IEEE 15.4k15-11-0479-00-004k

J. Schwoerer (France Telecom) – N. Dejean (Elster))Slide 1

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: [Elster & France Telecom proposal]Date Submitted: [13 July, 2011]Source: [Jean Schwoerer, Nicolas Dejean] Company [France Telecom R&D, Elster]Address [28 chemin du vieux chênes 38240 FRANCE ]Voice:[+33 4 76 76 44 83], FAX: [+33 4 76 76 44 50], E-Mail:[jean.schwoerer@orange-ftgroup.com]

Re: [.]

Abstract: [This document give information on the proposal that we submit]

Purpose: [Description of what the author wants P802.15 to do with the information in the document]

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.

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FTRD/ELSTERPreliminary Technical Proposal

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Sub-GHz wireless connectivity platform

• To meet battery powered devices– Low amounts of data with low radio traffic– Ultra-low power management to reach multi-year

operation– Long range (high link budget) for cost effective

network infrastructure and long operating range in real world environments

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Sub-GHz wireless connectivity platform

• To support reliable communications– Spread spectrum

• To support programmable parameters– Data rate, carrier frequency, output power

• To offer carrier-grade network– Ability to host multiple applications on a single network

• To be compliant with regulations over the world– NA, Europe, Asia, Japan

• To be cost effective with reasonable ROI

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Wireless network capabilities

• Star, tree, and mesh topology• Prevent over-hearing• Reliable transmissions for robustness

against interferers and jammers• Efficient medium access system for

coexistence of co-located networks in the same area

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• Sub-GHz ISM license free bands 915MHz, 868MHz, 316-433MHz

• Low data rate and narrow bandwidth• GFSK modulation• flexible FHSS spread spectrum for reliability and coexistence

• Programmable output power (power savings)• QoS management (RSSI, energy counter, class of device, …)• Automatic Frequency Control (top performance over full lifespan)• Automatic Sensitivity Control (robust to interferences in noisy area)• Both asynchronous and synchronized network operation

Fundamentals – RF features

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• data rate• Low data rate: ~20kbps // 50kHz Bandwidth

• Highly sensitive receiver• -113dBm @ 20kbps

• Programmable output power• Low data rate: +14dBm/+27dBm for end-points & +27dBm/+30dBm for range extenders &

AP

• High link budget• 127dB with +14dBm > 1km LOS @ -3dBi coil antennas• 140dB with +27dBm > 3-4km LOS @ -3dBi coil antennas

• Radio range extender• Native repeater function in all devices (truly mesh with all devices)• All devices are Full Function Device while cost is similar to Reduced Function Device

Fundamentals – RF features - Cont’d

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• Intra frame Frequency Hopping– Frame is sliced in blocks (block length is user configurable)– Hopping occurs every block– x16 channels in EU (868-870 MHz)– x50 channels or less to comply with FCC part.15-247 (915 MHz)

• FEC: several potions under study• Block code (255,131)• Convolutional codes K=7 (171,133)

• Data interleaving + LSFR data scrambling (whitenning)• Spread data and code bit among data blocks• Maximize transmission success on the first attempt

Fundamentals – Reliable Comms

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Operating Mode• Rx, Standby Mode with programmable period (duty cycle) • Resources management based on 15.4e MAC Layer• Push mode with TDMA management to limit overhearing• CSMA-CA• Tx, Rx at any time from any device (alert notification)

Power Consumption• Target of 15µA operating current

Fundamentals – Cont’d

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Low data rates vs Packet size• PPDU up to 2047 bytes are considered• Low data rates are used• MHR represents a non negligible overhead• Packet fragmentation into data blocks at the PHY

layer will help to avoid the useless repetition of the MHR

• Data block can be sent over different channels for taking advantage of channel diversity

MAC Layer compatibility

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15.4e TSCH resources management• Time Slot Channel Hopping defines the automatic

repetition of a slotframe based on a shared notion of time• TSCH Allows the devices hopping over the entire channel

space in a slotted way thus minimizing the negative effects of multipath fading and interference while avoiding collisions

• Slotframe is configurable through the definition of the channels used, the number of slots and the duration of the slots

MAC Layer compatibility

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Packet fragmentation in a slotframe• As an example, with a 10kbps data rate and ½ FEC, 16

bytes can be transmitted in a ~25ms slot 128 slots are required for transmitting 2047 bytes

• An adaptation layer between PHY and MAC needs to be defined for hopping on PHY fragments instead of MAC frames

• This adaptation layer must also define a group ACK mechanism allowing the detection of the corrupted fragments and their retransmission

MAC Layer compatibility

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Thank You