Vendor Spotlight: Subcarrier Communications

Over the past several WISPA shows I have had the opportunity to chat and get to know CEO John Paleski from Subcarrier Communications (www.subcarrier.com). John is very in-tune with how the WISP industry functions in terms of tower needs.  Many of the big tower companies tack on so many fees with their towers it makes leasing a tower out of reach for many. Add on the processes in place can be a deterrent to getting equipment in place.

Subcarrier has addressed many of these hurdles for the WISP industry.  Reasonable rates for tower rent are always a concern, but if the business model is there for the WISP, they are not the primary concern many times.  Not only has subcarrier realized many WISPs are utilizing smaller equipment, but things like huge application fees are a negative for the smaller WISP. Subcarrier knows what is on their towers. Such a simple thing means a rapid and smooth deployment for the WISP.  After several conversations with JOHN, it is apparent he knows just about every tower in his inventory.  He can tell you if they will support what you are wanting to hang on that tower without running a $2000 engineering study right off the bat.  On the flip side, he isn’t compromising safety or integrity of the tower.  Many towers, such as old AT&T long lines towers were built to such high specifications if you just apply a little common sense and some quick figuring you know the typical WISP deployment isn’t going to add any significant amount of loading on the tower.

I believe that John thinks the same way many of us in this industry do.  An empty tower is not making anybody any money.  If it makes sense for both parties then a deal can be made.  Too many of the larger tower companies only look at deals that make sense for them.

I would encourage any of you looking for towerspace to check out the sites Subcarrier has.  Check out their interactive Google Search to see if they have some towers you could use. Tell them Justin sent you over.

Justin @ WISPAMERICA

I will be attending WISPAMERICA next week.

I will be a panelist on the Transitioning from a bridged to a routed network on Monday from 2:15-3:15
I will be moderating the Layering Redundancy across the network on Monday from 3:45-4:45
On Thursday I will be a panelist on Advanced BGP from 2:15-3:15

You can find me hanging around the Cambium Networks booth as a Certified Cambium Consultant offering free consultation for folks looking to integrate cambium into their network.  If you don’t see me just ask one of the Cambium team members to point me out.

I will also be happy to talk about peering with MidWest-IX and general ISP consulting as well.

Tower Suppliers

One of the more common questions we get asked about is towers, tower mounts, and where to get them. If you are looking to mount to Rohn towers check out our friends over at ISP supplies. They have many of the mounts you would need for Rohn 25-65 and some of the other Rohn series towers.  They will also be an exhibitor at the Upcoming WISPAMERICA in booth 700.

If you have larger towers or larger requirements check out companies such as SitePro1 or Tessco.  Both of these companies carrier mounts designed for monopoles and larger carrier style towers.

Form 477 and Mapping

Recently the FCC has put out a press release about updating the national broadband map. If you are a WISP and wondering why you aren’t on there ask your self this question: Have you been filing your form 477? If not, then that is why.  If you are an ISP you are required to file form 477.

So, where do you begin? The above link will get you started.  If you are confused by census tracts, blocks, 15 digit codes for, and the sheer amount of formatting you need to know you have come to the right place. Also, for you facebook users I will share a link to the WISPAMERICA 2018 session in Birmingham about what forms to fill out.

Option number one is your WISP billing platform may already support doing something with form 477.  Many of the billing platforms geared toward the WISP industry already support form 477 exporting.  Check with your vendor or have a conversation with one at an event such as the upcoming WISPAMERICA.

Second is an online service such as www.towercoverage.com.  While many folks know towercoverage for their RF propagation maps, they can also turn data you can use for form 477. Here are some searches from the towercoverage.com wiki to get you started on their 477 support.  If you are going to WispAmerica check them out in booth 600.

Lastly, but not least, we have firms such as wirelessmapping.com. Not only can they help you generate maps and data, but they can help you turn your data into marketing as well.   They are also able to make sure you are filing your paperwork properly and in the correct format. In my local area, I see companies that do not have a coverage listed on the national broadband map.  I can only assume this is an honest mistake due to an error in a census block mistake or improper coding.

If you don’t file your Form 477, not only are you doing yourself an injustice but not letting the government know you are there, but you are skirting the law as well.  If the government does not know you are providing broadband to an area, they may let your competitor overbuild on taxpayer money.  You are missing out on opportunities as well as potential fines.

My Home Lab/Testing ground

A few days ago, my buddy, Greg Sowell posted his Mobile Home Lab. I figured I would show off the rack in my home office.

This is a mixture of gear that powers the basic network for the network in my home and for testing, blog posts, support, and videos\. Each floor of our 3 story home currently has a Unifi Access point on it powered by a toughswitch POE.  My top level, which is where my office is has a unifi pro that does both 2.4 and 5GHZ.  The other levels just do 2.4ghz.  This will change once I get a POE switch that does 48volt to power the UNIFI pro.  I have stuck with UNIFI because of the bar in our house.  Any self-respecting geek needs a guest wifi network.  WPA keys are too hard to dish out for those late arriving guests after some rounds of crown and coke.  So a Cloudkey makes guest access an easy venture.

As stated before the UNIFIs are powered by a Toughswitch, and the PRO has a 48VOLT POE and is linked into a port on the tough switch.  This switch is then uplinked into one of the gig links of the active 2950 switch.  Various other devices, some not plugged in at the moment due to need to get to a cubby hole for a roof project, are plugged into the 100 meg ports on this 2950.  Things such as the DVR for the security system, network printers, ethernet to my desk for testing, network drives, etc.  The other gig port is uplinked to our internet router.

Our internet is handled by a workhorse Mikrotik 493AH. This has a Comcast cable and a local WISP connection, which is a backup.  From this router, I am initiating several VPN, EOIP, and other tunnels to various clients and remote networks.  If you notice, this router also has a little rubber duck antenna.  Inside is a r52 card that is usually disabled by default.  This is a backup network for testing if I suspect an issue on the internal wireless network. I can log in, enable the card, and associate to the SSID and see if things are okay, at least as okay for 802.11b/g speeds.

 

Most everything else is for Cisco certification testing and keeping up on those certs as well as labbing up scenarios. As you guys will hear on our latest podcast, GNS3 and packet tracer are great, but sometimes you can’t beat actual hardware.

I too have a console server for turning my devices on and off. I do not have fancy remote access turned on, but I can remote to 6 devices at a time without getting up and moving the 4 feet to move a cable.  Welcome to the future!

Run down of some equipment
Cisco 2950 (one production and one lab)
2x Cisco 3750
Cisco 3640
Cisco 3560-X
Cisco 1841
Various Mikrotik routers
Ubiquiti EdgeRouter Pro
Ubiquiti EdgeSwitch 16
(The infinity is going into production soon at a data center)

The Cisco 2541 at the top is a shelf for the monitor for the DVR.  Make a great shelf!  In the future, I hope to add a Juniper router and some more gear.  As always, if you are a manufacturer I would be glad to review some of your gear and even do some configuration videos on it.

On a side notes, you don’t see much wireless gear.  That is a separate spot in my office.

Everything you wanted to know about Root Name Servers

One of the foundations of the Internet is DNS.  We have talked about DNS alot.
http://www.mtin.net/blog/?s=DNS&submit=Search

There have been TBW Podcasts about DNS

So are you ready to get your geek on?
Let’s start with who operates the root name Servers. A quick visit to:
http://www.root-servers.org/

NetNod will explain the rest

Aligning an 80GHZ link at a mile and other licensed backhauls

Recently we had a teaching moment for a couple of folks who had not had much experience with aligning higher frequency antennas with very tight beamwidths.  This particular day we were aligning 2 foot Siklu 80GHZ antennas.

One of the questions we often get asked is how do you align these? These questions are usually asked by someone who is familiar with aligning 5ghz antennas with a 10 or 20 degree beam which you can eyeball and has tried a microwave shot. They find out it is much harder.  The higher you go in frequency the tighter and smaller the beam is.  Distance also affects how far off you can be.  Think of it as a laser pointer.  If you have ever taken a laser pointer out at night and shone it a long distance you will notice even the slightest movement will cause it to jump inches, even feet.  Keep laser pointer analogy in mind for this next section.

In order to understand alignment, we need to understand lobes on an antenna. An antenna is just a device that focuses radiation in a direction.  In a licensed microwave setup, these antennas focus the radiation in a tighter “beam”.  Let’s go back to our laser pointer analogy.  Some laser pointers project a smaller dot at 10 feet than others.  Same for antennas.   The diagram below shows what is called the main lobe and the side lobe.

The way to get the best signal is to get both dishes locked on to the main lobe. Sounds easy right? With higher frequencies, you are talking about millimeter waves. This means the main lobe may only be 3mm wide, about the size of this text on a laptop screen.  Now imagine trying to keep that 3mm beam in the center of a paper plate at a mile.  On top of that, the difference between the main lobe and locking onto a side lobe could be the difference of 1-2mm. A slight wind can move a dish 2mm.

To give you a real-world example. A 2ft 23 GHz antenna having 3 dB beamwidth of 1.6 degrees. Allowing for a path length of about 2.5 miles (this is licensed 23GHZ) the actual beamwidth at the receiving antenna is around 370 ft and is, therefore, likely to be greater than the height of the tower. If the antenna’s out of horizontal by even a couple of degrees to start, the antennas will miss by around 460 ft and not be able to “see” each other. This can be amplified as frequency and distance increase.

This is all fine and dandy, but what about the practical world? How do I align the thing?
It all starts with the FCC path coordination paperwork you will receive on your licensed link. There is a wealth of information in here.  It tells you all of the following:
-Your mounting height (this is typically already known)
-Your heading (more on this in a bit)
-The antenna angle downtilt or uptilt (very important)
-The expected signal target

Armed with this information you will have all of the information you need to align the link.  From this point, the philosophical side of things kicks in.  Some tower climbers are good with using a compass to get their exact bearings.  Others have high dollar tools to do it all via GPS such as microwave path alignment from Sunsight.

What everyone doing alignment should have in their toolkit are the following:
-A small magnetic bubble Level. We want to make sure we start with a level mount.  We would be fighting an uphill battle if the pipe or standoff we are mounting to is not level.

-An angle Finder is very helpful for determining the antenna down or uptilt per the path calculation.

Obviously, the above tools are just one of many examples.  There are more expensive ones and bare bones ones.  Tools are only as good as the person using them.

-Ratcheting wrenches for the left and right and up and down adjustments.
Having ratcheting wrenches makes fine-tuning a very easy process.  You will see why later.

-A good hands-free communication method.  Depending on the tower FM communications may or may not work.  Cell phones may or may not work. Being able to talk to the crew on the other end is crucial.  And yes, to make this smooth you want a crew on the other end.

Aligning backhauls, especially microwave, is a skilled trade.  With any skilled trade, you will get all kinds of tips and tricks of the trade.  Some you may use, others you may not.  Ask any Carpenter, Drywaller, or Mason and they will tell you little tips and tricks. They probably all are great and will work, but you may only use some of them.  I am going to tell you mine. You may find others you like better.

We always start with a google earth plot of the path. I call this Phase 1.  The goal of phase 1 is to get the radios talking.  We make sure the line is exactly on the two points, not just approximate.  If the backhaul it on the left side of the tower, we draw the line to/from the left side of the tower.  We then pick 2-3 landmarks along the path as we can.  We start with something close to the tower the climber should be able to see.

In our photo above we have picked out two reference points close to the tower the climber can see.  The first is the clump of trees on the climbers left.  The path passes “just to the right” of the edge of the end of the trees.  The second reference is the intersection of the county roads about 2-3 miles out.  Our path should be just to the right of those.  That point of reference is more of a sanity check. More than anything. The climber at the other end has a similar printout.   I have found communication during this process works best if both climbers and someone logged to at least one radio on the ground with a laptop are on a conference bridge.  Many radios have lights, tones, or multimeter outputs to indicate signal.  Some modern radios only have web-interfaces and apps.  Hold a phone while trying to align can be cumbersome.  This is where the guy on the ground can take some load off what the climbers are doing.

Regardless of the mechanics of the radio, the goal of Phase 1 is to establish a radio link, no matter how bad it is. Now, here is where the real meat and potatoes of backhaul alignment come into play.  This is a very deliberate and calculated process.  Your goal at the end of the entire alignment process is to end up with the following diagram

What many folks don’t realize is it is possible to establish a signal on a side lobe. So how do you know if you are on a side lobe? Here is how we start phase 2. This is what I call fine-tuning. Real original huh? Depending on good, or lucky you were during phase 1 you may have a long way to go or a short way to go to meet target.  Remember that in your paperwork we talked about earlier?  One side and one side only starts moving their fine adjustment on their antenna to the left and right and up and down.  This is typically called sweeping.  The key thing to note here is you need to find the very edges of the radio signal, not just the lobe you happen to be on.

Let’s take a real-world example to explain how sweeping affects main and side lobes.  At the start of this article, we mentioned an 80ghz link.  With our phase 1 rough alignment, we were able to get linked at a -86.  The target was a -32.   The first side to start alignment started sweeping to the right, signal started going from a -86 down to a -72 rather quickly. This was using very small turns of the adjustment.  The ratcheting wrench was only clicking 1-2 times for each 2-3 db of signal change. Once it reached a -72 it started climbing back up.   The climber then kept going to the right to find the edge of the signal, not just the lobe we were on.  The signal started getting worse until we were back into the upper 80’s.

Now, the climber brings the alignment back to the left, and stops at the -72 and makes a mental note of where that is in relationship to the overall placement of the dish, etc.  Some mounts have distinct notches, some guys use markers, others just remember.  Now the climber continues on to the left and the -72 gets worse and goes back down to the -86 and continues to get worse.  So the climber, at least for now, has found the sweet spot for the left and right alignment.  The climber also knows this will probably change, but has found it for now.   Climber repeats the same procedure for the up and down. Due to the anglefinder, the climbers have with them they feel pretty confident they are fairly close with the up and down so they do not adjust the up and down travel as much as the procedure goes on.

Next, the other side does the same procedure the first side did. They do the left to right and get the signal down to a -62. Essentially, what the climbers are trying to do is find the center, which will contain the strongest signal, by sweeping past the other signals.  Keep in mind there may be only millimeters separating these other lobes.  Due to physics, and the shape of the signal, the first lobe is actually stronger than the edges of the main beam.

Say what? The first lobe is stronger than the edges of the main beam? Yes, but not stronger than the main beam.  Let’s go back to our installers. They have each had a go around at alignment and are only at a -62.  On a 5ghz backhaul that would be respectable, depending on your noise floor. But we are 30db away from our target of -32. Some climbers, incorrectly I might add, try to do a shortcut by scanning in an x pattern instead of x and y-axis separately. This makes it easier to lock onto a side lobe.

80ghz backhaul

So now our first climber goes back to making the left and right adjustments.   At this point, the installer finds something odd.  He has gotten the signal down to a -55, but that’s the best he can do. Even a small turn jumps the signal up    Then our installer remembers the above statement.  The first lobe is always stronger than the edges of the main beam.  He gets the signal back down to a -55 and turns the alignment over to the other side.

Here is a very important thing to note.  Both of our installers have now “gotten a feel” for the few turns needed to adjust the signal on these dishes.  To them compared to 5ghz dishes, these are very tiny and almost insignificant movements. But they sure make a difference in signal.  Now our installer at tower B has his second alignment session.  As he is making adjustments the signal is not changing.  He is moving his wrench for what seems like forever and the signal is barely moving, Any other time their signal would have been a -90 or dropped.  What has happened here? The main lobe of one side has locked onto the first lobe because it is always stronger.  Since the main lobe is bigger it seems like it takes forever to make any change.  If we had a guy on the laptop he was probably also probably seeing very mismatched data rates.  One side was probably much higher than the other by a large margin.

Then boom, all of a sudden the signal goes from a -55 to a -42.  A 17 db jump!   We can now tell we are on the main lobe.  If the laptop person looks at the data rates now they should be more balanced.

Data Rates on a Mimosa B11 Rates properly aligned but not fine-tuned

At this point, it is just a simple matter of each side making finer and finer adjustments back and forth to get the signal down.  If you think of the above circle/crosshair you are making smaller and smaller adjustments to nudge toward the center of the circle. This is where the ratcheting wrenches help by giving a very measured amount of travel.  This helps with the whole feel of alignment.  Much of it is feel to see how much you can move the adjustment mechanisms to make the numbers move.  Sometimes it may be a single click of the wrench.  Sometimes it may be one or two.  It just depends.  As you get closer and closer to target you are moving the adjustment less and less.

As you get closer and closer to target you need to be thinking about how tightening down the adjustment bolts will affect the alignment.  Even tightening them down snug can affect the signal.  That extra amount movement to tighten them down can move them slightly past their alignment center.  You may need to take into account the amount of travel it takes to tighten down the adjustment bolt into account on smaller dishes.  If it takes a half turn of the bolt to get it tight you may need to stop a half turn and tighten “into” target.  As you tighten it down fully that is where you end up in align.  If you wait until you are in align and then snug it completely down, the force of snugging it down may pull it past and you will end up with a worse signal.

This article sprinkled in some examples from a real-world install, with some theory, with some practical knowledge. Your mileage and experience will vary.  Your experience with 6ghz vs 80ghz will vary as well. Each frequency will have it’s own quirks and tricks.