Black Rock City Wifi Summit 2018

The Black Rock City Wifi Summit 2018 took place last Wednesday. As with previous summits that I’ve attended, it was an interesting discussion with a Burning Man tech staff, artists, and various theme camp representatives. The venue was the Thunderdome conference room at the Burning Man Headquarters.

Rolf (sp?) with the org lead a general presentation on the goals, issues and plans for this coming year. In general, he’s asking for frequency coordination to help facilitate access by everyone, to lower noise and such.

The past two years has had troubles with connectivity. For the most part, things just didn’t work. Connecting a NanoBeam to the sector antennas on the NOC tower didn’t work. The ISP had major routing issues and they were late in bringing the backbone online.

The plan for this year is to provide configuration files before heading out to the playa. These are designed to configure a NanoBeam NBE-5AC-GEN2. Other Ubiquiti gear may work but they’re testing and providing configuration for the NanoBeam.

The link between a NanoBeam and the NOC tower gear is on the 5Ghz band. The org is requesting that city participants stay off the 5Ghz band to help facilitate infrastructure connections. Local wifi in camps, art installations, mutant vehicles, etc. should be on the 2.4Ghz band. If the access point provides both 2.4Ghz and 5Ghz access, the org requests that the 5Ghz band be disabled. Doing so will help to keep the noise floor lower on that band.

If you already have a project in the works that is using 5Ghz for communications, don’t fret too much. The org will not be using the upper most channel on the 5Ghz band. That’s 5.825Ghz with a 20Mhz bandwidth. It should be easy enough to configure any radio gear already in use to use that channel. Hopefully there won’t be too much interference with other users on the band.

The plan is for the backbone to be live by 8/20. It consists of (2) 130Mbps connections to the ISP. For folks arriving on playa before gate opens, net access has the potential of helping communications greatly. For a city with a population north of 70,000, it’s going to be interesting to see how the available bandwidth holds up. I can easily see throttling of non-org access occurring as the week progresses. That said, I’m glad that the Burning Man org is working to share the resources they have with the city at large.

There was a short discussion on power. The gist is that the Ubiquiti radios want a stable 24v power source. Grounding the radios is also a good thing. That means driving a copper round bar into the playa 2′ – 3′. And use a surge suppressor. There is lightning and static on the playa that can quickly turn the gear into used carbon.

There was also a mention that microwave based communication equipment doesn’t like to sway. So using a pole that’s too high and moves in the wind will cause connectivity issues with the NOC tower.

If you’re planning to attempt local wifi via the org’s backbone, here’s the hardware you’ll most likely need. At least this is the gear I’m planning to bring on playa:

  • Ubiquiti Network NanoBeam NBE-5AC-GEN2
  • Ubiquiti Network Unifi AP AC Lite
  • network switch
  • 24v dc-dc converter
  • some power source, most likely 2 solar panels and 2 12V deep cycle batteries
  • surge protector for use between the NanoBeam and the switch
  • grounding rod
  • mast / tower along with equipment to secure it

It sounds like the org will be using Ubiquiti Network Rocket Prism AC radios behind their sector antennas. I’m not sure if I can gain access to one before heading out to the playa but it would be nice to test the gear and configuration before heading to the dust.

The org asked for the community to help each other out during the week with doctors hours. Basically we define a schedule and recruit volunteers who are willing to be a network doctor. When someone on playa has an issue, they can come to one of these doctors for help. There was also a mention that doctors may also want to be on a particular MURS radio channel during their office hours. I’m intrigued by this idea and intend to host some time at my camp.

There was also a discussion on the use of APRS for tracking mutant vehicle telemetry data. Someone mentioned putting together an on-playa web service that provides a map of the city along with locations of mutant vehicles or anything else using APRS. Unfortunately I didn’t catch the person to talk more before the summit ended but I really like the idea.

As with many summits like this, my to-do / wish list has just expanded:

  • create a local status dashboard for the network connection
    • raspberry pi based
    • ping to local nanobeam
    • ping to tower antenna
    • ping to google
    • current bandwidth in use through local radio
    • local radio ip address
  • bring some fox hunting gear for 2.4Ghz and 5ghz
  • set up a server with ubiquiti’s access point management system (unifi controller?)
  • configure for a captive portal w/ timeout
  • allow other access points to be adopted and push a stable, usable configuration to them
  • host network doctor’s hours
  • test the configuration on litebeams (LBE‑5AC‑Gen2) as I have a couple left over from another project
  • find my murs radios and verify that they still work
  • find a good dc-dc power filter

Good luck and come visit me at Frozen Oasis, we have killer margaritas!

Tags : , ,

Haiku

I have a habit of writing haiku, good and bad. Some political, some humorous and some only make sense to me. I’ve been posting to Twitter and Facebook but I’m moving away from using them. As such, I’m trying out a new micro.blog site, https://haiku.micro.blog/. Take a look, follow if you’re interested. Let me know what you think.

[Update] http://haiku.peterkropf.com is now active. Wahoo!

Black Rock City Wifi Summit 2015

The Black Rock City Wifi Summit 2015 took place yesterday. It was an interesting discussion with a collection of people from inside the Burning Man organization and artists / community who want to provide wifi to their art installation and camps. It was held at the Internet Archive which is a very interesting idea / place.

Tidbits

There are some bits of information that I learned or re-learned while at the summit.

BRC internet basically uses all the available bandwidth coming into Gerlach, around 40Mb/s, to support all the services for a temporary city of 70,000 people.

In 2014, the bandwidth was maxed out on Thursday before the event started.

Internet access is becoming / has become critical for the support of Burning Man. Without it, the event might not be able to take place.

Ubiquiti AirMax protocol deals well with the hidden node problem.

It’s important that the uplink antenna be stable and pointed at the center camp. Movement or misalignment of the antenna causes problems for everyone in that sector by reducing the available bandwidth.

The uplink antenna needs line of sight to the center camp tower.

If you need to use tape to seal anything, use aluminized hvac tape instead of duct tape. The glue on duct tape deteriorates rapidly in the heat and dust of the playa. The aluminized tape will last much longer.

During the weeks before and the event, download is maxed out. The week after, it’s the upload bandwidth that’s maxed out.

At 4:00 and A there’s usually a phone booth that uses VOIP to allow calls to the outside world. Calls are limited to 3 minutes. Because of bandwidth usage, the other side will be able to hear you while you might not be able to hear them. That makes for interesting conversations when you’re stoned.

Don’t use 5Ghz band for access points or other projects. It’s used for the uplinks and putting up local access points (or anything else) in the 5Ghz band will just interfere with the uplinks.

There’s lots of local, on playa bandwidth available. If there’s lots of data that you

Mount the local access points 6 or 7 feet in the air, no higher. This will help reduce interference and the hidden node problem on the local wifi connections.

If there’s any data you want to make available, consider setting up a server on the playa. If you do, let the folks on the BRC wifi mailing lists know about it. They may be able to help let people know about the server by including it on the captive portal page, setting up a dedicated IP address and / or a DNS entry.

Protect the access point and uplink power sources from water and dust. A simple way to do this is to put them in a tupperware type container. Cut a notch near the edge to allow any wires into the container and seal it closed.

There are no guarantees. The bandwidth available is completely subjective to the current needs and wifi in camps and art installations is at the bottom of the priority list.

Lastly and perhaps most importantly, the folks running the BRC network are at Burning Man to enjoy themselves. Leave them alone and talk with other camps and installations about any issues that you may be experiencing.

Setup On The Playa

There are two main components needed to setup wifi on the playa – an uplink radio and an access point. The uplink radio runs in the 5Ghz band and the access point in the 2.4Ghz band. The recommended uplink radio is the NanoBeam from Ubiquiti. A NanoBridge will work if you have a spare one laying about. The recommended access point is a Ubiquiti Unifi AP.

To start, reset the NanoBeam to factory settings before bringing to the playa can help you save some hassles and wasted time on playa. With it reset to factory defaults, mount it with a clear line of sight to the center camp tower and power it up. It should connect and start provisioning. This can take a while, as in hours depending on what else is going on. Use a laptop to monitor the setup and configuration.

After the NanoBeam has connected, been provisioned and received it’s IP address, connect and power up the local access point.

Consider a Unifi AP Outdoor. The rain last year helped several people discover that the Unifi AP’s aren’t waterproof. Water and playa dust will do corrosive wonders to exposed connections.

Note that the UniFi AP Outdoor 5G runs in the 5Ghz band, don’t use it.. Why? Because 5Ghz is used for the uplinks.

The configuration of the Unifi AP’s that’s downloaded from the playa NOC will most likely include a captive portal that times out after some period. This will help manage the bandwidth needed since you’ll have to re-accept the terms and conditions page to connect back to the Internet.

If you don’t use a Unifi AP, set your access point SSID to the camp name / location and make it discoverable. Set up a captive portal for your users. It’ll help manage available bandwidth and provide service to the community:

Projects

I’ve been toying with different ideas for project on the playa of which two seem to be most likely to happen this year.

Wifi Kiosks

The first is a local wifi spot and map server but since there will be playamap onsite and there’s lots of local bandwidth available, I think the mapping may get put on the back burner for this year.

It turns out that there were a few like minded people at the summit talking about projects to bring wifi to the masses. I’m planning to work with the folks at http://ki7wv.net/ to create some solar powered wifi kiosks and distribute them on the playa.

Trasher

Set up a Raspberry Pi image that pulls SNMP status from the Ubiquity NanoBeam uplinks. This will allow an uplink operator to get an idea on how well their connections works over time.

I’m currently thinking this can be done with Cacti or Nagios or perhaps just a simple Graphite setup. I think Nagios is way overkill for this but we’ll see. Some experimentation needs to be done…

Tags : , ,

Battery Life, Part II

I previously posted about monitoring how long my vx8-dr would last on different types of batteries. One of the things that I noticed was that there is a relationship between battery voltage level and the output power but I had no way of watching what was happening. So I invested in a Diamond SX-600 SWR & power meter along with an MFJ-261 dummy load and re-ran parts of the battery test.

2,000 mAh lithium ion w/ power

vx8-dr 2000mAh power

relative time voltage wattage
0:00:00 8.2 4.2
1:35:31 8.0 4.2
3:59:07 7.7 4.1
5:50:41 7.6 4.1
7:16:26 7.5 4.1
8:21:35 7.5 4.1
9:19:13 7.4 4.0
11:04:18 7.4 4.1
12:33:02 7.3 4.0
13:56:41 7.2 3.9
14:37:08 7.0 3.8
15:10:24 6.9 3.0

This is pretty much what I would expect. As the power available from the battery goes down, the output power on the radio goes down.

AA alkaline w/ power

vx8-dr aa alkaline power

relative time voltage wattage
0:00:00 4.2 0.90
1:48:19 3.7 0.15
2:40:05 3.7 0.10

This, ladies and gentlemen, is utterly ridiculous! Starting with fresh AA alkaline batteries, the output is less than 1 watt and it quickly deteriorates from there.

I swapped out the AA alkaline for AA lithium ion and found a similar output power level. Since it started with less than 1 watt output power, I didn’t bother running through the whole test. This was not at all what I expected, The input power voltage level is critical for the vx8-dr to perform well.

My original intention was to use AA lithium ion and / or AA alkaline batteries as a backup power source for the vx8-dr in the event of an emergency. This now looks like a bad plan. Running on anything less than the lithium ion battery packs has a detrimental effect on output power. It might do as a backup to the backup power but I don’t think it’s a good idea to count on it.

Right now, I’m thinking multiple 2,000 mAh lithium ion battery packs, a charging dock and perhaps a solar panel to charge it all. Plus an automotive plug adapter. And a plug w/ anderson powerpole connectors.

This was an interesting experiment!


 

Update:

I was asked about the discrepancy between the maximum measured power out of 4.2 watts with the battery voltage of 8.2 and the published maximum of 5.0 watts. I have a couple thoughts on that though they’re not based in much more that aether.

  1. The published specs may be coming from theoretical maximums.
  2. The published specs may be coming from values measured in a lab under ideal conditions.
  3. Maybe the battery’s just not quite fully charged.
  4. The SX-600 power meter may be off calibration.

I did plug the radio into the wall wart that comes w/ the charger. The voltage showed at 10.8v and the output power at 4.3 watts. Using the automotive cigarette plug, the voltage shows at 12.8v and the output power was measured at 4.5 watts.

BTW, the manual for the vx8-dr has specs for the supply voltage maxing out at 12v.

From all this, I take the maximum output wattage as being 4.5 with a more typical of 4.0 to 4.2.

Tags :

Battery Life

I had an experience a few weeks ago whereby I couldn’t join the ORCA net on my vx8-dr because of a low battery. From that, I thought I’d run a test to look at how long different types of batteries run in the vx8-dr. The basic protocol is to setup the vx8-dr to transmit APRS location messages on a regular basis and measure the battery voltage over time. The voltage measurement comes from the vx8-dr itself. Yes I’m trusting that it was accurate but with the test running the same way across all the types of batteries, I think it’ll be a valid test. Besides, the reading from the vx8-dr is what I’ll be using in the field.

The vx8-dr can use 4 different types of batteries: 2,000 mAh lithium ion, 1,100 mAh lithium ion, AA alkaline and AA lithium ion. I ran a set of tests over the course of 8 days.

2,000 mAh lithium ion

vx8-dr 2000mAh

relative time voltage
0:00:00 8.2
1:04:28 8.1
2:05:27 8.0
3:14:07 7.8
4:58:20 7.7
6:04:41 7.6
6:46:38 7.6
7:43:17 7.5
8:34:24 7.5
9:30:31 7.4
11:21:29 7.3
12:22:51 7.3

1,100 mAh lithium ion

vx8-dr 1100mAh

relative time voltage
0:00:00 8.2
0:00:00 8.2
2:15:51 7.8
3:06:14 7.7
3:58:57 7.5
6:27:44 7.4
8:01:43 7.1

AA alkaline

vx8-dr aa alkaline

relative time voltage
0:00:00 4.2
0:43:23 3.9
1:26:23 3.8
2:02:19 3.7
2:46:57 3.6
3:43:42 3.6
5:02:25 3.5
8:15:51 3.3

AA lithium ion

vx8-dr aa lithium ion

relative time voltage
0:00:00 4.5
1:23:24 4.3
3:33:47 4.1
5:19:44 4.1
9:04:00 3.9
9:55:36 3.9
20:56:06 3.7

I unintentionally left the vx8-dr running over night and the battery level only dropped 0.2 volts. That was very unexpected.

Conclusion

I came to a few conclusions from this test:

  1. Measuring the voltage will most likely be a good way to keep track of when to change batteries.
  2. Just measuring the voltage doesn’t provide any data on how well the transmitter is working with the available voltage / power.
  3. Judging by the AA lithium ion battery test, I need to re-run the 2,000 mhA and 1,100 mHa test. It looks like the voltage level of the lithium ion batteries may not be linear. That may put a kink in the use of the battery voltage to determine remaining power.

I’ll re-run the 2,000 mHa and 1,100 mHa tests over the next few days to see how long the batteries last. Perhaps lithium ion batteries don’t have a linear voltage level over regular usage.

More importantly, I need to expand the tests to determine the output power level as the batteries are used. I’m not yet sure how to do that. Maybe it’s time to invest in an RF power meter.

 

Tags :