non-fragmented SDU. CGU NDSL WMAN - 61 Payload Type Payload Type indicates whether MAC subheaders (P acking/Fragmentation/Grant) acking/Fragmentation/Grant present or not. packing/ fragmentation 000100 000011 packing/

fragmentation/ grant/ p+g/ f+g CGU NDSL WMAN - 62 MAC Subheader Three types of MAC subheaders may be present. The fragmentation subheader contains information that ind icates the presence and orientation in the payload of any fra gments of SDUs. (e.g. long Ethernet packet) The grant management subheader is used by an SS to co nvey bandwidth management needs to its BS. The packing subheader is used to indicate the packing of multiple SDUs into a single PDU. (e.g. ATM cells)

CGU NDSL WMAN - 63 Fragmentation Subheader format CGU NDSL WMAN - 64 Grant Subheader format If the CID is classified as UGS (incremental mode) is used to request to be polled for a different, non-UGS connection set when service flow has exceeded its transmit queue depth CGU NDSL WMAN - 65 Packing Subheader format

CGU NDSL WMAN - 66 MAC Management Messages MAC Management messages on the Basic, Broadcast, and Initial Ranging connections shall neither be fragmented nor packed. 1 byte CGU NDSL WMAN - 67 MAC Management Messages CGU NDSL WMAN - 68

MAC Management Messages CGU NDSL WMAN - 69 MAC Management Messages AAS : adaptive antenna system CGU NDSL WMAN - 70 SS Initialization Overview Downlink Sync Auth. Key Xchange Get Uplink Parameters

Setup Time Register Ranging Capability Negotiation DHCP Download Configuration File Setup connection

and service flow CGU NDSL WMAN - 71 Steps 1) Scan for downlink channel and establish synchronization with the BS 2) Obtain transmit parameters (from UCD message) (uplink channel descriptor) 3) 4) 5) 6) 7) 8)

9) 10) Perform ranging (RNG-REQ and RNG-RSP) Negotiate basic capabilities Authorize SS and perform key exchange Perform registration Establish IP connectivity (DHCP) optional Establish time of day optional Transfer operational parameters (TFTP) optional Set up connections Option : indicated by REG-REQ message CGU NDSL WMAN - 72 Uplink Channel Descriptor (UCD) message Configuration Change Count

Incremented by one (modulo 256) by the BS whenever any of the values of this channel descriptor change. This value is also referenced from the UL-MAP messages. Ranging Backoff Start Initial backoff window size for initial ranging contention Ranging Backoff End Final backoff window size for initial ranging contention Request Backoff Start Initial backoff window size for contention BW requests Request Backoff End Final backoff window size for contention BW requests

All above parameters are expressed as a power of 2. Values of n ran ge 015 the highest order bits shall be unused and set to 0 The Uplink_Burst_Profile is a compound TLV encoding that associates wit h a UIUC (uplink interval usage code) CGU NDSL WMAN - 73 Frame Structure (TDD) DIUC 0 1-6 7-12 13 14 15

Usage frame control TDM Burst Profiles TDMA Burst Profiles reserved Gap End of DL-Map OFDM example UIUC 0 1 2 3 4-9 10

11 12-14 15 Usage reserved Request Initial Ranging reserved Data Grant Burst End of UL-Map Gap reserved Extended SSTG: Subscriber Station Transition Gap

DIUC: Downlink Interval Usage Code UIUC: Uplink Interval Usage Code Preamble Preamble TDM Portion Broadcast Control DIUC = X DL-MAP TDM DIUC a


Ranging Opportunities (UIUC = 2) Request Contention Opps (UIUC = 1) Collision Access Burst SS 1 Scheduled

Data (UIUC = i ) ... SS N Scheduled Data (UIUC = j ) UL-MAP Access Burst Downlink subframe structure

Bandwidth Collision Request Bandwidth Request Uplink subframe structure CGU NDSL WMAN - 74 Uplink map (UL-MAP) message Uplink Channel ID (for Channelized PHY) UCD Count Matches the value of the Configuration Change Count of the UCD, which describes the uplink burst profiles that apply to this map.

Allocation Start Time Effective start time of the uplink allocation defined by the UL-MAP units are PHY-specific (pp. 153) minislots : SC and SCa PHY layers symbols and subchannels : OFDM and OFDMA PHY layers Map IEs (Information Elements) The contents of a UL-MAP IE is PHY-specification dependent. CGU NDSL WMAN - 75 Uplink interval definition Request IE BS specifies an uplink interval for bandwidth requests The character of this IE changes depending on the type of CI D used in the IE

Broadcast or multicast CID (poll) : an invitation for SSs to conte nd for requests. Unicast CID (poll) : an invitation for a particular SS to request b andwidth part of a QoS scheduling scheme that is vendor dependent For bandwidth request contention opportunities, the BS shall allocate a grant that is an integer multiple of the value of Ba ndwidth request opportunity size (in unit of physical slot (PS )) which shall be published in each UCD transmission. CGU NDSL WMAN - 76 Uplink interval definition Initial Ranging IE An interval is allocated in UL-MAPs

the maximum round-trip propagation delay plus the transmissio n time of the RNG-REQ message For ranging contention opportunities, the BS shall allocate a grant that is an integer multiple of the value of Ranging requ est opportunity size, (in unit of PS) which shall be published in each UCD transmission. Data Grant Burst Type IEs provide an opportunity for an SS to transmit one or more upli nk PDUs. CGU NDSL WMAN - 77 Ranging request (RNG-REQ) message transmitted by the SS

at initial ranging (initialization) and data grant intervals (periodically) To determine network delay To determine power To change downlink burst profile If sent in a data grant interval, the CID is always equal to the Basic CID. the SS received the UCD CGU NDSL WMAN - 78 Ranging Request (RNG-REQ) message when the SS is attempting to join the network, two parameters are included in the RNG-REQ message Requested Downlink Burst Profile (1 byte)

Bits 0-3 : DIUC Bits 4-7 : 4 LSB of Configuration Change Count value SS MAC Address during initial ranging on the SSs Basic connection, the parameter MAC Version is provided 1 : 802.16-2001 2 : 802.16c-2002 and its predecessors 3 : 802.16a-2003 and its predecessors 4 : 802.16-2004

AAS broadcast capability may be included in the RNG-REQ me ssage: Applied for SCa/OFDM/OFDMA CGU NDSL WMAN - 79 Ranging Request (RNG-REQ) message after the SS has received an RNG-RSP, two parameters are included in the subsequent RNG-REQ message : Requested Downlink Burst Profile (1 byte) Bits 0-3 : DIUC Bits 4-7 : 4 LSB of Configuration Change Count value Ranging Anomalies (1 byte)

Bit #0 SS already at maximum power. Bit #1 SS already at minimum power. Bit #2 Sum of commanded timing adjustments is too large. CGU NDSL WMAN - 80 Ranging response (RNG-RSP) message transmitted by the BS in response to a received RNG-REQ may also be transmitted asynchronously to send corrections based on measurements that have been made on other rece ived data or MAC messages CGU NDSL WMAN - 81

Ranging response (RNG-RSP) message Ranging Status 1 = continue, 2 = abort, 3 = success, 4 = rerange Timing Adjust Information (signed 32-bit) Power Adjust Information (signed 8-bit, 0.25 dB units) Downlink Frequency Override Center frequency, in kHz, SS redoes initial ranging. Uplink Channel ID Override Licensed bands: The identifier of the uplink channel with which the SS i s to redo initial ranging License-exempt bands: The Channel Nr where the SS should redo initia l ranging.

Downlink Operational Burst Profile (2 bytes) Byte 0: the least robust DIUC that may be used by the BS for transmissi ons to the SS. Byte 1: Configuration Change Count value of DCD defining the burst pr ofile associated with DIUC. CGU NDSL WMAN - 82 Ranging response (RNG-RSP) message Basic CID (2 bytes) A required parameter if the RNG-RSP message is being sent on the Initial Ranging CID in response to a RNG-REQ message that was sent on the Initial Ranging CID. Primary Management CID (2 bytes) A required parameter if the RNG-RSP message is being sent on the Initial Ranging CID in response to a RNG-REQ

message that was sent on the Initial Ranging CID. SS MAC Address (48-bit) A required parameter when the CID in the MAC header is the Initial Ranging CID. Offset Frequency Adjust Information (signed 32bit, Hz units) fine-frequency adjustment within a channel AAS broadcast permission CGU NDSL WMAN - 83 Ranging response (RNG-RSP) message WirelessMAN-SCa or WirelessMAN-OFDM PHY-specific parameters Frame Number (3 bytes) the corresponding RNG-REQ message or subchannelized initial ranging indicatio n (for OFDM) was received.

When Frame Number is included, SS MAC Address shall not appear. Initial Ranging Opportunity Number (1 byte) Initial Ranging opportunity within the frame in which the corresponding RNG-REQ message or subchannelized initial ranging indication (for OFDM) was received. If not provided, and Frame Number is included in the message, Initial Ranging Op portunity is assumed to be one. WirelessMAN-OFDM PHY-specific parameter Ranging Subchannel WirelessMAN-OFDMA PHY when an initial ranging message based on code division multiple access (CD MA) is received, Ranging code attributes (OFDMA time symbols reference, subchannel refe rence, and frame number)

CGU NDSL WMAN - 84 Registration request (REG-REQ) message Include parameter: Primary Management CID (in the generic MAC header) The CID in the generic MAC header is the Primary Management CID for this SS, as assigned in the RNG-RSP message. CGU NDSL WMAN - 85 Registration request (REG-REQ) message The REG-REQ shall contain the following TLVs: Hashed Message Authentication Code (HMAC) Tuple Shall be final attribute in the messages TLV attribute list .

In Mesh Mode, message digest is calculated using HMAC_KEY_U. IP Version SS Capabilities Encodings Vendor ID Encoding Vendor-specific information Convergence Sublayer Capabilities ARQ Parameters

For PMP operation, the REG-REQ shall contain the following TLV s: Uplink CID Support SS management support w/ or w/o secondary management connection IP management mode CGU NDSL WMAN - 86 Registration response (REG-RSP) message Include parameter: Primary Management CID (in the generic MAC header) Response 0 = OK 1 = Message authentication failure CGU NDSL WMAN - 87

Registration response (REG-RSP) message The REG-RSP shall contain the following TLVs SS Capabilities Encodings Response to the capabilities of the requester provided in the R EG-REQ. indicates whether or not the capabilities may be used. IP Version Vendor ID Encoding Vendor-specific information

ARQ Parameters ARQ and fragmentation parameters specified by the BS to com plete ARQ parameter negotiation for the secondary manageme nt connection. IP management mode Response to REG-REQ indication of whether or not the reques ter wishes to accept IP-based traffic on the Secondary Manage ment Connection, once the initialization process has completed . CGU NDSL WMAN - 88 Contention resolution Collisions may occur during Initial Ranging and Requ est intervals. After a contention transmission,

the SS waits for a Data Grant Burst Type IE in a subsequent map (bandwidth request) waits for a RNG-RSP message (initial ranging) truncated binary exponential backoff with the initial backoff window and the maximum backoff window are controlled by the BS are specified as part of the UCD message and represent a p ower-of-two value. Request IEs or Initial Ranging IEs allocate contention intervals in the UL-MAP messages Random backoff (in slots) may across multiple intervals assi gned in IEs. CGU NDSL WMAN - 89

Contention resolution retry when range timeout (200ms no range response) data grant timeout (10ms no data grant - service QoS dependent) Until reaches the maximum number of retries while deferring, if SS receives a unicast Request IE or Dat a Grant Burst Type IE, it shall stop the contention resoluti on process BS may set up the Request (or Ranging) Backoff Start an d Request (or Ranging) Backoff End to emulate an Ethern et-style backoff by setting Request (or Ranging) Backoff Start = 0 and Request (or Ranging) Backoff End = 10 in the UCD message Open issue for optimize window (beyond the scope of standard)

CGU NDSL WMAN - 90 Transmission opportunities The size of an individual transmission opportunity for each type of contention IE shall be published in each transmitted UCD message. The BS shall always allocate bandwidth for contention IEs in integer multiples of these published values. WirelessMAN-SC system for example, frame duration =1 ms,

each PS = 4 symbols, each minislot = 2 PSs, uplink preamble =16 symbols = 2 minislots, SS transition gap (SSTG) = 24 symbols = 3 minislots. For QPSK, each transmission opportunity requires 8 minisl ots: 3 for the SSTG, 2 for the preamble, and 3 for the bandwidt h request message. This payload requirement would be specified as a value of 16 ( ??? pp. 167) assigned to the UCD TLV Bandwidth request opp ortunity size CGU NDSL WMAN - 91 Transmission opportunities One Request IE with 24 minislots indicates there will be three transmission opportunities CGU NDSL WMAN - 92

PHY Layer CGU NDSL WMAN - 93 Multiple Access and Duplexing On DL, DL SS addressed by BS in TDM stream On UL, UL SS is allotted a variable length TDMA slot Time-Division Duplex (TDD) DL & UL time-share the same RF channel Dynamic asymmetry (also named as Demand Assigned Multiple Access : DA MA) Half-duplex SS does not transmit/receive simultaneously (low cost)

Frequency-Division Duplex (FDD) DL & UL on separate RF channels Static asymmetry Full-duplex SSs supported Half-duplex SSs supported SS does not transmit/receive simultaneously (low cost) Need resynchronization CGU NDSL WMAN - 94

TDD Frame Frame duration: 0.5/1/2 ms (SC) , 2.5/4/5/8/10/12.5/20 ms (OFDM) , 2 /2.5/5/8/10/12.5/20ms (OFDMA) Physical Slot (PS) = 4 symbols (SC/a) , 4/sampling_freq (OFDM/A) Minislot : A unit of uplink bandwidth allocation equivalent to n physical slots (PSs), where n = 2m and m is an integer ranging from 0 through 7. Time counter (29-bit) 29-bit resolution equals 1/16 of the PS duration. This allows the SS to track the BS clock with a small time offset. CGU NDSL WMAN - 95 Adaptive Burst Profiles Burst profile Modulations and FEC

Dynamically assigned according to link conditions Burst by burst, per subscriber station Trade-off capacity vs. robustness in real time Roughly doubled capacity for the same cell Burst profile for downlink broadcast channel is wellknown and robust Other burst profiles can be configured on the fly SS capabilities recognized at registration SBC-REQ/RSP CGU NDSL WMAN - 96

System Parameters QPSK, 16-QAM and 64-QAM CGU NDSL WMAN - 97 Radio Link control RLC control transition of burst profile power level ranging RLC begins with periodic BS broadcast of the burst profiles that have been chosen for the uplink and downlink

according to rain region and equipment capabilities. capabilities Burst profiles for the downlink/uplink are each tagged with a Downlink/Uplink Interval Usage Code (DIUC/UIUC). (DIUC/UIUC) CGU NDSL WMAN - 98 Ranging and Power Control During initialization, the SS performs initial power leveling and ranging using ranging request (RNGREQ) messages transmitted in initial maintenance windows. windows The adjustments to the SSs transmit time advance, as well as power adjustments, are returned to the SS in ranging response (RNG-RSP) messages.

messages For ongoing ranging and power adjustments, the BS may transmit unsolicited RNG-RSP messages commanding the SS to adjust its power or timing. It is not included in burst profile CGU NDSL WMAN - 99 Burst Profile Set of parameters that describe the uplink or downlink transmission properties associated with an interval usage code (IUC).

The burst profile to use for any uplink transmission is defined by the Uplink Interval Usage Code (UIUC). Each UIUC is mapped to a burst profile in the UCD message Each profile contains parameters such as a) b) c) d) modulation type forward error correction (FEC) type preamble length guard times

CGU NDSL WMAN - 100 Burst Profile If the received CINR goes outside of the allowed operating region, the SS requests a change to a new burst profile using one of two methods If the SS has been granted uplink bandwidth, it shall send a DBPC-REQ message in that allocation. The BS responds with a DBPC-RSP message. If grant is not available and the SS requires a more robust burst profile on the downlink, it shall send a RNG-REQ message in an Initial Ranging interval. Note : using the Basic CID of the SS

CGU NDSL WMAN - 101 Burst profile transition C/(N+I) :carrier to noise and interference ratio Ranging request (RNG-REQ) or downlink burst profile change request (DBPC-REQ) As SS receives unclear signals! Transition to a more robust burst profile.

CGU NDSL WMAN - 102 Burst profile Transition C/(N+I) :carrier to noise and interference ratio As SS receives strong signals! Transition to a less robust burst profile. CGU NDSL WMAN - 103 Burst profile threshold

C/(N+I) :carrier to noise and interference ratio CGU NDSL WMAN - 104 Map relevance and synchronization (TDD) ATDD : adaptive time division duplexing CGU NDSL WMAN - 105 Map relevance and synchronization (FDD) CGU NDSL WMAN - 106 Map relevance WirelessMAN-SC PHY & WirelessMAN-OFDM PHY

Allocation Start Time (AST) is subject to the following limitatio ns: FDD : minimum AST value = round trip delay + Tproc , maximum AST value = Tf (i.e., the beginning of the next frame). TDD : the AST value is either the ATDD split or the ATDD split + Tf. The allocation shall be within a single frame. WirelessMAN-SCa PHY & WirelessMAN-OFDMA P HY Allocation Start Time shall be subject to the following limitatio ns: Minimum value: Allocation Start Time Tf Maximum value: Allocation Start Time < 2 Tf

CGU NDSL WMAN - 107 Optional MAC AAS Support Adaptive Antenna System (AAS) - optional the use of more than one antenna element, can improve ran ge and system capacity by adapting the antenna pattern and concentrating its radiation to each individual subscriber. Support in WirelessMAN-SCa, OFDM, and OFDMA spectral efficiency can be increased linearly with the n umber of antenna elements achieved by steering beams to multiple users simultaneously so as to realize an inter-cell frequency reuse. signal-to-noise ratio (SNR) gain realized by coherentl y combining multiple signals, and the ability to direct t

his gain to particular users. MIMO/SIMO/MISO. CGU NDSL WMAN - 108 Optional MAC AAS Support provides a mechanism to migrate from a non-AAS system to an AAS enabled system dedicating part of the frame to non-AAS traffic and part to AAS traffic time CGU NDSL WMAN - 109 Optional MAC AAS Support Alerting the BS about presence of a new SS in an AAS

system AAS BS may reserve a fixed, pre-defined part of the frame as initial-ranging contention slots (called AAS-alert-slots) for this alert procedure FDD/TDD support use channel state information of both downlink and uplink Two ways : (reciprocity) using the uplink channel state estimation as the downlink channel state (TDD) (feedback) transmitting the estimated channel state from the SS to BS. (FDD or TDD) using two MAC control messages: AAS-FBCK-REQ and AAS-FBCK-RSP The BS shall provide an uplink allocation to enable the SS to transmit

this response. Using FDD, the BS shall issue AAS-FBCK-REQ messages. Using TDD, the BS may issue AAS-FBCK messages. (pp. 165) CGU NDSL WMAN - 110 Burst FDD Framing Allows scheduling flexibility CGU NDSL WMAN - 111 Uplink TDD/FDD Subframe (ranging) (band. req)

UIUC: Uplink Interval Usage Code CGU NDSL WMAN - 112 TDD Downlink Subframe The bursts are transmitted in order of decreasing robustness. DIUC: Downlink Interval Usage Code CGU NDSL WMAN - 113 FDD Downlink Subframe TDMA portion: portion transmits data to some half-duplex SSs (the ones scheduled to transmit earlier in the frame tha

n they receive) Need preamble to re-sync (carrier phase) CGU NDSL WMAN - 114 Receive/transmit Transition Gap (RTG) in TDD A gap between the uplink burst and the subse quent downlink burst in a TDD transceiver. Not applicable for FDD systems transmit/receive transition gap (TTG) : similar CGU NDSL WMAN - 115 Adaptive PHY Adaptive modulation

CGU NDSL WMAN - 116 Nine Data Rates in 802.16 Modulation Schemes : QPSK, 16-QAM and 64-QAM 20 MHz/channel (4M PSs/frame/ms = 16Msymols/ms) 32Mbps / 64Mbps / 96Mbps 25 MHz/channel (5M PSs/frame/ms = 20Msymbols/ms) 40Mbps / 80Mbps / 120Mbps 28 MHz/channel (5.6M PSs/frame/ms = 22.4Msymbols/ms) 44.8Mbps / 89.6Mbps / 134.4Mbps Uplink mandatory US European

downlink mandatory 0.5, 1 or 2 ms CGU NDSL WMAN - 117 10-66 GHz PHY parameters CGU NDSL WMAN - 118 DCD and UCD downlink channel descriptor (DCD): A MAC message that describes the PHY characteristics of a downlink channel uplink channel descriptor (UCD): A medium access control message that describes the PHY c

haracteristics of an uplink. CGU NDSL WMAN - 119 Uplink PHY CGU NDSL WMAN - 120 Downlink PHY CGU NDSL WMAN - 121 Shortened FEC blocksTDMA/TDM case Reed-Solomon over Galois field GF(256) TDMA w/

TDM w/o CGU NDSL WMAN - 122 IEEE 802.16a Medium Access Control Modifications and Additional Physical Layer Specifications for 2-11 GHz CGU NDSL WMAN - 123 802.16a PHY Alternatives Different Applications, Bandplans, and Regulatory OFDM (WirelessMAN-OFDM Air Interface) 256-point FFT with OFDM (TDD/FDD)

OFDMA (WirelessMAN-OFDMA Air Interface) 2048-point FFT with OFDMA (TDD/FDD) CDMA ranging code Single-Carrier (WirelessMAN-SCa Air Interface) TDMA (TDD/FDD) BPSK, QPSK, 4-QAM, 16-QAM, 64-QAM Most vendors will use Frequency-Domain Equalization for solving d elay spread issue CGU NDSL WMAN - 124 Key 802.16a MAC/PHY Features

2-11GHz License-exempt band 5-6 GHz OFDM/OFDMA support ARQ Space-Time Coding (STC) There are two transmit antennas on the BS side and one reception antenna on the SS side. Dynamic Frequency Selection (DFS) license-exempt Adaptive Antenna System (AAS) support Mesh Mode Optional topology for license-exempt operation only (TDD only)

Subscriber-to-Subscriber communications Complex topology and messaging CGU NDSL WMAN - 125 Features OFDM (WirelessMAN-OFDM Air Interface) Two contention based BW request mechanisms Bandwidth Request Header Focused Contention Transmission with Contention Code over Content ion Channel consisting of 4 carriers OFDMA (WirelessMAN-OFDMA Air Interface) Two contention based BW request mechanisms Bandwidth Request Header Specifies a Ranging Subchannel and a subset of Ranging Codes tha

t are used for contention-based BW requests (CDMA mechanism) The WirelessHUMAN system provides optional support for Mes h topology. topology Unlike the point-2-multipoint (PMP) mode, there are no clearly separ ate downlink and uplink subframes in the Mesh mode. CGU NDSL WMAN - 126 Mesh-based WirelessMAN Source: Nokia Networks CGU NDSL WMAN - 127

Mesh Networks Mesh systems typically use omnidirectional or 360 steerable an tennas, but can also be co-located using sector antennas. Directed Mesh (DM) : The realization of a physical mesh using s ubstantially directional antennas. Nodes : systems in Mesh networks Mesh BS : a system that has a direct connection to backhaul servic es outside the Mesh network. Mesh SS : all the other systems of a Mesh network Neighbor : The nodes with which a node has direct links Neighborhood :Neighbors of a node form a neighborhood (one-h op) Extended neighborhood : all the neighbors of the neighborhood (two-hops)

CGU NDSL WMAN - 128 Mesh Networks Using distributed scheduling, all the nodes including the Mesh BS shall coordinate their transmissions in their two-hop neighborhood and shall broadcast their schedules (available resources, requests and grants) to all their neighbors. (Optionally) the schedule may also be established by directed uncoordinated requests and grants between two nodes. Nodes shall ensure that the transmissions do not collide with the traffic scheduled by any other node in two-hop neighborhood. CGU NDSL WMAN - 129

Mesh Networks Using centralized scheduling, scheduling the Mesh BS shall gath er resource requests from all the Mesh SSs within a c ertain hop range. determine the amount of granted resources for each li nk the grant messages do not contain the actual schedule, but each node shall compute it by using the predetermined algor ithm with given parameters. QoS is provisioned over links on a message-by- mess age basis. CGU NDSL WMAN - 130

Mesh Networks 48-bit universal MAC address When authorized to the network the node receives a 16-bit node identifier (Node ID) upon a request to the Mesh BS Node ID is transferred in the Mesh subheader, which follows the ge neric MAC header, in both unicast and broadcast messages. For addressing nodes in the local neighborhood, 8-bit link identif iers (Link IDs) shall be used. The Link ID is transmitted as part of the CID in the generic MAC header in unicast messages. The Link IDs shall be used in distributed scheduling to identify re source requests and grants. Since these messages are broadcast, the receiver nodes can de termine the schedule using the transmitters Node ID in the Mes

h subheader, and the Link ID in the payload of the MSH-DSCH ( Mesh Mode Schedule with Distributed Scheduling) message. CGU NDSL WMAN - 131 Mesh Networks 8 bits Messages with larger Drop Precedence shall have higher dropping likelihood during congestion. CGU NDSL WMAN - 132 IEEE 802.16 and 16a Mesh topology *

Mesh topology * 5-6GHz 5MHz/channel ; 200 channels HUMAN : High-Speed Unlicensed Metropolitan Area Network CGU NDSL WMAN - 133 OFDM/OFDMA raw bitrates (Mbps) CGU NDSL WMAN - 134 Adaptive Antenna System A system adaptively exploiting more than one antenna to improve the coverage and the system

capacity Adapt the antenna pattern and concentrating its radiation to each individual subscriber The spectral efficiency can be increased linearly with the number of antenna elements steering beams to multiple users simultaneously so as to realize an inter-cell frequency reuse Reduce interference CGU NDSL WMAN - 135 THANK YOU ! Questions ? CGU NDSL WMAN - 136

Recently Viewed Presentations

  • WJEC GCSE Geography A Autumn CPD 2013 Todays

    WJEC GCSE Geography A Autumn CPD 2013 Todays

    Arial MS Pゴシック WJEC 1_WJEC WJEC GCSE Geography A Autumn CPD 2013 Today's agenda Item Level Data Walled Garden Item Level Summary (Candidates) Item Level Summary (Candidates) Item Level Summary (Candidates) Centre Performance in Context Centre Performance in Context Using...
  • irony lesson - Troup County

    irony lesson - Troup County

    Read the following examples of irony. Determine which of the three types of irony are being used. 1. When Mr. Goodenwell saw his baby boy Vince for the first time, he swore that he'd do anything to protect the little...
  • Data Mining - University of Minnesota

    Data Mining - University of Minnesota

    Introduction to Data Mining, 2nd Edition by ... Given a test record, xi Support Vector Machines What if the problem is not linearly separable? Support Vector Machines What if the problem is not linearly separable? Introduce slack variables Need to...
  • Lecture L004 Sources of Information for The Communicator

    Lecture L004 Sources of Information for The Communicator

    Indirect, via social media networks. The general public will be a source of information to the communicator as well. This information can come from the things that people call or email about, or questions they ask. That will tell you...


    HOW TO MAKE ROQUEFORT FIRST STEP : MILK COLLECTION ewe herd born and breeded in Aveyron race of ewe : Lacaune's ewe The ewes must be breeded in mountain Milk collection only in spring and summer SECOND STEP : PASTEURISATION...
  • IPv6 pour les Nuls - download.microsoft.com

    IPv6 pour les Nuls - download.microsoft.com

    IPv6 pour les Nuls. 10 février 2011. Marc MichaultArnaud LheureuxTechnologist Lead PFE- Security. SidemSystems Solutions Microsoft France. date
  • Key Terms Ekphrastic poetry: Poems that comment on

    Key Terms Ekphrastic poetry: Poems that comment on

    Key Terms Ekphrastic poetry: Poems that comment on another art form. Art describing art eg. This poem (an art form in itself) comments upon paintings.
  • ISACA April 17, 2003 - IEEE

    ISACA April 17, 2003 - IEEE

    7-Step Guide to Pass the CISSP Exam Phoenix IEEE Computer Society February 11, 2003 Debbie Christofferson, CISSP, CISM Sapphire-Security Services