Project: ieee p802. 15 Working Group for Wireless Personal Area Networks (wpans)

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

• Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

• Submission Title: [Time Slotted, Channel Hopping Field Experience]

• Date Submitted: [1 Sep, 2008]

• Source: [Kris Pister, Lance Doherty, Rick Enns, Kuor Hsin Chang, Clint Powell, José A. Gutierrez, Ludwig Winkel] Companies [Dust Networks, Freescale, Emerson, Siemens AG]

• Address [30695 Huntwood Avenue, Hayward, CA 94544 USA; 890 N. McCarthy Blvd, Suite 120, Milpitas, CA 95035 USA; 8000 West Florissant Avenue St. Louis, Missouri 63136 USA; Siemensallee 74, Karlsruhe, Germany]

• Voice:[[phone], [phone], [phone], [phone], [phone], [phone]]

• E-Mail:[[e-mail], [e-mail], [e-mail], [e-mail], [e-mail], [e-mail], [e-mail] ]

• Re: [n/a]

• Abstract: [This document proposes extensions for IEEE802.15.4 MAC]

• Purpose: [This document is a response to the Call For Proposal, IEEE P802.15-08-373-01-0043]

• Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

• Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

Overview

• Presents empirical result from a multi-channel multi-hop Industrial Deployment

• This is one of many working examples using TSCH technology.

• Other examples at end of presentation if time permits

• Measurement was taken for 26 days on all pair-wise channels in the network

Network Topology & Location

• Network Topology & Location

• Network Protocols

• Time-Averaged Statistics

• Time Series Data

• Reliability in Uncertain Conditions

• Summary of Results

44 Nodes

• 44 Nodes

• Gateway circled

• 2.5 hop mean

• Printing factory

• 15,000 m2
• 3 floors
• Concrete & steel

Each node has two parents

• Each node has two parents

• Childparent connection is a path

• TDMA hopping over 16 channels of 2.402.48 GHz

• Each path composed of 16 path-channels

• Stability is the hop-by-hop packet success rate

• We measured stability on all path-channels

What does a path-channel look like?

• What does a path-channel look like?

• How does it vary with time?

• Let’s look at all 16 channels for a single path over time

Are paths geographically correlated?

• Are paths geographically correlated?

Path diversity

• Path diversity

• Have multiple parents for each node

• Frequency diversity

• Hop equally over all available channels

• Time diversity

• Link-layer ACKs and retries
• Tolerate duplicates

44 nodes, 80B payload per packet

• 44 nodes, 80B payload per packet

• 33 packets per 15 min per node

• 3.6 million packets, 17 lost

• 99.9995% reliability over 26 days

• All data secure and encrypted

Assuming 2xAA batteries (3000mAh)

• Assuming 2xAA batteries (3000mAh)

Average over time and frequency  good paths

• Average over time and frequency  good paths

• Individual frequencies have periods of poor performance

• Time-varying behavior unpredictable

• Use network protocols to get mean behavior

Industrial environments have varying channels

• Industrial environments have varying channels

• Low-power single-channel systems will have failures

• Cannot predict performance

• Average-case modeling software not applicable
• Site surveys cannot capture behavior

• Problems would be more severe with interference

• Can appropriately overprovision to get reliability

2006: Cherry Point Refinery

• Scope limited to Coker facility and support units spanning over 1200ft

• No repeaters were needed to ensure connectivity

• Electrical/Mechanical contractor installed per wired practices

• >5 year life on C-cell

2006: Cherry Point Refinery

• Scope limited to Coker facility and support units spanning over 1200ft

• No repeaters were needed to ensure connectivity

• Electrical/Mechanical contractor installed per wired practices

• >5 year life on C-cell

• >99.9% reliability

Wireless HART interop demo, ISA 2006

Grane Platform, North Sea

• 22 pressure sensors

• 2 hour installation vs. 2 days

Pharmaceutical Process Monitoring

Urban Infrastructure: Parking Monitoring

• SF pilot 07: hundreds

• LA pilot 08: 40,000

Reliable Performance in Harsh Environments