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- Опубліковано 3 лис 2024
- Here is a video of the latest and greatest in the cell site technology.
This Cell Site is self contained in a unit called a "walk in cabinet" WIC.
every thing is assembled at the factory in these WICS and it is shipped directly out to the site. Crews just have to install electrical and pour a concrete slab. Once all that is done the tower crew comes and builds out the tower top and wires in all the fiber and DC power going to the tower top equipment.
This is a much newer version as compared to my orginal "Cell Site Walkthrough" video.
Sorry for the wind noise in advance.
If you enjoy this video and enjoy the telecom world Consider joiung my discord in the link below.
We talk about almost everything tech related and always have a great time.
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I don't know what's weirder, that UA-cam randomly suggested this video, or that I watched the entire thing.
Never knew I wanted to know this stuff before :)
I work for a fiber service provider so I do get to see a few cell sites. When I started I still remember this one site that we provided a single t1 to, half of the t1 was for CDMA and the other half for TDMA. Cool video man.
Over 100 gig fiber to sites now. Nuts.
@@davewood406 The one in this video is connected with lowly, pedestrian, old fashioned 40gb.
@@User0000000000000004 he said 10g in some replies.
@@User0000000000000004 he replied 10gig
I'm an older Software Engineer that has been in the business since the late 90s. Worked for a bit at a telecom and have worked in operations as well so I've been to some massive data centers.
That said, thanks so much for all of these amazing videos! Especially the long lines one! I grew-up near one of those towers in rural Colorado and randomly researched them awhile back, so I really enjoyed looking at the inside of one.
I know just enough about DC power, data centers, etc to understand all of the stuff you talk about and it's super fascinating to get these virtual tours of things I'd never get to see in daily life. Keep up the great work!
Very cool.
As a ham radio and electronics guy, I love the nice organization of everything.
And anyone (some ham operators) who say grounding isn't important... take a look at a site like this (and/or a commercial broadcast station) to see how it's done!
Thanks a lot for sharing!
I showed a hobby other than ham that simply rolling out conductive screen and grounding it under their portable aerials give them a huge boost to reception.
This is almost certainly R56 compliant, yes.
Grounding is paramount!
Gotta love admiring cell tower. No sarcasm I do enjoy it
When he says ""coax is a thing of the past" is he referring to the fact that the transmitters are on the top of the tower as opposed to being in the cabinet.
Yes
@@ATI556 I think he means it's not COAX any more, but FIBRE OPTICS
It’s a refrence to RRU (remote radio unit) the transmitter/receiver unit is up the top and all that goes up is 48v (normally) and 1 or 2 fibres (depending on unit. Etc) per radio
I had no idea, what was meant, thanks
Between line loss in coax and having to pressurize coax. I see why they'd want to move away from it. And hard-line is expensive.
Cool to see someone else's installation.
Before I retired, I worked for a cell provider in Canada. I could walk into this WIC and be right at home. Same Netsure power, same Powersafe batteries, same router, same baseband.
The only real difference is the make of the generator and the 66 blocks.
Rogers? Haha
What's are the model numbers of the router and BBUs shown in this videos? I would love to read and learn more about them. Also I see what appear to be rj45 cables going from the BBUs and router to two small boxes with a coax cable on the other end. I am guessing the coax goes to a smaller antenna. Are those used for remote management? If yes, how does the company connect to them (i.e. via another cell tower, radio link, something else)?
It's nice to see that some of the old installation art has endured till today. I remember back in the 1970's watching the Western Electric guys lacing in wires and cables on a cable rack. It was a work of art that they took pride in.
I've been doing work for various cell carriers in Canada for almost two decades and i gotta admit I always enjoy entering a new shelter and seeing its layout. Nice vid!
Really interesting, I see these cabinets driving around and always wondered what they looked like inside and what all was in there.
By far the best cell tower location video I've seen. Thank you VERY much for this! I'm really interested in this kind of thing!
Agreed. Well done, I’ve climbed a few in tx. 15+ yrs mostly carrier work, some FAA. Ended on acas tickets/troubleshooting. (Fr probably too much info
Great video, good info, but please get a wind screen!!
That was really interesting to me. I always wondered what type of equipment was in those sites these days. Thanks for the tour.
Very cool stuff for tech nerds like myself. I am surprised to the part where he said the internal cabinet temperature is around 100 degrees. I knew those cabinets had air conditioning but I would have thought they kept those cabinets a lot colder than 100 degrees. Learned something new today.
I was questioning that too; that's pretty high operating temp for industrial grade electronics; the component life is getting reduced that high.
You don't need to be at 69F, but 85F is much easier to maintain, and probably a lot better for the parts. And the people.
@@baylinkdashyt There's probably a technician override control that can turn the air conditioner on when they are in the shelter. Or I would come up with one!
Strikezorbs do protect from damage caused by lightning strikes. Equipment that takes a direct hit is toast, but anything else connected to it, wont suffer, all the zorbs will ground out and will dissipate the charge safely bringing everything to the "same reference".
Plenty of times ive had tower strikes and the only thing wrong was a DC circuit breaker.
Raycap makes brilliant gear, just weird to get used to when wiring.
🤜🤛
For what its worth: we kept losing equipment at this tower during lightning storms (it was the tallest tower in the area), before we completely relaunched services on the tower (colo); we "spared no expense" and it paid off, went from being the most troublesome site to being "problem free" for ~5 years. Speaking of, batteries due for replacement...
Raycap is no joke on the protection aspect. They make a solid arrestor that has been proven time and time again and it was a pleasure to order from them and build out their products onsite. I have a AC lighning arrestor on my main panel at one of my comm sites and those are the real deal. Best you can find and the only true lightning arrestor out there.
@@ATI556
I have plenty of sites without them; but the one site that was constantly getting hit: it's been a huge game changer. Tower is a 500' "monster" in the middle of a quarry pit, and literally nothing that tall for as far as the eye can see in all directions.
Was used as a terrestrial TV tower back in the day, now runs an FM station, commercial, our B42/43 LTE equipment and some other odds and ends.
Raycap is great. When I was a tower hand and Nextel was still around, at the microflect ports Nextel supplied polyphasers and a trapeze rack for all the coax to pass through prior to jumping to the Motorola gear inside. Some of my friends in the industry from the east coast (Georgia) told me a similar story where they had to install a total separate ground ring for the BTS equipment to help isolate the T-storm tower strikes from frying all of the electronics down in the building. I’ve never heard of such a thing in the west areas that I’ve worked on.
Really cool video, thank you for recording and sharing! It's hard to get a look at how this kind of infrastructure is done. I found it cool that the shelter and generator are both on stilts above the ground. Extra flood protection, I suppose! Did you say that the site is not hooked up to a provider? So it's just idle? With batteries from 2020, seems like a huge expense to deploy the site and not have it in use!
Having fiber to the RF section up top must be better in so many ways - No need for any waveguide stuff, no losses from any coax, no coax needed at all, fiber is cheaper, smaller, lighter, RX sensitivity is higher since the receiver is RIGHT THERE on the antenna, higher order distortions in the RF sections are lower since there's less impedance mismatching and other reflective distortions you get from coax and connectors, you also don't need as much / as aggressive RF filtering, the RF tuning can be perfectly matched at the factory, the cabling is smaller and lighter, less TX loss since the transmitter is connected directly to the antenna.... only downside is the expensive RF stuff is way up in the air - but by the time that stuff starts dying, it's probably time to replace and upgrade to a new generation anyway!
The ones in my town are covered in 5g graffiti "death mast" "we do not consent" etc . Gets washed off every few weeks but quickly returns. Nutters
Yes, we had similar graffiti here, too. I wonder if people complaint while the tower wasn't even active (and didn't even had RRUs installed).
Our old building has an old Corning mini-cell site fed by microwave and it's a whole rack for old PCS 1900mhz. And the building has a ton of Heliax (stiff coax) to the various building antennas via big and hot distribution amplifiers. A newer building we have has a 1U Spidercloud min-cell fed by private fiber with building antennas connected via Cat6 ethernet.
Very interesting. Thanks for sharing!
Please do more videos like this, great content!
I find it pretty amazing that 48 volts is one of the very few constants in the industry. Even have a nice collection of old base station 48v psu's that that are great for powering solid state homebrew transmitters
Forty-eight volts has been a standard in the telephone industry for a very long time. The Bell System set that standard way back using 48 volts for the talk circuits.
@@williamjones4483 Indeed. -48 goes back to at least the 1950s, and maybe a few decades before that.
Fellow scoper here. Keep up the good work buddy
What specifically are you powering with the 24v on a brand new site? The old analog cells were 24v and the first generation of CDMA too but "Toll" or backhaul equipment was all -48V, that got fixed over the years where it all went -48V but some stuff took longer to convert over so converters remained. I've only ran into a handful of AT&T sites that still had surviving converters, with unlabeled GMT panels split -48 on one side and 24 on the other. You find that out with a burn on your finger.
I used to work for the generator company on that site . It’s a 10kw DC generator . I would go to Verizon sites
all over and commission the units .
This was fascinating. Very good presentation.
When a local tower was getting upgraded near me, I talked with the guys, and they told me about how they were ripping out the coax and putting fiber in about 8 years ago. For a fixed wireless ISP I worked at for a while, all the 5Ghz radios these days are powered off POE, and we would have a few POP sites that had 48V and fiber to run everything. I still find it odd that the "Ham Radio" guys don't have radios that are POE-powered and ditch the coax, but most of those guys would probably think it's voodoo magic or something.
As a WISP/FISP operator and ham radio operator POE isn’t common in ham because of the power requirements for the transceivers are much higher then POE can handle. POE maxes out around 2 to 3a at 48v. Ham radio base transmitters need minimum of 8a at 12v
Lower frequencies generally used by hams means that the loss across simple coax arrangements is far far lower.
The Icom IC-905 features a remote radio unit, so they do exist. It does 144, 430, 1200, 2400, 5600 MHz and 10 GHz (10GHz with optional transverter).
Ever see a Motorola Quantar? what about TXRX VHF Duplexers? can't really just mount that stuff on the tower at 400ft. also LDF5-50a has about .449db loss per 100ft at 150mhz
@@Dratchev241 What about 4GHz?
Seems like the ice bridge wouldn't be to keep ice off the cables as much as it would be to take the impact of ice falling off the tower.
Yeah, he did mention that.
That S9500-30XS is so cool. I'll never get to touch that kind of hardware where I work. Cheap place where my pushing for 40G core with redundant storage instead of a few racks full of bare metal is falling on deaf ears. That ufispace stuff is so cutting edge that almost everything I looked up from them is "if you have to ask, you can't afford it". Either that or they only have one or two customers in the entire continent so never need to sell openly. Don't know. Still cool to look at.
Would love to see more cell content
A work of art.
Ive wanted to see this kinda thing for a long time!!
Good stuff man, on the fuse panels the white blades are just called blanks. Keeps curious people/animals from causing a short. That type of panel is a GMT panel, thus the fuses in it are GMT fuses. These days most of the newer panels can take up to 15amp fuses and some even 20.
Aka cricket fuses!!
Much more interesting then I thought it would be, thanks! I just assumed it worked like an FM transmitter with the transmitter in the shack and coax going up the pole, instead that's all up in the antenna 📶
As the frequencies increase, the coax losses would be too great, so most things now have changed to remote radio units.
This was the case with GSM(-R), but coax creates losses. Nowadays, at least many of the installations here in Germany have a 10ft coax run from the RRU to the antenna and fiber going directly into the antennas for TDD 4G/5G.
Do you know why the telephone company uses positive ground? Positive grounding has been used in the telecommunications industry for many years, primarily because the grounded positive electrode of a battery bank will corrode at a much slower rate than a grounded negative electrode.
I'd always been told that it was because cathodic transfer *in the underground wiring* would go *onto* the wires, making them thicker, rather than out of the wires... eventually making them open up.
It blocked corrosion in the olden days - in today's world no copper ever comes in contact with the environment so I assume the -48v is no longer a credible reason but just stuck with the industry; maybe someone can clarify why we continue with -48v standard
@@bubba1984 Plain Old Telephone Service (POTS) still works on -48 volts DC and it's all interconnected. FYI Ringing current is still 90 volts 20-30 hz.
@@bubba1984 this exactally. There is still -48 V rectifier gear that’s 30 + years old feeding metro Ethernet. That’s no advantage to adapting a new standard, and there are still lots of copper lines out there- though they are dropping day by day. In my county we have lots of ADTRAN DSLAMs that are fed from bonded t1s. Fiber is terminated at maybe every 3-4 muxes and then fed over copper to the adjacent muxes, using t1 repeaters if required. 90% of lines leave the serving wire center on fiber, but 95% arrive at the customer prem on copper ( POTS, ADSL, HDSL). The -48 helps protect the copper by repelling negative ions that corrode metal. Even the side that is grounded at the CO will have a slight negative voltage just outside the CO. Same technology is used on underground propane tanks, boats, and pipelines.
@@bubba1984 -48V is cheaper to run. The AC/DC power conversion, copper cabling, DC bullet breakers, and DC equipment is the cheapest over the the other options. -48V systems would use 1/0 power cable with 100amp breakers and the same manufacturer (Nokia 2G BTS) on 24V would need 4/0 cable and 250amp breakers. Depending on how far the cabinet is from the power source, the copper price comparisons were steep. Plus we had to install 750 MCM L3 grounding for the 1800W DC power plant and in the 2010’s 750 MCM was around $33 a LF. A copper thief’s dream hit.
How did it take me so long to find ypur channel..great stuff. Keep it up!
Nice video! I was tower lead for 5 years and a construction manager building new greenfield sites, collocations, and MODs. I also worked on DAS headend jobs and small cell buildouts. I think I know whose tower this was built for, they have a huge bundle of close out documentation and they don’t want to pay much per scope anymore. It’s really jacked up the tower industry since it took hold in 2009 and it’s gotten worse over time.
I hear you man the private sector wireless industry defiently hasnt been the same since I got in 2016. It used to be a great industry to be in and then ATT and VZW adjusted there payout methods and drove the industry into the ground in about 4 years. ATT changed their drivers to T5 RIP
Cool stuff, man! Thanks for the sweet video!
This is really cool, thanks!
We just need to know how to get free service, what switch we flip?
Very neat video. The ambient low frequency noise in the WIC sounds like a diesel locomotive prime mover in notch 8; full throttle. Wonder how the audio harmonics do that, when it's clear there isn't a running engine at all. Strange but very neat!
Great, insightful video.
I assume the shelter is built/cables routed in such a way that critters such as snakes and mice can't get in and cause problems.
Heh, I'm in Fredericksburg for the long weekend (family still lives there; I used to). Curious where that site is, given that it's single-tenant.
If this is recent, the 850 leg there is NR rather than LTE, as AT&T (given mention of FirstNet this is an AT&T site...I'm not spilling any beans here not mentioned in the video) has run 10x10 n5 here since they turned off 3G, and IIRC 5x5 n5 before that.
Curious whether the 700 fiber covers B29 or just B12, as AT&T runs both here.
Also surprised there's neither 1700/2100 (AWS) nor 2300 (WCS) on this site as those seem to be used heavily here since AT&T has decent market share and needs something to keep the network running reasonably well when you aren't within range of the small cells (which have mmW, LAA, and B2/B66) on Main Street. Less surprised that there's no C-Band there as I'm pretty sure there are only one or two sites with that live here (I caught one around when the eclipse happened).
A lot has changed since the ‘90s.
Very cool!
Thank you, very neat and cool
I think the red lights on the antenna look pretty in the nighttime sky...
Pretty informative video. Nice to see the inner workings of one of these towers.
A big question that wasn't answered is why -48VDC? Why is it reverse polarity? Then there's several times you mentioned 48VDC without the "reversed" prefix, is this a slip or are these +48VDC? What's the point/reason for running reversed polarity?
was wondering the same....
It is all -48v DC. As such it is understood and not always cited in casual conversation. This all has roots in telephony.
DC power was selected for noise considerations way back in the day. Probably shortly after the telegraphs demise. Believe it or not the old school POTS (plain old telephone service) had phenomenal sound qualities between 300-3.3Khz. AC power is very dirty, and induces a lot of noise that propagates at great distances. Especially when running tens of millions of miles of copper wire in parallel. Many filters of varying complexity would have been required to meet the sound quality requirements. So instead they set the equipment to operate on direct current.
Reverse Polarity: When they decided to push power from the central office to the subscribers (prior there were batteries in the subscribers phone) electrolysis became a problem. In a positive power environment the wires and all infrastructure would corrode because they are the anode. By reversing the polarity and connecting the positive to earth ground the infrastructure becomes the cathode and is not subjected to the corrosion.
@@ShainAndrews I can understand why they decided on DC, because WAAAy back in Jr High, for a school project , I wired two phone receivers together. and used a 6 volt wall wart to power it. even with a dc output and internal filtering caps, I could still hear some AC ripple. so I used a 9 battery, and Viola! problem solved. Ma Bell would have been proud! 😁
@@GothGuy885 LOL. Back in the day I could tell you how many switches were setting up a call just by the ticks and hums before the call would switch to line voltage. Really is fascinating stuff. Sometimes I wonder what we would have if Bell wasn't broken up.
@@ShainAndrews Thank you for the explanation; it makes sense. I've been in the basements of lots of CO's and wondered about this when I looked at the battery racks. Some of these Central Offices are creepy places, especially the cable vaults.
Get that CASS Audit done 😉
Ps - WIC’s kinda suck, limited space compared to the shelter sites. Better than outdoor cabinets though.
Two Words.. WIND SCREEN
Since you're calling them BBUs i suspect what's going on here is like what cable companies do. They send their signals out via fiber and when it gets to your neighborhood it's converted back to electrical signals. So the BBUs actually generate the RF modulation then convert it to light. Send it via fiber where the RRUs convert it back to electrical signals, amplify and filter it and send it to the antenna. Makes sense now.
Has a badass sounding name too, “RF over glass”
Just packets mate. Everything is just packets being sent over different mediums. Copper, RF, fiber optic, free space optics. The back bone doesn't care. We segment customers on VLAN's and throw their hot dogs down the hallway.
Between the 3G and 4G network overlays the equipment OEMs needed to work around the latency and one of the workarounds was getting rid of the typical 7/8’s or 1-5/8’s” coax and replacing it with a DC power and fiber trunks (or hybrid). They then designed the RRU/RRH to be installed on the same antenna mast or had it built directly inside the antenna themselves. The BBU down in the 23” rack would do the processing and link back to the switch. They could also link sites in fiber rings for additional capacities if it was available. I remember when I first started as a CM I was building new sites that were including 3G UMTS equipment with the plan to launch within a year. After UMTS was launched, I was given the direction that if I was on a site MOD walk and the old TDMA Nortel equipment was still running to shut down all of its DC breakers as those old dinosaurs were now over the hill. The equipment footprint comparisons are crazy both at the shelter level as well as at the switch side too. Removing TDMA and GSM gave back soooo much square footage
@@JV-wl6ex What? Ha? How is coax a latency issue? Light and RF travel at the same speed of light. Actually you could introduce latency in the conversion from RF to fiber and back. I'm sure moving to fiber was a cost cutting move. When fiber became cheaper to implement then copper and the technology got to the speed it could handle that fast and wide of spectrum from RF to fiber, it was a no brainer. After all that cut down on a lot of copper issues. From possible gas filled copper, RFI from other sources and then static discharges from nature (lightening). Fiber looked really good. 23" rack? Uh, does telecom use different size racks then the standard 19"? Interesting.
Whats the reason for using -48vdc instead of more common positive side?
It's a throwback to telephone exchange power systems using -48v to avoid corrosion of the copper subscriber lines
@@JohnWatkinsUK ok, that actually makes sense, since I do underground propane tank bonding, it now makes a lot of sense.
I did never expect they already put fiber + low voltage DC aöll the way to the top of the tower ...
wow, I'm absolutely not used to see neat cabeling in videos from North America (I alwas have to think at the overhead wire mess) ...
As a data center worker I am surprised by the temp that is maintained inside these, amazing.
This equpment has an ambient temp of about 103. blew my mind when I first heard about it but makes sense since its agiant heat sink. they are desiged to run hot.
Would cost them a lot less to keep them cool in the Summer as well if the whole system is designed that way vs having to keep stuff at human comfortable ambient temperature.
I think he has it backwards. Usually the vent fan is if the HVAC fails, it will maintain the site at a survivable temperature. If the vents fan is your primary means of cooling, you are getting insects, dust and humidity inside, and the humidity will condense as the site cools off at night. An AC is essentially a dehumidifier. But most of the gear should be rated to 113 deg F.
@@country_boy9180 actually what I stated is correct the Fans run until the wic gets to 103 degrees then the AC kicks on. This was a directive straight from the customer.
This is all hardened equipment. Not something you want to scale out for a data center. There are efficiencies lost operating at thermal extremes, and a premium paid to operate at those extremes.
I'm in school for electrical engineering. Hearing "Coax is a thing of the past" feels like heresy because we learn that if every wire could be a coax cable, the world would be a better place lol.
There's still a bit of coax, from the remote radio units to the antennas unless the RRUs are the massive MIMO units with the built in antennas or the other combined RRU/antenna units. It just doesn't go all the way up from the cabinet any longer.
What model is this router ? Looks like NCS540 IMO.
I'm curious why he keeps referring to the 48 VDC supply as "reverse polarity", what does he mean by that?
the "hot" leads are negative(-) polarity, the positives are ground(+).
Thanks, that was my hunch.
POTS and apparently cell sites, use -48VDC. There is an engineering reason for it (corrosion, I think)
@@antimaga856 Half the voltage drop would be one reason, if there was some sort of corrosion reason you could just change the polarity I'd think.
I've dealt with engineers of all stripes, actual and telecom. Ask 5 this question you'll get 12 and half answers.
@@antimaga856correct a positivity charge helps to reduce corrosion
So are the RF signals generated in the base units down in the rack and are they carried through fiber up to the antenne units which has een amplifier.? Or is the RF signal being generated in the antenna unit at the top of the tower But that makes me think, what happens if such a cell antenna fails. You will have to climb up there and replace the entire antenna unit.?
There is no RF generated in the shelter or on the ground.
The transmission is done directly behind the antenna from a remote radio unit RRU. If a RRU fails then a tower crew comes out to replace the RRU. That being said RRUs don't often break. They are very solid pieces of equipment.
Very good video! There is no fiber connection from a nearby landline? The tower radios are all linked together with the rack switches in the WIC? That makes this a node that receives, repeats and broadcasts the different radio signals.
He said a couple times that the site isn't in service. They're probably waiting for that. This is a regular cell. Theres radios up on the tower, fiber comes dow the tower and into the DUS/BBU shelves and another fiber from each shelf comes to that black site router shelf(called a SIAD) which is a SAR, Service Aggregation router. Which routes and MUXes them on to one fiber to whatever fiber provider.
@@davewood406 appreciate the clarification!
Correct, this site was brand new and was in the process of being handed off to the customer. They had not yet connected their backhaul.
It is interesting how the telco system was originally built around -48 VDC, and it has remained the same ever since. I would guess that -48 VDC is still used because changing to anything else (like a more common 12 VDC) would be such a huge cost systemwide that it is cheaper to stay with what works?
I’d guess that -48 telco battery was used way back when telco started stringing a single pair, 2 each copper wires, to each telco customer. The power was created by installing huge banks of wet-cell batteries. Power company connection was floated across these batteries to both run the network plus also this kept the telco network operating during power outages. Heck, telco customers never lost service even if everything else was dead. As for -48 instead of +48 volts??? Back when automobiles started using electrical power, cars were -6 volts DC. Could this be similar to the original TELCO network?
12V has too high current draw and losses over distance compared to 48V.
Negative with reference to ground to prevent corrosion of the twisted pairs underground.
I was told that -48v equipment used less AC power than 24v so it was cheaper per cell site which was a huge cost savings over thousands of towers across the country. Cell sites use gel cell batteries which are crazy heavy. in one of the carriers CO/switch there were battery shelves which had 4 12v batteries are integrated inside straight from the factory so you didn’t need to daisy chain them in series to make your 48v . I was watching a contractor use home brewed weird equipment plus a pallet jack just to get the battery shelves delivered inside the switch. They then had to mount 4 to 8 shelves stacked depend what they had room for and finally wire each cluster to parallel power bus bar and connect the battery overheating alarm cables. I found out later after I left the switch the battery contractor had an accident and pinched a finger off by accident trying to man handle those huge batteries.
12v sucks because you need such heavy cables to transmit power even short distances. I wish cars were 48V.
Great tour, thanks!
Are older site's coax being actively changed out to RRU's with fiber or just through attrition as new equipment is being built out?
ever since UMTS was shut down we now remove all Coax on the upgrades.
@ATI556 Thanks. I installed giant MTS and IMTS 100-watt VHF Mobile phones in the mid 70's. Only 1 site with 2 channels was available in a county of 75,000. Only Doctors and lawyers could afford them. Can you imagine that ? When I saw the first pamphlet describing a 3-watt cellular network, I thought they were crazy, "they'd have to put up sites all over the place!"
Well, 50 years later, here we are (and I'm still working public safety communications) YeeHaa.
That's so cool! The primary site router looks like a Cisco router. Is it effectively connecting the cell network to the rest of the internet? Do you have any additional information on its throughput to handle the amount of data going through it? I'm really curious if my IP address for my cell phone is just being NAT-ed to that router's public IP.
It’s a plain wrap Cisco. All the docs you get are Cisco but it’s not labeled as such. Probably whatever OEM they’re using at the time. It’s a service aggregation router. Last upgrade was 10gig to backhaul.
I bet they use carrier nat
This is not Cisco. This is a completely new brand called ufispace all open source and requires no activation license. The actually name is a disaggregate router.
Back in 2022 ATT internally announced it was slowly going to be dropping Cisco due to support concerns and subscription fees adding up.
@@davewood406not a Cisco router. Look up Ufispace. New brand ATT switched too.
@@ATI556 I upgraded and scripted hundreds of them since about 2020. The documentation was a mix and match of cisco and UFIspace, they must have had a falling out during the planning of the upgrade but it wasn't evident.
The new Muxers for C-band backhaul are called Cienas but they aren't branded Ciena and the documentation references Ciena and an Ericsson version. Which stinks because the Ericsson unit is only 2 or 3 RU and the one they are using is more like 7. All the sites were walked and bid considering the smaller unit...
Wow I’ve never seen or worked on a site that has zero coax hardlines going up the tower. Have been to hundreds of sites but left the industry 3 years ago.
Got to wonder what the RF exposure is at the bass of the tower. You have an RF radmon? Is it chirping?
No RF exposure on the ground its mainly only an issue when on the tower. Unless it's a rooftop
A lot of the time it's difficult to even test the site from the base of the tower, as the RF gets projected outwards. Sometimes you have to walk a bit away from the site before you get any signal.
So when this site is active how many cell phones can be using this site while in range of it?
They answer is always the same. It depends.
how long can the battery/generator setup sustain the site (in a power outage)?
72 hours on the diesel gen and about an hour on the batteries.
Can anybody tell why its so common to use -48V ref to GND as a power line here, instead of +48V ref to GND? Is it something to do with surviving lightning strikes?
Legend has it positively charged ground systems help to prevent corrosion.
Also on in telecom the positive is bonded to ground.
@@ATI556 Oh, thanks a lot! I got it!
@@ATI556 It is not legend. Positive side is the anode for electrolysis. Thus making all the infrastructure the anode and subjected to aggressive corrosion.
Would you say that almost everything is fiber even fiber comes from the internet company and goes right to the cell towers
pretty much
Wait... you're sending *fiber* up the pole?
So the RF is *in the tower head*, not in the hut?
Isn't that a bad plan, maintenance experience wise?
Stuff is ultra reliable, like decades between failures
@@motjones2341 Well, I suspect it's one lightning strike between failures.
Here in Florida, that rules that approach out completely.
I assume your a contractor, But I wonder if AT&T is aware that you're filming a site of theirs!
for anyone wondering those batterys are it POWERSAFE® SBS XL-12V BATTERIES. WHICH IS $655 FOR 1 BATTERY
and they are also 4 years old already....
@@bitcoredotorg ya thats a common issue of the coorperate lag we have. by the time the cell site finishes engineering and approvals from the RAN team and local jurisdiction it can be several years. Its not uncommon to see a site with 10 year old batteries in some cases.
That is actually a pretty good price for that much power. Being that high of voltage helps. I wish cars were 48V.
Why reverse polarity negative voltage?
So all the cell processing is done remotely? I seem to recall we used to have Base Station Controllers that would handle a lot of the local stuff.
That's what those DUS/BBU shelves are doing. That and the RRUs on the tower near the antennas. Basically what they did was split the Base stations, the mostly RF side went on up top and the rest went into the shelter(roughly). Things got tiny in the process. Most of the reason is to get the receivers closer to the antennas.
No big coax cable means cheaper builds and cheaper lease space.
BSCs are still used for 2G, and RNCs for 3G, where these are still used, but for 4G and 5G (SA) there's a direct connection from the cell site baseband back to the core network (MMEs/AMFs). The same type of BB unit as seen here can be used for 2G, 3G, 4G or 5G on the site itself.
@@paulsengupta971 I haven’t been to t-mobile in the last couple years but vzw and att mobility have everything on BBU/DUS. All the old bays are cold. Probably just the little independent networks still leaning on the old gear.
What do you mean by alarms?
Usually environmental alarms like intruder / door alarm, mains failure, rectifier failure. high temperature etc.
-48v, doesn't sound tooo far off from good ol Power over Ethernet, except bigger, a lot bigger.
Telephony predates Ethernet...
Whoa!
What is -48 volts?
been since 2010 since I been on a site used to service HVAC
Last cell tower shack I was in was around 2001 - things have changed A LOT! There used to be a TON of RF stuff and cabling in the shack, multiple racks worth, now it's a 1U box that feeds fiber up to the tower!
where do the alarms go?
there is a grey 110 block box eight above the drop down desk at the end of the video. The alarms were terminated to that then all the reporting was done on the physical BBU where all the fibers were running too.
They peel a TDM channel from the Ethernet circuit just to connect the alarm 66 block back to their local switch
Oh boy, get a $2 wind shield for that microphone - unfortunately I could only understand half of the interesting stuff you're talking about!
Audio is fine on pc
There's a lot of wind noise on a decent soundsystem. If your speakers can't do much below 150 Hz you probably won't hear the wind noise though ;)
I could hear it just fine on my phone. 🤷🏻♂️
Ako poh si carmelita Reyes Timoteo Taga Apalit pang
🤙👍
What's the temperature inside there?
80
Is that little cabinet a generator?
Yes 48vdc gen
@@ATI556 Very cool, who makes it?
@alanlocke7639 polar power
This guy needs to learn how to apply a wind screen for his microphone.
Gusto Sana mam ser paupa lupa ko Gawin o cellsite
Do not sit on the work table.
You apologized for the noise inside. Yes it was noisy. But, your voice was completely understandable. Outside, the wind was rendering your voice largely unintelligable. For crying out loud, edit in a voice over. It isnt hard.
Check your hearing. I understood him just fine even with the wind noise
You have too much time on your hands Jim!! 😅
Dude, isn't this a bit risky posting this for all to see? Like we have plenty of Iranians, Chinese and Russian hackers and terrorists that are just dying to get into our infrastructure and jack it up.
I don't see any big issues - didn't show any login pin codes on the doors, or keys on video, no IP addressing to be seen, no customer information (customer being the carriers), and it's effectively a site ready for a telco carrier to deploy their gear to.
If an enemy was going to attack wireless infrastructure, they would target one of their local or nationwide switches/CO. What’s to say that they don’t already have a back door into Nokia/Ericsson/Samsung’s BBU’s head end equipment. So much equipment was made where we don’t even have the slightest what chips have been baked into their equipment prior to the new laws that were enforced. Most fab ed equipment came from places that we don’t tolerate anymore even if Hauwei was banned they had other ways to infiltrate.
@@JV-wl6ex Your lack of understanding does not change the complexity of the world around you.
@christopherbenedetto Obfuscation is NOT security. You clowns and your bogeymen.
@@ShainAndrews I understand everything very well, I’ve been in this industry for over two decades. Try and help your keyboard warrior comments by using real-time examples rather than spewing out a slanted opinion without any info to back your statement.