Mobile/Wireless System Network - ajou.ac.krwinner.ajou.ac.kr/publication/data/invited/2011_comm... · 2011-08-29 · Part 1: Mobile/Wireless System MAC Wireless MAC Protocol Overview

Jae-Hyun Kim

Mobile/Wireless System Network이동 및 무선통신 단기강좌

2011.08. 25건국대학교 새천년기념관

Jae-Hyun Kim([email protected])

School of Electrical and Computer Engineering AJOU University

Homepage: http://ajou.ac.kr/~jkim

Jae-Hyun Kim 2

Agenda

Part 1: Mobile/Wireless System MACWireless MAC Protocol OverviewPerformance Analysis Methods for Wireless MAC ProtocolIEEE 802.16 System OverviewMajor TechnologiesCase Studies

Part 2: Handover in Mobile/Wireless SystemHandover OverviewLayer 2 Handover (IEEE 802.16e System based)Layer 2.5 HandoverLayer 3 HandoverApplication Handover

Part 3: Mobile/Wireless System NetworkNetwork Design IssuesNetwork Architecture/Protocol Stack

Jae-Hyun Kim

Wireless Communication Technologies

3

Out

door

Stationary

Walk

Vehicle

Indo

or

Stationary/Desktop

Walk

Mob

ility IEEE802.11

Transmission Rate

3Gcellular

Mbps1 10 1000.1

2G cellular

400

IEEE802.16

802.15.1 802.15.4a/b 802.15.3 802.15.3a

1000

IMT-Advanced

RFID, Sensor network

WAN (Wide Area Network)-Large coverage, High cost

MAN (Metropolitan Area Network) - Large coverage, Moderate cost

LAN (Local Area Network) - Hot Spots, Moderate cost

PAN (Personal Area Network)- Connectivity, Low cost

BAN (Body Area Network) - Identification, Low cost

Jae-Hyun Kim

Wireless Communication Technologies

4

Jae-Hyun Kim 5

Part 1: Mobile/Wireless System MAC- Wireless MAC Protocol Overview

- Perfomance Analysis Methods for Wireless MAC Protocol

- IEEE 802.16 Systems Overview

- Major Technologies

- Case Studies

Jae-Hyun Kim 6

Wireless MAC Protocol Classification

Wireless MAC Protocols

Contention-FreeContention-Based

Static ResolutionDynamic Resolution Dynamic Allocation Static Allocation

Probabilistic ID Probabilistic Reservation Token Passing

TDMA

FDMA

CDMA

OFDMA

IEEE 802.11e

IEEE 802.15.3

IEEE 802.15.4

Hybrid

Time of arrival

high priority to oldest one

Exponential Backoff

IEEE 802.3/11/16

Binary Tree

RFID

Aloha

CSMA

PRMA

DOCSIS

IEEE 802.16

MSAP

BRAM

RFID : Radio Frequency ID, CSMA : Carrier Sense Multiple Access, PRMA : Packet Reservation Multiple Access

DOCSIS : Data Over Cable Service Interface Specification, MSAP : Mini Slotted Alternating Priority, BRAM : Broadcast Recognition Access Method

Jae-Hyun Kim 7

Wireless MAC Protocol Classification

Beacon #mContention

Access Period MCTA1 MCTA2 CTA

1CTA

2 … CTM n-1

CTAn

CFP (Contention Free Period)

Beacon #m CAPAsynchronous Isochronous Asynchronous Isochronous

CFP (Contention Free Period)

Super frame #m-1 Super frame #m Super frame #m+1

1,000 ~ 65,535μsCSMA/CA

Data/ControlS-ALOHA

Data/ControlTDMAData

- MCTA : Management Channel Time Allocation

IEEE 802.15.3 MAC Frame Structure (IEEE Std 802.15.3™-2003)

Jae-Hyun Kim 8

Wireless MAC Protocol Performance

Performance MetricsThroughput

MAC Level Throughput (Goodput): MAC Layer Data Rate (bits/sec)Channel Throughput : The fraction of time that useful information is carried on the channel

Packet Delay (Access Delay) The time from the moment a message is generated until it makes it successfully across the channel

Packet Drop Probability The probability is that a packet is dropped

Jae-Hyun Kim 9

Wireless MAC Protocol Performance

Performance Analysis Method Rigorous Probability Based

Binary Tree Based Algorithm : Switching system, RFID Anti-collision etc. Markov Chain Model

Slotted Aloha (finite user model), Binary Exponential Backoff algorithm (CSMA/CA)Characteristics

Exact analysis methodHigh Computational Complexity

M/G/1 Busy Period AnalysisSlotted Aloha (Infinite user model) , CSMA/CA Characteristics

Difficult to model the system and to find the probability distributionTFA (Transient Fluid Approximation)

Slotted Aloha, CSMA/CACharacteristics

Low Computational Complexity, Easy to model the systemNeed the verification using the simulation

Jae-Hyun Kim 10

- Infinite User Model : M/G/1 Busy Period Analysis - Finite User Model : Markov Chain Analysis

Slotted Aloha 성능분석

Jae-Hyun Kim 11

Slotted Aloha (M/G/1 Busy Period Analysis)

System modelInfinite population Packets transmission time : TPacket arrival (Poisson distribution) : λ packet/secOffered load (new arrival + backlogged arrival) : g Total average number of transmission per slot : G =gTI : Idle period, B: Busy period, U : Useful periodThroughput (S) : [ *]

[ *]E U USE C B I

= =+

Busy Period Idle Period

CycleCycle

Slot

: colliding packets : successful slots

Jae-Hyun Kim 12

Idle Period

A random variable describing the number of slots in the idle period : The probability of some packets

In general, the length of the idle period is seen to be geometrically distributed

Average length of idle period

[ * 1] [ ] 1- [ ] 1 gT

P I P Some packets scheduled in first slotP No packets scheduled in first slot e−

= =

= = −

[ * 2] (1 )gT gTP I e e− −= = −

( ) ( )1[ * ] 1 k=1,2,...

kgT gTP I k e e−− −= = −

11 gTI

e−=−

*I

( ) ( )

( )!

k gT

k

gT eP t

k

−

=

Jae-Hyun Kim 13

Busy Period

The number of slots in the busy period :

Packets must be scheduled for transmission in each and every one of the first k-1 slots and none scheduled in the kth slots

Expected value of B

*B

( ) ( )1[ * ] 1 k=1,2,...

kgT gTP B k e e−− −= = −

1gTB

e−=

Jae-Hyun Kim 14

Useful Period and Throughput

The probability that a given slot in the busy period is successful

Throughput (S)

1

gT

gT

gTee

−

−−

( * )*[ * | *] 1 ,0

1 1

k B kgT gT

gT gT

B gTe gTeP U k B k nk e e

−− −

− −

= = − ≤ ≤ − −

[ * | *] * 1

gT

gT

gTeE U B Be

−

−= ⋅−

[ ] [ [ * | *]] 1

gT

gT

gTeU E U E E U B Be

−

−= = = ⋅−

[ *][ *]

gT GE U US gTe GeE C B I

− −= = = =+

Jae-Hyun Kim 15

Slotted Aloha (Markov Chain Analysis)

System modelFinite number of users

Number of users : M (each with a single buffer)Packets transmission time : T (slot duration)Thinking state (No ready packet)

Packet generation probability : σBacklogged state (Transmission was unsuccessful)

Packet retransmission probability : vLet denote the number of backlogged users at the beginning of the kth slotThroughput (S) : expected fraction of slots containing useful transmission

*( )N k

sucS P=

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Steady-State Probability

Steady-State ProbabilityLet be the steady-state probability of the system being in state i

Let be the steady-state transition probability

State Transition Rate Diagram of Finite Population Aloha

iπ

lim Pr[ *( ) ]i k N k iπ →∞= =ijp

lim Pr[ *( ) | *( 1) ]ij kp N k j N k i→∞= = − =

0 1 2 i M

i

ToMi+2i+1

Fromi+1

From01

i-1

To i-1

… …

The number of backlogged

users

PΠ = Π

Jae-Hyun Kim 17

State Transition Probability

1

1 1

1

0 1

(1 ) (1 ) 1

1 (1 ) (1 ) ( ) (1 ) (1 )

( ) (1 ) 1 (1 ) 1

(1 ) 1

i M i

i M i M i i

ijM i i

j i M j

j i

iv v j i

iv v M i v j ip

M i v j i

M ij i

j i

σ

σ σ σ

σ σ

σ σ

− −

− − − −

− −

− −

< −

− − = − − − − + − − − = =

− − − − = + − − > + −

Pr[i backlogged users transmit in a slot / j in backlog]= (1 )i j ijv v

i−

−

Pr[i thinking users transmit in a slot / j in backlog]= (1 )i M j iM ji

σ σ − −− −

Jae-Hyun Kim 18

Performance Analysis of Slotted Aloha

Total throughput (S)

As a special case, we do not distinguish between backlogged packets and new packets (v = σ)

1 1

( ) Pr[Successful slot/ i users in backlog]

(1- ) ( ) (1 ) (1 ) (1 )suc

i M i i M i

P iv M i iv vσ σ σ− − − −

=

= − − + − −

0[ ( )] ( )

M

suc suc suc ii

S P E P i P i π=

= = =∑

1( ) (1 )MsucP i Mσ σ −= −

1[ ( )] (1 )MsucS E P i Mσ σ −= = −

When Mσ = G, 1

1MGS G

M

− = −

M →∞GS Ge−=

Jae-Hyun Kim 19

Throughput Graph with Finite and Infinite Number of Users

Red Curve:Blue Curves:

0 0.5 1 1.5 2 2.5 30

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Offered load (G)

Thro

ughp

ut (S

)

GS Ge−=1

1 , 4, 7, 10, 13, 16, 19MGS G M

M

− = − =

M increases

M increases

Jae-Hyun Kim 20

Performance Analysis of Slotted Aloha

Expected delayWhen the system is in state i there are M-i thinking users each generating packets in every slot with probability σ

Average delayb : the average rate at which packets join the backlog

: the average amount of time spent in the backlog (by Little’s formula)(S-b)/S : a fraction of the packets is never backlogged (need only ‘1 slot’)b/S : a fraction of the packets suffers the backlog delay

[( ) ] ( ) ( )iS E M i M i M Nσ σπ σ= − = − = −∑: the average number of backlogged usersN

11 1 1 1S b b N N MDS S b S Sσ

−= ⋅ + + = + = − +

/N b

(1)

Jae-Hyun Kim 21

Delay vs. Throughput

M increases, Delay (with saturated throughput) increases

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

102

103

104

Throughput(S)

Exp

ecte

d D

elay

(D)

M=10M=20M=30M=40M=50

M increases

Jae-Hyun Kim 22

IEEE 802.16 Systems

Jae-Hyun Kim 23

Wireless Metropolitan Area NetworkBroadband Wireless AccessCoverage area : 1 KmMax Data Rate : 120Mbps~

IEEE 802.16 Air Interface StandardIEEE 802.16 : Air Interface (MAC and 10 ~ 66 GHz PHY)

WiMAX forum coordinating interoperability testingInteroperability documentation in development

P802.16a : amendment, 2 ~ 11 GHzLicensedLicensed-exempt

802.16 Standard defines 4 PHY ModeWirelessMAN-SC (Single Carrier)WirelessMAN-SCaWirelessMAN-OFDMWirelessMAN-OFDMA

IEEE 802.16 Overview

SS BS SS

SS

SS

Metropolitan Area

Jae-Hyun Kim 24

IEEE 802.16 TGs

TG1 – Air Interface (MAC and 10 ~ 60 GHz PHY)TGa : Amendment 2, PHY spec. for 2 ~ 11 GHzTGc : Amendment 1, Detailed System Profiles for 10–66 GHz TGd : Amendment 3: Detailed System Profiles for 2-11 GHz TGC :

TGC/C1 : Protocol Implementation Conformance Statements for 10-66 GHz WirelessMAN-SC Air Interface TGC/C2 : Test Suite Structure and Test Purposes (TSS&TP) for 10-66 GHz WirelessMAN-SC Air Interface TGC/C3 : Radio Conformance Tests (RCT) for 10-66 GHz WirelessMAN-SC Air Interface 10-66 GHz WirelessMAN-SC Air Interface

TGe : Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands (Mobile Wireless MAN)

TG2 : Coexistence of Fixed Broadband Wireless Access Systems

TGa : amendment to IEEE Std 802.16.2

Jae-Hyun Kim

FDD vs. TDD

FDDThe uplink and downlink channels are on separate frequencies.

TDDThe uplink and downlink transmissions share the same frequency but are separated in time

25

BroadcastFull Duplex

Capable SSDownLink

UpLinkHalf Duplex SS #1

Half Duplex SS #2

Frame j-2 Frame j-1 Frame j Frame j+1 Frame j+2

Down Link Subframe Uplink SubframeAdaptive

Bandwidth Request Slots

UpLink-MAP

DownLink-MAP

0.5 Sec / 1 Sec / 2 Sec

Jae-Hyun Kim 26

Frame Structure of IEEE 802.16 OFDMA TDD Mode Pr

eam

ble

DL

_MA

PFCH

DL

burs

t #1

(car

ryin

g th

e U

L_M

AP)

DL burst #3

DL burst #4

DL burst #2

DL burst #5

DL burst #6R

angi

ng

Prea

mbl

e

DL

_MA

P

FCHUL burst #1

UL burst #2

UL burst #3

UL burst #4

OFDMA symbol number

Subc

hann

el lo

gica

l num

ber

DL TTG UL RTGSlot Slot

Slot Slot

…

…

…

Slot One sub-channel

DL PUSC : two OFDMA symbolsDL FUSC : one OFDMA symbolUL PUSC : three OFDMA symbolsDL/UL AMC : two, three or six OFDMA symbols

PUSC : Partial usage of subchannelsFUSC : Full usage of subchannelsFCH : Frame control headerTTG : Transmit/receive transition gapRTG : Receive/transmit transition gap

k k+1 k+3s

s+1

s+L

CQ

ICH

, AC

K C

H

Jae-Hyun Kim 27

IEEE 802.16 Frame Structure

The frame structurePreamble: time/frequency synchronizationFCH: MAPs lengths, modulation and coding, usable subcarriersDL_MAP & UL_MAP: Burst profile (time, frequency, modulation, coding)DL/UL data burstsUL control channel

Ranging, CQI (Channel Quality Indicator) feedback, UL acknowledgement (ACK)

2 types of subcarrier permutation mode in 802.16 OFDMAThe distributed subcarrier permutation mode

PUSC, OPUSC, FUSC or OFUSC modeThe adjacent subcarrier permutation mode

AMC mode-OxUSC : Optional x Usage Sub-Channel

Jae-Hyun Kim

Adaptive Burst Profiles

Burst profileModulation and FEC (Forward Error Correction)

Dynamically assigned according to link conditionsBurst by burst, per subscriber stationTrade-off capacity vs. robustness in real time

Roughly doubled capacity for the same cell area

28

Jae-Hyun Kim

Localized and Distributed Resource Allocation

29

Adjacent Subcarrier Allocation (AMC)• Make better use of multiuser diversity• Low velocity user• Band AMC scheduler

Distributed Subcarrier Allocation (FUSC, PUSC)• Average intercell interference, avoid deep

fading by selecting subcarriers pseudo randomly• High velocity user• Diversity scheduler

Combined OFDMA Signal

Subcarrier allocated to User 1

Subcarrier allocated to User 2

Jae-Hyun Kim

UL Control Channel: Ranging

PurposeTime synchronization and power control in uplink channel

ApplicationsInitial and HO ranging: network entry and initializationPeriodic ranging: mobility provisioning Bandwidth request ranging: contention-based bandwidth request

General ProcedureRanging subchannel allocated by UL-MAP messageAn MS randomly selects a CDMA ranging code in a subset of ranging codesA BS sends RNG-RSP message with ‘status = success’A BS allocates a bandwidth by UL-MAP message to the MSThe MS transmits RNG-REQ message and continues with regular network entry

30

Jae-Hyun Kim

UL Control Channel: CQICH and ACK

CQICH Allocated to an MS using a CQICH control IEUsed to report the DL CINR (Carrier-to-Interference-plus-Noise Ratio)This channel occupies one UL slot in the FAST-FEEDBACK region allocated through UL-MAP messageFor diversity sub-channels

An MS reports the average CINR of the BS preambleFor band AMC sub-channels

An MS reports the differential of CINR values of five selected frequency bands

UL ACK ChannelTo support HARQ ACKAllocated using a HARQ ACK region allocation IEThe MS can quickly transmit ACK or NACK feedback for DL HARQ-enabled packet data using this UL ACK channel

31

Jae-Hyun Kim 32

IEEE 802.16e Functional Structure

Application service

SFID-CID mapping

Fragmentation / De-fragmentation

ARQ (Selective Repeat)

Scheduler (UGS, rtPS, ertPS, nrtPS, BE)

MAC PDU

Concatenation / Deconcatenation

HARQ

Resource allocation

PHY PDU

DL/UL-

MAP

MACmanagement

Handovermodule

(Backbone communication:

BS only)

Mobility(SS only)

Ranging

Band AMCscheduler

CDMAcode

Upperlayer

CS

MAClayer

PHYlayer

Controlflow

Messageflow Diversity

scheduler

Burst

MACPDU

MACPDU

MACPDU...

BurstBurst

MAC SDU

Fragmentof MAC SDU

Fragmentof MAC SDU BlockBlock

BlockBlockBlockFragmentof MAC SDU

Fragmentof MAC SDU

BlockFragmentof MAC SDU

Fragmentof MAC SDU

Non-ARQ Queue ARQ Queue

MAC SDUMAC SDU

PayloadHeader Sub-header PayloadHeader Sub-

header

Scheduled

UL control channel

SINR / PERmodeling

Burst 1

Burst 2

Burst 2

Burst 2

Burst 3

Burst 5

Preamble

FCH

DL

-MAP

UL

-MAP

Burst 1

Burst 2

Burst

3

Burst

4

Traffic DataTraffic DataTraffic Data

CQI

Jae-Hyun Kim 33

Convergence Sub-layer

CID MappingClassifier assign SDU to CID according to

SSID, destination IP sour./dest. address, TOS field, Port Number, etc.Related to Grant per SS or Grant per Connection discipline

Upper Layer

Classifier

SDU

CID 1CID 2CID 3

CID n

{SDU, CID,…}

Upper Layer

Reconstitution

{SDU, CID,…}

SDUSAP

SAP

SAP SAP

CS LayerCS Layer

SAP : Service Access Point

Jae-Hyun Kim 34

Scheduling Types

− Traffic Priority−HTTP−Best-effortBE

− Minimum Reserved Traffic Rate

− Traffic Priority−FTP

−Support non real-time service flows based on polling basis

nrt-PS


− Maximum Sustained Traffic Rate

− Maximum Latency

−MPEG video−Support variable size

real-time service based on polling access

rt-PS



− Maximum Latency

−VoIP with silence suppression−Variable size

vocodec

−Support variable size real-time service at periodic interval

ert-PS


− Maximum Latency− Tolerated Jitter

−VoIP without silence suppression

−Support fixed size real-time service at periodic interval

UGS

QoS ParameterApplicationDefinitionService

- UGS :Unsolicited Grant Service - ertPS : extended real-time Polling services- rtPS : real-time Polling Service - nrt-PS : non-real-time Polling Service - BE : Best Effort

Jae-Hyun Kim

UGS (Unsolicited Grant Service)

Scheduling SchemeConstant bit rate: VoIP service without silence suppressionPeriodically allocates a grant without a bandwidth request processTo reduce the bandwidth request delay and signaling overhead

35

Basic data transmission• BW request delay and signaling

overhead by (1) • Affected by traffic load

UGS• Periodic BW allocation can

reduce the BW request process

Jae-Hyun Kim

rtPS (real-time Polling Service)/nrtPS

Scheduling SchemeVariable bit rate: video streaming service (MPEG4), FTP servicePeriodically allocates a bandwidth to send a bandwidth request messagePI of rtPS is generally smaller than that of nrtPS

36

rtPS/nrtPS• Periodic polling can avoid a

random access process

Jae-Hyun Kim

ertPS (extended real-time Polling Service)

Scheduling SchemeVariable bit rate with a strict delay constraint: VoIP service with silence suppressionPeriodically allocates a grant and uses a Piggyback scheme to change a grant size

37

Problem of UGS

Problem of rtPS

ertPS• Piggyback using the remained BW• BW-REQ message through the

allocated BW• Reduce the wasted BW and signaling

overhead

Jae-Hyun Kim

BE (Best Effort)

Scheduling SchemeDelay tolerable service: HTTPContention-based bandwidth request

Bandwidth request rangingUses CDMA code in OFDMA PHY mode to reduce the collision probabilityContention resolution protocol: Truncated binary exponential backoff (BEB)

38

BE

Jae-Hyun Kim

Bandwidth Request Methods

Bandwidth requestSSs use to indicate to the BS that they need UL bandwidth allocationStand-alone BR header, Piggyback request (Grant management subheader)All requests for bandwidth shall be made in terms of the number of bytes

Two types of BRIncremental

BS shall add the quantity of bandwidth requested to its current perception of the bandwidth needs of the connection.

AggregateBS shall replace its perception of the bandwidth needs of the connection with the quantity of bandwidth requested.

The Type field in the BR header indicates whether the request is incremental or aggregate.

39

Jae-Hyun Kim

Polling

A BS allocates bandwidth sufficient to respond with a BRUnicast Polling

All PHY modesA BS allocates sufficient bandwidth for an SS to respond with a BR

Multicast or Broadcast PollingSC (Single Carrier) PHY and OFDM PHYIf insufficient bandwidth is available to individually poll many inactive SSs, some SSs may be polled in multicast groups or a broadcast poll may be issued.The contention resolution algorithm is applied

40

Initial Ranging Period

Data Transmission Period of SS1

DataTransmission Period of SSN

Contention Period

●●●

CollisionRequest Bandwidth

Request Bandwidth

Jae-Hyun Kim 41

MAC PDU Transmission

MAC PDUs are transmitted in PHY bursts A single PHY burst can contain multiple Concatenated MAC PDUsThe PHY burst can contain multiple FEC blocksMAC PDUs may span FEC block boundariesThe TC layer between the MAC and the PHY allows for capturing the start of the next MAC PDU in case of erroneous FEC blocks

MAC Message SDU 1 SDU 2

PDU 1 PDU 2 PDU 3 PDU 4 PDU 5

P FEC 1 FEC 2 FEC 3

MAC PDUs

Header Sub-header

Burst

- P : Preamble

Jae-Hyun Kim

Case Study 1:AMR Codec based Dynamic UL BW Req./Allo. Scheme

Motivation– Main QoS Requirement: Sensitive to delay requirement– Main Traffic Features of the VoIP Service: VoIP traffic rate is variable

• Repetition of the Cycle of the talk-spurt and silent-period• Talk-spurt: traffic rate can be variable according to the network condition (AMR, EVRC)• Silent-period: Silence descriptor (SID) frame can be generated with different period or random

interval– History of the UL BW Req./Allo. Scheme for VoIP Service

To meet delay requirement

- Persistent BW Allo. Scheme

(UGS in DOCSIS)

To improve the system efficiency (ON/OFF period)

- Dynamic BW Allo. Scheme (UGS-AD in DOCSIS and rtPS in IEEE

802.16)

To improve the system efficiency

(Traffic Rate Variable in Talk-spurt)

- Dynamic BW Allo. Scheme

(ertPS in IEEE 802.16e)

To improve the system efficiency

(Traffic Rate Variable in

Silent-period)

- ???

42

Jae-Hyun Kim


For the AMR Speech Codec– Main Traffic Features: Talk-spurt 20msec, Silent-period 160msec

Conventional ertPS

43

Jae-Hyun Kim

Proposed scheme– Interworking between App. and MAC

• Detect the VoIP Speech Codec in App.(AMR)• Use the VAD of VoIP Speech Codec• Separated Action due to VAD

– Dynamic Grant Interval– Dynamic Grant Size

44


if codec == AMR thenif VAD == Talk-spurt then

Grant for every 20 msec;

elseGrant for every 160

msec;end if

end if

Jae-Hyun Kim

Numerical Results– VoIP Capacity: maximum number of supportable VoIP users– Throughput : Received bits per second

The proposed algorithm can increase the VoIP capacity by 26% compared to the conventional ertPS

S.M Oh, S.H. Cho, J.H Kim, J.H Kwun, “An Efficient Uplink Scheduling Algorithm with Variable Grant-Interval for VoIP Service in BWA systems,” IEICE Trans. Commun., VOL.E91-B, NO.10 OCTOBER 2008. 45


Jae-Hyun Kim

Case Study 2:MPEG4 Codec based Dynamic UL BW Req./Allo. Scheme

Motivation– QoS Requirement: Video Telephony (delay < 50 msec in wireless networks)– Main Traffic Feature for MPEG4: Repetition of the Group of Picture (GOP) pattern (I

frame, B frame, P frame) • I frame : ave. 4742 bytes, min 4034, max 5184• B frame : ave. 147 bytes, min 35, max 882• P frame : ave. 259 bytes, min 100, max 1663

ertPS• Large Wasted Resource

rtPS• Access Delay: > 20 msec

Large Difference Size among the I, B, and P

Frame

Periodically Grant

Proposed BW Req./Allo. Scheme

Estimate Grant Sizebased on GOP

pattern

Merits- Efficiently Use the BW- Reduce the Access Delay

46

Jae-Hyun Kim

Case Study 2:MPEG4 Codec based Dynamic UL BW Req./Allo. Scheme

Simulation Results– Normalized Resource Utilization (%): Resource for information / Total resource– Ave. Access Delay (msec): Average time to send a video frame from SS to BS

0102030405060708090

100

UGS ertPS rtPS Proposed Scheduler

02468

101214161820

UGS ertPS rtPS Proposed Scheduler

Normalized Resource Utilization (%) Access Delay (msec)

The proposed algorithm can efficiently use the radio resource by about 99 % and send a video frame with average access delay 11 msec.

J. S. Kim and J. H. Kim, "MPEG-4 codec based uplink resource allocation scheme for the video telephony service in IEEE 802.16e/m system," in Proc. CCNC 2010, Las Vegas, USA, 9-12. Jan. 2010.

47

Jae-Hyun Kim

Case Study 3: BW Request Scheme for BE Services (SMS Service)

Motivation– Main Traffic Feature: Insensitive to delay requirement– Conventional BW Req. Scheme: Random Access– History of the BW Req. Scheme for BE Services in BWA Networks

DirectContention

Scheme

- Pure Aloha

- Slotted Aloha

Indirect Contention Scheme

- Short Message BW Req. Scheme

(DOSCIS, IEEE 802.16)

collision resolution algo.

- Binary Exponential Backoff Algo.

(DOCSIS, IEEE 802.16)

Random AccessShould we immediately request the

required BW for BE service ???

It may be NO

• It is possible that a BE packet is sent without contention.

• The system overhead for BW req. can be reduced.

48

Jae-Hyun Kim

•BW Req. with Uplink Periodic Ranging•Merits

- Avoid the Contention- Reduce the System Overhead for the BW Req.

For the Ranging Mechanism– Uplink periodic ranging is required to maintain a connection

• Unstable due to Traffic Load

• BW Req. Slot is needed

Conventional ertPS Proposed

49


Jae-Hyun Kim

Numerical and Simulation Results– Uplink throughput: Received bit per second – Utilization (for given same traffic load): Used resource / total resource

It can improve the system capacity by 11 %compared to that of the conventional system

오성민, 김재현, 김봉찬, 김성완 "광대역무선통신시스템에서상향링크대역폭요청장치및방법," 국내특허, 출원일 : 2010.02.18 출원번호: P2010-0014505 50


Jae-Hyun Kim 51

Part 2: Handover in Mobile/Wireless System

- Handover Overview

- Layer 2 Handover (IEEE 802.16e System based)

- Layer 2.5 Handover

- Layer 3 Handover

- Application Handover

Jae-Hyun Kim

용어정의

이동단말

MN (Mobile Node), MS (Mobile Station), UT (User Terminal)기지국 또는 접속점

AP (Access Point), BS (Base Station)PoA (Point of Attachment)

CoA (Care-of-Address)RCoA (Regional Care-of-Address)LCoA (On-link Care-of-Address)

RouterPAR (Previous Access Router)NAR (New Access Router)MAP (Mobility Anchor Point)MAG (Mobile Access Gateway)LMA (Local Mobility Anchor)

52

Jae-Hyun Kim

이동통신망상호공존요인

이동통신망 상호 공존 요인경제적 요인

기존 통신망의 재활용을 통한 망 설치 비용 절감

서비스 특성에 따른 망 선택을 통한 서비스 비용 절감

기술적 요인

단일 통신망으로 사용자의 요구를 만족시키기 어려움

높은 전송속도, QoS, 고속의 이동속도

53

통신망의 변경에 따른 서비스의 단절을줄이기 위한 이동성 보장 기술 필요

Jae-Hyun Kim

핸드오버의정의

IETF (Internet Engineering Task Force)The process by which an active MN changes its point of attachment to the network, or when such a change is attempted

WINNER (Wireless World Initiative New Radio)The process in which the radio access network changes the radio transmitters or radio mode or radio system used to provide bearer services, while maintaining a defined bearer service QoS and minimum added system load

IEEE 802.21 MIH(Media Independent Handover)The process by which a mobile node obtains the preservation of facilities for supporting traffic flows upon occurrence of a link-switch event

54

- J. Maner, and M. Kojo,“Mobility related Terminology,“ RFC3753, Jun., 2004- WINNER, “D4.1: Identification and definition of cooperation schemes between RANs “, internal deliverable, IST-2003-507581 WINNER, Jun., 2004- IEEE P802.21™/D01.00, “IEEE P802.21/D01.00 Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover

Services,” Mar., 2006

Jae-Hyun Kim

핸드오버 기술분류

55

Handover classification

Necessity of handover

Network types involved Frequencies engaged

Triggering object User control allowance

Number of connection involved

Handover in

same network

technology

Handoverin

different network

technology

Horizontal handover

Verticalhandover

Handover between

access pointoperating on same frequency

Handover between

access pointoperating

on different frequency

Intra-frequency

Inter-frequency

Mobile initiatedBS initiated

Mobile decisionBS decision

Initiation Decision

User sets preference of

handover decision

User cannot control

handover decision

Proactivehandover

Passivehandover

Handover must be executedin order to

avoid disconnect

Handover may be executed to improve

the quality ofservice

Obligatoryhandover

Voluntaryhandover

Mobile node maintain only one

connection

Mobile node can maintain more than two

connection

Hard Handover

SoftHandover

Mobile node switches

connections in same

access point

SofterHandover

N. Nasser et al, “Handoffs in Fourth Generation Heterogeneous Networks” IEEE Commun. Mag., vol. 44, no. 10, Oct. 2006, pp. 96-103.

Jae-Hyun Kim

핸드오버평가척도

56

척도

신뢰성(Reliability)

연결성(Seamless)

간섭 회피율(Interference Prevention)

부하 제어(Load

Balancing)

핸드오버

수행 횟수

정의 필요 기술

• 핸드오버 이후 서비스의 품질이 일정하게 유지되는 정도

• 핸드오버를 수행할 단말에게 제공할 수 있는서비스 품질 정보를 기반한 핸드오버 결정 기술

• 핸드오버를 수행하는 동안 서비스의품질이 일정하게 유지되는 정도

• 핸드오버의 이전에 이동 단말에 관한 정보를 상호교환하는 기술

• 핸드오버 제어 정보의 재전송 기술

• 핸드오버 수행 단말의 무선 채널과동일 또는 인접 채널을 사용하는 단말로인한 간섭에 대한 회피 정도

• 송신 전력을 제어하는 전력 제어 기술

• SINR에 따른 핸드오버 결정 기술

• 간섭 회피 기술

• 기지국 또는 접속점의 가용한 자원을 균일하게 유지하기 위한 제어

• 기지국간 부하제어 기술

• 셀부하 정보를 기반으로 하는 핸드오버 결정 기술

• 품 질저하 극 복 및 서 비스 요 구를충족시키지 위해 시행되는 핸드오버 횟수

• 상대적 임계값을 이용한 핸드오버 결정 기술

N. Nasser et al, “Handoffs in Fourth Generation Heterogeneous Networks” IEEE Commun. Mag., vol. 44, no. 10, Oct. 2006, pp. 96-103.

Jae-Hyun Kim

계층별핸드오버기능

57

Layer 2

Layer 2.5

Layer 3

Layer 4

or upper

Jae-Hyun Kim

2계층이동성보장기술

−핸드오버 관련 정보 측정 기술 (Scanning)−트리거 (Initiation)−핸드오버 결정 (Decision)−핸드오버 수행 (Execution)−상향링크 정보를 이용한 핸드오버

58

Jae-Hyun Kim

2계층이동성보장기술과정

59

Serving cell Target cell

Measurement

Trigger

Trigger threshold

Hysteresis

Decision & Execution

Jae-Hyun Kim

핸드오버관련정보측정기술

현재 통신 조건에 적합한 무선 통신망을 찾기 위한 정보의

획득 방법

측정 정보

물리계층 측정 정보

Received Signal Strength Indicator(RSSI), Signal to Interference plus Noise Ratio(SINR), etc.

상위 계층 측정 정보

Cell load, User preference, QoS, etc.

측정 대상

Preamble signal, feedback report, pilot channel

60

Jae-Hyun Kim

핸드오버관련정보측정기술:IEEE 802.16e의 Scanning

핸드오버에 적합한 인접 기지국을 결정하기 위하여 serving BS와 neighbor BS의 신호 측정

61

BS #1 (Serving)MS BS #2

(Target)BS #3

(Target)

MOB_NBR-ADV(N_NEIGHBORS =2)

MOB_SCN-REQ(Scan duration = N frames, Interleaving interval = P

frames, Iteration= 2 times)MOB_SCN-RSP

(start frame = M frames, duration = N frames)

Synchronize with BS #2, measure metrics

M frames


Non-scanning interleaving Interval (P frames)



Scanning Interval

duration = N frames

Scanning Interval

duration = N frames

Data Traffic (if any)

Scanning request by MS

Scanning procedure

IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broad-band Wireless Access Systems, Feb. 2006

Jae-Hyun Kim

핸드오버관련정보측정기술:IEEE 802.16e의 Association

Scanning 동안 예상 기지국과 정보 교환Ranging parameter(power offset, CDMA code, etc.)와 Basic service capability 정보 획득

Association levelLevel 0: Scan / Association without coordination

Contention based ranging Level 1: Association with coordination

Unicast ranging인접기지국에서 유효한 CDMA ranging code와 transmission opportunity(Rendezvous time) 전송

Level 2: Network assisted association reportingMulticast ranging인접 기지국에게 유효한 CDMA ranging code코드만 할당 받음

Ranging 구간은 serving BS에게 부여 받음

62

Jae-Hyun Kim

핸드오버관련정보측정기술:IEEE 802.16e의 Association

63

BS #1(Serving)MS BS #2

(Target)BS #3

(Target)

MOB_NBR-ADV (N_NEIGHBORS =2)

MOB_SCN-REQ(duration = N frames, Association level)

MOB_SCN-RSP(start frame = M frames, duration = N frames,

Association parameter)


M frames


Scanning Interval duration

= N frames

RNG-REQ(Association : Initial ranging)

RNG-RSP(Ranging parameter, service level)

Scanning request by MS

RNG-REQ(Association : Initial ranging)

RNG-RSP(Ranging parameter, service level)

Scanning with Association procedure


Jae-Hyun Kim

트리거 (Trigger)

측정된 정보를 기반으로 핸드오버 알고리즘에 특정한 행동을취하도록 명령하는 것

측정된 링크 품질이 임계값 이하일 경우스케닝, 핸드오버 시작

L2 트리거물리적인 정보를 기반으로 한 트리거

Signal strength, Interference level, BER/PER(Packet Error Rate), Power control results

서비스 측면에서 알고리즘에 의한 트리거

QoS violation, CAC&CF(Connection Admission Control & Connection Forwarding), Location, Velocity, A priori-knowledge(history, preference), Service availability

64

Jae-Hyun Kim

MOB_BSHO_REQ(Recommended BS=BS#2, BS#3)(BS#2 service level prediction =2)(BS#3 service level prediction =2)

(Resource Remain Type = MS resource retain)

HO-pre-notification(MS identifier, connection parameters,

capabilities, required BW and QoS )

트리거(Trigger):IEEE 802.16e의핸드오버 초기화과정

65


(Target)BS #3

(Target)

MOB_MSHO_REQ(Recommended BS = BS#2, BS#3)

(Neighbor BS#2 : CINR = v1)(Neighbor BS#3 : CINR = v2)

HO-confirm

HO-pre-notification(MS identifier, connection parameters, capabilities, required BW and QoS )

HO-pre-notification-response(Ack, lower QoS class)

HO-pre-notification-response(Ack, same QoS class)

MOB_MSHO_RSP(BS_ID = BS#3)


capabilities, required BW and QoS )HO-pre-notification

(MS identifier, connection parameters, capabilities, required BW and QoS )HO-pre-notification-response

(Ack, same QoS class)HO-pre-notification-response

(Ack, same QoS class)

Handover initiation

by MS request

Handover initiation

by BS request


Jae-Hyun Kim

핸드오버결정 (Decision)

핸드오버 결정 요인수평적 핸드오버

신호 품질 및 망내 자원 상황

수직적 핸드오버

망내 부하, 서비스 가격, 지원 가능한 통신 속도, 보안, 이동 속도및 전력 소모

IEEE 802.16eMS initiated & decision, BS initiated & MS decisionSignal strength, cell load, QoS level

66

Jae-Hyun Kim

MOB_HO_IndicaitonDecision to cancel

handover

핸드오버결정:IEEE 802.16e의핸드오버결정

67


(Target)BS #3

(Target)





HO-confirm





MOB_HO_Indicaiton(Time=L frames)

Release channel with BS#1

Decision to execute handover

Data traffic


Handover initiation

by MS request

Jae-Hyun Kim

핸드오버수행

Serving BS와의 연결을 종료하고 target BS와의 무선 링크를재설정 하는 과정

Seamless handover (Handover interruption time 고려)끊어짐 없는 핸드오버를 제공하기 위해서는 서비스 별로 정의된지연한계 이내에 핸드오버 수행을 완료해야 함

68

Application

Conversational voice

Video phone

Telemetry

Interactive games

Telnet

One-way delay

<150 msec preferred, <400 msec limit

<150 msec preferred, <400 msec limit

< 250 msec

< 250 msec

< 250 msec

Voice messaging

Video phone

< 1 sec for playback, < 2 sec for record

< 4 sec /page

3GPP TSG-SA Working Group 1, TSGS1#4(99)529, 5-9 July 1999

Jae-Hyun Kim

핸드오버수행:IEEE 802.16e의핸드오버수행

핸드오버 수행 절차Down link synchronization

하향 채널 동기, preamble detectionDL-MAP/ UL-MAP detection

하향링크 주파수 조정

RangingCID(Connection ID) 할당, 상향링크 frequency/uplink power/time 조정

Ranging 방안물리계층에 따라 달라짐

Time slot으로 구분(OFDM, SC(Single Carrier), SCa PHY)Time slot과 CDMA code로 구분 (OFDMA PHY)

접근 방안

경쟁기반 접근 방안

비 경쟁기반 접근 방안69

Jae-Hyun Kim

핸드오버수행:IEEE 802.16e의핸드오버수행

70

MS BS #2(Target)

Fast Ranging_IE(UL_MAP)

RNG-REQ(MS MAC address, Serving BS_ID, Raging Purpose Indication, HMAC/CMAC)

RNG-RSP(MS MAC address, Basic CID, Primary CID, HO Process Optimization, CID Update, CMAC)

Complete Initial Network Entry (after handover)

UL-MAP IE()BR Header

Downlink traffic

UL_MAP : CDMA Allocation IE()

RNG-REQ (CDMA code + Contention)(MS MAC address, Serving BS_ID, Raging Purpose Indication, HMAC/CMAC)

RNG-RSP(MS MAC address, Basic CID, Primary CID, HO Process Optimization, CID Update, CMAC)


UL-MAP IE() : CDMA Allocation IE()

BR Header

Downlink traffic

CDMA Code for Handover RangingRNG-RSP

(Raging status = Success)

CDMA Code for Bandwidth Request (BR)

OFDM PHY

Non-contention based ranging

Using Fast ranging IE() when scanning

has done with association

OFDMA PHY

Contention based ranging

Without association


Interruption time

Interruption time

Jae-Hyun Kim

IEEE 802.16e의 2계층핸드오버과정

Initiated by MS request

71


(Target)BS #3

(Target)





HO-confirm

Fast Rainging_IE(UL_MAP)

RNG-REQ



HO-pre-notification-response(Ack, same QoS class)


MOB_HO_Indicaiton(Time=L frames)

Release of MS

RNG-RSP


Initiation

Decision

Execution


Jae-Hyun Kim

연구 배경IEEE 802.16e 와 같은 TDD OFDMA 에서는 셀 내의 MS의 위치와분포에 따라 Uplink와 Downlink의 채널 품질이 다를 수 있음

주기적인 Scanning으로 인한 통신 두절이 있음

특징주기적인 Scanning 구간 대신 핸드오버 요청 시에만 주변 기지국의신호를 측정

핸드오버 결정 요인으로 Uplink와 Downlink를 모두 고려

Case Study 1:상향링크정보를이용한핸드오버

Jae-Hyun Kim

MS BS#1(Serving)

BS#2(Target)

BS#3(Target)

Th1 : Uplink 를 고려한 핸드오버 결정 임계값

Th2 :AMC 유저를 위한 핸드오버 임계값

Th3 : 상향링크를 고려한 핸드오버 대상 기지국 결정임계값 (UL hysteresis사용)Th4 :통신을 위한 최소 Downlink 신호품질 임계값

Th5 : 하향링크를 고려한 핸드오버 대상 기지국 결정임계값 (UL hysteresis사용)Th6 : 통신을 위한 최소 Uplink 신호품질 임계값

Case Study 1:상향링크정보를이용한핸드오버과정

(user ID, resource allocation informatio)

Uplink

신호품질 측정

Uplink 신호 품질 측정 결과 보고

Downlink 신호품질 측정

Downlink 신호품질 측정 결고 보고

Downlink와 Uplink를 고려한 핸드오버 결정

43__ & THPTHPP DL_targetservingULtargetUL >>−

65__ & THPTHPP UL_targetservingDLtargetDL >>−

S. H. Cho et al, “Hard handoff scheme exploiting using uplink and downlink signal in IEEE 802.16e system”, VTC 2006 Fall

Jae-Hyun Kim

Case Study 1:상향링크를이용한핸드오버성능평가

OPNET을 이용한 상향 링크 신호 측정상향 링크 사용자의 분포에 따른 비대칭적인 상향링크 신호 품질상향 링크를 고려하여 상향 링크의 신호 감쇠로 인한 outage probability를 줄일 수 있음

74

<Uplink>

BS1

BS2

<Downlink>

Jae-Hyun Kim

2.5계층이동성보장기술

−IEEE 802.21 Media Independent Handover (MIH)

75

Jae-Hyun Kim 76

IEEE 802.21 MIH

최적화된 핸드오버를 수행하기 위하여 필요한 망에 관련된정보와 무선링크의 정보의 제공

2계층 이동성관리 기술의 정보와 상위계층 이동성 관리 기술의 연동

MIH 제공 서비스Event servicesCommand servicesInformation services

SIP MIPv4 MIPv6 HIP …

Upper Layer (L3 and above)

MIH function

IEEE802.3

IEEE802.11

IEEE802.16 3GPP 3GPP2

Lower Layer (L2 and below)

LinkEvents

LinkCommands Information

Service

MIHEvents

MIHCommands

InformationService

< MIH 프로토콜 스택>

IEEE 802.21/D03.00, “Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover Services”, December 2006

Jae-Hyun Kim

IEEE 802.21 MIH:Multiple Access Network Reference Model

MIH provides convergence of link-layer state information from multiple heterogeneous access technologies

Supported by existing SAP in IEEE 802.xNot exist SAP for MIH in 3GPP/3GPP2

MIH defines MIH_3GLINK_SAP to use MIH for 3GPP/3GPP2

77- LSAP : Link Service Access Point - LLC : Link Layer Control -SAP : Service Access Point -MLME : MAC Layer Management Entity

- PLME : Physical Layer Management Entity - CS : Convergence Sublayer

Jae-Hyun Kim 78

IEEE 802.21 MIH: MIH Services

Media independent event services하위 계층의 상태 변화를 상위 계층에 알리는 역할 수행

이벤트 생성 위치에 따른 분류Remote event : 다른 망 요소에서 생성된 이벤트Local event : 동일한 망 요소에서 생성된 이벤트

이벤트 인식 위치에 따른 분류Link event : PHY, MAC MIHMIH event : MIH L3+

Jae-Hyun Kim


이벤트 내용에 따른 분류State change event

MAC또는 PHY 계층의 상태변화ex) Link_Up, Link_Down

Parameter event링크 계층 파라미터의 변화ex)Link_Parameter_Change

Predictive event과거와 현재의 조건을 기반으로 링크의 변화 예측 정보 알림ex)Link_Going_Up, Link_Going_Down

Synchronous event링크 계층 동작에 관한 정보 알림ex)Link_Handover_Complete

Transmission event링크계층에서 상위 계층 PDU의 전송상태 알림ex)SDU_Transmit_Status

79

Jae-Hyun Kim 80


Media independent command service링크의 상태를 결정하고 다중모드 단말을 제어명령 생성 위치에 따른 분류

Remote command : 다른 망 요소에서 생성된 명령Local command : 동일한 망 요소에서 생성된 명령

명령 인식 위치에 따른 분류MIH event : L3+MIHLink event : MIH PHY, MAC

Media independent information service핸드오버에 필요한 정보를 획득하기 위하여 사용됨

Neighbor map, link layer information, availability of service

Type

0x0 : Core MIH specific IEs

0x2 : Vender specific IEs

0x3 : Working group specific IEs

Jae-Hyun Kim


−Mobile IP−Fast Mobile IPv6 (FMIPv6)−Hierarchical MIPv6 (HMIPv6)−Proxy Mobile IPv6 (PMIPv6)

81

Jae-Hyun Kim

Mobile IP

설계 목적IP를 사용하는 MN의 이동시에도 연결을 유지하기 위하여 개발됨

MN의 이동에 의한 PoA의 변경시 IP 주소의 변경이 요구됨

이동 전에 연결한 TCP연결을 유지하기 위해서는 IP 주소의유지가 필요

특징두 개의 IP 주소(Home address, Care of Address)를 유지

기본적인 과정Agent discovery

MN의 이동에 따른 IP 주소의 변경 필요성을 발견하는 과정

Registration변경된 IP주소를 변경하는 과정

Data transfer변경된 IP주소로 IP패킷을 전송하는 과정

82

Jae-Hyun Kim

Mobile IP:동작절차

Agent Discovery

83

0. MovementMN MN

AP1 AP2

FA1 FA2

HA

2. Agent Advertisement Message1. Agent Solicitation Message

CoAgeneration

RegistrationData transfer

3. Registration Request

Binding cacheHome

addressCoA

Life

time

4. Registration Reply

Visitor tableHome

address

HA

address

Link level

address

Life

time

CN MN Payload

Src. Dest.

CN MN PayloadHA CoA

Encapsulation

CN

Jae-Hyun Kim

Fast Mobile IPv6 (FMIPv6)

설계 목적경로최적화를 통한 망 효율성 향상

핸드오버에 의한 패킷 손실 감소

Binding Update에 의한 핸드오버 지연 감소

특징new PoA의 발견시 old PoA를 통한 binding update

L3 핸드오버 이전에 old PoA에서 미전송된 패킷을 터널링시킴패킷 손실 감소

핸드오버 동안 터널링된 패킷 수신핸드오버 지연 감소

CoA 관리를 CN(Corresponding Node)이 수행

HA(Home Agent)를 경유하지 않음경로 최적화

MN가 현재의 AR에 L2 연결을 유지하고 있는 동안에 L3 핸드오버수행

CoA 등 MN에 대한 정보를 미리 공유

AR 정보 교환 프로토콜이 필요84R. Koodli,“ Fast Handovers for Mobile IPv6,“ RFC4068, Jul.,2005

Jae-Hyun Kim

Fast Mobile IPv6 (FMIPv6):동작절차

85

0. Movement 7. Movement

1. RtSolPr

2. PrRtAdv

3. FBU

4. HI

5. HAck

6. FBAck

8. FNA

9. BU

MN MNMN

AP AP

Old PoA New PoA

CN

-RtSolPr : Router Solicitation for Proxy Advertisement -PrRtAdv : Proxy Router Advertisement -FBU : Fast Binding Update- HI : Handover Initiate -Hack : Handover Acknowledge -FBAck : Fast Binding Acknowledgment

-FNA : Fast Neighbor Advertisement -BU : Binding Update

Jae-Hyun Kim

Hierarchical MIPv6 (HMIPv6)

설계 목적MIPv6 에서 잦은 핸드오버시 MN과 CN 사이에 발생하는 Binding update의 부하를 줄이기 위함

특징망을 계층 구조로 관리

상위 MAP의 변경에 따른 RCoA의 변경 필요시에만 HA와 CN에게Binding update

MAP(Mobility Anchor Point)Local HA(Home Agent) 의 역할

RCoA (Regional Care-of-Address)최상위층의 MAP에 따라 결정되며 HA에 등록되는 CoA

LCoA(On-link Care-of-Address)같은 MAP의 네트워크 안에서 구별가능 한 CoA

86H. Soliman, C. Castelluccia, K. El Malki and L. Bellier, “Hierarchical Mobile IPv6 Mobility Management (HMIPv6)”, RFC 4140, August 2005

Jae-Hyun Kim

Hierarchical MIPv6 (HMIPv6):동작절차

87

MAP1

AR1 AR2

MAP2

AR3 AR4

CN

1. Router Advertisements2. Binding Update

(RCoA1 RCoA1)

(LCoA1 LCoA2)

HA

0. Movement 4. Movement

Care- of-Address

(RCoA1)

(LCoA1 )

3. Binding Update Acknowledge

Care- of-Address

(RCoA1)

(LCoA2 )

5. Router Advertisements

Care- of-Address

(RCoA2)

(LCoA3 )

6. Binding Update

(RCoA1 RCoA2)

(LCoA2 LCoA3)

7. Binding Update Acknowledge

MN

Jae-Hyun Kim

Proxy Mobile IPv6 (PMIPv6)

설계 목적IPv6 지원 망에서 단말이 이동관련 시그널에 관련하지 않고 이동성을제공하기 위함

특징네트워크 기반 Mobile IPIP mobility 에 의한 단말의 변화 없음

Tunneling overhead 감소

MN과 HA,CN 간의 Binding Update overhead감소

Mobile IPv6의 재사용

실제 구현 및 설치에 용의함

위치정보 보안 강화

MN-HoA(Home-of-Address)를 유지하여 위치추적이 쉽지 않음

88S. Gundavelli, K. Leung, V. Devarapalli, K. Chowdhury and B. patil, “Proxy Mobile IPv6”, draft-ietf-netlmm-proxymip6-00.txt, April 8, 2007

Jae-Hyun Kim

Proxy MIPv6 (PMIPv6):동작절차

89

MN

MAG2MAG1

LMA

AAA-server

CN

1. Router Solicitation

0. Movement

2. AAA Query

3. AAA Reply

4. Router Advertisement

IP addressconfiguration

(MN-HoA)

5. Proxy BU

6. Proxy BU ACK

Update Binding cache

Entry for the MN

- Proxy BU : Proxy Binding - Proxy BU ACK : Proxy Binding Acknowledge MAG (Mobile Access Gateway)

- LMA (Local Mobility Anchor) -AAA : Authentication Authorization Accounting

Jae-Hyun Kim


−SIP−Application layer handover

90

Jae-Hyun Kim

SIP(Session Initiation Protocol)

IETF에서 세션(session)을 관리하기 위하여 정의응용계층 프로토콜

Initiation, management, termination of sessions across packet network

re-INVITE를 사용한 이동성 보장 기술에 참여 가능

SDP (Session Description Protocol)세션에 관련된 보다 자세한 정보를 관리

Session name and purposeTimes the session is activeMedia to useInformation where to send and receive mediaContact information

91

- J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and, E. Schooler,“ SIP : Session Initiation Protocol,“ RFC3261, Jun., 2002- Yung-Mu Chen et el. “SCTP-based handoff based on MIH triggers information in campus networks,” Feb., 2006, ICACT 2006, vol(2), pp. 1297 - 1301

Jae-Hyun Kim

SIP(Session Initiation Protocol): Session initiation procedure

92

MN MNMN

AP AP

Proxy

ServerProxy Server

Location/Redirect

ServerProxy

ServerUser Agent

1. INVITE 1. INVITE

2. 302

(Moved Temporarily)

3. ACK 4. 180(Ringing)

200(OK)3. ACK

5.re-INVITE

Jae-Hyun Kim

Application layer handover

핸드오버 지연을 최소화시키기 위하여 망의 도움없이다중경로/다중세션 기술을 사용하여 접속망을 변경하는과정

배경Coexistence

향후 통신 서비스는 CDMA2000, UMTS, WiBro, WLAN 등의다양한 무선 통신망이 상호 공존할 것으로 예상됨

Multi-interface support하나의 MN이 여러 개의 RAT를 사용함

각 RAT는 독립된 interface를 가짐

MN은 multi-homing 기술을 지원함

93오성근, 김재현, 이현진, “사용자 단말에 의해 제어되는 끊어짐 없는 서비스 방법 ,” 특허 출원중

Jae-Hyun Kim

Application layer handover:Reference Architecture

94

Application program/ User Interface

RTP/RTCPSIP

SCTP, TCP, UDP

PDCP

Service Continuity Management

MAC

Application

Transport

Network

Link

Physical

SDP

1

3

9

8

4

7

5

1 사용자 정책 및 서비스 정보

망 탐색 결과 (RAT정보, 신호세기, 지연)

서비스 플로우의 정보

Time stamp 정보

다중 세션 연결 요청

QoS monitoring 정보

다중 세션 연결 정보

Sequence 정보

사용자 선호도

다중 라디오 연결 요청

단일/다중 연결에 따른 필요 자원양

경로별 MIMO stream 수, MCS level, BLER 정보

2

3

4

5

6

7

PHY

User plane Control plane

Information Management

Session Management

Network Selection

QoE Management

Network Mearsurement

2

8

6

9

10

Link Manager

10

a b

c

a 세션간 서비스 스케줄링 기능

서버간 동기화 기능

ARQ 동기화 기능

사용자 중심 MIMO 모드 설정 기능

RB 요청, 반납 및 공유요청 기능

b

c

11

11

필요 기능

교환 정보

제어 정보

데이터 패킷

IPv4, IPv6, MIP

RRC

Traffic Junction Management

RLC

e

d

e

Traffic Condition Indicator

12

12

d

Jae-Hyun Kim 95

Application layer handover:Handover Decision Module

Handover decision module의 기능

Handover decision

Information Management

QoS Management

Sequence Management

Handover Management

From User interface

Handover policy of user

From MIH

Available RAT

information

User preference

RAT information

QoS monitoring

information

Handover control(Measurement, Modem

on/off, Link setup, Registration request)

Session Duplicate

Request

From SDP,SIP

Service flow information

Service flow information

Session control(Session generation,

termination)

Control

Multi session identifyFlow 1 Flow 2

Concatenated Flow

User

Jae-Hyun Kim

사용자중심이동성제공

RAN 1 RAN 2

MN

Signal Qualityfor RAN 1 Signal Quality

for RAN 2

Measurement triggerMIH Handover magt.

GW GW

Service flow

Handover init. triggerMIH Handover magt.

MeasurementLink setup

Handover decision triggerMIH Handover magt.

Session request

Session Request

Service flow

RAN2 modem up

Flow 1Flow 2

ServiceIP1 Data

IP2 Data

AAA server

AAA server

Jae-Hyun Kim 97

Part 3: Mobile/Wireless System Network- Network Design Issues

- Network Architecture/ Protocol Stack

Jae-Hyun Kim 98

Wireless Network Design Issues:1-tier or 2-tier Network Architecture

1-tier or 2-tier Network Architecture

Jae-Hyun Kim

Wireless Network Design Issues:1-tier and 2-tier 장·단점

Consideration of Function Positioning in Wireless Networks

99

Functions 2-tier ASN model 1-tier ASN model Related End-to-End

QoS performance metric

L3 Handover Functions Positive if in an ASN-GW NegativeTransmission DelayDelay JitterPacket Loss Rate

L2 Handover Functions Positive if in a BS Positive if in a BSTransmission DelayDelay JitterPacket Loss Rate

ARQ Functions Positive for handover process if in an ASN-GW

Negative for handover process

Transmission DelayDelay JitterPacket Loss Rate

Admission Control Positive if in an ASN –GW Negative Call Dropping Rate

Scheduler Positive if intercellcoordination is required

Positive if fast feedback is required

Data RateTransmission Delay

Intercell Interference Mitigation (IIM)

Functions

Positive to centralized scheme

Positive to distributed scheme

Data RatePacket Loss Rate

Jae-Hyun Kim

Wireless Network Design Issues :QoS and Mobility Provisioning

Wireless Network ArchitectureQoS Policy Server Positioning SIP Server Positioning

100

• MeR (Mesh Router)- MN 무선 통신 인터페이스

- MR 무선 통신 인터페이스

- MeR 무선 통신 인터페이스

• MR (Mobile Router)- MN 무선 통신 인터페이스

- MR 무선 통신 인터페이스

- MeR 무선 통신 인터페이스

•MN (Mobile Node)- MR, MeR 무선 통신 인터페이스

• 무선 망 설계 고려사항

- 백본링크 단절 시 연결성

- MN/MR의 이동성

+ 통신환경의 잦은 변화

+ 망 토폴로지 변화

Jae-Hyun Kim

Wireless Network Design Issues:Mobility Provisioning

Considerations of Network Architecture Design

101

• 무선 망 IP 도메인 구성 방안

Jae-Hyun Kim



102

• HA의 위치 구성 방안

Jae-Hyun Kim



103

• 무선 망 subnet 구성 방안

Jae-Hyun Kim



104

• 무선 망 IP 주소 할당 방안

Jae-Hyun Kim

Wireless Network Design Issues:Protocol Stack for Mobility Provisioning

PMIP & SIP

105

Application

SDP

SIP Client

Transport

Internet

Network access

Physical

Measurement

HO Trigger

Link establishment

Management

plane

Event driven

command

Control plane

User plane

Application

SIP Registrar

SIP Proxy

Internet

Routing table

Network access

Physical

Measurement

HO Trigger

Link establishment

Management

plane

Control plane

User plane

Proxy update

Application

SIP Registrar

SIP Proxy

Internet

Network access

Physical

Management

plane

Control plane

User plane

Routing update

Routing table

SIP Location

Proxy update trigger

Tunneling

Buffer

Event driven

command

Tunneling

Buffer

Binding table or visitor table

Binding table or visitor table

Tunneling

Buffer

Tunneling

BufferBinding update Binding update

Binding update request

IP generation

Network prefix

transfer

re-invite trigger

re-INVITE

SIP를 사용할경우의 요구 기술

PMIP를 사용할경우의 요구 기술

MR이동 및 공통요구 기술

Proxy update

SIP를 위한 trigger PMIP를 위한 trigger 공통 요구 trigger

Jae-Hyun Kim

Wireless Network Design Issues:QoS Provisioning

정책기반 QoS 보장 참조망 구조 설계고려사항

백본 링크 단절 시 연결성 > 효율성

백본 링크 단절 시 연결성통신연결: 상대단말의 위치 정보SIP 서버

정책연결: 저장된 정책 정보Policy 서버

SIP 서버Local SIP Proxy 서버, Local SIP Location 서버, Global 서버

유선백본링크 연결 시: Global 서버

유선백본링크 단절 시: MeR 단 SIP Location 서버

Location 서버간 동기화 유지

MR-MeR 백본링크 단절 시: MR 단 SIP Proxy 서버

Full-Distributed 구조

Policy 서버정책 수행 시 PEP PDP 정책 결정 요청

PEP cache 정책 임시 저장

MeR 별 구분된 정책 수행 고려

Half-Distributed 구조

Local Server

SIP/Policy

(Proxy, Registrar, Location)

SIP (Proxy, Registrar)

Global Server

106

• PEP: Policy Enforcement Point

• PDP: Policy Decision Point

Jae-Hyun Kim

End-to-End QoS 보장 구조계층별, 네크워크 별(액세스, 백본) QoS 보장 구조 설계

<End-to-End QoS 보장 구조>

Wireless Network Design Issues:Protocol Stack for QoS Provisioning

107

Jae-Hyun Kim

Control PlaneEnd-to-End 통신 연결 시 signaling에 필요한 기능 설계


Wireless Network Design Issues:Protocol Stack for QoS Provisioning

108PEP: Policy Enforcement Point PDP: Policy Decision Point

Jae-Hyun Kim

User PlaneEnd-to-End 통신 시 QoS 보장에 필요한 기능 설계


Wireless Network Design Issues:Protocol Stacks for QoS Provisioning

109

Jae-Hyun Kim 110

Data Center

Network Reference Architecture (UMTS Rel99)

Jae-Hyun Kim 111

PHY

Protocol Stack for UMTS PS service (Data)

UE

Air

SGSNUMTSNode-B

PHY

TCP/UDP

ATM

AAL2

DchFP

Phys

IP

PDCP – Packet Data Convergence Protocol Iu-UP – Iu User Plane GTP – GPRS Tunneling ProtocolDch-FP - Dedicated Channel Framing Protocol PHY-UP- Physical Layer User Plane MAC_d – Media Access Control for DCH IP - Internet Protocol TCP - Transmission Control Protocol UDP- User Datagram Protocol

Application

PHY_UP

MAC_d

RLC

PDCP

IP

ATM

AAL2

DchFP

ATM

AAL2

DchFP

ATM

AAL2

DchFP

PHY_UP

MAC_d

RLC

PDCP

ATM

AAL5

UDP/IP

GTP_U

Iu-UP

ATM

AAL5

UDP/IP

GTP_U

Iu-UP

ATM

L2

(AAL5)

UDP/IP

GTP_U

GGSN

ATM

L2

(AAL5)

UDP/IP

GTP_U

External

ATM AAL2 ATM AAL2ATM AAL5

IubUu Iur Iu-ps Gn

UMTSCRNC

UMTSSRNC

ATM AAL5

Jae-Hyun Kim 112

PHY

Protocol Stack for UMTS CS Service (voice)

UE

Air

WAGUMTSNode-B

PHY

ATM

AAL2

DchFP

Phys

PHY_UP

MAC_d

RLC

ATM

AAL2

DchFP

ATM

AAL2

DchFP

ATM

AAL2

DchFP

PHY_UP

MAC_d

RLC

ATM

AAL5

Iu-UP

ATM

AAL5

Iu-UP

Ethernet

UDP/IP

TAG

Ethernet

ATM AAL2 ATM AAL2ATM PVC

IubUu Iur Iu-cs Gn

UMTSCRNC

UMTSSRNC

ATM AAL5

AMR

Application

PDCP – Packet Data Convergence Protocol Iu-UP – Iu User Plane Dch-FP - Dedicated Channel Framing ProtocolPHY-UP- Physical Layer User Plane MAC_d – Media Access Control for DCH IP - Internet Protocol TCP - Transmission Control Protocol UDP- User Datagram Protocol

AMR G.711

ATM

UDP/IPAAL1

Jae-Hyun Kim 113

WiBro Protocol Stack

WiBro PHY

WiBro MAC

WiBro PHY

PSS

WiBro MAC

RAS ACR

Air

PHY

IP

TCP/UDP

Application

PHY PHY

MAC

IP

Hbis/ GRE

MAC

ACR Control

IP

Hbis/ GRE

MAC

PHY

MAC

IP

TCP/UDP

Application

Servers

전용선 Ethernet/ POS

WiBro 프로토콜 스택

Hbis: ACR-RAS 간 프로토콜 GRE: Generic Routing Encapsulation ( Tunneling Protocol) POS: Packet over SONET ※ 참고 : KRNET 2006 - H1

Jae-Hyun Kim

LTE Protocol Architecture

1-tier Network Architecture

eNB

PHY

UE

PHY

MAC

RLC

MAC

PDCPPDCP

RLC

PDCP: Packet Data Convergence Protocol, NAS: Non Access Stratum

eNB

PHY

UE

PHY

MAC

RLC

MAC

MME

RLC

NAS NAS

RRC RRC

PDCP PDCP

< Control Plane>< User Plane>

[Reference] 3GPP TS 36.300114

Jae-Hyun Kim

Summary

Part 1: Mobile/Wireless System MACWireless Channel Variation based Technologies

AMC, MIMO, Scheduler, and so on.Application Traffic Feature based Technologies

Scheduler, HARQ, and so on.

Part 2: Handover in Mobile SystemL2 : Measurement, Decision, Call SetupL2.5 : TriggerL3 : IP Address Acquisition and DeliverL4+ : Path Selection and Change

Part 3: Mobile/Wireless System NetworkConsiderations of Network Design

QoS and Mobility Functions Positioning2-tier Network Architecture 1-tier Network Architecture

Fast Transmission115

Jae-Hyun Kim

Reference

[1] R. Rom and M. Sidi, “Multiple Access Protocols Performance and Analysis”, Springer-Verlag[2] S.M Oh, S.H. Cho, J.H Kim, J.H Kwun, “An Efficient Uplink Scheduling Algorithm with Variable Grant-Interval for VoIP Service in

BWA systems,” IEICE Trans. Commun., VOL.E91-B, NO.10 OCTOBER 2008.[3] J. S. Kim and J. H. Kim, "MPEG-4 codec based uplink resource allocation scheme for the video telephony service in IEEE 802.16e/m

system," in Proc. CCNC 2010, Las Vegas, USA, 9-12. Jan. 2010.[4] 오성민, 김재현, 김봉찬, 김성완 "광대역무선통신시스템에서상향링크대역폭요청장치및방법," 국내특허, 출원일 : 2010.02.18 출원

번호: P2010-0014505[5] J. Maner, and M. Kojo,“Mobility related Terminology,“ RFC3753, Jun., 2004[6] WINNER, “D4.1: Identification and definition of cooperation schemes between RANs “, internal deliverable, IST-2003-507581 WINN

ER, Jun., 2004.[7] IEEE P802.21™/D01.00, “IEEE P802.21/D01.00 Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independe

nt Handover Services,” Mar., 2006.[8] N. Nasser, A. Hasswa and H. Hassanein, “Handoffs in Fourth Generation Heterogeneous Networks” IEEE Commun. Mag., vol. 44,

no. 10, Oct. 2006, pp. 96-103.[9] WINNER, “ D4.3: Identification and definition of cooperation schemes between RANs –final deliverable” IST-2003-507581 WINNER,

Jun., 2005[10] IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broad-band Wireless Access Systems, Feb. 2006[11] 3GPP TSG-SA Working Group 1, TSGS1#4(99)529, 5-9 July 1999 [12] S. H. Cho et al, “Hard handoff scheme exploiting using uplink and downlink signal in IEEE 802.16e system”, VTC 2006 Fall[13] IEEE 802.21/D03.00, “Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover Services”,

December 2006[14] R. Koodli,“ Fast Handovers for Mobile IPv6,“ RFC4068, Jul.,2005[15] H. Soliman, C. Castelluccia, K. El Malki and L. Bellier, “Hierarchical Mobile IPv6 Mobility Management (HMIPv6)”, RFC 4140,

August 2005 [16] S. Gundavelli, K. Leung, V. Devarapalli, K. Chowdhury and B. patil, “Proxy Mobile IPv6”, draft-ietf-netlmm-proxymip6-00.txt,

April 8, 2007[17] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and, E. Schooler,“ SIP : Session

Initiation Protocol,“ RFC3261, Jum., 2002[18] Yung-Mu Chen et el. “SCTP-based handoff based on MIH triggers information in campus networks,” Feb., 2006, ICACT 2006,

vol(2), pp. 1297 – 1301[19] 오성근, 김재현, 이현진, “사용자 단말에 의해 제어되는 끊어짐 없는 서비스 방법 ,” 특허 등록[20] 추상민, 오성민, 조성현, 김재현 "모바일 와이맥스 시스템에서의 종단간 서비스 품질 향상," 한국정보과학회논문지, 제 35권 5호,

pp.415-424, 2008년 10월.

116

Jae-Hyun Kim 117

Thank you !!

Documents

Mobile/Wireless System Network - ajou.ac.krwinner.ajou.ac.kr/publication/data/invited/2011_comm... · 2011-08-29 · Part 1: Mobile/Wireless System MAC Wireless MAC Protocol Overview