Tag Archives: wireless worker

Wade4Wireless BlogCast

Small Cells? What hell is a small cell?

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OK, what the hell is a small cell? Well, let me tell you about small cells. It’s like putting the cell site where the people are, I mean right where the people using the most data. Suddenly you have a cell that can service a group of people with little RF loss and high data throughput. This is a great thing for carriers because it relieves the macro from the loading it would have from one area in its larger coverage area. That is the goal of the small cell, to alleviate the loading and add coverage. I will concentrate on the outdoor small cells for this article but the indoor may be very similar, just less up front work.

So putting a small cell in should be easy, right? I mean if any of you worked with Wi-Fi you would think you can just pop up an access point and you have an instant hot spot. Well, there is so much more to it than that. The carriers will need to do some work up front is they are to put it in their system. They need to do the RF design, loading study, and coverage analysis. They will probably study the analytics to see where the need is based on coverage and macro cell loading, (data and voice). This is prior to placing the small cells in the macro coverage area. They will look at each sector of a Macro site.

The other challenge is putting the backhaul in. It usually will be fiber, about 10 to 100Gbps backhaul provided to the router connected to the small cell. This is usually a Service Aggregate Router, (SAR). Backhaul quality is everything because you have to make sure you have quality of service. Here is where the LTE small cells have a huge advantage because they have a complete IP backbone, unlike most 3G stuff out there, LTE will be a cleaner deployment. All this is done before they decide to deploy anything.

So mounting the unit will not be too hard, but the connection of the backhaul will require fiber skills. They may have wireless backhaul in some areas, if they connect from the wireless backhaul to the SAR it will be using a fiber jumper. Fiber will be the key to most small cell backhaul connections. The one exception may be if the cable companies step up with a cable backhaul for small cells, they call this Data Over Cable Interface Specification, (DOCSIS), which should be a game changer if it becomes mainstream. Then you could use a standard cable connection for backhaul. This may or may not work because carriers seem to like a dedicated connection back to their core or to one of their cell sites. This is a dedicated connection that would give them security and complete control. It’s what most of them want to do. They don’t just tie into an internet connection like a Wi-Fi connection would. It’s just not that easy at this time. If you’re interested in LTE backhaul, there is a good overview at http://lteuniversity.com/get_trained/expert_opinion1/b/skrishnamurthy/archive/2013/04/01/why-ethernet-backhaul.aspx to explain in more detail.

So let’s look at what we’ve done, we’ve completed the engineering, defined the spots where we wanted it. We then narrowed the spot by finding a mounting location, a pole or a building top, then we found a mounting location that has a fiber connection near it, (fiber is not everywhere), now we finally have the exact location to mount it. Then we have to get a lease, this is all part of site acquisition! We need to work out all of those headaches. If you are not familiar, you don’t just go out and mount it to a pole.  You need to find out who has rights to the pole or building, who you lease it through. Then you may or may not need to do a structural analysis on the mounting asset. You will need to do a site design drawing for the documentation prior to the mounting of the asset. What about permits? The local municipality or city wants to take their cut and they want to know what is mounted where. So you will need to make sure all the permitting is completed, this usually slows down the process even more and cost money because you need to file paperwork and often need to hand deliver the documentation.

OK, location found, fiber nearby, mounting asset identified, leasing completed, permitting completed, now we can mount and move ahead, right? OK, now we need to follow the engineering, install the unit, connect the fiber, power to the unit. Did you say power? Did anyone order power? This is something else that needs to be taken care of, power at the pole.  So now, at a pole we need fiber and power. Both have a long lead time.

OK, pole, permitting, lease, power, fiber, so now we can mount, and connect it up. Then we’re off to the races. Well, it is mounted to the pole so we are good there. We connected the backhaul to the SAR, we are good there. We now power it up and it should work, right? Make sure the antennas are facing the proper direction and the tilt is set up properly. Now you need to make sure it is provisioned properly, that means that the SAR has to be integrated, then the small cell has to be integrated, then the carrier will want to make a test call and they may or may not want to optimize it with someone doing a walk test. Remember, if the cell has any problems it could create more problems with self interference. The engineering has to take that into consideration. Self interference is taken very seriously because it will create dead spots.

Once the small cell is up and running, life is good in that area, loading is off the macro and on the small cell. The carriers plan to put 10s of thousands of these in. I believe that if the FCC allows more bandwidth to be freed up for LTE, this will be the way that utilities will access their fixed networks. Public Safety already is carving out their chunk of LTE bandwidth. I think that they will rely heavily on small cells because they need coverage in specific areas. Let’s face it, LTE and small cells will be an amazing thing as the world of data takes over. Video will not be just for entertainment, it will be the requirement both ways, video streaming up to the network and down to a device.

OK, now I gave you a background, how does it affect the field worker? Well, you may need to be certified to mount the small cell by the OEM. Remember that the warranty will be affected if you mess something up. Also, this is going to have intricacies that may be affected by how you mount it. Antenna direction, fiber skills, and power connection could all play into this. The Power Distribution Unit (PDU) may be mounted at a different location to power the SAR and Small Cell. You need to know what you are doing to make the connections. It will take skills. Chances are good that you will need to make a test call for the integration phase, provisioning, to be completed. You may need to program the SAR by connecting your laptop to it and uploading a specific configuration file. You need skills! This isn’t Wi-Fi, it’s carrier grade equipment. If you do tower work you know the difference.

I plan to do more on small cells in the future. This is something I have been working on and I have more information to share.

Let me know what you’re struggling with out there in the field. I would like to write about something that could help. Let me know what you think by leaving a comment or hitting me up on Facebook or reach out to me on LinkedIn at www.linkedin.com/in/wadesarver/! I am looking for tower pictures on Facebook page! I am working on a new book, an aid for the field worker and I plan to have a new website ready soon. I have been very busy on other projects but I think that it should happen soon.

Hey, I talk about learning fiber training and I see that JDSU has free webinars on fiber, go their website here and see if you can learn more about fiber! The webinars are free!

To learn more about LTE and Small Cells;

http://lteuniversity.com/get_trained/video_tutorials/default.aspx

http://www.alcatel-lucent.com/solutions/small-cells

http://www.thinksmallcell.com/

http://www.qualcomm.com/solutions/wireless-networks/technologies/1000x-data/small-cells

http://www.3gpp.org/hetnet

http://www.ericsson.com/res/thecompany/docs/press/media_kits/hetnet_infographic_vertical_04.pdf

http://en.wikipedia.org/wiki/Small_cell

http://www.wilson-street.com/2013/10/how-to-deploy-metro-cells-infographic-3-part-1/

http://www.wilson-street.com/2013/10/how-to-deploy-metro-cells-infographic-3-part-2/

http://www.wilson-street.com/2013/07/public-access-small-cells-roadmap-to-successful-deployments/

http://electronicdesign.com/engineering-essentials/understanding-small-cell-and-hetnet-movement

 

 

 

Wade4Wireless BlogCast

Raise awareness! Does your customer love the tower climber? Time for action!

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Hello all,

By the way, I have my Blog Cast live on iTunes now. Subscribe if you dare!

Let me ask you something, does your customer really care about you? I see that the safety initiatives are all led by the carriers, NATE, and the tower companies. Hey climbers and engineers, are you represented? I’m sure you are by the contractors out there that tell you the project needs to be done yesterday. So they have created the stand down week and the new NATE site, http://natehome.com/100-tie-off-24-7 to encourage 100% tie off campaign. That will raise awareness in most of the industry. What about the people who don’t know what you do? Well, it’s up to you as a group to raise awareness. Let’s see if this works.

Let’s make people aware, when go to a carrier’s store, ask them what their company is doing to promote tower climber safety? (Verizon Wireless, AT&T Wireless, Sprint, and T-Mobile to start with) Do you think that most device sales people know that you risk your life to make sure that they can text their friends? Now is that time! Let them know that you play a key role in the industry. Send an email to the carriers, get the email from your bill or their website, and ask them what they, the carrier, are doing to ensure that you are safe! It’s a simple question. Better yet, ask your family and friends send an email to ask the carriers what they are doing to make sure that the people they love are safe! It’s a team effort to ensure that the world knows about the climbers and engineers that work out at the tower sites! The carriers are very influential in this industry. They spend a lot of money on lobbyists to make sure that deployments go smoothly. Let’s make sure that they know that the worker needs their support. PCIA made announcements how they were working with the governments to ensure a smooth wireless roll out by overriding additional permitting.

Broadcast workers should be doing all that they can to be sure that you are safe. The TV and radio people should all know the stations that they work for are doing all that they can to ensure climber safety! Reach out to your favorite show, by phone or by email and ask them what they are doing! Trust me, most people in broadcast have a great deal of respect for you when they know what you do. 

Do you do government work? Well, are they making sure all of the climbers are properly trained and have all of the safety gear that is needed to do the job safely? Don’t call any governments, they probably have no idea about anything outside of their office. However, you could look up your congressman, but unless it’s an election year they may or may not answer you. It takes big numbers to get their attention. If congress or the house interests you then go here and here . For the president you can go here but I think he has bigger things to worry about. Now OSHA can be reached here. OSHA is who should be looking after the worker, so they would be the best contact if there is an incident. OSHA is there to help, they would be the ones I would call on for help and they are taking an interest in climbing in the USA. However, only reach out to them if you see a problem. I do think that regulation of the climbing industry will be coming. Look at all of the accidents out there. Not just the ones we heard about but the ones that are not reported. There are many. I would like to think that OSHA, EPA, and the FCC are doing all that they to make sure that people are safe. One of the problems in the USA is that crossing departments causes more problems. I think that they could learn from police task forces. I talked with several drug enforcement agencies that pulled in resources from the state police, local police, the FBI, the Coast Guard, and army so that they could work together to catch the bad guys. I am hoping that OSHA and the EPA and the FCC would create, if they didn’t already, a coalition to make sure that workers that are exposed to RF and tower dangers would be represented properly. I plan to release a post with more information soon.

Let me know what you are doing with this article! Something or nothing, email to the carriers? What?!? Let me know!

OK, I have 2 books, Worker’s Aid and An Introduction to Tower Climbing.

HPIM2418
Wade4Wireless
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Wade4Wireless BlogCast

RF Awareness, are you aware? Seriously, are you? Episode 002.

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Hello all,

To listen in a new window go here BlogCast!

I am not sure if you are aware but David Horn wrote a blog at http://www.lbagroup.com/blog/fcc-contractor-rf-training/ about the mandate issued by the FCC, http://www.fcc.gov/document/verizon-pay-50k-resolve-radiofrequency-exposure-investigation%20 about Verizon Wireless getting slapped with a $50K fine. So now working there you are required to take RF Awareness training. Why? Because of RF exposure on 2 east coast rooftops. Look at the links, then come on back and I will tell you a story of someone who reached out to me about his RF exposure nightmare. Special thanks to Clifford Wilcox for sharing this on Facebook!

So, I was conversing with someone, (I will reveal his name if he would like me to but not until he explicitly gives me permission) on Facebook about his RF exposure experience. He was working close to an antenna, broadcast, and had major problems afterwards. I am going to quote exactly what he sent to me. He got ill and went to an expert to find out what the problem was, this is the report he got back from them. Let me point out that all of these problems happened in exposure that was less than 45 minutes. It was broadcast so it was high power and this is analog, which as far as I know is no longer used in the US, so things have changed.

Here is the edited report, I removed names and the identification information;

“I have gone through an analysis to try to bracket what I think you may have been exposed to. This is an estimate only! It would take considerably more time to model the batwing elements in detail. Hence, I have used a simple dipole element to estimate local fields near the element and what you might have been exposed to.

My assumptions: Frequency of exposure: NTSC analog TV signal Antenna: 12 bay batwing, Harris TAB-12H Power gain: 11.3 FCC licensed ERP for station at the time: 316 kW

Based on these assumptions, if the station were operating at FULL power of 316 kW ERP, this would imply approximately 932 watts of rms (average) power into each bay of the antenna. If the station was operating at 10% of normal power while you were working on it, the power would be, of course, one-tenth as much, or 93.2 watts per element.

I calculated the electric field strength parallel to a dipole radiator (I realize that the element is really a batwing design but that would take a lot more time to model) and found that at a distance of 1 foot from the element, the maximum electric field strength would be equivalent to a plane wave equivalent power density of about 46 milliwatts per square centimeter at full power or 4.6 milliwatts per square centimeter at one-tenth normal power. Please keep in mind that this is a value where the RF field will be maximum along the radiating element and at a distance of 1 foot from it. Since you were sitting on the element itself, the RF field that at least part of your body would have been exposed to would be much greater. I did not explore calculations at closer distances to the element since this would take additional time to make sure that the theoretical model is calculating correctly.

The accepted maximum permissible exposure (MPE) for occupational exposure in the channel 7 frequency band is 1 milliwatt per square centimeter. These results would suggest that at the presumed safe operating power level of one-tenth normal power, your exposure could easily have been as much as 4.6 times the MPE. Because you were actually sitting right on the element, I would expect your exposure to be substantially greater than my one-foot number but without more careful and detailed analysis, I can’t say exactly what it might have been.

Based on my own experience in climbing towers to make RF field measurements, I know that sometimes there can be miscommunications between the field guys and the tech controlling the station. While I have no information to suggest that this might have been the case, it is relevant to understand that were the station actually operating at its normal full power, the exposure would have been substantially greater, namely, about 46 milliwatts per square centimeter. This is, then, 46 times the MPE and would have resulted in very significant thermal loading on the body!

If the body is exposed to a uniform RF field over the whole body equal to 4.6 times the MPE, the thermal load imposed on the body could be about 130 watts. This power would be distributed throughout the body and while above the accepted limit of about 28 watts (equivalent to exposure at the MPE), would likely have been felt but, in my opinion, not necessarily hazardous. I say this because the MPE has a built-in safety factor of 10 in it. But, if you were exposed to the full power of the station, the thermal load on your body could have been in the neighborhood of 1,300 watts! This is a completely unacceptable value and would be almost five times the hazard threshold (i.e., the hazard threshold can be thought of as a power deposition of about 10 x 28 watts or about 280 watts – in other words, the safety factor of ten has been removed and we are now right at the hazard threshold).

The 1,300 watt thermal load figure is approximately 12 times the body’s basal metabolic rate of 105 watts (i.e., the thermal generation of your body just sitting still). This kind of thermal loading would have been distinctly felt by you as getting hot! It is my understanding that you were told that the station was operating at the so-called safe level of only 1/10th normal power. And, if this is true, then your exposure, while still above regulatory limits, might not have been sufficient to result in a hazard. But, IF, by chance, the station was operating at full power, your exposure would have not only been way, way above regulatory limits, you would have, in my opinion, been sort of cooked. I am only trying to give you some perspective on your possible exposure. Apparently, we don’t really know for absolute sure what power the station was operating at. A first start would be to get copies of the station’s log book during the time you were working on the tower to see if there is validation of what they told you about what power they were really operating at.

In summary, even at the one-tenth power operation, I think that there is a high likelihood that you would have been exposed to RF fields exceeding the worker MPE, though it might have not resulted in reaching the actual hazard level of energy absorption rate. On the other hand, if the station were to have operated at full power, your exposure would have not only exceeded the worker MPE, but it would have likely resulted in significant body heating, well beyond the level that is believed to be hazardous. Because you were exposed while sitting on the top batwing for at least 30 minutes, the issue of time-averaging is not relevant.

One other point. The exposure limits are based on limiting the rate of energy absorption in the body as a whole, what I have been discussing above, and in local parts of the body. You can think of this as though there is a power deposition limit as averaged over the whole body mass as well as a power deposition limit for any given specific point in the body. I have only addressed the case of the average over the whole body in this analysis. The issue of what the localized RF absorption rate may have been in various parts of your body is another question.

I hope this provides useful information to you in regard to your exposure while working on the tower”

USA TV broadcast frequencies [http://en.wikipedia.org/wiki/North_American_television_frequencies]

OK, there are a lot of “what-ifs” in this report but it doesn’t change the fact we all need to be educated and aware. So RF awareness is something we all need! You need to be aware of what is on the tower. I say it all the time, there are more risks than the fall. Wake up people! We need to work together to provide a safe work environment. Let’s learn from these mistakes and make it a safer future for all wireless field workers. Awareness is the first step! Jimi Hendrix asked, “Are you experienced?” [ https://www.youtube.com/watch?v=zg2segLZoeA ]so I am asking you, “Are you aware?” [I don’t have a video, sorry]. Aware of the risks out there beyond the fall. Wake up and be aware! This is a brotherhood and a team, together we learn and teach each other. It’s more that climbers, it’s the wireless field workers that need to work together.

After I put this together I feel we should consider having everyone wear RF alert monitors while working, especially on rooftops. I would only wear them at broadcast sites if I climbed, but I am thinking we should make them standard equipment for all workers at the tower site. Let me know what you think.

 

OK, shameless plug time. My new book is out, I create a Wireless Field Worker’s Aid for Tower Site Work

I am working on getting out on Amazon, not quite there yet.

PDF on Gumroad (Credit Card) https://gumroad.com/l/RSJZ

PDF on Sellfy (PayPal) https://sellfy.com/p/kxAw/

If you want to reach out to me, Facebook is the best way, Feel free to Twitter or Google+ or email wade4wireless@gmail.com to reach me as well. Or leave a comment on this blog.

Wade4Wireless BlogCast

Tower painters, be smart! Episode 003.

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Hey all,

To listen in a new window go here BlogCast,

If you paint towers then be aware that there may be more dangers than paint dripping on your truck. There are studies out about the long-term effects of inhaling paint.  The good news is you will be outside and it’s usually windy when you do it. However, the risk is there. If you can make sure you take the precautions needed so you don’t inhale anything bad. When Utility workers were surveyed who worked with painted for a long time, here is what was reported. This is from a report in PaintSquare,

“The research examined memory, attention and processing speed in 2,143 retirees who had been potentially exposed to three types of solvents in their careers:

  • 33 percent had been exposed to chlorinated solvents;
  • 26 percent had been exposed to benzene; and
  • 25 percent had been exposed to petroleum solvents.

All three solvents are widely used in various products throughout the paint and coatings industry.

The workers’ average lifetime exposure was ranked as none, moderate or high, based on company records, the nature of their jobs, and on when their last exposure occurred.

Participants took eight tests of their memory and thinking skills an average of 10 years after they retired, when they were an average age of 66. (Ninety percent of workers retired between ages 50 and 60.)

Researchers also accounted for factors such as education level, age, smoking and alcohol consumption. They did not control for factors such as cardiovascular disease, diet or physical activity and concede that these may play a role in cognitive functioning.”

Remember that there are more hazards out there than falling. Falling is obvious, it’s the long-term hazards that everyone ignores until they are in the business for 10 or more years. For me it’s my rotator cuffs that just ache, what is it for you?

For more information go to; http://www.paintsquare.com/news/?fuseaction=view&id=11416&nl_versionid=4091

HPIM3234

Hey, if you can like me on Facebook and Google+ and Twitter.

My next book is ready, I should release it as soon as I update my website. I am slow but I am trying to get you quality as well as information. Let me know what I can do to help you guys out. If you want me to talk about something, then let me know. I have more about small cells to talk about.