Measure what each tethering method costs in battery and throughput

short · 40 min · Objective 1.3

Task

Compare USB, Wi-Fi hotspot and Bluetooth tethering on your own phone by measurement rather than by reputation, and record the battery cost of each.

Steps

  1. Record the starting battery percentage and the phone's data counter in lab/tether/start.csv with header method,battery_start,data_start.
  2. For each of USB, Wi-Fi hotspot and Bluetooth tethering that your phone supports: connect, transfer the same modest fixed amount of data, and record throughput in MB/s.
  3. Record results in lab/tether/results.csv with header method,throughput_mbs,battery_used_pct,minutes,charging.
  4. Write lab/tether/metered.md recording whether your computer treats the hotspot as a metered connection by default, and what changes when it is marked metered.
  5. Write lab/tether/recommend.md: given 'one laptop, four hours, battery matters', state which method you would use and why, citing your own numbers.

Verify

awk -F, 'NR>1 && NF>=3 {n++} END {print n" method(s) started"}' lab/tether/start.csv
awk -F, 'NR>1 && NF>=5 {n++} END {print n" method(s) measured"}' lab/tether/results.csv
awk -F, 'NR>1 {print $1}' lab/tether/results.csv | sort -u | wc -l
grep -Eic 'metered' lab/tether/metered.md
grep -Eic 'mb/s|mbs|per cent|%' lab/tether/recommend.md

Two or more distinct methods measured with both throughput and battery cost, the metered note present, and a recommendation that cites a number. A recommendation with no number in it is a preference.

Notes

Marking a hotspot as metered is the single control that stops a laptop spending a phone's allowance on updates. It is worth showing to any user who tethers.

This is an independent study companion for CompTIA A+ Core 1 220-1201 and is not produced by or endorsed by CompTIA.