What does the 4G video data calculator estimate?
An MDVR records video to its card or disk and sends only part of it over the mobile network. The rest of the video stays on the unit until someone asks for it. Three kinds of traffic use the SIM: live view, alarm clips and retrieval of recorded video.
This calculator adds them up for one vehicle and for the fleet. It shows the data on a normal day, the data in a month that includes incident-review days, and the SIM plan that holds it. A third tab turns the live streams into the link your server needs.
What drives the data bill
Live view
Sub stream
- Data moves
- While someone watches
- You control
- Minutes, channels, quality
- First saving
- Watch one channel
Alarm clips
Upload quality
- Data moves
- After each alarm
- You control
- Length, channels, quality
- First saving
- Upload fewer channels
Retrieval
Main stream
- Data moves
- When you request video
- You control
- Minutes and channels asked
- First saving
- Request the exact minutes
- Bits and bytes differ by 8. Bitrates are in bits per second and plans are in bytes. Divide by 8 before you compare them.
- Every channel counts. Two channels in a clip carry twice the data of one.
- Review days are the spikes. Pulling ten minutes of main-stream video can cost as much as a couple of days of routine data.
Inputs you need from your device settings
| Input | Where to find it | Tip |
|---|---|---|
| Sub-stream bitrate | Device video settings | Per channel, in kbps. The presets are typical values only. |
| Clip settings | Alarm and upload settings | Seconds before and after the event, channels, and upload quality. |
| Live view minutes | Control room practice | Ask the people who watch. Guessing low is the common error. |
| Review days | Incident log | Count the days a manager pulled recorded video last year. |
| Plan size | SIM contract | Check whether the plan is per SIM or pooled across the fleet. |
How the data is calculated
All sizes are decimal: 1 MB = 1,000 KB, 1 GB = 1,000 MB and 1 Mbps = 1,000 kbps. Plan sizes use the same convention.
A normal day
A month and the plan
One megabit per second is 0.125 MB per second, so one minute at 1 Mbps is 7.5 MB. The 80% line is a convention, not a rule from any operator.
Server link
Worked example: four channels at 100 kbps
- Live view: 4 channels x 100 kbps = 400 kbps. One hour is 400 x 3,600 / 8 / 1,000 = 180 MB.
- Month: one hour a day for 30 days is 5.4 GB. A 2 GB plan allows about 22 minutes a day.
- Server: each vehicle needs 0.4 Mbps. A 6 Mbps link with nothing kept free carries 15 vehicles. Keeping 30% free it carries 10.
- Retrieval: one minute of a 2 Mbps main stream is 15 MB, so ten minutes is 150 MB.
The calculator opens with different example values, so the screen will not match this example until you enter it.
How to read the results
- A normal day shows where routine data goes. If live view leads, set a viewing policy first.
- The plan lamp reads fits, tight or too small, with the share of the plan used. Tight means a busy month can go over.
- The savings table ranks the settings changes by the data they save. Agree them before you buy the plan.
- Server link shows the incoming Mbps for the busiest moment, and how many vehicles the link carries.
Common mistakes when sizing video data
- Mixing Mb and MB. A 1 Mbps stream is 0.125 MB per second, not 1 MB.
- Planning for clips only. A few minutes of daily live view can exceed all alarm clips.
- Ignoring review days. The month that follows a serious incident is the month that breaks the plan.
- Using the main stream for live view. It carries several times the data of the sub stream.
- Copying numbers from another maker. Published figures vary by network and settings, and some tables are wrong by ten times. Use your own device settings.
Assumptions and limits
Results are estimates. Real data depends on the network, the codec, the scene and the settings. The stream bitrates, clip size, snapshot size, tracking data and plan sizes on this page are typical values, not Tracom device specifications, so replace them with your datasheet values. Operator prices, speed limits after the cap and roaming are not included. Measure a week of real use before you sign a fleet plan.