Sunday, August 26, 2012

Internet at Orkeeswa- Manual

8/24/12

tl;dr: TO RECHARGE THE INTERNET CREDIT, take the sim card out of the shiny white VodaFone USB modem and put it into the regular Airtel USB modem. Then plug the regular Airtel modem into the computer, use an Airtel credit voucher to add money, and choose a (volume-based) bundle as usual.

How the system works:
The basic idea is to improve the reception of the USB internet sticks (modems) we normally use to access the Internet. The large antenna mounted on the roof is connected to the USB modem via a large data-carrying cable. The USB modem plugs into a 3G router, which takes the Internet access provided by the sim card inside the modem and produces wireless signal which can be picked up by multiple computers in the area. Since wireless signal does not penetrate solid walls very well, the wireless hotspot created will usually be limited to a single room.

Setup:
The antenna and cable are mounted permanently on the building. One end of the cable is connected to the antenna, and the other end should be connected to a small converter (a short piece of cable with one large end connector and one tiny one) that should be plugged into a port on the side of the shiny white Huawei USB modem. The USB modem should be plugged into the USB port of the black D-Link wireless router. The router needs to be plugged into power in order to work.

How do I know it's operating properly?

INDICATOR LIGHTS:

USB modem:
When the modem is plugged into and receiving power from the router, a light on the top of the modem should be either blinking or steady. A blinking light means it is detecting or attempting to connect to a network, and a steady light means it has successfully registered on a network and is connected to the Internet.
If the light is green, the modem is connected to a 2G (GPRS or EDGE) network, and the connection may be very slow. If it is light blue or dark blue, the modem is connected to a 3G (HSPA/HSDPA or W-CDMA, respectively) network, and the Internet should be fast. The light blue light indicates the fastest type of network.

Router:
When the router is plugged into power, it automatically turns on and begins operating. There are several useful lights on top of the router:

1. The leftmost light, a circle with a check mark inside, is the system check light- it should be green and steady or blinking very slowly at all times, meaning the device is receiving power.

Troubleshooting: If the system check light is not on, check that the power cord is firmly and stably plugged into the socket. If so, check that the extension cord is working, and then check that the power in the room is working.

2. Directly to the right of the system check light is the Internet connection light, which looks like a picture of the earth. When data is being transferred over the Internet connection, the light flickers. Otherwise, as long as the modem is connected to the Internet, it is steady. When there is a 3G connection, the light is green; on a 2G connection, the light is orange.

Troubleshooting: If the Internet connection light is not on, check that the USB modem is plugged firmly into the USB port in the back of the router. If so, check to see if the sim card is still inside the modem. If it is, the sim card may be out of credit. See the credit recharge instructions below, under Maintenance.

To the right of the Internet connection light is the wireless light, which looks like 3 curves next to each other. When data is being transferred over the wireless connection (e.g. when the router is providing Internet to a laptop), the light flickers. Otherwise, as long as the wireless is turned on in the modem configuration, the light is steady.

Troubleshooting: If the wireless light is not on, the wireless capability of the router may have been turned off (allowing Internet access only via Ethernet cable). You can turn the wireless back on by changing the wireless setting in the router configuration.

Specifications:

Antenna: 2.4 GHz 24dBi antenna with an N-type female connector on the end of the cable. Purchased in the US from ZDA Communications for $65 including shipping and brought over in a suitcase.

Data-carrying Cable: LMR-400 coaxial cable with an N-type male connector on one end (mated to the N-type female antenna), and with an N-type female connector on the other end (inside the building).
At the Computer Lab, the cable is a single 12-meter (40-ft) cable.
At the Laguna Beach House, one 12-meter cable was not long enough to reach from the antenna into the office. There is a 12-meter cable attached directly to the antenna, and another 6-meter (20-ft) cable attached to the end of the first cable that extends into the office.
Cables were purchased online from Amazon in the US for $20-$50 each depending on the length, and brought over in a suitcase.

Router: D-Link Wireless Router 113 (DWR-113), purchased for $70 (110 Tzsh) at Sound & Vision in Arusha.

USB modem: Huawei E160E, originally from Vodafone. Purchased from Ebay UK for $37 and ordered to the US, shipped over using DHL or brought over by a volunteer. If you need to use the modem with your computer for some reason, and your computer tells you to install the pre-loaded Vodafone software, please DO NOT do so! The modem is unlocked already, and should be recognized by the older (red) Airtel/Zain interface.

Maintenance:

Data Recharge:
You will not be able to recharge the credit on the sim card using the unlocked VodaFone USB modem. Take the sim card out of the unlocked modem and put it into a regular Airtel USB modem. (There should be one in the router box.) Then plug the Airtel modem into a computer, use an Airtel credit voucher to add money, and choose a (volume-based) bundle as usual.

Router Configuration:
To configure the router, turn the router on and connect an Ethernet cable from one of the Internet ports in the back of the router (numbered 1 through 4) to the Ethernet port on your computer. Open a web browser such as Mozilla Firefox or Google Chrome and type in the URL window: http://192.168.0.1; this is the IP address of the router. If it doesn't work, check the Ethernet connection on both ends, and try refreshing the browser a few times. The URL should take you to an admin login page that requires a username and password.

User Manual:
Documentation for the router can be found on Computer X (to be filled in later), or with Andy the volunteer if he is around.

One Step Forward, Two Steps Back


8/24/2012
Goodbyes are so hard.

On the students' last official school day with me, I taught my third enrichment science class for the Form 3s in which we set up a zinc-copper electrochemical cell. They usually do not do practical experiments in class; even the Tanzanian physics and chemistry teachers hadn't seen a real live electrochemical cell before. They were pretty amazed.
From left: Obedi, Some Random Student, Lota, and Dickson

Lota and Edu watching the teachers vs. teachers volleyball game after school

Jamani, I will miss these guys. I love them so much.
8/21/12

Today I got really worked up, and then blew off a lot of steam.

The power is out in the Orkeeswa science lab and computer lab, because something is wrong with the solar system. (And if you're thinking, "Woah! The entire solar system?!?!" don't worry- I mean the electrical system at the school.) On Saturday, a group from Engineers Without Borders that had come to plan Mungyere's solar power came to Orkeeswa to do a routine check-up on the system they'd designed and set up there. They'd taken the Mate (the programming interface) for the system and scrolled through the settings, checking to see if everything was okay, which they determined it was. This morning, when teachers began to discover that the power was out, a rumor spread that the engineers had made the system not work on purpose in order to sabotage the school. It was so upsetting to think that there was so much bad blood that they could come to such a conclusion; it is hard to write about even now.

All of the volunteers with engineering backgrounds who weren't teaching at the time (me, Jessica, and Andy) were ordered to fix the problem so they wouldn't have to call the engineers back. None of us are electrical engineers; none of us knew very much about how the system worked, and we understood just barely enough of the manual to scroll through the settings and determine that nothing seemed obviously wrong. The error messages were: "Battery voltage too high" and "AC output short." But I had no idea what to do about the battery voltage being too high, and we also tried turning off electricity to each of the rooms and trying to figure out where the short might be, to no avail. In conclusion, we each wasted about three hours of our lives because of pride and prejudice. People eventually became sane again and agreed to let Andy email Jeni, the main solar expert on the team. But it was crazy for a while.

Then I was called into a meeting today to talk about Internet policy; it's a conversation that has been delayed for about two weeks now because of scheduling issues. I expected a serious discussion about starting to get funding for the data plans from Airtel, and what the Internet would be used for in the computer lab, and by whom. Instead, the immediate resolution reached was to delay these decisions until a longer-term volunteer could arrive to manage the use of the computer lab and take over computer classes. Until then (which might be two months from now or later), neither students nor teachers will be able to access the Internet. All of these educational resources IEFT had been so keen to have will remain floating around in the tubes for a long while before being pulled into existence at Orkeeswa. Bummer.

After that, I didn't really want to talk to anyone, so I went into the science lab and threw all of my energy into making lab safety posters for the following two hours. It was extremely therapeutic.

Very proud of my lab safety and fire extinguisher posters. Credit due to Jessica for all the rest.
I am in the process of writing up the documentation for the Internet system, a very short and clear page that can be put up on the wall next to the router. Will have this done by the end of the week.


8/22/12


The shelf for the wireless router is now up.
What will go on the shelf when the system is all set up (minus the USB modem and coax cable)
8/19/12

Today is Eid! And so is tomorrow. Unfortunately, that means Orkeeswa and most businesses will be closed until Tuesday. With only 10 days left here, time is getting a little short; I'll have to test the new USB modem with the wireless router on Tuesday in both the computer lab and the LBH, and then hopefully go to Sound & Vision in Arusha on Wednesday to purchase another 3G router for the computer lab. (The Internet speed turned out fine.) On that day, I should also go to the Airtel store to find out whether it is really true that they have a time-based monthly data plan for 30,000 shillings, which I've so far only seen on their website. There is still so much to be done! But at least I know roughly what it is.

I encountered an interesting problem a few days ago: I stopped being able to recharge the Airtel sim card from the unlocked Huawei E160E USB modem (with the external connector) that I'd ordered off ebay UK.

(Not sure if I mentioned this before, but I had that and the crc9 to N-male pigtails sent to the DHL office in Arusha, where I picked them up with absolutely no problem. This was probably helped by the fact that it was a very small package, and my dad officially listed the item as being valued at $5 so that customs would not try to confiscate it.)

I believe I had been able to recharge it fine at least once before, and was very confused. I thought it might be because the firmware on the Huawei modem was somehow not communicating with the sim card correctly, or maybe the Airtel interface for connecting to the Internet wasn't communicating with the towers properly. The effect was very distressing, because when I ran out of Internet credit at the school, I was not able to recharge it with the credit voucher I had by SMS-ing the recharge code through the interface (*104*voucher code#). Even the balance-check code (*102#) was not working. At first I feared that Airtel might have figured out a way to block unlocked modems, which would have made it difficult to make the connection as stable as with the specially-ordered pigtails.

I now think it was a combination of the firmware and interface. I tried both codes with an old-model Huawei E173 proprietary Airtel modem (gotten by Brandt at Shoprite), and the slightly different Airtel interface that had come loaded on it. The *102# code worked fine, but the recharge (*104*...#) did not go through. The error message was: "Receive: Failed" or sometimes "Receive: Timeout." Then I tried the recharge with the sim card in the new model of USB modem sold by Airtel, a ZTE MF190 loaded with the latest interface software. It didn't work with that particular voucher I had (which I think was just bad) but I ran all these tests again with new vouchers and found that the recharge worked fine in the new modem with the new interface. The new interface doesn't work with other modems; I'd been using the older interface with the unlocked Huawei modem. Maybe the older software also shouldn't recognize other modems either, and it just does so because the unlocked modem is also from Huawei. I'll have to try different modems with different interfaces to gather more information about this problem; if the other volunteers also start having trouble recharging their sim cards with credit (as most of them use older modems with older interfaces), it'll be evidence that Airtel is trying to phase out the older interfaces in general, so the school will have to use one of the new modems just for credit recharging (which will be annoying, but not impossible). If we manage to get the unlimited monthly plan for the school, this will only have to be once a month.

8/18/12

The signal reception at the current height of the antenna turned out to be fine (consistently 3 bars HSPA). Perhaps I was being paranoid... but then again, maybe I could have gotten 5 bars.

8/17/12

I suppose the setup of the antenna at the school computer lab/library building is now finished, but I'm not quite happy with it. The reason is that the antenna is mounted not quite at the height of the peak of the roof, which may well be too low to get a very fast 3G connection (HSPA/HSDPA as opposed to W-CDMA). During testing, I found that the height at which I started receiving HSPA/HSDPA signal was around two feet above the peak of the roof. I had assumed when we started building that since our 20-ft pole had been more than high enough to reach the peak at the Laguna Beach House, it would be the same for the other building. The buildings look similar enough; they are both one-story concrete boxes with corrugated tin roofs. But as it turns out, the computer lab building's roof is steeper (which I noticed briefly during testing but didn't think it important), and the wall under it is slightly taller, so where we wanted the antenna is slightly higher than where we could safely mount it with proper lightning protection.

I should have measured beforehand how high the pole would come up above the roof, but instead I rushed ahead with construction without checking, which was foolish. If the Internet in the computer lab ends up being significantly slower than at the Laguna Beach House, I will take pains to redo the entire setup, probably to the great frustration of Elifuraha the fundi. But it should not take more than three school days- the first day to remove the grounding system and the new concrete base for the antenna pole, and the second two to either extend the antenna pole by splicing on another piece of pipe under it, or cutting down the pole and re-mounting it atop a small, high-up ledge on the side of the building that I hadn't previously considered as a good base for the pole. After looking at it a second time (and considering that the Internet might be half the speed it could be because of the missing height), I think we could make it work.

I'm glad that we at least got 2 feet of extra height because I noticed my mis-assumptions when I went to mount the antenna. We had already attached the grounding wire to the pole (a 20-ft long, 2-inch diameter black pipe) before putting it through the hole we made in the tin roof. (The choice of location for the hole was at least obvious, because there was only one place on the edge of the roof that was not covered with plaster.) There was a limited length of ground wire at school- just a little over 20 feet (the piece that was left over from the 50-ft piece we had cut for the LBH ground). So at the time I thought it would be fine to raise the antenna just a few feet by placing cinderblocks underneath the base and then turning that makeshift base into a big concrete block at the end- then it would still be possible to use that piece of ground wire. In the end, we took a piece of pipe from the storage container that had been left over from the LBH installation, cut it to about 2 feet, cut one end into four pieces which we splayed apart, stuck the bottom of the antenna pole inside it, and put concrete in the bottom of the 2-ft extension.

Mounting the antenna on the computer lab/library building with Elifuraha the fundi
Elifuraha mixes a bucket of sand, a lot of "aggregate" (the rocks), composite cement mix, and a lot of water to make concrete. I tried to help, but it required more strength than I have. :/

Concrete poured into the hole at the bottom of the pipe. We later bordered it with a box so the concrete block would be nice and square. The blue pipe is the conduit for the grounding wire, which runs down inside the antenna mounting pipe.

Internet at Mungere?


8/12/2012

Today I'm in Mtowambu- the name breaks down to Mto wa mbu (River of Mosquitoes). There is quite a lot of water here; it’s in the Rift Valley, so water flows down from the escarpments on either side, and the water table is high. They even have rice paddies! Thankfully, we have insect repellent and bed nets for the mosquitoes.

Jessica and I are visiting another volunteer-based school in Mtowambu called Mungere, where our host brother works. So far, it seems to not really be built yet; there's only one teacher's office and two classrooms, but no toilets or kitchen or anything else. The first year of students has been chosen- there are like 40 "preform" students, or students who are undergoing crash-course English training for a few months before staring Secondary school in total-immersion English. (In government schools, the preform period is only about 2 weeks; no wonder students generally fail to learn the material. Even the Orkeeswa Form Fours this year can't read their textbooks effectively, and they're the best and brightest from the region.)

A team from Engineers without Borders has come out for two weeks to build a set of composting toilets and make plans for the solar system. Afterward, they will climb Mt. Kilimanjaro for a whopping $1450 per person. Jessica and I are invited, but the price is a bit steep; plus, we've recently been asked by Orkeeswa to install a second Internet setup for the student computer lab, so we’ll have to get on that. In any case, the founder of this school wants us to come back, and one of her lures was to throw us in with all these lovely engineers with different knowledge sets- I must admit it's working pretty well. One of them is Jeni, who used to work in aerospace, has her own solar energy company, and is in charge of setting up the solar system. Ada is a civil engineer who just has a huge amount of energy and always itching to get as many things as possible done right now- she designed the composting latrines, and she and her fellow engineer Valerie are in charge of getting those built within the next 2 weeks. And there's a really cool techy French guy named Anatol who also worked as an aerospace engineer but is now a programmer. I got to introduce him to the Fieldtest app, which allows you to find out details about the Internet connection on an unlocked, jailbroken iPhone. He also has experience designing solar systems, so he and Jeni have somewhat opaque discussions sometimes- but I ask lots of questions so it's not that bad.

It’s really nice to have Junior around again! He's such good company, and always introduces me to people as his littlelest sister (which is slightly annoying, but in a nice way- I like having a sibling for once). I think I might really enjoy coming out here again to work with this school. But I also really miss home.

8/13/2012

Internet at Mungere seems possible:

1. I know where the cell towers are that provide what weak 3G signal there is on the roof of the first classroom block. Although at its best, the 3G signal strength was only -98 dB and around -110 dB on average. The towers are atop the part of the escarpment of the Rift Valley that overlooks Lake Manyara. They are hidden from view at the school behind a portion of the escarpment that juts out between the towers and the school.

2. I observed that there is much better 3G signal (-70s to -80s dB) less than half a kilometer away from the school, where the line of sight to the towers is not blocked. Perhaps just a little more height off the roof would be enough to improve reception to that level; or maybe a building can be built within the campus grounds in a spot with particularly good reception.

3. There will be two decently powerful antennas left over from this project; if I am planning on coming back to implement an Internet system at Mungere, it would be convenient to leave at least one of the antennas with them (and not have to deal with TZ customs again).

Sunday, August 5, 2012

Internet at Orkeeswa


We have wireless Internet access at the school!

Yesterday we finished mounting the antenna permanently in the roof of the Laguna Beach House. We drilled a hole in the corrugated metal roof on the side closest to our target tower, and chipped a large hole in the concrete wall against the building for the pole to sit in. Then we secured the cables to the underside of the roof along the side of the building using really cheap but effective flexible metal cable clamps called “Elegant Clips,” which were nailed into the rafters and bent around the cable. We attached the cable along the wall until we reached a convenient flower-shaped vent on the side of the building, which we widened a little bit to thread the cable inside.

Transporting the pole to the school- we tied it to the Land Rover using a bit of twine.
Mounting the antenna on the pole 
Jessica the Riveter (making the hole in the wall for the pole to sit in)
The pole in the hole
We made a small hole in the roof for the pole to stick through. 
Adding the coax cable 
Cable mount (with the nail not fully hammered in)
Cable running into the vent
Me, Elifuraha (the fundi) and J 
Heehee
Since our 40-ft LMR-400 coax cable wasn’t quite long enough to get from the antenna into the office, we were planning to use a 40-ft and a 20-ft cable in series. It turned out really nicely that the first 40-ft cable reached just far enough to go into the vent, so the connection with the 2nd cable was inside and taped to the ceiling. Even so, I will probably seal up that connection with some gaffe tape and epoxy in case any rain drips in through the vent and decides to take a walk along the cable.

Cable coming into the vent, taped to the ceiling, and entering the office through a hole in the doorframe.
Hoorah!
Then we drilled a hole in the office doorframe, threaded the cable through, and secured it with some more cable clips. The end of our cable will eventually be gaffe-taped discreetly to the bottom of the wall, but first we have to receive the crc9 to N-type pigtail (connector cable) so we can tape everything down as nicely as possible. People tend to appreciate nice-looking things more.

To recap: the free end of our 2nd cable was attached to a N-type male to stripped wire pigtail, which was plugged into the crc9 antenna port on the circuit board of an Airtel 3G modem stick. The modem is plugged into a wireless router, which sits on the concrete sill of a glassless window between the main administrative office and the main conference room; this successfully gives both rooms wireless Internet access. Later, a cabinet might be installed on that sill that opens into the office; this might weaken the signal to the conference room, but probably not as much as a concrete wall would.

Browsing with one computer- success! 
Browsing with 2 computers- more success! 
When the whole thing was set up, I tried to show Peter Luis how well it worked. The first time J and I had tested the wireless in those two rooms on Tuesday, we had been able to browse quickly on separate computers at the same time; at one point, she was downloading videos while I was on gchat. Of course, it didn’t work the first few times he tried loading gmail on his computer. But it was working fine on mine, and we determined that Peter’s computer was in general really slow. After about 10 minutes and restarting the browser a couple of times, he was able to access non-html gmail and his chat loaded- this doesn’t happen at most Internet cafes, even in Arusha. He was very impressed, until he clicked on a link one of his co-workers in the US had sent him about Snoop Dog claiming to be the reincarnation of Bob Marley. He seemed to get the impression that teachers weren’t going to use the Internet for useful things, and that IEFT wouldn’t be able to afford the data for teacher use. But we’re going to have a meeting about Internet use policy in about two weeks (since Peter will be away next week). Maybe we can set a time limit per teacher per day, to give them an incentive to use their time wisely while not detracting too much from their productivity if they choose not to.

Next Monday we will be driving a grounding rod into the ground, and testing the reception with our big antenna on the roofs above the lower teacher offices.

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J was sick yesterday and most of today; she had a stuffy nose, nausea, and slight fever, and was really tired, so we rescheduled our second enrichment physics lesson for the science-oriented 9th graders, which was supposed to be on Friday. Today, after eating a ton of delicious potatoes (with rosemary) cooked by Mama for lunch, J feels much better but still not entirely well. If she still feels odd on Monday, we’re going to ask Peter to take her to get checked for malaria at Dr. Danny’s. But apparently people here generally get malaria like once every 5 years; it’s considered equivalent to a really bad cold/flu that requires special medicine. For people who have access to treatment, it’s not that bad, but for Maasai living out in the villages, it often goes untreated.

This morning I went to school on my own to help the Chemistry teacher Bendera with a Form 4 practical on reaction rate. The experiment was to combine a constant amount of HCl with Sodium thiosulfate (Na2S2O3) of various concentrations, all clear solutions, in a conical flask atop a piece of paper with an X drawn on the center, and use a stopwatch to time the progress of the reaction until the solution had become too cloudy for the X to be seen. I had prepared 0.1 M HCl and 0.05 M Na2S2O3 the day before, but on the first demonstration trial that Bendera performed for the kids this morning in class, we found that those concentrations were simply too low. It took 9 minutes for the reaction to occur with the highest concentration of Sodium thiosulfate. So we sent the kids out on break for a few minutes (at which point one of the kids actually went home) and whipped up some new solutions- 1 M HCl, and 0.5 M Na2S2O3. These worked fine; the reaction times ranged from about 10 to 60 seconds each. Nonetheless, it would have been really nice to have tested out this lab beforehand, or at least to have looked up online what appropriate concentrations would be for the reactants. The former might be really hard for a teacher who lives far from school and doesn’t have access to any of the classrooms outside of regular school hours, but the latter could be easy with Internet access, if it is allowed.

Finding bulbs for what are currently the sucking pipettes needs to be a priority; Mbayana, one of the Form 4 students, told me today after the lab that he expected people to be quite likely to accidentally suck liquid into their mouths during the official exam practicals due to anxiety. I am concerned.

I really like working with the Form 4 students; maybe it’s because they are around my age, generally seem to work very hard, and because I sort of like how cheeky they are- they have a lot of character. It’s hard to think that most of them will probably not pass the Form 4 exams with the marks to move on to Forms 5 and 6. But at least they will have the opportunity to repeat the year at Orkeeswa.

There is also a new program at the school starting next week called “Study Camp,” in which Form 4 girls will be staying for a few days each week until the exams in newly converted dormitory rooms at the Laguna Beach House. Girls have much fewer opportunities than boys to study at home because they have so many chores to do, so this could be a huge help to them. J and I are excited to stay a few nights at Study Camp to help tutor and watch over the girls.

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Pole sana! The charger for our huge battery pack burnt out three weeks ago when I unwittingly plugged it into the 220-volt outlet without knowing that it was only rated for 120-volt input. The sad thing is that I didn’t find out until the battery pack ran out a few days ago; we’re going to look for a charger with the same specs in Arusha, but we’re not too optimistic about finding one.

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Alex (our awesome office manager) left for England forever to go propose to his girlfriend. We are so happy for him, but will miss him greatly!

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Last week we went to see a newborn baby! Her name is Swabra, which is a Muslim version of Subira, which means Patience. She is the newest daughter of Jessica’s host family from last year, and was only 14 days old when we went to visit:

J and Swabra 
I also drew a picture of my host brother. (I also did one of J and one of Malkia, but those are unavailable at the moment.) Oddly enough, for the first time I’m finding it easier to draw people from real life than from pictures. I think my drawing style is changing.

Drawing of host brother
Drawing Malkia