NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)
description
Transcript of NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)
![Page 1: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/1.jpg)
NS-2 NIST add-onIEEE 802.16 model (MAC+PHY)Miray Kas
28 Jan 2008
![Page 2: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/2.jpg)
Outline
MAC Layer overview Basic Data about PHY Layer List of Available/Unavailable Features Available Features
Convergence SublayerMAC Common PartPHY Layer
Comments on Unavailable Features
![Page 3: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/3.jpg)
![Page 4: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/4.jpg)
Basic Data on IEEE 802.16 Standards (1)
![Page 5: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/5.jpg)
Basic Data on IEEE 802.16 Standards (2)
![Page 6: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/6.jpg)
Why NS-2 & WiMAX Ns-2:
De facto Standard for Simulation of Networks
Not so many WiMAX modules available:NIST
Most reliable Only one that has mobility functionality
Chang Gung University TaiwanState University of Campinas Brazil
![Page 7: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/7.jpg)
ns-2 vs. ns-3 environment ns-2 since 1996 ns-3 in progress, no initial alpha release ns-3 : Rewrite of core simulator
802.11 PHY cleanupns-2 integration with ns-3 tools to parse output data (tcpdump and Ethereal)(Dynamic) Calendar Queue NIST WiMAX ns-2 port to ns-3
![Page 8: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/8.jpg)
![Page 9: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/9.jpg)
Main Features of WiMAX Module PHY:PHY:
OFDM
MAC:MAC: PMP modeTDD
Builds on ns2 legacy code Implemented in C++
![Page 10: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/10.jpg)
Convergence Sublayer Classifying higher layer PDUs into appropriate
connections Delivering resulting CS PDUs to MAC SAP
associated with the service flow. Suppressing / Rebuilding payload header
information Used for Internet Protocol (IP)
Point-to-Point Protocol (PPP)
Ethernet (IEEE 802.3)
![Page 11: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/11.jpg)
Convergence Sublayer
![Page 12: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/12.jpg)
Convergence Sublayer
![Page 13: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/13.jpg)
Convergence Sublayer
![Page 14: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/14.jpg)
MAC Sublayer - Addressing & Connection
Initialization of BSInitialization of BS Initial Ranging( ) Padding( ) Broadcast( ) Adaptive Antenna System( )
Initialization of SSInitialization of SS Initial Ranging( ) Padding( ) Broadcast( )
During network entry, following are set up:During network entry, following are set up: Basic CID( ) Exchange time urgent MAC mng. msg Primary CID( ) Longer delay tolerant MAC mng. msg Secondary CID( ) DHCP, TFTP, SNMP Data CIDs Current model supports only one
![Page 15: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/15.jpg)
MAC PDU Format
0 or more sub-headers0 or more sub-headers
0 or more fragments0 or more fragments
Fixed LengthFixed Length
Virtual PHY header : Used to carry physical information such as frequency, modulation…
![Page 16: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/16.jpg)
Mutually ExclusiveMutually Exclusive
HT = 1
HT = 0
![Page 17: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/17.jpg)
![Page 18: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/18.jpg)
![Page 19: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/19.jpg)
![Page 20: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/20.jpg)
Construction & Transmission of MAC PDUs 3 steps:
Receive, classify, put in the connection queueSchedulingTransmission
Construction:Fragmentation & PackingCRC calculation
![Page 21: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/21.jpg)
Scheduler Service Flow classes are implemented
UGS, nrtPS, rtPS, BE
Current one does not use service classes Best Effort Scheduler with Round-Robin algorithm
Allows custom implementations One default for SS and BS each
Replace current one by a TCL command $mac set-scheduler $scheduler
![Page 22: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/22.jpg)
Scheduler
![Page 23: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/23.jpg)
QoS
Structure supports Service FlowsertPS not implemented
Scheduler does not use them No Admission Control during creation of flows
Accept all requests from MSs List of flows in each SS
StaticStored by ServiceFlowHandler
![Page 24: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/24.jpg)
![Page 25: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/25.jpg)
Contention Resolution BS has full control on downlink Collisions possible in uplink
Initial Ranging RequestBandwidth Request
BS decides contention slots Binary exponential backoff window
SS decides how many minislots to defer
![Page 26: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/26.jpg)
Contention Slot
![Page 27: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/27.jpg)
Contention Request
![Page 28: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/28.jpg)
TDD
Uplink transmissions occur after downlink transmissionsat each frame
![Page 29: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/29.jpg)
Frame Structure
![Page 30: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/30.jpg)
Network Entry & Initialization Steps:
Scan downlink channel Obtain transmit parameters Initial ranging Registration
Following can be configured: Timers to perform channel scanning Frequency of the DCD/UCD messages Parameters for initial ranging (backoff window size
& # of slots per frame) Channel allocation
![Page 31: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/31.jpg)
Network Entry
![Page 32: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/32.jpg)
Scanning
Related to Handover procedure
When link quality weakens MS scans to find another BS
Send MOB-SCN_REQ to current BS to request scanning interval
![Page 33: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/33.jpg)
Scanning
![Page 34: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/34.jpg)
Scanning Modes
Without association MS attempts itself
Association Level 0 – w.o. Coordination Target BS has no information about scanning MS
Association Level 1 – with Coordination Serving BS negotiates with target BS
Association Level 2 – Network Assisted Not implemented yet.
![Page 35: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/35.jpg)
Scanning WiMAXCtrlAgent
Extends Agent
Has three functions:Exchange DCD/UCD info btw. BSs
Trigger sending of NBR-ADV msg. to MSs
Synchronize BSs (serving & target)
![Page 36: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/36.jpg)
Ranging
DefinitionA mechanism to allow an SS to maintain link
quality by adjusting its 1-) Transmission power 2-) Modulation
Uplink Ranging = Initial Ranging + Periodic Ranging
Downlink Ranging = No periodic ranging
![Page 37: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/37.jpg)
Ranging (Current Situation in the Module)
No algorithm to make use of ranging capabilities
Periodic ranging not implemented
CDMA request not implemented
Only to add latency to the network entry
Mechanism implemented not applicable to OFDMA
![Page 38: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/38.jpg)
Timers WimaxFrameTimer WimaxRxTimer WimaxDCDTimer WimaxUCDTimer WimaxRngIntTimer WimaxLostDLMAPTimer WimaxLostULMAPTimer DLTimer ULTimer
WimaxT1Timer WimaxT2Timer WimaxT3Timer WimaxT6Timer WimaxT9Timer WimaxT12Timer WimaxT16Timer WimaxT17Timer WimaxT21Timer
WimaxMobNbrAdvTimerWimaxScanIntervalTimerWimaxRdvTimerWimaxT44Timer
Mobility Mobility ExtensionsExtensions
![Page 39: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/39.jpg)
PHY Layer
Only OFDM is implemented
OFDMA WirelessMAN-SC WirelessMAN-SCa WirelessHUMAN
Missing Yet!!!Missing Yet!!!
![Page 40: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/40.jpg)
PHY Layer Configurable parameters (TCL):
Transmission power Cyclic Prefix Frequency Frequency bandwidth Modulation
Computed values: Sampling frequency OFDM symbol time duration Xmission time of a packet acc. to its size and modulation Max packet size for a given modulation and # of available
OFDM symbols
![Page 41: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/41.jpg)
PHY Layer Default:Default:
OFDM_BPSK_1_2 modulation OFDM_IDLE
Supported Modulations:Supported Modulations:
States:States: OFDM_IDLE OFDM_SEND OFDM_RECV OFDM_RX2TX OFDM_TX2RX
![Page 42: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/42.jpg)
PHY Layer
![Page 43: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/43.jpg)
Available/Unavailable Features
![Page 44: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/44.jpg)
Open to Improvement WirelessMAN-OFDMA physical layer
ARQ (Automatic Repeat Request)
Error Correction
Service Flow and QoS scheduling
Call Admission Control
Periodic ranging and power adjustments
![Page 45: NS-2 NIST add-on IEEE 802.16 model (MAC+PHY)](https://reader035.fdocuments.in/reader035/viewer/2022062410/5681593b550346895dc67603/html5/thumbnails/45.jpg)
Will be Still Missing…
ATM Convergence Sublayer Mesh Mode Physical Layers
WirelessMAN-SC WirelessMAN-SCa WirelessHUMAN
Frequency Division Duplexing (FDD) Authentication