13 May 2009 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Battery Operated Sensing Device Requirements for 802.15.4g] Date Submitted: [12 May 2009] Source: [Kendall Smith, Mark Thompson] Company [Aclara RF] Address [23905 Mercantile Rd., Beachwood, OH 44122] Voice:[+1.216.896.8552] E-Mail:[mthompson@aclara.com, ksmith@aclara.com] Re: [IEEE 802.15.4g Working Group] Abstract: Discussion of a proposal to add provisions for Battery Operated Sensing Devices. Purpose: To allow for battery operation in 802.15.4g network 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. Kendall Smith, Mark Thompson, Aclara RF

Battery Operated Sensing Device Requirements for 802.15.4g 13 May 2009 Battery Operated Sensing Device Requirements for 802.15.4g This discussion covers both PHY and MAC design considerations (Yes, I know that 4g is a PHY specification) This is a critical and urgent component of 802.15.4g Kendall Smith, Mark Thompson, Aclara RF

What is battery operation? (for SUN) 13 May 2009 What is battery operation? (for SUN) AMR / AMI / SmartGrid device powered by a battery Any device with a limited power budget Devices designed to operate at low power Cost Size Thermal limitations Power source limitations Kendall Smith, Mark Thompson, Aclara RF

Why battery operation is important 13 May 2009 Why battery operation is important Classic battery-powered applications Gas and water metering High Voltage locations FCIs, transmission circuits Operation during power outages Every device becomes battery powered Often the most “interesting” times Energy scavenging devices The ultimate lower energy devices Low cost devices Power supply costs can dominate Kendall Smith, Mark Thompson, Aclara RF

Why battery operation is non-trivial 13 May 2009 Why battery operation is non-trivial 20 year operation is the expectation 20 year operation is difficult to achieve Beyond the shelf life of most battery chemistry Beyond the life of many battery containers Not practical to replace batteries Cost of replacing battery dwarfs battery cost Kendall Smith, Mark Thompson, Aclara RF

Why battery operation is non-trivial 13 May 2009 Why battery operation is non-trivial Battery life should align with device lifetime Battery chemistry is often corrosive to electronics Battery life is not easy to figure Much more complex than (Ah / avg_draw) Kendall Smith, Mark Thompson, Aclara RF

What makes a SUN standard conducive to battery operation? (1) 13 May 2009 What makes a SUN standard conducive to battery operation? (1) Short messages Minimum TX on-time Fast data rate Minimum listening time Minimize RX on-time Allow one-way messaging Kendall Smith, Mark Thompson, Aclara RF

What makes a SUN standard conducive to battery operation? (2) 13 May 2009 What makes a SUN standard conducive to battery operation? (2) Fast network join process Minimum listening before transmitting Low TX power Variable power capabilities Kendall Smith, Mark Thompson, Aclara RF

What makes a SUN standard conducive to battery operation? (3) 13 May 2009 What makes a SUN standard conducive to battery operation? (3) Minimum need for timekeeping Lessen requirements for Clock Minimum retry due to lost messages or collisions Minimal “hand-shaking” or message acknowledgements Minimize handling of other device’s messages Kendall Smith, Mark Thompson, Aclara RF

System Design Concepts 13 May 2009 System Design Concepts When network is a mixture of powered and battery devices: Asymmetric protocol(s) Take advantage of ability of powered devices to (listen constantly, respond quickly, etc.) Asymmetric link design, Edge device can have lower sensitivity receiver and lower power transmitter, powered device can have better receiver, higher power transmitter Kendall Smith, Mark Thompson, Aclara RF

13 May 2009 Suggestions Evaluate all SUN standard candidates for consistency with battery operation Ensure that power consuming behaviors are not mandated in the standard Coordination with 4e standard changes Insure that appropriate MAC changes are enacted with SUN release Kendall Smith, Mark Thompson, Aclara RF

13 May 2009 Thank you Kendall Smith, Mark Thompson, Aclara RF