Frequency does matter

Recently we installed a PTP 550 link for a client.  This is a connectorized version with 2-foot dishes on it for a four-mile link.  Overkill you say, but the idea is the dishes make up the gain and not transmitter power.  A much cleaner signal can be achieved which falls within the FCC guidelines for total EIRP.

So let’s get to it.  Our first image is out path.  This link had clear line of sight from a 150-foot foot water tower to a 240-foot tower.

Google Earth Path

The 240 Foot tower

150 Foot water tower

After getting out of the cold we let things burn in for a few days. This is what an initial spectrum analysis looked like.

Radio Frequency set on 5820 mhz

Radio Frequency set on 5200mhz

As you can see the RSSI was within 2 DB, which isn’t terrible.  However, due to interference, the MCS rates are markedly different, which is what results in the big differences in speed.  Please note this is only with one radio enabled and on a 20mhz channel.  We fully expect bigger speeds once we up channel sizes and enable the second radio.

WISPAPALOOZA 2018 ponderings and musings

Another WISPAPALOOZA has come and gone to Las Vegas.  If you are not familiar with WISPAPALOOZA it is one of the two major trade shows Wispa puts on each year.  The Las Vegas show is the larger of the two. If you are a Wireless Internet Service Provider (WISP), doing outdoor wireless networks, or involved in the WISP industry whatsoever this is the premier event for you.

Having attended several shows I have been able to see the evolution of the shows over the past X years. The industry has been evolving and this show highlights many of the evolutions the industry is undergoing.  This year billing, LTE, and business services needed by WISPs were prominent in the sessions and on the vendor floors.  Vendors such as Baicells, Cambium, Redline, and others were talking about their LTE offerings.

Other vendors such as  Ritalia funding and Unitel were there getting their message out to WISPs. As WISPs evolve, they are looking for services and products which help the business side of things.  This business side becomes as important in a mature WISP as the technical side is.

Another aspect WISPs look for as they grow are billing platforms.  Companies such as Sonar, Azotel, and VISP were represented at the Vegas show.  These can help your WISP streamline and automate operations.  The more you can stretch your resources the better.

 

One of the many sessions

Other themes of the show included fiber deployments, MDUs, and CBRS to name just a few. Knowledge exchange is a key highlight of shows such as this.  Operato

 

rs sitting around trading tips, war stories, and what is working and not working for them is invaluable.  The selection of the speakers and sessions highlight the pulse WISPA has on the industry as a whole.

Due to the varied mix of people in this WISP industry shows such as this are great for any level of employee.  Any employee will be able to find things they can be engaged with and hopefully add to their knowledge. As with any industry, making personal connections and people networking is huge these events. Being able to have a Rolodex of Vendors, distributors, consultants, and other folks in the industry are invaluable. Whether you forge relationships over a beer at the local bar, a walk down the strip, or just sitting at a table talking these conversations are something you can’t get anywhere else.

My week started with a 5 am arrival at the airport.  I was able to catch up with a friend in the industry over a coke at breakfast in the airport.  Even though he lives an hour south of me we don’t get together all that much.  He is a friend and someone who is doing cool stuff in the industry.  The ability to have that focused time is something many of us don’t get. We are so busy with our own lives we have to get into situations like that.  After landing in Vegas the intensity level ramps up.  You start seeing people you know and quick conversations turn into 20-minute conversations, and the next thing you know its 6 pm and you are just checking into your room. The next several days are more of the same.  Late nights, lots of conversations, lots of walking, and an overwhelming amount of information you will only begin to digest once you have a moment to relax. In the end it is a good kind of tired.

For more information and a show re-cap visit http://thebrotherswisp.com/ for a cast coming soon on a re-cap of some of the brothers discussing the show.

MTIN Family of Sites
https://j2sw.com
https://mtin.net/
https://www.indycolo.net

MTIN participates in FCC Commissioner Brendan Carr Visit

On May 3rd, On-Ramp Indiana and Beck’s Hybrids hosted FCC Commissioner Brendan Carr and Congresswoman Susan Brooks from Indiana District 5 to discuss rural broadband and technology.      We are extremely honored for the opportunity to share our experiences in deploying rural broadband with them.

The FCC defines broadband as any connection capable of 25/3Mbps.   47% of “rural” residents of Indiana District 5 do not have any choice for broadband internet.      There are over 2000 Wireless ISPs in our country working hard to fill the gap and provide affordable access to underserved areas.     While fiber, and other technologies will be part of the solution, we also are asking the FCC to work with WISPs to create an environment where we can access much needed spectrum to rapidly and cost effectively deploy broadband in rural areas.

A special thanks to Beck’s Hybrids (Sonny, Brad & Jeremy) for hosting the meeting at their incredible facility in Atlanta, IN.    They are a huge proponent of rural broadband as it helps achieve their mission of helping farmers succeed.    Rural Broadband is helping move the immense amount of data collected in modern farming into the computing data centers for analysis.   The end result is a more efficient and productive farming process which greatly benefits our economy.

We would also like to thank Justin Wilson of MTIN Consulting for assisting in the presentation.      Thanks also to Tracy Barnes & Ryan Heater with Lt Governor Crouch’s office, and Jodi Golden with the Office of Community and Rural Affairs, we appreciate you attending and it was great to meet everyone!

20180503_135630

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.

Everything you wanted to know about NTP

Network Time Protocol (NTP) is a service that can be used to synchronize time on network connected devices.   Before we dive into what NTP is, we need to understand why we need accurate time.

The obvious thing is network devices need an accurate clock.  Things like log files with the proper time stamp are important in troubleshooting.  Accurate timing also helps with security prevention measures.  Some attacks use vulnerabilities in time stamps to add in bad payloads or manipulate data. Some companies require accurate time stamps on files and transactions as well for compliance purposes.

So what are these Stratum levels I hear about?
NTP has several levels divided into stratum. All this is the distance from the reference clock source.  A clock which relays UTC (Coordinated Universal Time) that has little to no delay (we are talking nanoseconds) are Stratum-0 servers. These are not used on the network. These are usually atomic and GPS clocks.  A Stratum-0 server is connected to time servers or stratum-1 via GPS or a national time and frequency transmission.  A Stratum 1 device is a very accurate device and is not connected to a Stratum-0 clock over a network.  A Stratum-2 clock receives NTP packets from a Stratum-1 server, a Stratum-3 receives packets from a Stratum-2 server, and so on.  It’s all relative of where the NTP is in relationship to Stratum-1 servers.

Why are there levels?
The further you get away from Stratum-0 the more delay there is.  Things like jitter and network delays affect accuracy.  Most of us network engineers are concerned with milliseconds (ms) of latency.  Time servers are concerned with nanoseconds (ns). Even a server directly connected to a Stratum-0 reference will add 8-10 nanoseconds to UTC time.

My Mikrotik has an NTP server built in? Is that good enough?
This depends on what level of accuracy you want. Do you just need to make sure all of your routers have the same time? then synchronizing with an upstream time server is probably good enough. Having 5000 devices with the same time, AND not having to manually set them or keep them in sync manually is a huge deal.

Do you run a VOIP switch or need to be compliant when it comes to transactions on servers or need to be compliant with various things like Sox compliance you may need a more accurate time source.

What can I do for more accurate time?
Usually, a dedicated appliance is what many networks use.  These are purpose built hardware that receives a signal from GPS. the more accurate you need the time, the more expensive it will become.  Devices that need to be accurate to the nanosecond are usually more expensive than ones accurate to a microsecond.

If you google NTP Appliance you will get a bunch of results.  If you want to setp up from what you are doing currently you can look into these links:

http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html

How to Build a Stratum 1 NTP Server Using A Raspberry Pi

 

Building a Stratum 1 NTP Server with a Raspberry Pi

 

Antenna Interference issues

Recently, we had a client question why we didn’t mount antennas higher up on a tower with an FM repeater on it. The top of the tower has an FM repeater on it so we mounted the equipment about 25 feet below that.

When you are talking about antennas and transmitters the basic thing to remember is it’s all radiation.   Good antennas have predictable drop off patterns and, when paired with a good transmitter, have crisp frequency drop offs.  However, there is still radiation emitting from feedline and the antenna on the tower. Many FM repeaters use a dipole design.  Some are folded, others are different types.  Below is an antenna pattern from a Dipole antenna.

As you can see there are a few patterns radiating from the antenna.  These patterns should be taken into consideration when mounting your equipment near FM, UHF, or VHF systems. Radiation may interfere with things such as your cat-5, or your PIM.  In an earlier article, I talk about low-pim cables and what affects PIM.  This is very important when you are deploying LTE gear.  RF radiation from high power transmitters can cause PIM issues if the wavelength happens to coincide with the wavelength of the other transmitter.  This does not mean they are on the same frequency.  Remember, in RF you have full wave, 3/4,1/2, and 1/4 wavelengths to deal with.

Other things to consider are near and far field patterns.  If you want some heavy reading you can read about it on Wikipedia.

Our next issue and the most common issue is the radiation getting into our Ethernet cables as well as our radios on the tower.  Below illustrates the propagation of signals coming out of an antenna on the top of the tower.  If you notice, some of the radiation is directed underneath of the antenna. Any equipment mounted too close underneath will be bombarded with radiation.

Too much radiation can cause link negotiation issues,  signal degradation,  and other issues.  By moving our antennas out of the patterns of other antennas we can make for a more reliable system.  This is one case where higher on the tower is not always better. Just because another antenna is not mounted in front of another it does not mean they are in each other’s radiated patterns.