Agree that one-way notifications are a dominant pattern especially in financial markets.
For performance, when a high QoS delivery semantic is required, optimistic async one notification protocol is at play. This requires session context, idem potency (unique message ids), sequencing, resend/gapfill request, message grouping within a session (async progressive batching) and multi-hop message routing/addressing.
This is basically a repeat of tcp/ip at a "messaging" layer above transports (smtp, http, straight tcp/ip (ala sockets), X10, ftp, and queuing (MQ, AMQP, Tib) and UDP/IP multicast (reliable w/ Forward error correction-FEC). WS-Addressing begins to meet some of these patterns but falls short. It though can be extended. WS-Reliable messaging is to queuing paradigm oriented as is AMQP but provide some core required semantics (sequencing, session, etc).
Regards,
Derek LaSalle
I like the concept of One-way Communication. I just hope
that train hasn’t already left the station. Security, as reflected
in the first bullet of slide 3 of this NIST presentation http://collaborate.nist.gov/twiki-sggrid/pub/SmartGrid/AugustWorkshop/PAP15_-_Security_v1b.ppt
is probably less controversial.
Best,
B.O. December 17, 2009
Robert Old
Siemens Industry, Inc.
Building Technologies
1000 Deerfield Pkwy.
Buffalo Grove, IL 60089-4513
Tel.: +1 (847) 941-5623
Skype: bobold2
bob.old@siemens.com
www.siemens.com
This link should take you to the
AHAM white paper: http://www.aham.org/smartgrid
AHAM and the industry they
represent should be congratulated for taking the effort to review the issues
and clarify their position via this white paper. As a consumer-focused
industry that is independent from the energy industry, this is a bold step and
represents a level of commitment to the development of a smart grid. As
you know, I spent the greater part of 8 years building a perspective for the
appliance industry with a charter to see how appliance design should (or will)
be impacted by changes envisioned in the energy industry. Below I commented on
several points AHAM seems to be making in the white paper. Note that
these are my personal observations and don’t necessarily represent those
of any particular organization:
1.
Regulatory impact:
Page iii states “existing residential tariffs and rate structures do
not provide sufficient economic incentive to spur maximum consumer
participation in the use of Smart Grid technologies”. Page 10
continues this thought with “tariffs that would encourage widespread
adoption of these practices are currently not in place” and “The
pricing structure must allow manufacturers to build devices or appliances that
are capable of managing this benefit and provide consumers with the proper
incentives.”
2.
Appropriate consumer electricity pricing will
be the key driver to motivate development and consumer acceptance:
Combine the regulatory issue AHAM raised (see #1 above) with several other
statements in the document regarding “the consumer as the decision
maker” it leads to a conclusion that AHAM feels appropriate pricing
is the appropriate the motivator for manufacturer and consumer acceptance.
3.
Scalability and flexibility in the appliance
path to the smart grid: The document spoke of appliances that
could receive messages from the smart grid (or meter), but in the future be
reconfigured to receive their messages from a home energy management system
(EMS). This was referred to as ability to support varying levels of
sophistication (p 12). If we loose track of this aspect we will limit the
number of devices that can participate. On page 12, AHAM points out the
need for a “communication standard that allows seamless upgrade of the
energy management inside the home.” If done properly, we can
eliminate the need to upgrade the appliance to switch from a prices-to-devices
model to a home energy management system model. This is also one of the
concepts that tends to support the simple connector that Brian Seal is
leading. If the appliance shifts from taking input from the utility, via
AMI for example, and now takes it from an EMS, only a simple external interface
could be changed if necessary.
4.
Clear boundaries of control: This
could be considered as a method to minimize issues with privacy, security,
safety and consumer acceptance and perhaps one of the more key positioning
statements in the document. Several issues mentioned on pages 13 - 15 may
be viewed as contrary to some current paths in the smart grid roadmap
today. For example “In all cases, the Smart Appliance will
retain control of the appliance response to a signal from the utility company”
was a statement I expected but perhaps one that carries differences with
certain industry approaches. The paper also clarified that AHAM members
do not support an emergency comment to stop and appliance without the ability
for a consumer to override. The AHAM paper goes a bit further with the
statement that “The boundary of the utility’s reach should
end at the smart meter”.
5.
One-way communication: ensures
consumer and appliance safety, privacy, and security issues. Several
statements to this effect include “the smart meter should appear to
the residence as a one-way, read-only device to provide pricing, usage, and
requests for load reduction”. Although the AHAM document did
not tie all the issues addressed by one-way together, in summarizing and
considering this issue it does seem logical that if the communication is only
one-way, the issue of invasion of privacy is dramatically reduced.
Regardless of one’s position in the one-way vs two-way debate, we have to
consider that the consumer privacy issue could be managed to a significant
degree by limiting to one-way. Another factor is that the cost of two-way
may still need economic justification from the consumer and manufacturer perspective
represented by these AHAM position statements.
A statement in the AHAM document
that stands out as, perhaps, a summary of the position statements is “The simplest
and most straightforward way for the utility to verify that its message was
received and the load was reduced is to read the meter.”
Perhaps AHAM is saying that the summary of their work indicates that if you
have the ability to motivate (pricing / tariff) and send a cost-effective signal
(one-way) and have focused attention on a smart meter able to be read at any
point in time, we have enabled the majority of the benefits. The AHAM
perspective is that a simple signal followed by verification at the meter
should tell us what we need to know and that perhaps additional technology only
adds cost and risk.
Gale
Gale
R. Horst
Electric Power Research Institute
(EPRI)
942
Corridor Park Blvd.
Knoxville,
TN 37932
Office: 865-218-8078
Mobile: 865-368-2603
ghorst@epri.com
http://www.smartgrid.epri.com
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