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#365616 - 27/12/2015 02:36 Campus wireless network question
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
So I've been tasked with setting up a college campus with a wireless network. In Zambia. By the last week of January.

There are several buildings are between 250 and 800 feet apart. There is no way to run cable between buildings, all links must be wireless. There is currently no internet available on the campus.

I'm not terribly experienced with this sort of thing once the installation gets larger than a small business.

My knee-jerk reaction is to get some Ubiquiti gear and roll out the network that way. I set up a church campus with Ubiquiti stuff last year and liked working with it, but all the AP's were connected by cables.

Is this easily doable with Ubiquiti gear?

Before I go and order any equipment, are there any other solutions I should look into?
_________________________
~ John

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#365617 - 27/12/2015 03:01 Re: Campus wireless network question [Re: JBjorgen]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Well, you can do it with wireless distribution, and it will all work.

But wired is always better than wireless, and running cat5e (up to about 300' between switches) isn't difficult if the ground is not paved .. just trench it a few inches below the surface using a garden spade to open up a small slit in the earth, a spade width at a time.

If things ARE paved, then that won't work.

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#365618 - 27/12/2015 07:00 Re: Campus wireless network question [Re: JBjorgen]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Eventually, they will run wires between the buildings, but for now I need to get something up and running and I have one week working mostly alone. Some of the runs between buildings will probably require fiber eventually. For now let's just stay limited to wireless. I'm very limited on time to acquire the equipment and test it out before flying halfway around the world to a place with no internet access to install it.
_________________________
~ John

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#365619 - 27/12/2015 08:38 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Originally Posted By: JBjorgen
... a place with no internet access to install it.
Internet access is possible almost anywhere, if there is money for the equipment and the service costs. Satellite Internet services exist, costs vary.

Having Zero Internet access is very different from limited Internet service. If at all possible I suggest you arrange for some Internet access, even if only for 'priority' use to resolve problems and keep the project moving forward.

Once installed, will this campus network have an Internet connection to the outside world?

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#365620 - 27/12/2015 08:49 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Originally Posted By: JBjorgen
Eventually, they will run wires between the buildings, but for now I need to get something up and running and I have one week working mostly alone. Some of the runs between buildings will probably require fiber eventually. For now let's just stay limited to wireless. I'm very limited on time to acquire the equipment and test it out before flying halfway around the world to a place with no internet access to install it.
Local labor is not possible for creating shallow trenches for the cable?

If the trench is dug in sections (maybe 50 or 100 feet at a time) you could do the actual cable laying yourself to ensure it is not harmed by sharp rocks or otherwise. Instruct the 'work crew' how to cover the cable with soil and keep small rocks away. With some luck you could have cables laid between the important links.

I suggest laying more than one cable in each trench, perhaps as many as three or four running in parallel, separated by at least an inch or two (the more space the better). That way if a single cable gets damaged you have a chance of a neighboring cable remaining intact.

Assume all the buried cables will eventually fail, of course.

You may be forced to use fiber or coax if you cannot use repeaters spaced along the UTP/CAT5/CAT6 runs.

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#365621 - 27/12/2015 08:53 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Originally Posted By: JBjorgen
Eventually, they will run wires between the buildings, but for now I need to get something up and running and I have one week working mostly alone. Some of the runs between buildings will probably require fiber eventually. For now let's just stay limited to wireless. I'm very limited on time to acquire the equipment and test it out before flying halfway around the world to a place with no internet access to install it.
Are you also constrained on budget and equipment costs?

Having equipment spares and alternate (or optioned up) configurations on hand may be important to meeting the time schedule. Shit happens, stuff breaks, requirements change once on the ground, problems arise. All this adds to the purchase costs up front, even if some of the stuff never gets used.

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#365622 - 27/12/2015 09:27 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Originally Posted By: JBjorgen
Eventually, they will run wires between the buildings, but for now I need to get something up and running and I have one week working mostly alone. Some of the runs between buildings will probably require fiber eventually. For now let's just stay limited to wireless. I'm very limited on time to acquire the equipment and test it out before flying halfway around the world to a place with no internet access to install it.
How much data traffic is this network supposed to handle?

Radio links between buildings must be configured carefully if you need a lot of bandwidth, especially if within the buildings there is going to be lots of WiFi traffic and the long run radio links are on the same frequencies.

Using non-WiFi frequencies for the building to building links would be better. Do you have direct line of sight between buildings or will the radio signals have to get around obstructions?

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#365623 - 27/12/2015 20:52 Re: Campus wireless network question [Re: JBjorgen]
sein
old hand

Registered: 07/01/2005
Posts: 893
Loc: Sector ZZ9pZa
John, I'd definitely like to help you where I can with this project. Have some experience with Ubiquiti including their PtP gear and can definitely help point you in the right direction with regards to product choice and potential pitfalls.

Do you have any plans for the campus? Feel free to PM me. I am also available on email and Skype if you would like to talk through a gameplan.
_________________________
Hussein

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#365625 - 28/12/2015 05:44 Re: Campus wireless network question [Re: K447]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
All good questions. I know this all seems a bit crazy. Honestly, the only reason I'm involved is that my father was just named president of the college and wants something up and running for the spring semester starting in January. He'll be there for the last three weeks of January and wants to fly me in the final week to install the network. Let me address some of the questions:

Originally Posted By: K447
Internet access is possible almost anywhere, if there is money for the equipment and the service costs. Satellite Internet services exist, costs vary.


True. An the plan is to eventually find a good solution and bring internet in. The campus is extremely remote ( google map ). The problem is they they want a network of some kind setup at the beginning of the semester so I've got just a couple weeks to whip something together. I'm going to try to get someone to get at least a SIM card with a data plan. Then if I get in a jam, I can climb Mt. Kazemba, and I can get a signal smile

Originally Posted By: K447
Local labor is not possible for creating shallow trenches for the cable?


Good point. I have a ready supply of labor from the local villages as well as the students. The ground is quite rocky and won't be easy to trench and the only tools available will be shovels. I'll check and see if I can have someone track down some network cable in Lusaka and bury it before I arrive. That said, at least one of the runs is over 800 feet and across an ( admittedly unpaved ) road with unknown power availability along the run. For at least the longer runs, for now wireless is the best option.

Originally Posted By: K447
Are you also constrained on budget and equipment costs?


Yes. Very much so. I plan to bring at least a couple spares of whatever I bring. Professors fly in from the US regularly to teach the students compressed courses so they can bring replacements if the spares get put into service.

Originally Posted By: K447
How much data traffic is this network supposed to handle?


Minimal. Mostly database updates for administrative data, print jobs, moving files around. Honestly I don't think there's even an expectation of extremely high availability. Even the power is pretty unreliable. For now, I think they just want the capability to administrate the place without running paper all over the campus. They can then build the network out over time for more reliability and capacity.

Originally Posted By: K447
Do you have direct line of sight between buildings or will the radio signals have to get around obstructions?


Yes, line of site won't be a problem. Possibly a few tree branches, but minimal. Interference from other radio signals definitely WILL NOT be an issue. They are way far from civilization and didn't even have power until recently. The neighbors live in grass and mud huts.

Originally Posted By: sein
John, I'd definitely like to help you where I can with this project.


I'll PM you what I have for the site plan. It's possible to measure the approximate distance between buildings using Google Earth as well.
_________________________
~ John

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#365627 - 28/12/2015 08:34 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Intermittent electrical power... Are the computers using battery backup or laptop style with built in batteries?

Are you also providing networked data/file sharing, email server, etc?

Is data integrity a concern between power outages and potentially weak/unreliable WiFi network links?

Regarding stable power for WiFi repeaters and other gear, 12 volt batteries can be a potential work around. Big car or truck batteries can power network gear for a long time. Periodic recharging can be done via connection to a portable generator or even jumper cables to a running truck or car.

Technically the batteries should be 'deep discharge' type for longer useful life, but regular truck/car batteries (aka engine starting batteries) tend to be more commonly available. And those will work well enough as long as they are regularly recharged before being allowed to drain very low.

Just need a simple box to tuck the equipment into and have the big battery sitting nearby. Keep the battery well ventilated and not in the same cabinet as the electronics. Sulfuric acid fumes from the battery can degrade electronics gear.

Power over Ethernet is one way to get electricity to remotely mounted equipment. Downside is that long wire runs limit the maximum available current. 48 volt PoE has less wireline voltage losses than 12 volt PoE. Or just run a dedicated power cable in a parallel trench.

Buried network cable should not be the thinly protected above ground stuff. Burial tends to be hard on the cable so the type intended for burial has a very tough outer jacket to resist crushing and intrusion of sharp edged rocks, etc. Of course the tough direct burial cable type costs more and may be hard to source locally.

You only have one week on the ground there due to other commitments elsewhere?


Edited by K447 (28/12/2015 08:53)

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#365628 - 28/12/2015 12:07 Re: Campus wireless network question [Re: JBjorgen]
K447
old hand

Registered: 29/05/2002
Posts: 797
Loc: near Toronto, Ontario, Canada
Originally Posted By: JBjorgen
...

Originally Posted By: K447
Local labor is not possible for creating shallow trenches for the cable?


Good point. I have a ready supply of labor from the local villages as well as the students. The ground is quite rocky and won't be easy to trench and the only tools available will be shovels. I'll check and see if I can have someone track down some network cable in Lusaka and bury it before I arrive. That said, at least one of the runs is over 800 feet and across an ( admittedly unpaved ) road with unknown power availability along the run. For at least the longer runs, for now wireless is the best option.

An alternative to burial for cables is to run them through pipes laying on the ground. The pipes provide protection for the cable inside from physical impact damage but must be somehow held in place so they don't get shifted sideways by people or vehicle tires.

Irrigation pipes are one possible source for local pipe. If using metal pipes I would try to find some plastic pipe or hose to sleeve inside to keep the network cables from touching the metal pipe walls and avoid cable damage from sharp edges where the metal pipe sections join.

I wish you well with your project.

One method to pull cables through a long pipe is to use a vacuum cleaner at one end to suck a soft ball or sponge with a long string attached. The ball draws the thin string through the pipe, then attach a stronger rope to the string. Pull that through, then use the rope to pull the cables through. Draw another thin string through with the cables so that you can pull another cable later, should the need arise.

To reduce friction while pulling the cables through, dribble dish washing liquid hand soap onto the cable as it enters the pipe. The soap acts as a lubricant but should not attack the plastic materials of the cables. Grease and petroleum products should not be used with electrical and networking cables.


Edited by K447 (28/12/2015 12:14)

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#365669 - 01/01/2016 10:16 Re: Campus wireless network question [Re: K447]
pedrohoon
enthusiast

Registered: 06/08/2002
Posts: 333
Loc: The Pilbara, Western Australia
Originally Posted By: K447


Irrigation pipes are one possible source for local pipe.


+1, poly water pipe is available in 200m rolls, is smooth inside to ease pulling the cable through, can be curved around obstacles but needs to be buried as it doesn't provide crush protection.
_________________________
Peter.

"I spent 90% of my money on women, drink and fast cars. The rest I wasted." - George Best

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#365730 - 09/01/2016 06:29 Re: Campus wireless network question [Re: JBjorgen]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Thanks to some pointers from Sein, I think I've got a good network design and I'm flying out in the morning for Zambia to install it. Will update with my success or failure after I return on the 20th.

Hasta luego.
_________________________
~ John

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#365731 - 09/01/2016 16:45 Re: Campus wireless network question [Re: JBjorgen]
sein
old hand

Registered: 07/01/2005
Posts: 893
Loc: Sector ZZ9pZa
Good luck!
_________________________
Hussein

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