Editing MayFirst2012NYCCrateDeployment (section)

= Narrative =

[[File:May1_traffic0.png|frame|center|alt=Router traffic chart|Router Traffic Chart (UTC timezone)]]

Above is a chart of 4G network uplink bandwidth throughout the day. Measured by the pfSense
router, this is traffic to the internet from the basecrate, including that from
the repeater, but not including "local" traffic, eg serving up the chart
itself. Time is UTC, so "16:00" is noon EDT (rough start of deployment), grey
lines are 10minutes. Maroon in download, grey is upload.

We started the day with fully charged batteries at Bryant Park, where a series
of stationary events were taking place and a crowd had gathered. The crate was
powered up at '''11:40am EDT''' right next to a row of television vans (with their
own radio equipment). The crate was on the sidewalk at street level at 41st St
and 6th Ave; the park itself is elevated about 2 meters, with a broad
stairwell leading up.

By '''12:05''' we had tested and found "good signal" for the main SSID around the
entire park lawn. Some users had trouble connecting directly to the basestation
using iPhones; other phones had no trouble connecting. The bandwidth chart
shows very low usage for a period here, there may have been a misconfiguration?

At '''13:20''' (17:20 in chart) we turned on the repeater; it's battry voltage was
12.44v. The repeater's 2.4GHz radio was set to channel #1 to avoid interference
with the basestation radio. There was another strong station on channel 1
(SSID: "warroom"), and we may have been clobbering that. Around this time we
moved the crate up into the park itself and stood it on folding chair to get it
off the ground by a foot or two; this greatly improved signal strength. The
bandwidth charts show mostly intermitant download.

Around '''14:23''' (18:23 in chart) we began marching/rolling down 5th Ave to Union
Sq, which took about 40 minutes. We saw pretty heavy upload traffic during this
period. Bryan rolled the case on the opposite side of the street from the march
and monitored uplink connectivity while Pablo took the repeater in the crowd
and told marchers that connectivity was available.

By '''15:00''' we had arrived at Union Sq and took a break at the north end of the
plaza for some food. We opened the crate and powered down for a few minutes at
'''15:15''' (19:15 in the chart, note "gap"). Crate battery voltage was 12.00v open
circuit (no load).

After about 40 minutes we made our way south in the square. The repeater
battery died at about '''16:00''' (with 11.90v), so it ran about 2.5 hours. 

At around '''16:30''' we made a few signal strength measurements across about 15
meters of very dense crowd (in front a concert stage just north of 14th St and
Broadway) and got poor signal and throughput. At this point the batteries died
in the smartphone being used for testings, so the signal quality measurement
could be due to low power. Chart shows we had some strong down/up usage during
this period. We had the crate up off the ground at about chest height on a
stone wall, but not above heads or with clear lines of sight to the crowd,
which may have diminished signal propagation. After about 40 minutes the crate
was moved south of the crowd to a new location before the start of a large
organized march, and the batteries probably died shortly after that.

The pfSense logs indicate no traffic after '''17:30''', and we have notes of only
"questionable connection quality" at '''17:00''' (checked with a borrowed phone).
It was discovered that the batteries were dead and inverter was in alarm at
'''17:55'''. This means the batteries held out for almost 6 hours, which is pretty
good. 

The final basestation battery voltage was 11.10v, which is very low ("deep
cycle", would cause damage a regular non-AGM lead-acid battery).