Aug. 21, 2008 – In our continuing discussion, Cees Links, CEO of Greenpeak Technologies, tells of the value in using wireless mesh networks for real time location systems, and the limitless future by tying it to RFID.ffice:office"
In the node systems that you work with, is there any relevance to the route that the data must take? Is it ambiguous, where one node speaks to all other nodes; or do you have predetermined routes of data?
LINKS: There are different networking concepts and the two dimensions are the most known ones. We support both; both a sort of a spark configuration like a real nerve system. This is a mesh situation that is self healing, and self forming. If there is one route not available anymore, it ultimately finds a new route to make sure that the message is coming across. That type of protocol we support in either way, correct.
Does one use more energy than the other?
LINKS: Clearly the star network is, from an energy management perspective, the most controllable. The mesh network is more complex. But, also there are tricks to manage that situation.
That has a lot of do with timing. If you make sure that all the nodes wake at the same time and go sleep at the same time, actually they can be awake for one millisecond and be asleep for nine hundred, for ninety-nine milliseconds and the system is using very little energy, but still can preserve a total mesh environment that way.
It is my understanding that you haven’t worked much with asset tracking versus transmitting sensor data. Would the tracking of assets, either real time or in simple asset tracking, change the amount of data flow and therefore change the power usage?
LINKS: Well, actually asset tracking or RFID or logistical management is a very interesting area for sensor control networks in general. Also it is very interesting from my wireless perspective, because assets have the intention to move around and that is something you want to control. So you can look at it purely from a perspective of 'where is something?' I am talking about RTLS type of applications.
It is also interesting from a perspective of what happens with a container during a trip. What was the minimum/maximum temperature it was exposed to be at, or was it the maximum acceleration? In other words, did it drop and was damage caused to the loads, by improper handling of the transportation company, etc.
There is all kind of interesting sense and logistics around RFID. And we think that our solution is very capable of handling that.
Some companies that are selling RTLS solutions use this sales point is it fits into your existing Wi-Fi infrastructure. Is that something that sort of works against Greenpeak?
Do you sell against that notion in a way, or is your solution really for where there is no existing infrastructure? Is there a cost-effective reason for them to either add to their infrastructure or change it?
LINKS: In terms of RTLS systems based in Wi-Fi, they clearly have the advantage being able to use the existing Wi-Fi infrastructure. However, Wi-Fi based end nodes are very expensive and need a lot of battery power, because Wi-Fi never has been developed for low power environments.
What you see in today’s RTLS systems is that it can be applied on relatively expensive groups, yet can carry the cost of tag. That can go easily up from $25 to $100. If you are talking about RTLS systems that should be able to carry a much lower type, cost of goods, then 802.15.4, is a very good alternative, in particular, because it requires significantly less power, and therefore, can become maintenance free.
But, also the whole cost structure around 802.15.4, is significantly lower cost compared to a Wi-Fi environment. So it is kind of a tradeoff. It depends on the total system. But, if you have many groups that are relatively low priced, then I would say 802.15.4 is a way better choice.
It sounds like you have been involved in all sorts of different creative systems; and I get the sense that you talk with a lot of forward thinking people.
LINKS: I am very impressed by the number of different type of sensor networks that can be used. You know, I am also almost to the point of being shocked how big each of these opportunities are. I mean, we know that, for instance, there are many cell phones and the market of cell phones is very large. What I found out in RFID, every application in RFID can be as large as the whole cell phone markets.
And if you think about the number of cows and the number of tags and things to be measured, it is just phenomenal. I found the same thing for agricultural, fruit chain management logistics. In almost every application that you are looking at, it is just very, very large.
