ieee802.15.4a: ultra low power transceiver for wireless

IEEE802.15.4a: Ultra Low Power Transceiver for

Wireless Sensors Enabling Precision Location

Mr Ciaran Connell (CEO) & Mr Michael McLaughlin (President & CTO)

DecaWave

Wireless Factory Workshop

15 -16 December 2008 – ETSI, Sophia Antipolis, France

“The Internet of Things”A World where anybody or anything can locate and communicate with any other body or thing, made possible by pervasive, extremely low power, low cost, high data rate wireless transceivers.

Our Vision

UWB for Precision Locating

Time

Direct path through partition

(Time of flight for this 1st path gives distance)

Reflection off ceiling

Reflection off wall then ceiling

Reflection off wall

(Receive Signal Strength is dominated by this path which has been attenuated by long flight path)

ceiling

Resolving Multipath Components, given that• Resolution α 1/BW• d = c.tthus• 802.15.11: 20MHz 1/BW = 0.05µs = 15m =>=>=>=> low resolution• 802.15.4a: 1300MHz 1/BW = 0.8ns = 24cm =>=>=>=> very high resolution

Wireless Personal Area NetworkIEEE802.15.1

(Bluetooth)RFID IEEE802.15.4

(ZigBee)IEEE802.15.3a IEEE802.15.4a IEEE802.15.3c IEEE802.15.6

Utility Cordless Identification ControlFile Transfer

(Wireless USB)Location plus

ControlVideo Link

(Wireless MM)Body Area Networks

Freq Range 2.40-2.48 GHz1 band in kHz

8 bands in MHz3 bands in GHz

868 MHz902-928 MHz2.40-2.48 GHz

3-10 GHz (USA)6-8.5 GHz (Europe)

7-9 GHz (Japan)

3-10 GHz (USA)6-8.5 GHz (Europe)

3 bands in 60GHz Band

(2 bands similar US & Japan, 1 different)

ModulationGFSK, π/4 DQPSK,

8PSKFSK, ASK, PSK,

BPSK,FM, AM

BPSK(868/915MHz)OQPSK(MSK)

(2.4GHz)

QPSK(MB-OFDM)BPSK/QPSK(DS-UWB)

PPM with BPSK In standards discussion

Multiple Access

FHSS TDMA/FDMA CSMA/CATFI-OFDM

(MB-OFDM)Ternary CDMA

(DS-UWB)

FDM / CDMA / Time Hop

Duplex

Source: IEEE & DecaWave

Duplex (Uplink/Downlink)

TDD TDD, TDM TDD TDD TDD

Channel Bandwidth

1 MHz Typically200kHz/500kHz 2 MHz

528 MHz(MBOFDM)1.368GHz, 2.736GHz (DS-UWB)

500MHz, 1.3GHz

# Channels 79As required by local

radioregulations

1 (868MHz)10 (915MHz)16 (2.4GHz)

13 (MB-OFDM)

2 (DS-UWB)

30 (USA)16 (Europe)12 (Japan)

Peak Data Rate3Mbps 848 kbps

20 kbps (868MHz)40 kbps (915MHz)250 kbps (2.4GHz)

480 Mbps typical1 Gbps planned

850 kb/s mandatory110kb/s, 6.81Mb/s

& 27.24 Mb/s optional

1.4Gbps, 2.8Gbps4.2Gbps

• "An international standard for an ultra-low complexity, ultra-low cost, ultra-low power consumption alternate PHY for IEEE Std 802.15.4.”

Standards IEEE 802.15.4a

802.15.4aRatified Q1 ‘07

Location,Communication,

Control

27 Mbps, 500m range,

with location & mobility

802.15.4aBaseline: Q1 ’05Completed: Q4 ’06Ratified: Q1 ‘07

• Decawave’s IP (patents and trade secrets) allows us to have an ultra-low complexity coherent receiver, thereby giving the benefits of superior range at ultra-low power and ultra-low cost

IEEE Standard UtilityCapability

mobilityRatified: Q1 ‘07

ScenSor (Seek, Control, Enable, Network / Sense, Obey, Respond)

2

3

4

5Price

Location PrecisionIntegration

( € 2 in volume )

( +/- 10 cm )( 7mm2 90nm RFCMOS )

Precision Location: The Future

0

1

2

Range

Tag Density

Standards BasedPower Consumption

Data Rate

Availability

( 25m NLOS, 70m LOS and �500m LOS @ 110kbps )

( > 11,000 tagsIn 20m radius )

( IEEE802.15.4a )

( Prototypes Jan ‘09Silicon Aug ‘09 )

( 6.8Mbps )

( runs off a single watch Battery for 10 years )

TP TG RG TP TG RG

Non Line Of Sight (NLOS) Range

• is the range when operating in the presence of obstructions, such as walls and objects • ScenSor’s performance is better than WiFi• allows RTLS to be deployed in WLAN APs with current density profile of WLAN APs.

ScenSor’s Range

Line Of Sight (NLOS) Range

• is the range when operating without obstructions, such as walls and objects • ScenSor’s performance is significant• allows RTLS to be deployed in very large factories.

4a Receive Signal Buried In Thermal Noise

4a Receive Signal @ 110kps and noise at -29dB SNR. This corresponds to a distance of 500 meters outdoors, 40 meters indoors

4a Receive Signal @ 6.8Mbps and noise at -11dB SNR. This corresponds to a distance of 100meters outdoors, 22 meters indoors

5

6

7

8

9

10

11

12

13

14

15C

hann

el

Bandplan Facilitating WorldWide Deployment

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000

1

2

3

4

5

Frequency, MHz

Japan @ >50MbpsJapan with DAAKoreaKorea with DAA or LDC

USAUSA indoors and outEuropeEurope with DAA or LDC

4a 500MHz4a >1GHz802.11 / Zigbee

DecaWave’s 4a Channel Model

0.5

0.6

0.7

0.8

0.9

1

p E(E

)

20Mhz

500Mhz

25

30

35

40

45

50

Pat

h Lo

ss (dB

s)

Attenuation of worst 10% ofchannels at 10 meters

-15 -10 -5 0 5 100

0.1

0.2

0.3

0.4

E (dB)

p E

100

101

102

0

5

10

15

20

distance (meters)

Pat

h Lo

ss (dB

s)

UWB Path Loss

Worst 10% of UWB Path LossNarrowband Path Loss

Worst 10% of Narrowband Path Loss

802.15.4a FEC and Symbol Structure

IEEE 802.15.4a was designed to be used by either a coherent or non−coherent receiver

IEEE 802.15.4a Ranging Options

Two way ranging option

4a4a

IEEE 802.15.4a also has the option of being transmit only

AP0 AP1

d14

Wireless 4a AP Clock Synchronisation

AP3

d01

d03

AP4

AP2d12

d

d24

AP3 d34

Central Location Engine

Precise distances between nearby APs are known to the Central Location Engine

Development Plan & Prototype

• Prototypes in-house• 7 customers ordered set of

5 prototypes delivery Jan’09• First Silicon Aug’09• Production Ready Silicon

Q1 ‘10.

Q1 ‘10.

ieee802.15.4a: ultra low power transceiver for wireless

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