iso-compliant css wireless congress 2008 final

8/2/2019 ISO-Compliant CSS Wireless Congress 2008 Final

1/29

ISO compliant RTLS

based onChirp Spread Spectrum

Wireless Congress 2008, Munich

Systems & Applications

Albrecht RommelSystem [email protected]


2/29

Nanotron Technologies GmbH 2

Agenda

The ISO/IEC 24730 Standard

The ISO/IEC 24730-5 Air Interface

Example Systems based on 24730-5

Status ISO/IEC 24730-5 Standardization Process

Other RLTS Standards

Forecast on future Developments and Opportunities


3/29


ISO/IEC JTC1 SC31 Landscape

ISO (Internat. Org.for Standardization)

IEC (Internat.Electronical Commission)

JTC1 Joint TechnicalCommittee 1 (IT)

SC31Automatic Identification

And Data Capturing

WG1Carrier

WG2Structure

WG3Conform.

WG4RFID

WG5RTLS

TC1 ScrewsTC4 BearingsSteel, Petrol,

Food,

SC37

(Biometrics)SC17(Personal ID)

WG6MIIM

National Bodies(ANSI, DIN, JISC, ...)

ISO/IEC

24730


4/29


ISO/IEC 24730 Standard Parts

24730 defines components of RTLS systems

24730-1 Application Programming Interface (API)

24730-2: 2.4 GHz Air Interface

24730-3: 433 MHz proposal (withdrawn) 24730-4: GLS GeoLocatingSystem via Satellite (withdrawn)

24730-5: 2.4 GHz Personal Area Network (PAN) Air Interface

24730-6 UWB (t.b.d.)


5/29


ISO/IEC 24730 System

T

RR

R R

RTLSServer

RTLSApplication

API

24730-1

R

T

Reader

Tag (up to x 1000s)

Infrastructure (Vendor Specific)

Air Interface (24730-2, 24730-5, ...)AI

AI

24730 defines API and Air Interface

Infrastructure is Vendor Specific(wired / wireless)


6/29


ISO/IEC 24730 API and Air IF

RTLS

Server

RTLS

Application

Query

CloseSession()

Struct BlinkResponseQuerySession()

Struct SessionResponse

OpenSession()

Struct BlinkResponse

R

R

R

R

Re

ader

Infras

tructure

ISO/IEC 24730-1API

Vendor SpecificApplication

Specific

24730-5A

irInterface


7/29


24730-5 Air Interface

T R RTLSServer24730-5 Air Interface


8/29


24730-5 Physical Layer

Modulation

2-ary orthogonal CSS (mandatory)- 80/22 MHz Bandwidth, Center Frequency 2441.75 MHz1 RF Channel

- 22 MHz Bandwidth, Center Frequency 2412 - 2484 MHz, 14 RF Channels

8- or 64-ary orthogonal DQPSK-CSS (optional)

- 22 MHz Bandwidth: Center Frequency 2412 - 2484, 14 Channels

Data Rates 1 Mbit/s, 250 kbit/s


9/29


24730-5 Physical Layer2-ary Orthogonal CSS Modulation

Chirp BW 80 (22) MHz

Bit Rate = Symbol Rate- 1E6 bit/s

- 250 kbit/s

Simple Coding- 0 = Downchirp- 1 = Upchirp


10/29


Up-Chirp and Down-Chirp are orthogonaland easy to separate

Ranging and Localization: Simple and precise TOA (Time

of Arrival) evaluation

Up DownUp Up Down

O11 O 1

Up

Down

Correlator

24730-5 Physical Layer2-ary Orthogonal CSS Receiver

Reference Chirp


11/29


24730-5 Physical Layer2-ary Orthogonal CSS PHY Packet Format

Preamble (30 alternating bits)

Start of Frame Delimiter (64 bits)

PHY Header & MAC Frame


12/29


24730-5 Physical Layer2-ary Orthogonal CSS PHY Packet Format

Reference Modulator Diagram

Scrambler Polynomial g(D) = D7 + D4 + D0, EXORed with bit stream


13/29


Differential Quadrature Phase Shift Keying

Band plan corresponds with 802.11b

DQPSK-CSS approved in IEEE 802.15.4a

Chirp BW 22 MHz, 14 RF Channels

Sub-Chirp Freq. Offsets +/- 3.15 MHz

4 different Sub-Chirp Sequences:I, II, III, and IV (up to 4 x 14 channels)

Provides sub-chirp sequence division ANDfrequency division

Bit Rate- 1E6 bit/s (3/4 symbol mapping)

- 250 kbit/s (6/32 symbol mapping)

Symbol Rate

- 166667 symbols/s

24730-5 Physical LayerDQPSK-CSS Modulation


14/29


Pairs of Time Gaps defined Time Gaps applied alternately

between subsequent chirpsymbols

Provides sharperorthogonality between chirpsymbols

24730-5 Physical LayerDQPSK-CSS Sub-Chirps and Time Gaps


15/29


24730-5 Physical LayerDQPSK-CSS Reference Modulator


16/29


Data to 8-ary Bi-orthogonal Code Word Mapping (r=3/4)

Data to 64-ary Bi-orthogonal Code Word Mapping (r=6/32)For 250 kbit/s data rate, 6-bit data symbols are mapped to 32-chip

bi-orthogonal code words

24730-5 Physical LayerDQPSK-CSS Symbol Mapping

3-bit data symbol b0-2is mapped to 4-chipbi-orthogonal codeword c0-3


17/29


Preamble

SFD

24730-5 Physical LayerDQPSK-CSS Preamble and SFD


18/29


24730-5 MAC LayerMAC Frame Types


19/29


24730-5 MAC LayerMAC Frame Formats

ACK

Data

Broadcast

Request to Send

Clear to Send


20/29


24730-5 MAC Layer2-Way Handshake

SIFS (Short Inter Frame Space)= 8 s

T_round, T_replymeasured for Ranging


21/29


24730-5 MAC Layer3-Way Handshake

3-Way handshake initiates aRequest-to-Send and waits forClear-to-Send prior to datatransmission

Used to overcome hidden-node

problem: used for virtual carriersensing (see later)

T_round, T_replymeasured for Ranging


22/29


ALOHA Immediate Access w/o listening for any activity

CSMA/CA Enery detect

Average power sensing during CIFS period

Physical carrier senseSense for CIFS duration on medium

Virtual carrier senseEvaluating Type and Length fields of incoming traffic

For all 3 Methods above: Backoff when media is busy

24730-5 MAC LayerMedia Access Methods


23/29


Four Types of Tag Application Packets Command Packets

Used by infrastructure to transmit instructions to tags

Report PacketsUsed by tags to transmit information to the infrastructure

Ranging PacketsUsed for Ranging

Blink PacketsBroadcast packets transmitted by tags, e.g. for RTLS via TDOA

24730-5 Tag Application LayerTag Application Packet Types


24/29


5 different Tag Application States

Infrastructure can instruct the TAG application to go todesired states or to go through sequences of states

24730-5 Tag Application LayerTag Application States


25/29


Example System

R

R

R

R

R

R

Server

Ranging

Application

LocatingApplication

Server

Default State

(Broadcasting)

RangingState

BlinkState

SleepState

Default State(Broadcasting)

1

2

3

4

5

T

T

T

T

T

Infrastructureinstructs Tagto enter

Ranging State

Tag enters 24730-5

equipped area

Tag moves intoanother 24730-5

area


26/29


StandardizationStatus of 24730-5

S0 S5S2S1 S3 S4

PreliminaryStage

NP WD CDFCD

FDIS IS

PublicationStage

Ballots

ProposalStage

PreparatoryStage

CommitteeStage

ApprovalStage

CD ballotFeb. 04, 2009

Final CD ReviewOct. 19, 2008

CD BallotResolution

Mar. 04, 2009

March 2007


27/29


StandardizationOther RTLS Standards

ISO/IEC 24730-1 (API, common for all Air Interfaces) Stage 5 (IS) since Feb. 2006

ISO/IEC 24730-2 Stage 5 (IS) since Dec. 2006

BPSK DSSS (Direct Sequence Spread Spectrum) Modulation- Center freq. 2441,75 MHz, BW 60 MHz

- Data rate: ~60 kbit/s

- Packet length 56 - 152 bits

2-Tone OOK/FSK Modulation- Center Freq. 2441,75 MHz, BW 60 MHz

- Data rate ~20 kbit/s

- Packet length 88 - 188 bits

Short Distance Magnetic Link (115 MHz, 127 MHz)- Data rate 2,048 kbit/s


28/29


Forecast, future Developments

ISO/IEC 24730-6 (UWB) t.b.d.

ISO/IEC 24730-5 Improvement of Ranging/Localization Accuracy

Improvement of Power Efficiency

Development of Application Software for Emerging Markets & Applications


29/29


For more information..

Contact: Rainer Hach (24730-5 Editor)Albrecht RommelNanotron Technologies GmbH

Alt-Moabit 6010555 BerlinTel.: +49 (0)30 399954-0

e-mail: [email protected]@nanotron.com

Please check

Proceeding Papers

Thank You!

iso-compliant css wireless congress 2008 final

Documents