1. March 2010
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Recommendation on Data Rates for SUN
Date Submitted: March 15, 2010
Source: Chris Calvert, Dave Olson, Emmanuel Monnerie, Ruben Salazar, Nick West, Harry Sarkas
Company Landis+Gyr
Address Mill Creek Avenue, Alpharetta, GA USA
Voice: ,
Re: Comment Resolution for document # g-clause-6-fsk-phy-draft
Abstract: Recommendation to use data rates related to existing standards
Purpose: Clarification on comment #344 (reference document: g)
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
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2. The communicating meter
March 2010
The communicating meter
Communication Unit
NAN
Metering Unit
LAN
(Optical Port)
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3. Existing Standards IEEE 802 ANSI C12.21 ANSI C12.18 Communication Unit
March 2010
Existing Standards
Currently being amended by this Task Group
IEEE 802
Communication Unit
NAN
ANSI
C12.21
ANSI
C12.18
Metering Unit
LAN
(Optical Port)
Source : NIST Framework and Roadmap for Smart Grid Interoperability Standards
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4. March 2010
ANSI C12.18
Defines the meter’s optical port interface used for diagnostics, testing, manufacturing and maintenance.
Data rates based on EIA RS-232 standard
Specifies the following data rates: 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800,57600 bps
Required in most meters (>90% of RFQ’s in the USA)
Implemented by all meter vendors and meter communication module manufacturers
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5. March 2010
ANSI C12.21
Defines the meter communication standard via telephone modems, typically using ITU standard speeds: 9600bps (V.32), (V.33), (V.33), (V.34), 33600bps (V.34), 48000bps (V.92), 56000bps (V.90/V.92)
Used to be the only Standard WAN for the meter (mostly in commercial and industrial meters).
The interface between the meter and the communication module has always been based on EIA RS-232 standards.
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6. March 2010
RS-232 data rates in SUN
10’s of millions of ANSI-compliant communicating meters deployed since the 90’s in the USA.
The vast majority already support RS-232 data rates and is also using these rates for the NAN.
The most popular data rates for NAN already deployed are 2400bps and 9600bps.
The most popular data rates for SCADA devices already deployed are 4800bps, 9600bps and 19200bps.
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7. RS-232 data rates are easier to implement
March 2010
RS-232 data rates are easier to implement
The value represents the minimum multiplier that must be applied to the crystal frequency to be able to achieve the corresponding data rate.
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8. Consequences of the wrong choice
March 2010
Consequences of the wrong choice
Clocks and other hardware that are optimized for existing standards might not support the mandatory mode.
It would prevent millions of devices from becoming compliant with SUN standard.
Everybody will be penalized: our customers and the consumers…
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9. Spirit of the NIST Framework
March 2010
Spirit of the NIST Framework
“Architectures should be flexible enough to incorporate evolving technologies. They also must support interfacing with legacy applications and devices in a standard way, avoiding as much additional capital investment and/or customization as possible.”
Source : NIST Framework and Roadmap for Smart Grid Interoperability Standards
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10. Regional Applicability
March 2010
Regional Applicability
Countries that are using ANSI standards in the meter may prefer to implement RS-232 data rates.
Japanese band may require a data rate of 50kbps due to local constraints.
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11. Recommendation Use a data rate that is related to EIA RS-232 standard.
March 2010
Recommendation
Use a data rate that is related to EIA RS-232 standard.
The closest values to current proposal are 38.4kbps or 57.6kbps. These two choices will allow a better adjustment to local regulations (side-lobe emissions).
devices built around these data rates can usually be used at 51.2kbps, which is even closer to the current proposal (51200=38400*4/3).
This choice is the least likely to raise technical issues with existing devices.
Following this recommendation allows current devices an opportunity for migration within the spirit of the NIST Framework
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12. March 2010
Thank you!
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13. March 2010
Appendix
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14. March 2010
OFDM and RS-232 data rates
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