In Part 1, I talked a little bit about the vision for the internet of things, but I didn’t really define what I meant by the internet of things.
What I’m talking about when I talk about the Internet of Things is a profusion of small devices that are all connected to the network and therefore to the Internet. Whereas most of the things in your home that are connected to the network have keyboards and screens and are meant for you to interact with, I’m talking about things that instead have sensors and relays and actuators. In most cases, you won’t interact with them at all. They’ll just work automatically in the background either gathering data for you or controlling equipment. Most of these things you’ll set up and never touch them again, but they’ll be working quietly in the background for you day and night.
If you are as old as I am (and I hope you’re not!), you remember the first wave of personal computers: the Apple II, the CP/M machines like the Kaypro and Osborne, and the original IBM PC – these were amazing because they were real computers that could do useful things (spreadsheets, word processing, and calling bulletin board systems) but were small (the size of a suitcase, more or less) and inexpensive (a few thousand dollars – in the 1980s) enough for home use.
Raspberry Pi Zero – $5
The kinds of computers that we are talking about here are significantly smaller (typically the size of a credit card) and significantly less expensive (most under $100, many of them less than $10), even though they have 10-100x the computing power of those early personal computers. Instead of keyboards and screens, they have network ports and connections for various sensors and/or actuators; most can run for hours or days on a small battery – some can run for months. They can sit in in a tiny place, collecting data and transmitting it to the network, or waiting for a command to do something, for years.
Simple Air Temperature Sensor
Decagon Soil Sensor
There are also a wide variety of sensors available, from simple temperature or humidity sensors to weather sensors like anemometers and rain buckets to advanced soil sensors that can measure soil temperature, moisture, and electrical conductivity. There are even sensors for UV radiation, leaf wetness, and chemicals in air and water.
Simple small relay
But these little devices can do more than just sit passively measuring conditions. Devices can also be connected to allow them to take action, from simply turning something on to controlling complex machinery automatically. For instance, it is fairly simple to use a simple, small relay to turn an electrical machine on or off.
Raven PWM Valve
Multiple relays can be used for multiple devices, and relays come from very small, low-power devices to very high-power solid-state relays for switching very heavy loads. Many of these computers, however, also have the ability to output Pulse-Width Modulated (PWM) signals to control variable-rate devices like valves (control pressure through a water valve for irrigation or a hydraulic valve for controlling machinery) and pumps.
75 Amp Solid-State Relay
What ties it all together, of course, is two things: a network and software (both on the device and acting as some sort of “back end” to store and manage the data coming from these devices). Without software, any computer, even a $5 one, is just dead weight; without a network, it’s just sitting out in the field collecting data it can’t move to someplace it can be useful.
We know how to build the network – what Ayrstone does is give you the ability to build a strong, standards-based wireless network across your farm – and in part 3 we’ll consider the software part.
Much has been written about the use of remote sensors in farming, with soil sensors leading the way. I think it’s worthwhile to understand how these sensors work and what options are available
We have highlighted some of these products (gThrive, Farmx, Edyn), and there are others coming up including Cropx and AgSmarts that we have not been able to evaluate in depth yet, although they are very promising and appear to be more focused on “mainstream” agriculture rather than specialty crops.
The soil sensor people understand that, to have soil sensors near the plants, you have to have sensors that are battery-powered (because you don’t get enough sun under the canopy to use solar). Because of that, most soil sensors use a low-power radio system; many use a “Personal-Area Network,” usually based on the 802.15.4 low-power, low-bandwidth meshing standard. These networks allow the sensors to use very little power so the batteries can last for months or even years. Additionally, the bandwidth (the amount of radio spectrum they use) is so low that they can transmit a very long distance with minimal power – frequently hundreds of yards – and the meshing capability means they can cover a very large area in a couple of hops. So these sensor networks actually ARE practical for gathering data from sensors, even in a very large field.
gThrive sensors and gLink gateway – Courtesy of gThrive
However, these systems, just like your home WiFi network, require a “gateway” device out in the field to connect them to the larger network (your AyrMesh network or the Internet). The Edyn sensor is an exception, because it connects directly to your WiFi network, but it is primarily aimed at gardeners, not commercial agriculture. Davis Instruments uses the weather station as the Gateway device, which makes it simple, but it does not use a meshing system, which limits how many sensors you can deploy. For almost all systems, sensors are not directly on your network or the Internet – the field network is a special network that only “talks” to the gateway device, and the gateway device “talks” to a normal Internet Protocol network – and that is usually a cellular modem connected to the Internet.
A Gateway device for your sensor network (possibly multiple gateway devices if you want sensors in multiple fields), and
Cellular subscriptions for each gateway device.
This is a lot of “commitment” before you even figure out how to effectively use the sensors and the data that comes from them – thousands of dollars just to get started plus a monthly or annual commitment to get the data. These systems are being marketed primarily to folks growing wine grapes in California or vegetables in Arizona – high-value crops with severe water costs and restrictions.
There are changes coming, of course, but there are also ways to get started now with less commitment.
First, if you’re growing a few acres of cut flowers, organic vegetables, or other high-value, high-intensity crops, the Edyn system may be very useful. Put an AyrMesh Hub near your field and deploy the Edyn sensors and valves controllers. You don’t have to save a lot of time and water to justify the expense.
Davis Weather Envoy, courtesy of Davis Instruments
Second, Davis Instruments has a nice system that they don’t advertise much. Their Wireless Weather Envoy datalogger can be connected to any Ethernet network (e.g. a Remote AyrMesh Hub, an AyrMesh Receiver, or an AyrMesh Bridge) using their Weatherlink IP module. It can then connect to their Soil Sensor Station, which has up to four soil moisture and soil temperature probes. It will also connect to a Vantage Vue wireless weather station, which is a very high-quality, low-cost, integrated weather instrument cluster that you can put up in any field in a matter of minutes. There’s a small annual fee for their cloud-based Weatherlink service, but it makes the system VERY easy to use.
If you need more soil sensors, they also build an Envoy 8x, which has the ability to simultaneously “talk” to up to 8 stations – weather stations or soil stations – within about 1000 yards.
Either the Wireless Weather Envoy or the Envoy 8x can be tucked into the cabinet of the Tycon remote power system we recommend for field Hubs, Receivers, or Bridge radios, and powered from the auxiliary power output on that system.
Third, if you do want to deploy many soil sensors using a system like gThrive or Farmx, you can connect the gateways in each field to an AyrMesh devvice to avoid exorbitant cellular fees for each gateway device. Their gateway devices have Ethernet ports, so they can be connected directly to an AyrMesh Remote Hub, Receiver, or Bridge unit, and you can skip the cellular bills.
We’ll have more on weather and soil sensors – if you have questions or comments, please leave them here (for public response) or contact us.
I read a LOT about the “Internet of Things” (abbreviated IoT) is in the news lately; you probably have see it too, and there is a lot of excitement around it. And I would argue there’s good reason for that – it is going to change everything, perhaps more fundamentally than cellphones and, later, smartphones. But it is important to understand what the IoT is, what it is not, and how it will affect life on the farm.
Courtesy of Nest
The IoT is not a single thing or even a particular class of things; it refers to a new generation of devices that are connected to the Internet and perform some function, with little or no human interaction. There are already a LOT of good examples, from the Nest Thermostat to kid’s Arduino toys, from devices that can be handy almost everywhere like a network-connected lightswitch, to highly specialized devices like grain dryer controllers or irrigation controllers. I would argue that little of this stuff is new; the things we are seeing being touted as “IoT” devices are really the same as things we already have, just made smaller, smarter, and less expensive. Frequently a LOT smarter and a lot less expensive, which is important.
Belkin WeMo WiFi Outlet
But the profusion of little, inexpensive, smart things all over the place is having effects we can’t fully understand or appreciate yet. The one thing we can predict with some certainty is that the people who understand these devices and put them to use intelligently will see tremendous gains, just as those who started using computers intelligently saw huge benefits. The question, of course, is, “How do I use these devices?”
Technical knowledge is much less important at this phase than imagination – in all honesty, the most technically competent people miss a lot because they are too invested in how things ARE, so they cannot understand how things COULD BE. So I pose this question to you: what on the farm could be made better (faster, cheaper, more profitable, or more enjoyable) by little computers with accurate little sensors (for light, heat, moisture, position, motion, and lots of other things) and robust built-in data communications infrastructure (WiFi)? What could you monitor? What could you control remotely (or even automatically), especially using the data you are getting from monitoring?
We’ll explore this more in future blog posts, but I would like to hear what you have to say, as well.
As mentioned in an earlier post, we have been working with the RoyseLaw AgTech Incubator. One of the benefits of the program has been the ability to work with some of the most innovative companies coming up. This is one of those companies.
FarmX, based in Tulare, CA, has launched its FarmMap solution in CA and is introducing FarmMap with special pricing for existing Ayrstone customers. To take advantage of this offer, please complete this form.
FarmMap is a low-cost smart farm automation tool that uses scientific grade instrumentation to give you access to all the information you need about your farm in simple, secure, all-in-one tool. The FarmMap’s cloud platform gives you constant, secure access to your data, recommendations and field health.
FarmMap’s system of soil probes gathers information across your acreage with 1 probe for every 10 acres and connects your farm to the cloud. Each FarmMap sensor probes captures key environmental, soil and plant health data in real-time.
FarmMap uses state-of-the-art machine learning techniques to uncover opportunities to improve productivity and reduce the cost of inputs, such as water and fertilizer. FarmMap gives you the confidence to make accurate decisions quickly, accurately, saves you time and gets rid of guesswork.
This is another example of the kind of technology that is available at very low cost when you outfit your farm with an AyrMesh network – each field can be outfitted with a FarmMap gateway device to communicate with their soil sensors, and you can connect the gateways to AyrMesh components (Hubs, Receivers, or Bridge radios, depending on your network) to connect them to your network.
Click below for more information about FarmX and FarmMap:
gThrive is one of the companies I have been watching for a while, because I thought their technology was interesting. I think that the use of sensors for monitoring soil conditions is an excellent example of what technology can do for agriculture, but the existing solutions out there are simply too expensive for use outside of very high-value crops.
gThrive took the approach of using modern sensor and microprocessor technology and mating it with low-cost packaging to create a new soil sensor with more “intelligence” at lower cost than anything currently available on the market – hundreds of dollars per probe instead of thousands of dollars, with more sensors on the probe than had previously been possible.
The probes are simply plastic stakes, each of which has several sensors, a low-power CPU, a battery, and a low-power data radio, which communicates with their gLink base station. The gLink base station must be connected to the Internet via either a cellular connection or WiFi. This means, of course, that it can be easily added to your AyrMesh network, allowing you to have soil probes in multiple fields without having to rack up massive cellular data bills.
All data from the stakes are uploaded through the network to gThrive’s web site, which you can access from anywhere with any Internet-connected device. It’s a simple, clean, efficient system, and they have just started selling their system at the recent World Ag Expo.
Seeing products like this come to market validates the reason we started the AyrMesh product line – to help farmers get more data, faster and cheaper, and be able to do more on the farm. Products like this can dramatically add to the value of your AyrMesh Wireless Farm Network, and vice-versa. We wish gThrive all the best and look forward to working with them and other companies bringing new network-connected products to the ag market.
We didn’t invent the idea of putting WiFi on farms and ranches, although I think we’ve done a lot to popularize it. And it’s not really WiFi that’s important, it’s just having a farmwide network that you can connect to and move data with.
When we started, we realized there were two ways we could build out the farm wireless network, and that we’d need to support both ways. However, we had to start somewhere, and we knew that the best short-term “proof of concept” was using the mesh network approach: a bunch of high-power WiFi Access Points that are connected to the Internet and talk to each other using a meshing protocol. That’s what gave rise to the AyrMesh Hub.
Because the Hubs can be up to 2.5 miles apart, it allows you to extend your network out quite a ways from your home place, and that’s useful for a lot of people. It also allows you to “get in the game” for a minimal investment – a few hundred bucks for a Hub and a little time putting it up high and out in the clear gets you WiFi across your farmyard and out into your fields. Then you can extend the network from there with additional Hubs.
However, sometimes you just want to connect someplace into your network, and you don’t need to have WiFi. For those cases, a different approach is optimal: point-to-point microwave links, also known as “bridges.”
A bridge can use WiFi or a WiFi-like signal to connect two locations and pass data between them. Typically they are “Layer 2” devices, meaning that they work just like a long, wireless Ethernet cable. You plug one radio into your network (typically your router) and then plug the other radio into whatever you want to put on your network (a computer, IP camera, WiFi access point, etc.), and everything works just like it was plugged into your router.
The AyrMesh Bridge uses microwave radios that use the 5.8 GHz. band (used for 802.11 WiFi “a,” “dual-band n,” and “ac”), but they use a special “narrow-band” microwave signal that increases the range, reduces the effects of interference, and makes the signal invisible to WiFi “sniffers.”
Of course, if you are just connecting some distant device or devices into your network, you can also use an AyrMesh Hub and an AyrMesh Receiver. It will actually work the same way; the differences are:
The AyrMesh Bridge is just a wireless Ethernet cable that doesn’t provide a wireless signal usable by anything else. The AyrMesh Hub provides WiFi that other devices can use.
The AyrMesh Bridge is a “1-to-1” system, but you can have several Receivers talking to one Hub.
The Receiver can be up to 2 miles from the Hub, but the Bridge radios can be up to 5 miles apart.
It’s not necessarily an “either/or” thing. Several AyrMesh users are using the AyrMesh Bridge to reposition their Gateway Hub to the top of large structures (e.g. grain legs) to give the Hubs maximum range. A couple of people are using their Hubs for WiFi but providing connectivity to other buildings using Bridges (with the Hub and the Bridge radio mounted next to each other on top of the house or office). And you can use a Bridge connected to a Remote Hub to connect a device several miles away from the Hub.
There are a lot of folks out there selling wireless bridges – we think the AyrMesh Bridge is the best for one important reason: it’s the easiest to set up and use. No configuration is needed: you just connect both radios in the Bridge to your router. They download your configuration from AyrMesh.com and then all you have to do is mount them outside pointing at each other.
Now you know how to select an IP Camera, set it up on your farm, and view it from wherever you are, on or off the farm, which may give you a greater sense of security by itself.
However, you can’t watch what’s going on 24×7, and, with most cameras, you can’t go back and see what happened a couple of minutes ago (or last week). If you want to incorporate cameras as part of a security system (which may also include things like driveway sensors, indoor motion sensors, window/door open sensors, and other devices), then you should, at a minimum have some sort of recording, and probably some sort of motion detection on the cameras. What I have found to be best is some sort of system that is continuously monitoring the cameras, and, when motion is detected, it records the previous several seconds of video and keeps recording until after the motion stops. That way, I find, I get a nice, clear video of the mailman coming up to the box every single day (and, if I choose, a text and/or email with a picture of the mailman within a few seconds of his arrival).
But, seriously, if you are having trouble with intruders (people breaking into your storage sheds or stealing Anhydrous), getting notification and pictures of them is a good idea. For that, you need a Network Video Recorder (NVR). An NVR is a device that plugs into your network and monitors your IP cameras, allowing you to view several cameras at once and go back to see what happened at a particular time. Most modern NVR systems also have motion detection and multiple alarm functions (including email and tripping a relay to set off an alarm).
Swann DVR with cameras, courtesy of Swann
An NVR is different from a Digital Video Recorder (DVR), although both can be useful tools for farm security. A DVR typically has a number of coaxial inputs for cameras, so you can attach 4, 8, or 16 cameras to the unit using coaxial cable and it will continuously record the video from those cameras. Most modern DVRs also have an Ethernet port so you can connect them to your network and monitor the cameras from wherever you are. A DVR can be very useful anywhere you want several cameras in a single physical location, like your home, workshop, or storage shed, where you don’t mind stringing wires. Most newer DVRs can also detect motion send you an email or other form of alarm when they do.
Foscam indoor camera with storage – the little microSD slot under the antenna – courtesy of Foscam
Some newer IP cameras even have the NVR capability built-in, usually via an SD card slot. They store either still images or video to the SD card continuously so you can just “back up” while you’re viewing the cameras.
Almost all IP cameras have some form of motion detection, but many of them are effectively useless. There are three types of motion detection:
Overall picture motion detection – this just looks for the number of pixels changing in the frame and alerts if that number rises above a certain level. Unfortunately, this is almost entirely useless, because, if the sensitivity is high, it will “alarm” every time the lighting changes slightly, and if the sensitivity is set too low, it won’t alarm at all.
Setting a “zone” so the camera will alarm when the door is opened – courtesy of networkwebcams.com
“Zoning” motion detection – this allows you to put rectangles into the camera’s frame and only alarm if there are changes inside those rectangles. This works better, but you still get a lot of “false alarms.”
Object detection, courtesy of Sitehound
Object detection – this is an algorithm that can pick out moving objects in the video stream and distinguish them from changes in the background. This means that you only get an alarm when something moves, and you can set the size of the object that will set an alarm so you don’t get called every time a gnat flies by.
Most inexpensive cameras use the first type of motion detection, which means the on-camera detection is worthless. Almost all other cameras use the second type of detection, which is not useless but still not great. Some high-end cameras can do object detection, but they’re pretty expensive.
The better idea is to have your NVR software do the detection and alarming, rather than the camera. There are two ways to do this: using a dedicated NVR (a small computer running embedded NVR software) or running an NVR program on a desktop computer that’s on 24×7. There are advantages to either approach.
Using a dedicated NVR is simple: you set it up, add the cameras to it through the onboard user interface, and forward a port to it on your router so you can access it while you’re away. QNAP is a vendor that makes a large range of standalone NVRs that are compatible with a wide variety of cameras. In all honesty, I have never been able to evaluate one, but customers have reported good results with them. Synology has developed a pretty good reputations, also – both brands are generally available on Amazon.
The downside to the dedicated NVR is that only some cameras are supported (although the brands mentioned above support a huge number of brands) and that it is difficult to evaluate the software to tell how well it will work for you. The vendors don’t really provide much detail about how they detect motion, what options are available, and what the units can do.
Ubiquiti Cameras and NVR, courtesy of Ubiquiti Networks
Some camera vendors like Vivotek, GeoVision, and Ubiquiti sell both cameras and NVRs to work with their cameras in an integrated package. Going that way makes it easier to know your cameras will work the the NVR, but more difficult to evaluate whether you have the right cameras and NVR for your operation.
The other option for an NVR is to use an NVR program on a computer that’s running all the time. There are several of these programs, but the two most popular are BlueIris and SightHound. BlueIris is less expensive and runs on any Windows PC; SightHound is more expensive, but has a number of important advantages:
It runs on either Windows or Mac computers;
it is very easy to install, configure, and use; and
it features an advanced object-detection motion detection.
I’m an unabashed fan of SightHound – I have written about it before on this blog – although I have used BlueIris and it is also very good. I also like the Ubiquiti system (Note: Ubiquiti builds the hardware for the AyrMesh system), although I find their software to be a bit too complex for most users. It also integrates with their mFi sensors and switches for security and automation.
Dropcam – courtesy of Dropcam
There is actually a third option – a camera that automatically loads its video to a “cloud-based” NVR. Dropcam is a system that uses nice, small, relatively inexpensive indoor cameras, which automatically send their video stream to their cloud servers, without the need for port-forwarding. I have also written about Dropcam before on this blog. The big advantages with Dropcam is that they are VERY easy to set up and use, and the company is now part of Nest (maker of the Nest thermostat), which is part of Google – they have the resources to keep this going and expand those products to do a lot more in the future. The disadvantages are:
They currently only make indoor cameras; there is no outdoor option, and the cameras are not designed for outdoor temperatures.
They charge on a per-camera basis for the recording function. They charge $10 per month/ $99 per year for the first camera and $5 per month/ $50 per year for each additional camera (that’s for 7 days of recording; they charges for 30 days of recording are 3x higher)
There is no way to directly view the camera – the only way to view it is through the Dropcam website. This is not a big problem practically, but it does bug me a little. Even without a subscription, you can view the camera through their website and get notices when motion is detected, which is nice.
Whatever cameras and NVRs you choose, you’ll need to connect the cameras to the network, connect the NVR to the network, and make sure the NVR is “talking” to the cameras. You can then port-forward to the NVR (remember about this from the router series?) in order to access it from the Internet; that way you don’t have to port-forward to each of the individual cameras. You’ll need to fine-tune the sensitivity of each camera in order to get appropriate “alarms” for movement. You’ll also need to set the alarms up so they contact you appropriately. Setting up an email alarm is relatively easy, and all the cellular phone providers give you an email address that goes through as an SMS text message – for instance, on Verizon, if the phone number is 555-123-4567, you can email “email@example.com.” That way you can get a text message on your phone whenever motion is detected.
So, now you have cameras set up in the critical parts of your farm, which you can view through your NVR, and you are set up to get alerts any time something moves in the field of view of those cameras. All of this, of course, is made possible because of your AyrMesh Network, covering your farm with powerful IP connectivity.
And there’s still a lot more you can do with the network… stay tuned!
Many people start building an AyrMesh network on their property to provide Internet access across their acreage. However, having an Internet Protocol (IP) network across your property gives you the opportunity to connect devices on the property to help you be more productive, more efficient, safer, and happier.
When I ask people what else they’d like to do with their AyrMesh Network, the first thing that usually comes up is cameras – the ability to see their property remotely.
There are two distinct reasons for putting cameras on your property: the first is what I call “situational awareness” – being able to bring up a view of some part of your farm any time you want. The second is for security – automatically monitoring some view of your property and alerting you when something happens.
If you have animals on the farm, you probably worry about them – especially if your livelihood is tied up in them. One of the most common uses for cameras on the farm is to be able to check on the animals, whether it’s just so the kids can see the horses when you’re away or if you need to check on farrowing sows, calving cows, or foaling mares to protect your investment.
A lot of people also just want to be able to view some part of the property, like the driveway or the kid’s play area, so they can know what’s going on any time. Sometimes these cameras may be dual-purpose, serving both a security function and for situational awareness.
Putting a camera on your property gives you a “view” – you get the IP address of the camera from your router and you can bring up that view from anywhere on your property. Then you can do what’s called a “port forward” on your router to make your camera viewable from the Internet, wherever you may be. For instance, I always forward port 9001 to a camera in my living room. I can look at my public IP address on AyrMesh.com and find that it’s 126.96.36.199 (it’s not, but let’s pretend…), so I just need to point a browser to http://188.8.131.52:9001 and log into my camera (note: you HAVE to have a good, strong password on your camera).
Next we’ll talk a little about the different kinds of IP cameras and the tradeoffs and compromises you can make – see part 2 here.
It seems like every time you look around there’s a new crop of WiFi routers offering unbelievable speeds and ranges due to the use of a new WiFi standard. Years ago, WiFi started out with 802.11a (back in the last millenium) and then 802.11b, which gave way to 802.11g, which was replaced by 802.11n, and new routers use 802.11ac. And, if you’re wondering, yes, of course there’s a new one on the way, currently called “802.11ax.”
There are also many ancillary standards associated with these, even an 802.11z standard (having to do with extensions to Direct Link Setup, whatever that means). The “a,” “b,” and, to some degree, “g” standards are, for all intents and purposes, obsolete, because nobody has built equipment using those standards for a long time. On the other hand, all the standards are “backwards-compatible,” so the newest equipment can still interoperate with the oldest “a” and “b” equipment.
For us here in the Ayrstone labs, the amusing thing about all these advancements since 802.11g in 2003 is that they are squarely centered on one thing: improving indoor WiFi performance. The reason that amuses us, of course, is that it’s exactly the opposite of what we’re trying to do, improve outdoor WiFi performance. There has been almost nothing done to improve outdoor long-distance WiFi since the 802.11g standard.
Here’s a quick rundown of the various WiFi standards:
802.11 – 1997 – up to 2 Mbps on 2.4 GHz and InfraRed with WEP encryption
802.11a – 1999 – up to 54 Mbps on 5 GHz
802.11b – 1999 – up to 11 Mbps on 2.4 GHz
802.11g – 2003 – up to 54 Mbps on 2.4 GHz, WPA/TKIP encryption
802.11n – 2009 – up to 600 Mbps using both 5 Ghz and 2.4 GHz, MIMO, WPA2/AES-CCMP encryption, wide channels
802.11ac – 2013 – over 1 Gbps using both 5 GHz and 2.4 GHz and extra-wide channels, MU-MIMO
802.11g was the standard that made WiFi useful (effective data rates of over 20 Mbps) and safe. The original WEP encryption standard in 802.11b was fatally flawed and easily broken – we now consider it “anti-security,” because it gives the uninitiated the illusion of security but does not actually deliver any, much like having a door made of paper painted to look like steel. WPA/TKIP encryption is still considered unbreakable (when used with strong passwords), so 802.11g WiFi devices are still perfectly useful.
802.11n added even more unbreakable security (WPA2/AES-CCMP), which is designed for large networks and organizations. It also added MIMO (Multiple Input, Multiple Output), a way of using multiple antennae to increase the bandwidth and increase the range of the WiFi signal, especially indoors. A single antenna senses “multipath” (signals bouncing off the walls and other solid objects) as noise, because they are slightly out of synchronization with signals coming directly from the other station. MIMO antennas can “correct” and re-synchronize those multipath signals, improving indoor performance dramatically in some cases. 802.11n also introduced dual-band capability, using both the 2.4 GHz and 5.8 GHz bands to increase throughput, and “wide” channels – increasing the amount of electromagnetic spectrum used from 20 MHz per channel to 40 MHz. Wide channels increase bandwidth, but at the sacrifice of range. So you can get faster data speeds close to the WiFi Access Point, but speeds will drop off quickly as you move away.
802.11ac is the latest standard, and it adds on top of 802.11n. Specifically, it allows for extra-wide channels (80 or even 160 MHz in the 5 GHz band) and MIMO improvements. In particular, it adds “MU-MIMO” or Multiple-User MIMO to expand the advantages of MIMO to multiple users of a WiFi access point, as well as increasing the number of spatial streams (from 4 to 8) and offering improved modulation techniques on the wider channels (256-QAM).
So the improvements to WiFi since 2003 can be roughly broken down into 3 areas:
5 GHz – The higher the frequency of a radio signal, the more it behaves like light, so the more it is affected by solid objects. 5 GHz. signals disperse more in air, and pass through solids even more poorly than 2.4 GHz. signals (which don’t do very well). So, with some notable exceptions (very focused point-to-point links with very clear line-of-sight), 5 GHz is only useful indoors and for very short distances.
MIMO – MIMO is one of the most exciting improvements to WiFi, because it can dramatically improve indoor performance. Of course, both the access point (e.g. wireless router) and the client device (e.g. laptop) have to have MIMO to make the best use of it, but can really improve both range and throughput indoors. Outdoors, however, where there aren’t walls that signals can bounce off of, the value of MIMO is very limited.
Wide channels – I sometimes explain that radio signals are a lot like plumbing. If you have a water hose with a constant pressure, you can put a narrow nozzle on it and push a little water a long ways, or you can put a wide nozzle on it and push a lot of water a little ways. Wide channels are like a wider nozzle: more bandwidth that doesn’t travel as far.
The key to getting maximum range outdoors is to “squeeze” the stream down as much as possible to force it out toward the horizon. The AyrMesh Hubs do this by going somewhat against the “trend” in WiFi:
2.4 GHz only – for lower dispersion and best penetration of solid objects
SISO – focusing the radio signal (the spectral density) into a single beam for maximum range
Narrow channels – focusing the radio signal into the smallest channel width for maximum range
When we introduced the AyrMesh Hub2n, we noted that it uses 802.11n technology. However, while it does comply with the 802.11n standard, it is, essentially, using the 802.11g features present in 802.11n and almost nothing unique to the 802.11n standard.
That’s not to say that we’re not keeping close tabs on the improvements to WiFi and trying to figure out ways to improve our products. By moving to 802.11n, we picked up WPA2/AES-CCMP encryption, which is actually more efficient on many WiFi radios equipped with hardware encryption, and new modulation methods which may provide marginally better performance. Right now we don’t see any improvements from MIMO, for instance, but we may yet find a way to make use of it. We also have hope that new, more efficient modulation methods could provide us new ways to increase the range and throughput of outdoor WiFi.
We also made use of another WiFi standard in the Hub2n: 802.11s, the new WiFi meshing standard. Time will tell, of course, but we hope that adopting this standard will enable us to introduce new Hub models and other equipment without changing the meshing, effectively “future-proofing” the Hubs.
What this means is that now is the perfect time to build your Wireless Farm Network using WiFi: the technology is extremely well-proven, inexpensive, and reliable. There are lots of contenders to take the place of WiFi for outdoor connectivity, from Super-High-Frequency radio to “White Space” radios (using the unused frequencies in the Television band). None of them are going to offer anything close to the price/performance you can get today out of outdoor WiFi, at least for a very long time. So you can build your network well-assured that there isn’t something waiting in the wings to make your investment obsolete. There will never be a better time to build out your Wireless Farm Network.
The ASUS RT-N66U – a modern, high-end home wireless router
In the last article in this series, I discussed what a home router is and a little bit about how it works, as well as providing guidance on how to set up the DHCP server.
IP addresses on your LAN are assigned one of two ways: either by the router’s DHCP server, which provides them out of the DHCP address pool (which I suggested should be 192.168.1.50 to 192.168.1.254) or by statically assigning them yourself (which I suggested should be out of the remaining 192.168.1.2 to 192.168.1.49 addresses). Assigning static addresses is very seldom necessary on modern routers, however, because most modern routers have a feature called “DHCP Reservations.” This allows you to specify the MAC address of a device and make sure it is assigned the exact same address via DHCP every time it is connected to the router. Using DHCP reservations, you can ensure that your laptop always gets the same IP address without having to configure a static address for it (which is a pain, since you’d have to re-configure it every time you go to the coffee shop).
Using either static addressing or DHCP reservations, you may want to make sure that “infrastructure” on your home network, like file servers, entertainment systems, or security devices always have the same IP address.
Your router’s NAT usually automatically closes off all the ports on your public IP address, making it impossible to access anything on your LAN from the Internet. In most cases, that’s a good thing – you don’t want the Internet able to reach your private network. But, in some cases, you want to make devices on your network available from the Internet (ALWAYS protected with strong passwords, of course!). The classic example is the IP camera set to watch something important on the farm – it could be the front drive, livestock, or your machine shed – you want to be able to access it from wherever you are so you can check up on it. But you might also want to be able to check and operate machinery like your grain dryer, pumps, irrigation systems, HVAC systems, etc. from a distance.
The IP camera has a webserver that uses port 80 (usually) for its interface, so the trick of port forwarding is to open one port on your public IP address and tell your router to “forward” all packets coming to that port automatically to port 80 (or whatever port you configure) on the camera. So you “knock a brick” out of the router’s firewall by specifying one port on the public side (I like to use ports 7001-7099, because very few services use these ports) and forward that public port to a port on your camera.
The way you do this varies from router to router, but the drill usually entails going to the “port forwarding” interface on your router and specifying the incoming or public port (7001), the device that’s receiving the packets (your camera’s IP address – 192.169.1.something), and the port on the device that will receive the packets (port 80). Then, if your public IP address is 184.108.40.206, you can access your camera on the Internet at http://220.127.116.11:7001 (the IP address, a colon, and the port number). Some routers allow you to specify only certain incoming IP addresses that can access the camera, but that’s usually not a good idea because, for instance, if you want to look at the camera from your smartphone, you won’t know the IP address of the smartphone.
NOTE: some routers (stupidly, in my opinion) require that the port numbers on the public side and the private side be the same – they won’t forward port 7001 on the public side to port 80 on your camera. If you have a router like that, you’ll need to reconfigure your camera (or whatever device you have) to the appropriate port (e.g. 7001) port before you can do the port forward. You shouldn’t forward ports under 1024 unless you know exactly what you’re doing, because you might be disabling something your router needs to function properly. Forwarding extremely popular ports like 80, 20, 21, 22, 23, 25, etc. can also attract password crackers and other undesirable elements to your network.
Let me emphasize at this point the importance of a strong password on anything that’s exposed to the Internet – if you can access it, so can anyone else, so make sure it’s locked down.
On my own home network, I have several ports forwarded to different IP cameras around my property, as well as ports forwarded to my desktop Windows machine (using VNC so I can access it easily when I’m away) and my Linux development machine (using SSH). I can actually access any of those devices using my smartphone, so I can stay on top of things anywhere I have an Internet connection.