doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [PHY and MAC Proposals for battery-operated SUN] Date Submitted: [2 May, 2009] Source: [Takaaki Hatauchi] Company [Fuji Electric Systems Co., Ltd.] Address [1, Fuji-machi, Hino-city, Tokyo , Japan] Voice:[ ], FAX: [ ], Re: [] Abstract:[MAC and PHY proposal for g for Smart Utility Networks] Purpose:[Presented to the IEEE g SUN task group for consideration] Notice:This document has been prepared to assist the IEEE P 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 P

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 2 PHY and MAC Proposals for battery-operated SUN

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 3 Contents Metering System in Japan –SUN Applications –System Concept –Requirements MAC Proposal –Preferable MAC –Principle of MAC Operation PHY Proposal –Frequency Band –Modulation –Other requirements

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 4 Metering System in Japan

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 5 SUN Applications Gas, Water, Electric Metering Remote Control Sensor Monitoring and Alerting Home Security Door Locking Fire Alarm Home Appliance Control Shutting Meter off Gas, Water Leak About 5 Million AMR devices already installed in Japan

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 6 System Concept Networks in cluster housing SUN WAN Device New Gas Meter: connected to SUN/WAN devices SUN Device House to House Network

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 7 Layer Structure MAC Network PHY (15.4) 868MHz / 915MHz PHY (15.4c) 780MHz PHY (15.4d) 950MHz PHY Under 450MHz Application Amendment Proposals for IEEE g

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 8 Requirements for SUN Applications Communication Profiles –variable packet size –one communication per hour or day Battery Operation –over 10 years without maintenance Reliable Communication –mesh network without hierarchical topology –auto-healing, auto alternate routing (route diversity) Low Interference –100~1k devices are installed in a cluster housing Cost Effectiveness –license free band –easy installation with no or few configuration

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 9 Hierarchical network is not preferable –Coordinator / Router consumes more power than end device often installed where no AC power is available –Malfunction / power outage of a coordinator results in communication loss of all end devices below Coordinator router AC power required End device

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 10 Synchronous system is not preferable –Not suitable for low duty cycle system Tight requirement for crystal frequency Increasing power consumption with off-the-shelf crystal –Not suitable for multi-hop system Synchronization error accumulates with number of hops Synchronous to upper node Intermittent node Intermittent node Intermittent node

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 11 MAC Proposals

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 12 Preferable MAC Support for low duty cycle Occupation of wireless channel takes communication opportunities for other wireless devices Consuming as low power as possible Support for variable duty cycle depending on battery charge or power supply condition Different devices have different power conditions and requirements (lifetime, size of battery and so on) –Gateway, meter or sensor, etc. Support for nonhierarchical network In hierarchical network, a single point of failure at a certain node results in loss of link at neighboring nodes

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 13 Principle of operation -All nodes are repeating ID transmission and short period reception, intermittently (1) -When the transmission request is generated, set transmission destination and wait for ID reception (2) -Upon reception of ID from transmission destination, transmit data to the receiver at succeeding reception mode (3) -If failed, set different transmission destination and wait for ID Sleep mode (1) Sleep mode Wait for ID reception ID transmission Short period reception mode Active mode ID transmission (2) Sender (having data to send) Receiver (destination of data) Transmit request Data transmission (3) -> Low Duty Cycle Intermittent Receiver-driven Data Transmission

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 14 Access between devices with different duty cycle Support for variable duty cycles –Devices with longer duty cycle have less chances to relay packets, resulting less power consumption Wait for ID reception sender Receiver A Receiver B Shorter duty cycle Longer duty cycle Transmit request ID transmission Data transmission

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 15 Sample Listening system is not preferable –Waking up destination node by transmitting packet that is longer than the duration of sleep mode Wireless channel is occupied and cannot be used by other link –Less efficient when neighboring nodes are operating with different duty cycles Intermittent node Intermittent node Intermittent node

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 16 PHY Proposals

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 17 Frequency Band IEEE Sub GHz Bands –868MHz, 915MHz (15.4) –780MHz (15.4c) –950MHz (15.4d) Additional Band –Under 450MHz in Japan Reallocation of Under 450MHz Band for SUN Applications is under consideration in Japan

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 18 Modulation Requirement for SUN –Power consumption is higher priority than sensitivity due to battery operation Desirable Modulation –FSK –GFSK It’s possible to minimize the power consumption

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 19 Other Requirements Transmit Power –within the limit of license exemption Data Rate (s) –100kbps or higher In the case of Intermittent Receiver-driven Data Transmission, high data rates enables to shorten transmission time. It leads to reduction of power consumption and interference. Payload Length –Payload size has to be variable Duty Cycle Limitation –Up to 0.1% is preferred –Reduction of interference

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 20 Conclusion Overall requirement for SUN –Application under development in Japan is introduced –Battery operated, mesh network system MAC proposal –Intermittent Receiver-driven Data Transmission is proposed –Low and variable duty cycle, suitable for battery operation PHY proposal –Simple, narrowband modulation scheme, such as FSK / GFSK are preferable for minimizing power consumption –Under 400MHz band is under consideration for frequency band reallocation in Japan

doc.: IEEE g Submission May, 2009 Hatauchi, Fuji Electric SystemsSlide 21 Thank you for your attention Any Questions ?