Feb. 11, 2005TinyOS Technology Exchange 1 XMesh Routing Layer An open, flexible, and powerful...

Feb. 11, 2005 TinyOS Technology Exchange 1

XMesh Routing LayerAn open, flexible, and powerful technology for wireless embedded networking

Martin [email protected]

Crossbow Technology, Inc.

Mike [email protected]


Jason [email protected]

JLH Labs

Alan [email protected]


TinyOS Technology Exchange 2Feb. 11, 2005

XMesh Features

TrueMesh™ self-organizing, self-healing

Low Power Listening Upstream and Downstream

Time Synchronization Quality of Service (QoS)

Link-level acks End-to-end acks

Health Diagnostics

Streaming service Bulk transfer along

dedicated path

Extended Low Power End node / Send only Doesn’t route Hybrid star mesh

ZigBee™ Support Interoperability with popular

standards


Flaws with Star Topology Coverage Without mesh, irregular RF patterns create

holes in coverage map

AKA: Router Nodes, Coordinator Nodes, End points

Start with 11routers

Add 8 more

Still 3 nodesnot in coverage area


TrueMesh™ Coverage Area

With mesh, irregular RF patterns are beneficial and exploited

Start with 3

As you add nodes they build theirown coveragearea.


Shortest Path

0204060

80100120

11/18/200314:24

11/18/200319:12

11/19/20030:00

11/19/20034:48

11/19/20039:36

11/19/200314:24

11/19/200319:12

Date/Time

% P

ac

ke

ts R

cv

d/3

0 m

in.

Series1Series2Series3Series4Series5Series6Series7Series8Series9Series10Series11Series12Series13

Reliable MintRoute

0

20

40

60

80

100

120

12/29/20039:36

12/29/200314:24

12/29/200319:12

12/30/20030:00

12/30/20034:48

12/30/20039:36

12/30/200314:24

Date/Time

% P

acke

ts R

cvd

/30

min

. Series1

Series2

Series3

Series4Series5

Series6

Series7

Series8

Series9

Series10

Series11

Series12

XMesh vs. Shortest Path(Network: 13 motes; ~1 mote/900 ft2)(Network: 13 motes; ~1 mote/900 ft2)


Low Power Listening

Long Preamble: 140 ms Algorithm:

Wake up 8 times per second Sniff radio channel If preamble, receive data If clear, send if needed

time

125 ms 125 ms 125 ms 125 ms

82 us ADC Conversion Time

Radio RX Power-upADC Sample and Hold Completion

ADC Conversion

Start

RF Shutdown

ADC Conversion Complete

146 us Radio on time

Timing of Wake-up Check

Wake-up Threshold

Quiet Channel Average

RSSI Output

Fast Channel check: 140 µsec

ReceiverReceiver

Sender preamble

data

data

data


Low Power with Time Synchronization

Algorithm: Sender still sends preamble:

Receiver wakes up right before end of interval

time

125 ms 125 ms 125 ms 125 ms

ReceiverReceiver

Sender preamble

data

Long 140 ms Allows arbitrary new nodes to join mesh network

Short 25 ms Optimizes power when sending to nodes already in mesh

Standard 2 ms Optimizes communication speed for nodes talking to base

data

data


Power Savings w/ Time Synchronization

Testbed: 20 MICA2 Majority of the nodes 2

hops from the base station

Estimated battery lifetime 1.2 years @ 3-minute

reporting intervals Battery life depends on

type of sensor(s) attached to node.

Expected LifetimeSurge Time Sync (20 nodes)

00.511.522.533.544.5

0 20 40 60 80 100 120

Reporting Interval

Yea

rs


Streaming

Light path to one node:Bi-directional from leaf to base

Send message to special AM type Nodes along path go into

Full Power mode for a set time Allows for Bulk Transfer

PC


XMesh and ZigBee Interoperability

PC

XMesh commZigBee PAN comm

XMesh enables reliable routing

links to third party ZigBee devices

XMesh enables reliable routing

links to third party ZigBee devices

Hybrid Mote(FFD)

Hybrid Mote(FFD)

Hybrid Mote(FFD)

Hybrid Mote (FFD)

Hybrid Mote(FFD)

Extended Low Power Mote (RFD)


XMesh Routing LayerAn open, flexible, and powerful technology for wireless embedded networking

Thank you! Questions?


Supplemental


Simple Compilation with “extras”

freq

903 904 … 926

433 433.5

… 434.5

315

2405 2410 … 2480

make <platform> mesh,<routing> freq,<channel>

Uses command line “extras” in:tinyos-1.x/tools/make/avr

mesh

Description

HP Full power mode [ReliableRoute]

MINT Full power mode [MintRoute]

LPL Low Power Listening [Reliable_Low_Power]

LP Low Power with Time Sychronization [Reliable_TimeSynch]

ELP Extended low power (Reduced Functionality Device)

HPZ Full power for MICAZ


XMesh Active Messaging Services

#Define AM(He

x)

Description

AM_DEBUGPACKET 3 0x03

Reserved for Health packets from mote

AM_DATA2BASE 11 0x0B

Upstream data msg from node to base, no end-end ack

AM_DATA2NODE 12 0x0C

Downstream msg from base to node, no end-end ack

AM_DATAACK2BASE

13 0x0D

Upstream data msg from node to base, requesting end-end ack

AM_DATAACK2NODE

14 0x0E

Downstream msg from base to node, requesting end-end ack

AM_DOWNSTREAM_ACK

246

0xF6 Reserved for sending acknowledge messages down stream

AM_UPSTREAM_ACK

247

0xF7 Reserved for sending acknowledge messages upstream

AM_PATH_LIGHT_DOWN

248

0xF8 Reserved for lighted path downstream messages

AM_PATH_LIGHT_UP

249

0xF9 Reserved for lighted path upstream messages

AM_MULTIHOPMSG 250

0xFA Neighborhood Link Estimation

Feb. 11, 2005TinyOS Technology Exchange 1 XMesh Routing Layer An open, flexible, and powerful...

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