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Smart Grid StandardsWhy Wi-Fi may finally be ready for the smart grid
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Jun 8, 2011
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Now I'm back to tell you of another development – one that threatens to push ZigBee into a corner as a niche protocol for certain smart metering installations in certain parts of the country.
The Wi-Fi Alliance is making a concerted push to play a larger role in the smart grid. I am particularly intrigued by a new development called Wi-Fi Direct.
Wi-Fi is an umbrella term for a series of related wireless networking standards based on the IEEE 802.11 specification. It is far and away the world's leading standard for wireless local area networking. It is supported by the Wi-Fi Alliance, a 400-member association that markets, lobbies, tests and certifies products.
In the past few years, Wi-Fi has migrated from AC-powered routers to battery-operated smart phones. That's an important evolution. The biggest knock against Wi-Fi has been its power requirements, especially compared to ZigBee, which was designed from the ground up for low power.
The incorporation of Wi-Fi into battery-operated consumer electronics provides a powerful incentive for Wi-Fi chipmakers to continue to lessen the power requirements. When I chatted with Alliance Technical Director Greg Ennis, he claimed the latest low-power chips will support a 10-year battery life.
Wi-Fi Direct is a new offering that connects devices directly without the need for a hotspot. You can connect two phones to each other. Or two or more phones to a gaming console. Or a gaming console to a TV. And so on in any mix-and-match combination. If there is a hotspot around, Wi-Fi Direct products will link up to it. If not, they create their own personal area network on-the-fly.
To date, 85 Wi-Fi Direct products have been certified from 15 different companies. Research firm In-Stat forecasts 173 million Wi-Fi Direct devices will ship in 2011 – close to one in every five Wi-Fi devices shipped this year.
The Wi-Fi Alliance claims Wi-Fi is now suitable for smart meters. In theory, it will do all the same things as the ZigBee and HomePlug standards. (For instance, it will support the Smart Energy Profile 2.0.) But it can also open devices up to Wi-Fi's higher bandwidth and robust applications.
It's unclear to me whether and how this will work in the real world. I want to know more about Wi-Fi's power requirements. And about its abilities to accomplish mesh networking, whereby devices can relay messages from other devices.
But even though I don't have the technical chops to certify Wi-Fi's suitability, I'll bet there are some of you who can help. Please use the comment form to share your opinions or jump to our discussion forum and see what folks are saying about ZigBee's fate. Meanwhile, I urge you to consider Wi-Fi as one of your options for your next project. When a large Midwest utility made the evaluation for a stimulus-funded pilot set to roll out this fall, it decided that Wi-Fi was its best option.
Jesse Berst is the founder and chief analyst of Smart Grid News.com. He consults to smart grid companies seeking market entry advice and M&A advisory. A frequent keynoter at industry events in the US and abroad, he also serves on the Advisory Council of Pacific Northwest National Laboratory's Energy & Environment directorate.
| WiFi vs. Zigbee survival |
| Jesse, Good topic. I frequently hear the Silicon Valley computer crowd talk about how WiFi will take over. There is a long history of their doing that. However, a few points re your article: 1) Zigbee is a protocol that currently runs on a radio standard called 802.15.4. WiFi is another radio standard (not a protocol). As you noted, the Zigbee 2.0 spec is designed to enable all sorts of underlying communication technologies, including powerline. So, Zigbee implementations are likely to increase, even if WiFi radios become more competitive. 2) You did not mention two additional key issues re WiFi, i.e. a)Cost and b) specific requirements for utility applications (e.g. latency, security). Companies like Marvell have recently claimed that their radio chips can match the current price points of Zigbee/802.15.4 chips from major suppliers like TI which quotes their basic Zigbee chip at $2 in volume today. So far, higher end WiFi chips are far from that price point but of course volume is the great leveler in the chip business. 3) Many consumer and commercial product manufacturers to be competitive use semi-proprietary systems to meet the requirements of 2) above. Those exist in homes and commercial buildings today (e.g. in EMS building systems). My personal view is that what is needed are "bridges" that interconnect these various devices that are using various standards. I'm much more excited about such multi-protocol prototypes from leading companies like INTEL which has publicly demonstrated their current prototype to product developer since last Fall and I understand there are many more companies readying those for market. Unfortunately, many of the electric utility suppliers do not support communication from their AMI systems to gateways/bridges but perhaps that will change. So, the final issue is that the utility AMI system must either be upgraded or a special version of internet access supporting the concerns of utilities must be developed and adopted. CISCO seems to think that this can happen. My concern is that could take a long time since there is no overlord electric utility committee that can sanctify such a system for the country. John Antonchick Principal, NCN Associates |
| John Antonchick - 06/08/2011 - 15:58 |
| Wifi and more... |
| Ok Wifi Direct can be a solution. But there is a lot of questions about that: - which is the maximum distance beetween two devices ( for exemple the meter and another device)? - is there no problems of conflicts between different customers ( for exemple in multi residential buidings)? - what about security and Hacking? -Don't forget that that must be simple for the final customer ( today for a simple end user , it is not always easy to implement a WiFi connection).. that must be plug and play. |
| Philippe Sommereyns - 06/09/2011 - 07:04 |
| no overlord electric utility committee |
| In other countries there are though - The UK market model demands complete interoperability which can only be delivered with a National Standard, so there WILL be such a standard here. Every supplier's IHD (In Home Display) will need to talk to whatver Smart Meter is installed. Whatever standard wins here will have a market of 45 million meters (gas and electricity) and possibly more (Water?). The UK standard is likely to be published by end 2012 and if WiFi or Google hasn't got their act together pretty sharpish, it is likely to be ZigBee which wins out. |
| Paul Scotson - 06/09/2011 - 07:16 |
| WiFi |
| One thing that is being overlooked a lot is customer usability of this system. Smart metering lets the power companies see a lot of data and use it for their managing the grid, however the end user, ie the homeowner will probably like a set of tools to use themselves. Yes seeing how much energy I am using as a once daily snapshot is nice, however I do not want to have to go through google to do it, I don't particularly care for them snooping into even that aspect of my life as well. There are products out there now. The energy detective is one as an example, that allows the user to constantly monitor in real time what is going on with their home grid. This system uses wireless to goto the remote displays, however talks to the main MTU via the power lines via that protocol. Sending signals through the power lines during the zero cross over phase has it's own issues with communication reliability and noise etc. I bring this up, because a very important part of selling the whole smart grid to the customer is going to be about convincing them that THEY can use it as well, and not just the power company (whom folks have an general distrust of anyways). You show Joe the Bricklayer how HE can use the smart grid, and he immediately becomes much more willing to support it. WiFi has the capability of solving a lot of these issues, however wifi poses it's own set of problems as well. With more and more devices being wireless today, from routers, to thermometers, to rain gauges just to name a very small sampling, the 'bandwidth' in those areas is going to start getting very crowded, and noisy. Now there are security issues. At least with power line comms, as soon as you hit a transformer the signal is all but attenuated. Broadcasting it, lets anyone get into it. Let's say I have my wifi power meter hooked up through my router so I can access it at work to see if the A/C is kicking in. Now can the kid next door hack my internet access via my power meter? What other kind of trouble can one cause once they get in? I would like to see some real world testing before everyone hits the I believe button on this one. It could be a good step forward though if it does work. |
| Aaron Scholten - 06/09/2011 - 07:44 |
| ZigBee's future |
| Looking at the choices in the "ZigBee's future" poll, I feel like the real answer is somewhere in the middle of the two extremes here ("niche" / "rarely used" protocol versus "leading HAN standard")... To build on point #1 of John Antonchick's comment: The term "ZigBee" is becoming a bit hard to nail down these days, as even the ZigBee Alliance itself uses "ZigBee" as an umbrella term to represent several 802.15.4-based mesh networking standards (or at least protocol stacks) designed by the ZigBee Alliance. (There's the 2007-vintage "ZigBee Pro" upon which ZigBee's Smart Energy 1.x application profile was based. There's the emerging ZigBee IP protocol stack built on ROLL and RPL and IPv6. There's the RF4CE stack for point-to-point communications...) The SE 2.0 standard being developed by the ZigBee Alliance with the help of stack vendors, meter & HAN device OEMs, Cisco and various IETF members seems to be aimed at creating an application-level protocol that is pretty agnostic to the lower layers of the stack implementation (especially the physical layer, be it power lines, IEEE802.15.4-based radios at 2.4GHz or 900MHz, or IEEE802.11-based radios). This should hopefully allow for both WiFi-based and ZigBeeIP-based devices to flourish, potentially even in the same HAN (with the help of an Application Layer Gateway [ALG], which even facilitates the continued use of SE1.x-based devices in SE2.0-based HANs). Sure, there will be deployment scenarios and device use cases for which WiFi or PLC (power line carrier) is more appropriate than an 802.15.4-based "ZigBee" solution, but as there are several million meters in the world today (and some much smaller number of HAN devices) running SE1.x on a "ZigBee" networking solution (with millions more going into the UK over the next couple years of British Gas rollouts), I don't see ZigBee (in some form or another) disappearing from the HAN any time soon. Some of those SE1.x devices may upgrade to SE2.x; others may rely on the ALG as a solution for bridging the gap to the SE2-based HAN. But I don't see the meter manufacturers pulling out their ZigBee-based devices to stick in WiFi any time soon; if anything, I think the meters will go the way of the mobile phone, where they ship with a bunch of different types of radios for different comms protocols and allow the installer (the utility, typically) to pick the comms method that fits the deployment scenario. |
| Matt Dibb - 06/09/2011 - 07:44 |
| Wifi and more... |
| Philippe, - Wi-Fi Alliance claims a maximum distance of 656ft (more than 2 football fields). I'm sure this is open air testing no interference. Real world in the home distances will be much shorter similiar to coverage today. Wi-Fi also claims up to 250Mbps data rates. - I suspect WI-FI direct will add a new level of interference for the already overly crowded 2.4Ghz frequency range. - The same level of security supported today WPA2/AES. |
| D'Andre Ladson - 06/09/2011 - 08:05 |
| wifi vs zigbee |
| It's simpler than that: Why on earth do you want yet another wireless chip/radio/stack in your home or business when the one you have now can be extended or used? WiFi is a radio while ZigBee is a full 4 layer stack. ZigBee in the beginning did not use the Internet protocol stack but today because of market demand does. ZigBee is yet another protocol with a unique radio phy that I simply don't want in my home unless it removes WiFi completely and you run one IETF Internet stack from the building. |
| mike trust - 06/09/2011 - 12:27 |
| Zigbee or Wi-Fi direct |
| Zigbee has and will continue to have competition on all fronts; it is not a standard for anything at the moment. The introduction of Wi-Fi direct standard and Goog`s 6LoWPAN just show that the market and the technologies being fronted are and will continue to evolve, and in the name of technology bring it on. They all have plusses and minus`s but at the end of the day it`s about cost, benefits, performance, scalability, interoperability, interference, attenuation, power consumption, security etc. With hybrid Zigbee to Modbus and PLC systems for metering and the HAN coming out of Europe and Zigbee chip sets becoming cheaper, applications and devices becoming more numerous by the day. I would say it`s Google that has the real fight on its hands and even bigger one than it`s failed Google meter project, Wi-Fi direct has a better chance of survival lets hope it does not find the same fate as Wimax. My personal view is that the Wi-Fi Direct would be a good concentrator / bridge for Zigbee and PLC networks, LTE will probably follow the same path. |
| James Eades - 06/09/2011 - 13:43 |
| Why Wi-Fi may finally be ready for the smart grid |
| Hi Jessie, An interesting story. Just wondered if you are aware that the patent for WiFi belongs to the CSIRO in Australia and over the last few years, they have been successfully sueing corporations world wide for patent infringement. Might be interesting to get their take on the deployment of Wi Fi in Smart Grid applications. Rgs, Phil |
| Phil Epthorp - 06/10/2011 - 01:21 |
| ZigBee and Wi-Fi will coexist, but Wi-Fi will dominate |
| Wi-Fi will not replace ZigBee; instead, both ZigBee and Wi-Fi will coexist to enable Home area network (HAN) communications. ZigBee will likely become the dominant standard to communicate from the meter into the home, such as to a central energy management system (EMS). The central displays (EMS or Gateways), however, will likely communicate to smart devices in the home via Wi-Fi (not ZigBee). Why ZigBee from the meter to the home gateway? Because utilities have made major investments in smart meters that already house ZigBee chips. Modifying smart meters to communicate via WI-Fi is too much of a cost - so ZigBee wins here. Why Wi-Fi from the EMS or gateway to other HAN devices in the home such as PCTs and smart plugs? in the near term ZigBee will be a big player since most HAN devices have ZigBee chips. However, in the long term, customers will push vendors to develop products that are compatible with existing consumer electronics, such as smart phones and tablets. Preliminary results from many pilots show that customers don't want yet another device in the home; instead they want to use existing consumer electronics - so the smart phone and the TV are very like going to be places where customers will want to view and control energy. Hence, I predict that Wi-Fi will eventually supplant ZigBee in this space. Although some will make the case for Home Automation (HA) standards, I would bet that the predominance of Wi-Fi will erode HA. However, HA does offer a lot to consumers, including comfort, convenience, and control. So I guess HA will also be around for a while. But in the long term, I predict that one standard, namely Wi-Fi, will dominate eventually Smart meter manufacturers (such as Itron) and utilities have made major investments with the Installation of Zigbee radio chips inside smart meters. Hence, Zigbee will likely be the dominant communications vehicle from the meter into a central display, such an energy management system. How |
| Tim Rogers - 06/10/2011 - 23:01 |
| Interesting |
| Very interesting topic. I agree with Tim Rogers that Zigbee will domain Meter to HOME and Wifi will domain Home . However , it will take long time for Wifi to be dominant at home . We think IHD(in home display) is still necessary for end consumer because thru Smart phone/Computer they only can access the date but without controlling. Only depending on Display , they can control the appliance on/off . That is what really matter for end consumer. We are a manufacturer of IHD in china with very competitive cost structure. We can make IHD very attractive price for customer/utility to use. We welcome any partnership with us. henry@eco-smarter.com |
| henry huang - 06/15/2011 - 05:40 |
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