Feb. 11, 2005TinyOS Technology Exchange 1 XMesh Routing Layer An open, flexible, and powerful technology for wireless embedded networking Martin Turon Crossbow Technology, Inc. Mike Horton Crossbow Technology, Inc. Jason Hill JLH Labs Alan Broad Crossbow Technology, Inc.

TinyOS Technology Exchange2 Feb. 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 Doesnt route Hybrid star mesh ZigBee Support Interoperability with popular standards

TinyOS Technology Exchange3 Feb. 11, 2005 Flaws with Star Topology Coverage Without mesh, irregular RF patterns create holes in coverage map AKA: Router Nodes, Coordinator Nodes, End points Start with 11 routers Add 8 more Still 3 nodes not in coverage area

TinyOS Technology Exchange4 Feb. 11, 2005 TrueMesh Coverage Area With mesh, irregular RF patterns are beneficial and exploited Start with 3 As you add nodes they build their own coverage area.

TinyOS Technology Exchange5 Feb. 11, 2005 XMesh vs. Shortest Path (Network: 13 motes; ~1 mote/900 ft2)

TinyOS Technology Exchange6 Feb. 11, 2005 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 Fast Channel check: 140 µsec Receiver Sender preamble data

TinyOS Technology Exchange7 Feb. 11, 2005 Low Power with Time Synchronization Algorithm: Sender still sends preamble: Receiver wakes up right before end of interval time 125 ms Receiver 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

TinyOS Technology Exchange8 Feb. 11, 2005 Power Savings w/ Time Synchronization Testbed: 20 MICA2 Majority of the nodes 2 hops from the base station Estimated battery lifetime minute reporting intervals Battery life depends on type of sensor(s) attached to node.

TinyOS Technology Exchange9 Feb. 11, 2005 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

TinyOS Technology Exchange10 Feb. 11, 2005 XMesh and ZigBee Interoperability PC XMesh comm ZigBee PAN comm 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)

Feb. 11, 2005TinyOS Technology Exchange 11 XMesh Routing Layer An open, flexible, and powerful technology for wireless embedded networking Thank you! Questions?

Feb. 11, 2005TinyOS Technology Exchange 12 Supplemental

TinyOS Technology Exchange13 Feb. 11, 2005 Simple Compilation with extras freq … … …2480 make mesh, freq, Uses command line extras in: tinyos-1.x/tools/make/avr meshDescription HPFull power mode [ReliableRoute] MINTFull power mode [MintRoute] LPLLow Power Listening [Reliable_Low_Power] LPLow Power with Time Sychronization [Reliable_TimeSynch] ELPExtended low power (Reduced Functionality Device) HPZFull power for MICAZ

TinyOS Technology Exchange14 Feb. 11, 2005 XMesh Active Messaging Services #DefineAM(Hex)Description AM_DEBUGPACKET30x03Reserved for Health packets from mote AM_DATA2BASE110x0BUpstream data msg from node to base, no end-end ack AM_DATA2NODE120x0CDownstream msg from base to node, no end-end ack AM_DATAACK2BASE130x0DUpstream data msg from node to base, requesting end-end ack AM_DATAACK2NODE140x0EDownstream msg from base to node, requesting end-end ack AM_DOWNSTREAM_ACK2460xF6Reserved for sending acknowledge messages down stream AM_UPSTREAM_ACK2470xF7Reserved for sending acknowledge messages upstream AM_PATH_LIGHT_DOWN2480xF8Reserved for lighted path downstream messages AM_PATH_LIGHT_UP2490xF9Reserved for lighted path upstream messages AM_MULTIHOPMSG2500xFANeighborhood Link Estimation