WiMax Fi Wi - Trinity College Dublin · IEEE802.16 WiMAX 2nd: Add Indoor Subscriber Wi-Fi Station Business Access & Backhaul Consumer Broadband Access Hotspot Backhaul Wi Self Install

Meriel Huggard 4ICT9 2004-2005 –delivered by D.Lew

is2007

1

IEEE802.16

IEEE802.16

WiMAX

WiMAX

IEEE802.16

IEEE802.16

•What is W

i-Max?

•How does it differ from W

i-Fi?

•Is the standard finalised?

•What ca

n you do w

ith W

i-Max that you can’t do w

ith other

tech

nologies?

•Is it lik

e 3G?

•Is it availa

ble w

orldwide?

•What are the future challe

nges facing W

i-Max?


is2007

2

IEEE802.16

IEEE802.16

WiMAX

WiMAX

What is

What is W

iMax

WiM

ax

•Use

s microwaves for the w

ireless transfer of data

•Can be use

d for high-speed, wireless netw

orking at

distance

s of a few kilo

metres

•Wireless (Wi) M

icrowave Access (Ma)

•Use

s OFDM (which allo

ws for Non Line-of-Sight

communications and addresses multipath

issu

es)

•In

cludes TDD and FDD duplexingsu

pport

•Flexible channel size

s (3

.5MHz, 5 M

Hz, 10 M

Hz)


is2007

3

IEEE802.16

IEEE802.16

WiMAX

WiMAX

How does it differ from

How does it differ from W

iWi --Fi

Fi ??

•Wi-Fich

annels occupy a fixed w

idth of the

spectrum

•WiM

axwill allo

w channel size

s to be decided base

d

on requirements

•WiM

axworks in the license

d spectrum (1

0-66 G

Hz

with some systems operating in bands betw

een 2

GHz and 11 G

Hz). WiFiworks in the unlic

ense

d ISM

band.

•Wi-Fihas a range of about 100m, WiM

axwill

provide services over se

veral km.


is2007

4

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Wi

Wi --Fi

Fivs

vsWiM

ax

WiM

ax

•WiM

AXis designed to provide a higher level of

relia

bility and quality of se

rvice than W

iFi

•WiM

AXis a M

AN protoco

l that will be a w

ireless

alternative to D

SL and T1 level se

rvices for last m

ile

broadband access

•It w

ill act as a back

bone tech

nology for 802.11

hotspots.


is2007

5

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Towerstream

Towerstream, Boston

, Boston

•Towerstream

–Covering greater Boston &

greater

Providence

–12+ Cells in Service

–90%

Coverage

–Over 500 business customers

–5.8 G

Hz

•Multi-tiered Business Services

with SLA’s

–1 M

bps to 8 M

bps

•Courtesy

of ApertoNetw

orks

(2004)

•Coutese

yE. Ja

cobse

n Intel


is2007

6

IEEE802.16

IEEE802.16

WiMAX

WiMAX

BCL, New Zealand

BCL, New Zealand

•Broadca

st Communications Lim

ited (BCL)

Wholesa

le W

ireless Access N

etw

ork.

•Nationwide deployment from 74 Base

Stations Sites

•Netw

ork designed for 30,000

connections initially

;–

Expansion to 100,000 planned.

•Netw

ork covers around 100,000 sq km

•5.8 G

Hz sp

ectru

m

•Providing H

igh Speed links –longest

distance

of 50 km!

•Data &

Voice

–Each

CPE deliv

ers 2Mbit/s A

symmetric

DSL

–Up to four 64 kbps TDM voice lines

•Courtesy

of Airsp

anNetw

orks, 2004

•Coutese

yE. Ja

cobse

n Intel

Base S

tation

CPE

Range: 50 k

m

Wir

ele

ss D

SL

Covera

ge


is2007

7

IEEE802.16

IEEE802.16

WiMAX

WiMAX

The Standards

The Standards

See: http://ieee802.org/16/p

ublished.htm

l•

Drafts Under Development

–IE

EE D

raft 802.16f

•Active Standards

–IE

EE D

raft 802.16e

–IE

EE Standard 802.16-2004

–IE

EE Standard 802.16.2-2004

–IE

EE Standard 802.16/C

onform

ance

01-2003

–IE


onform

ance

02-2003

–IE


onform

ance

03-2004

•Obso

lete Standards

–IE

EE Standard 802.16-2001

–IE

EE Standard 802.16a-2003

–IE

EE Standard 802.16c-2002

–IE

EE Standard 802.16.2-2001


is2007

8

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Standards

Standards

•In

tel are m

ajor developers of WiM

axsilicon and

instrumental in standardising the tech

nology

•DigiW

eband Broadband Ireland have commercial

offerings in Ireland

•Certification –WiM

AXforum

•802.16e offers portable/n

omadic W

iMAX

•Allo

ws for mobility at pedestrian speeds (i.e. you

can w

alk around and m

aintain your co

nnection)


is2007

9

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Future Standards to be

Future Standards to be

developed

developed

•The first generation of 802.16e w

on’t allo

w fast

hand-off like on a G

SM netw

ork.

•True m

obility (high speed roaming (e.g. on a bus!))

will take some tim

e to develop and standardize and

will appear by the end of 2007 at the earliest.


is2007

10

IEEE802.16

IEEE802.16

WiMAX

WiMAX

What ca

n

What ca

n W

iWi --Max offer?

Max offer?

•Highly practical for use

in developing eco

nomies and rural

areas where the use

of wired broadband is not co

st

effective

•Allo

ws for rapid deployment

•Will spread the benefits of broadband to use

rs m

ore

quickly then possible w

ith a w

ired infrastrucu

tre

•Gives high connection speeds at distance

(cu

rrently you

can get a slow connection over a G

SM netw

ork, or a fast

connection if close

to an 802.11 acc

ess point). W

ill give

Wi-Fisp

eeds se

veral km from a transm

itter

–but max speed only w

hen nearer


is2007

11

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Benefits

Benefits

•Low installa

tion costs

•Last m

ile access via an external antenna (and

perhaps through a desk

top antenna near a

window).

•Easier to install than W

i-Fi(n

o need for ca

reful

alig

nment of acc

ess points) –goal of easy

self-

instalation


is2007

12

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Benefits

Benefits

The benefits w

ill beco

me m

ore apparent as the

tech

nology evolves:

•802.16e adds scalability and m

ulti-access

capabilities. (SOFADMA, Sca

lable O

FDM M

ulti-

Access).

•Channel size

s ca

n be varied depending on

requirements.


is2007

13

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Is it lik

e 3G?

Is it lik

e 3G?

•3G sits on a voice netw

ork

•3G has added data capabilities

•WiM

AXis a high speed data service specifica

lly

designed for the purpose

•Cellu

lar netw

orks evolved to m

eet data demands

•Roaming agreements evolved over time

•In

teroperability w

as also build

in over time

•WiM

axaim

s to offer these

from D

ay one


is2007

14

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Worldwide availa

bility?

Worldwide availa

bility?

•Need agreement on frequencies to use

•Three Frequencies under co

nsideration

•5.8Gz unlicense

d (sa

me as for WiFi). However the

fact that it is unlicense

d lim

its the transm

ission

distance

•2.5GHz and 3.5GHz have been targeted for license

d

use

throughout the w

orld.

•Negotiations are underw

ay at prese

nt.


is2007

15

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Future Challe

nges?

Future Challe

nges?

•Spectrum –

need w

orldwide agreements

•Living up to the H

ype!

•Wi-Fitook over 8 years from standardisation to roll-

out, so industry w

as well prepared

•WiM

axis evolving extremely rapidly.

•May be argued that the excitement needs to be

managed.

•In

tel talks of three-phase

roll-out and

implementation.


is2007

16

IEEE802.16

IEEE802.16

WiMAX

WiMAX

11stst: O

utdoor Subscriber

: O

utdoor Subscriber

Station

Station

Business

Business

Access &

Access &

Backhaul

Backhaul

Hotspot

Hotspot

Backhaul

Backhaul

Wi-Fi

Wi-Fi

802.1

6-2

004

Wi

Wi --FiFi

Premium

Premium

Residential

Residential

Service

Service


is2007

17

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Wi-Fi

2nd: Add Indoor Subscriber

2nd: Add Indoor Subscriber

Station

Station

Business

Business

Access &

Access &

Backhaul

Backhaul

Consumer

Consumer

Broadband

Broadband

Access

Access

Hotspot

Hotspot

Backhaul

Backhaul

Self Install Indoor

Self Install Indoor

Modem

Modem

Wi

Wi --FiFi

Wi

Wi --FiFi

802.1

6-2

004

Wi

Wi --FiFi

Wi

Wi --FiFi

Wi

Wi --FiFi

Wi

Wi --FiFi


is2007

18

IEEE802.16

IEEE802.16

WiMAX

WiMAX

3rd: Add Portable Clie

nt

3rd: Add Portable Clie

nt

Business

Business

Access &

Access &

Backhaul

Backhaul

Consumer

Consumer

Broadband

Broadband

Access

Access

Wi-Fi

Hotspot

Hotspot

Backhaul

Backhaul

Wi

Wi --FiFi

802.1

6-2

004

802.1

6e &

Wi

Wi --FiFi

Wi

Wi --FiFi

Wi

Wi --FiFi

Wi

Wi --FiFi

Wi

Wi --FiFi


is2007

19

IEEE802.16

IEEE802.16

WiMAX

WiMAX

WiM

AX

WiM

AX

Equipment and

Equipment and

Vendors

Vendors

•Base

Station: ~$50K

–CPE: ~$500

–Price

is expected to go down significantly after the interoperability

certification in 2006

•Vendors:

–AirSpanNetw

orks (A

S4030)

–Alvarion(B

reeza

MAX)

–TroposNetw

orks

–ApertoNetw

orks

–NaviniNetw

orks

–Others (Motorola, Nokia, etc.)


is2007

20

IEEE802.16

IEEE802.16

WiMAX

WiMAX W

hat about the Tech

nical Details?


is2007

21

IEEE802.16

IEEE802.16

WiMAX

WiMAX

WiM

AX

WiM

AX

•WiM

AX-Worldwide interoperability for Microwave Access

–It is a forum of product certification for interoperability

•Standard: IE

EE 802.16-2004

•Frequency

Spectrum:

–10 -

66 G

Hz (LOS)

–2 –

11 G

Hz (N

LOS) –both license

d and unlicense

d

•Last m

ile tech

nology (MAN/W

AN)

–Support point-to-point co

mmunication

–Support Q

uality of Service (QoS)

•Back

haul tech

nology for wireless LANs (8

02.11)

•Up to 50 km of range w

ith cell radius: 6-10 km

•Shared data rate up to 75 M

bps.

–Support 50 customers w

ith T1-rate w

ireless connections


is2007

22

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Wireless Frequency

Band

Wireless Frequency

Band


is2007

23

IEEE802.16

IEEE802.16

WiMAX

WiMAX

WiFi

WiFiand

and W

iMAX

WiM

AX


is2007

24

IEEE802.16

IEEE802.16

WiMAX

WiMAX

IEEE Standards

IEEE Standards

1. IE

EE 802.16-2001 (10-66GHz)

Air Interface

for Fixed Broadband W

ireless Acc

ess System

2. IE

EE 820.16a-2003 (2-11GHz) –

WiM

AX

3. IEEE 802.16-2004: (1

) + (2)

4. IE

EE 802.16.2 –

Coexistence

5. IE

EE 802.16c –System Profile for 10 -

66GHz

6. IE

EE 802.16e -

mobility


is2007

25

IEEE802.16

IEEE802.16

WiMAX

WiMAX

802.16 Physica

l Layer

802.16 Physica

l Layer

•Several PHYsare standardized:

–Single-carrier (S

C) for 10-66 G

Hz

–Single-carrier (S

C2) for 2-11 G

Hz

–OFDM for 2-11 G

Hz

–OFDMA for 2-11 G

Hz

•High degree of flexibility for co

st, ca

pability,

services, capacity


is2007

26

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Physica

l Layer

Physica

l Layer

•PHY is point-to-m

ultipoint and m

esh

topology

•LOS and N

LOS

–Multipath

may be significant (N

LOS)

•Channel BW –

1.5 to 14 M

Hz

•Advance

d power management

•In

terference

mitigation

•Adaptive Antenna System (AAS) and sectored

Antenna

•ARQ on a per-co

nnection basis


is2007

27

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Point

Point --toto-- M

ultipoint (P

2MP)

Multipoint (P

2MP)

•Wireless M

AN: not a LAN

•Base

Station (BS) co

nnected to public netw

orks

•BS serves Subscriber Stations (S

S)

–BS and SS are stationary

–SS typically

serves a build

ing (business or residence

)

•Provide SS w

ith first-m

ile access to public

netw

orks

•Multiple services, w

ith different QoSpriority,

simultaneously


is2007

28

IEEE802.16

IEEE802.16

WiMAX

WiMAX

WiM

AX

WiM

AX

Architecture (P2MP)

Architecture (P2MP)


is2007

29

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Mesh

Architecture (optional)

Mesh

Architecture (optional)


is2007

30

IEEE802.16

IEEE802.16

WiMAX

WiMAX

LOS

LOS vs

vsNLOS

NLOS

•In

general, >

10 G

Hz is LOS and <

10G can be either

LOS or NLOS


is2007

31

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Adaptive Antenna System

Adaptive Antenna System

(AAS)

(AAS)

•Optional in 802.16

•Use

multiple antennas to improve the coverage and

the system capacity.

•The spectral efficiency

is increase

d linearly w

ith the

number of antenna elements.

•AAS is able to improve the SNR gain by combining

multiple signals.

•AAS also reduce

s the frequency

interference

betw

een use

rs.


is2007

32

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Power Control

Power Control

•Power co

ntrol is use

d to improve the overall perform

ance

of the

system.

•It is im

plemented by the base station (BS) se

nding power co

ntrol

inform

ation to subscriber stations (S

S) to regulate the transm

itpower

level so

that the level rece

ived at the base

station is at a pre-

determ

ined level.

•The SS transm

its only enough power (as sp

ecified by the BS).

•The power co

ntrol reduce

s the overall power co

nsu

mption of the SS

and the potential interference

with other co

loca

tedbase

stations.

•For LOS the transm

it power of the SS is approxim

ately proportional

to it’s distance

(sq

uare) from the base

station. For NLOS it is heavily

dependant on the interference

.


is2007

33

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Dynamic Frequency

Selection

Dynamic Frequency

Selection

•Optional proce

dure, but required in unlic

ense

d

bands

•DFS consists of

–Requesting and reporting m

easu

rements

–Testing channels for the prese

nce

of primary use

rs

•Detecting primary use

rs

•Ceasing operation on a channel after primary use

rs

have been found

•Selecting and advertising a new channel


is2007

34

IEEE802.16

IEEE802.16

WiMAX

WiMAX

802.16 R

eference

Model

802.16 R

eference

Model


is2007

35

IEEE802.16

IEEE802.16

WiMAX

WiMAX

MAC Common Part

MAC Common Part Sublayer

Sublayer

•Supporting m

ultiple acc

ess

•In

the downlin

k, BS does not have to coordinate its

transm

issions, exce

pt for TDD (Tim

e D

ivision D

uplex).

•The uplin

k is sh

ared on a demand basis.

•The m

ultiple-acc

ess proce

dure in the uplin

k is im

plemented

using

–unso

licited bandwidth grants,

–polling, and

–co

ntention proce

dures.

•Vendors can have different im

plementations to optimize

system perform

ance


is2007

36

IEEE802.16

IEEE802.16

WiMAX

WiMAX

MAC

MAC-- C

PS: Duplex Sch

eme

CPS: Duplex Sch

eme

Support

Support

•On downlin

k, SS is associated w

ith a specific burst.

•On uplin

k, SS is allo

tted a variable length tim

e slot ,

for their transm

issions

•MAC support for duplex sch

emes

•Tim

e-D

ivision D

uplex (TDD)

–Downlin

k &

Uplin

k tim

e share the same R

F channel

–Dynamic asy

mmetry

•Frequency

-Division D

uplex (FDD)

–Downlin

k &

Uplin

k on separate R

F channels

–Static asy

mmetry


is2007

37

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Frequency

Frequency

-- division duplex

division duplex

(FDD)

(FDD)

•Separated frequency

channel for DL and U

L.

•Unframed FDD for full-duplex SS

•Framed FDD -

downlin

k in bursts


is2007

38

IEEE802.16

IEEE802.16

WiMAX

WiMAX

TDD Frame

TDD Frame


is2007

39

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Service Specific Convergence

Service Specific Convergence

Sublayer

Sublayer(S

SCS)

(SSCS)

•Accepting higher-layer data

•Classification (and proce

ssing) of data

•Deliv

ering data to the M

AC layer

•Rece

iving data from the peer entity

•Two convergence

sublayers:

–ATM CS

–Pack

et CS (Ethernet and IP)

•QoS


is2007

40

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Medium Acc

ess Control (M

AC)

Medium Acc

ess Control (M

AC)

•A M

AC frame consists of header, payload and CRC

•Frames ca

n be conca

tenated, fragmented, or

pack

ed

•One SS m

ay serve m

ultiple tenants


is2007

41

IEEE802.16

IEEE802.16

WiMAX

WiMAX

MAC Addressing

MAC Addressing

•SS has 48-bit 802.3 M

AC address

•BS has 48-bit base

station ID

–Not a M

AC address

•Connection ID (CID

)

–16 bit

–Use

d in M

AC PDU

–Note that MAC PDU does not have SS M

AC address or

BS ID

•why? co

nnection-oriented service


is2007

42

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Generic MAC H

eader

Generic MAC H

eader

•Q: Do you see the source and destination M

AC address?

•How does SS and BS acc

ept MAC frames se

nt to them?


is2007

43

IEEE802.16

IEEE802.16

WiMAX

WiMAX

MAC PDU Transm

ission

MAC PDU Transm

ission


is2007

44

IEEE802.16

IEEE802.16

WiMAX

WiMAX

SS O

peration

SS O

peration

Netw

ork Entry and Initialisation

Netw

ork Entry and Initialisation

1. Sca

n for downlin

k channel; synch

ronize w

ith BS

2. Obtain uplin

k transm

ission parameters

3. Perform

ranging (acq

uire tim

ing offse

t)

4. Negotiate capabilities

5. Establish connectivity (for upper layer)

6. Establish tim

e of day

7. Transfer operational parameters

8. Set up connections


is2007

45

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Channel Access and

Channel Access and Q

oS

QoS

•Pack

ets are associated w

ith a service flow

•A service flow has associated Q

oSparameters:

bandwidth, latency

, jitter, and throughput

•Service flows ca

n be static (p

reco

nfigured) or

dynamically

established

•The BS includes authoriza

tion m

odule that approves

or denies every change to the Q

oSparameters


is2007

46

IEEE802.16

IEEE802.16

WiMAX

WiMAX

QoS

QoSMech

anism

Mech

anism

•Sch

edulin

g services

–Unso

licited grant se

rvice (UGS) –for real-time fixed-size

pack

ets (VOIP,T1/E

1)

–Real-time polling service (rtPS) –for variable-size

pack

ets (MPEG video)

–Non-real-time polling service (nrtPS) –non-real-time

data w

ith variable-sized pack

ets (FTP)

•Best effort service


is2007

47

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Requests and G

rants

Requests and G

rants

•SSsca

n request bandwidth

•During these

requests, collisions ca

n happen

(CSMA).

•If the request is su

ccessful, the SS w

ill rece

ive a

data grant.

•There are incremental and aggregated requests.

•Requests are per co

nnections, but grants are per

SS only.


is2007

48

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Privacy

Privacy

Sublayer

Sublayer

•Privacy

-encrypting connections SS/B

S•

Encryption has tw

o component protoco

ls–

Enca

psu

lation protoco

l for encrypting pack

et data

–Privacy

key m

anagement (P

KM) protoco

l.

•Protection from theft of se

rvices

Privacy

Key M

anagement (P

KM) Protoco

l:•

Authoriza

tion

•Periodic re-authoriza

tion is required. (w

hy?)

•X.509 digital ce

rtificates.

•Keys and age m

ust be refresh

ed.

•Two sets of keys are alw

ays active.


is2007

49

IEEE802.16

IEEE802.16

WiMAX

WiMAX

Current projects within 802.16

Current projects within 802.16

•802.16e –

mobility (approved 7 D

ec 2005)

•802.16f published 1 D

ec 2005

•New project 802.16i opened 7 D

ec 2005

•Physica

l layer below 2 G

Hz

•MAC m

odification to support point-to-point (P

2P)

systems

Documents

WiMax Fi Wi - Trinity College Dublin · IEEE802.16 WiMAX 2nd: Add Indoor Subscriber Wi-Fi Station Business Access & Backhaul Consumer Broadband Access Hotspot Backhaul Wi Self Install