Mobile CCTV towers and ANPR cameras on 4G: sizing the connection and keeping it up
A tower on a building site is only as good as its mobile link. This guide covers uplink, data use, failover and the checks to run when a tower goes quiet, whether you hire towers, run them or fit the routers.
Start with the uplink
A camera sends video out, so what matters is the upload rate the site sustains at the antenna, not the headline download speed. Spec sheets quote top-end modem figures; Teltonika's RUTX11 page, for example, advertises cellular speeds up to 300 Mbps with carrier aggregation [5]. Treat that as a ceiling and measure the site.
Then add up every stream that can run at once: cloud upload, a guard's live view, an engineer connecting in. If the total nears the real upload rate on a busy evening, video stalls even with plenty of data left on the plan.
Speed and allowance are separate limits
Speed caps what is sent each second; the allowance caps the total. Bitrate links them. This table is plain arithmetic for a stream uploaded non-stop at a fixed bitrate (decimal gigabytes), not a measurement of any product.
| Stream bitrate | Per hour | Per day | Per 30 days |
|---|---|---|---|
| 0.5 Mbit/s | 0.23 GB | 5.4 GB | 162 GB |
| 1 Mbit/s | 0.45 GB | 10.8 GB | 324 GB |
| 2 Mbit/s | 0.9 GB | 21.6 GB | 648 GB |
| 4 Mbit/s | 1.8 GB | 43.2 GB | 1,296 GB |
Real bitrate moves. Axis says motion in the scene can raise bitrate significantly, and lists resolution, frame rate and night-mode noise settings among the video settings that affect it [7]. A busy scene can therefore use far more than a quiet one. Some cameras let you cap it. Axis's developer documentation describes a maximum-bitrate mode that limits the immediate network bitrate, and warns that an unrealistically low limit can hurt quality in motion-heavy scenes [6]. Its white paper says average bitrate with a maximum limit is probably the best choice in most cases [7]. Check your camera's manual.
Event clips, live viewing and ANPR
Live viewing can use more data than event clips. With assumed figures, thirty 20-second clips a day at 2 Mbit/s come to about 150 MB. One guard watching a 1 Mbit/s sub-stream for 30 minutes uses about 225 MB, so four sessions a day (0.9 GB) cost roughly six times the clips. Upload on motion and watch the lower-quality sub-stream; the CCTV router guide covers both.
ANPR changes the sums. Axis describes its licence plate application as running on the camera, which it says reduces bandwidth use [8]. SimFalcon's Irish ANPR page draws the same line: edge-processed systems may send only events or text records, while others upload images, clips or continuous health data [17]. Ask the platform supplier which applies before sizing the plan. See ANPR camera SIMs.
Failover: what a dual-SIM router does and does not do
On most dual-SIM Teltonika routers only one SIM is active at a time, with the other acting as failover; a few models run both together [1]. Switching follows conditions you set: weak signal, a data limit, no network, network denied, roaming, a missing SIM, or a failed data connection tested by LCP or ICMP echo, with an adjustable check interval and count (defaults of 30 seconds and 3 on the RUTX11 page) [2].
- Use two networks. Two SIMs on one network give little protection when that network fails.
- Set the data-connection test. The no-network condition applies when no network is detected, so for a tower that is registered but passing nothing you want the separate data-connection check [2].
- Rehearse it in the yard. A switch is not instant. Take SIM 1 out of service, confirm SIM 2 takes over, and see what happens when SIM 1 returns.
A multi-network SIM is a different tool. SimFalcon describes access to supported partner networks, subject to coverage and device capability [18], and says multi-network connectivity is useful for equipment moving between projects because network conditions change by site, though correct antenna placement and coverage testing still matter [16]. Neither approach fixes flat batteries.
Why prepay SIMs let towers down
Prepay suits people who top up and notice when something stops; a tower does neither. Terms differ, so read yours. Three Ireland's published prepay terms, as one example, say purchased credit expires after a set period and restrict the service to personal use. Three reserves the right to withdraw it if it believes it is being used commercially, and gives the use of a gateway as an example [14]. Its 28-day data add-on ends when the allowance is used or the period ends, whichever is sooner, after which standard prepay data prices apply until its next recurrence date [15]. SimFalcon's pricing page says plans are billed annually, or monthly for business volumes, so there are no PAYG top-up expiry issues [18].
Reaching the tower from outside
If the mobile network puts your SIM behind carrier-grade NAT, port forwarding on the router will often fail from outside. The IETF reserved 100.64.0.0/10 for the interfaces joining carrier NAT equipment to customers [9]; a mobile address in that range is a sign you may be behind one. To reach the recorder, use its maker's cloud service or a VPN. To check or change the router itself, remote management built for devices without a public IP address, such as Teltonika's RMS, avoids the same problem [4]. SimFalcon says private APN or managed remote-access options can be discussed for suitable business deployments [16].
Signal at the antenna, and old radios
Take readings where the antenna will sit, with the cabin or mast in place. Teltonika's bands, and its advice to weigh strength and quality together, are below [3].
| Reading | Excellent | Good | Fair to poor | Poor |
|---|---|---|---|---|
| RSRP | -80 dBm or stronger | -80 to -90 dBm | -90 to -100 dBm | weaker than -100 dBm |
| SINR | 20 dB or higher | 13 to 20 dB | 0 to 13 dB | 0 dB or lower |
ComReg's outdoor map shows predicted 2G to 5G outdoor coverage by address or Eircode [12]; use it to shortlist, then confirm with readings. Check old radios too: Eir is phasing out 3G from 1 October 2026, starting in Donegal, and Vodafone switched its 3G off in October 2024 [11]. ComReg's list of affected equipment covers alarms, trackers, automated gates and similar devices, and it advises checking with the supplier. It does not mention routers, but a router with a 3G-only modem would have the same problem, so check its specification.
When a tower drops offline
Work from the cheapest check to the site visit.
- One tower or all? If all vanished together, look at the platform, account or SIM provider first.
- Power. Towers often run on batteries with solar charging or hybrid power [10]; check the battery state first.
- Router status. Note the registered network, signal readings, mobile IP address and active SIM.
- Limits. A router-side data limit can switch mobile data off [2]; check it and the plan allowance.
- Signal. Compare readings with the table above, then check the antenna cable and connectors.
- APN. Registered but no address often points here. See APN setup.
- Recorder. Gateway, DNS and clock; the CCTV router guide walks through it.
- On site, take a photo of the router's status page first, so you can compare it after any change.
If the checks above do not settle it, these guides go further: weak or no network, SIM not connecting and replacing the SIM.
Data protection for site CCTV in Ireland
The Data Protection Commission treats footage of identifiable people as personal data and expects a legal basis, a way of telling people they are being recorded, footage kept no longer than necessary for its purpose, and secure storage [13].
Where SimFalcon fits
SimFalcon's Irish ANPR page says it does not need to supply the hardware, only the camera or router specification to check compatibility [17]. Its construction page describes multi-network connectivity, usage monitoring to spot a camera, NVR or router using more data than expected, and says it can assess common unlocked industrial and commercial routers, subject to modem and APN support [16]. Its pricing page says standard camera plans are generally intended for motion events, snapshots and uploads, and that continuous streaming can use substantially more data, so a business quote is needed to size the allowance [18].
Send the router model, camera count and viewing pattern through the contact page, or see construction site CCTV SIMs, pricing and coverage.
Sources
- [1] Dual-SIM Support (Teltonika Networks Wiki), checked 3 October 2026.
- [2] RUTX11 Mobile (Teltonika Networks Wiki), checked 3 October 2026.
- [3] Mobile Signal Strength Recommendations (Teltonika Networks Wiki), checked 3 October 2026.
- [4] RMS (Remote Management System) (Teltonika Networks Wiki), checked 3 October 2026.
- [5] RUTX11 industrial cellular router (Teltonika Networks), checked 3 October 2026.
- [6] Rate control (VAPIX) (Axis Communications), checked 3 October 2026.
- [7] Bitrate control for IP video (white paper) (Axis Communications), checked 3 October 2026.
- [8] AXIS License Plate Verifier (Axis Communications), checked 3 October 2026.
- [9] RFC 6598: IANA-Reserved IPv4 Prefix for Shared Address Space (IETF), checked 3 October 2026.
- [10] How Mobile Surveillance Towers Improve Site Security (Designing Buildings), checked 3 October 2026.
- [11] 3G retirement (ComReg), checked 3 October 2026.
- [12] ComReg's Outdoor Mobile Coverage Map (ComReg), checked 3 October 2026.
- [13] Guidance on the use of CCTV (Data Protection Commission (Ireland)), checked 3 October 2026.
- [14] Prepay Service terms (Three Ireland), checked 3 October 2026.
- [15] Three Prepay Data Add-on terms (Three Ireland), checked 3 October 2026.
- [16] Construction Site CCTV SIM Cards Ireland (SimFalcon), checked 3 October 2026.
- [17] ANPR Camera SIM Cards Ireland (SimFalcon), checked 3 October 2026.
- [18] SimFalcon Ireland pricing (SimFalcon), checked 3 October 2026.
Frequently asked questions
How much data does a CCTV tower use?
It depends on bitrate and how often footage is watched. A 2 Mbit/s stream uploaded non-stop is about 21.6 GB a day, while thirty 20-second clips at the same rate are about 150 MB. Live viewing can add more than the clips.
Does dual-SIM failover mean the tower never goes offline?
No. It only helps if the second SIM is on a different network, the switch conditions are set and tested, and the tower has power. On most dual-SIM Teltonika routers only one SIM is active at a time.
Why not put a prepay SIM in a tower?
Prepay terms are written for people who top up and watch their balance. For example, Three Ireland's published prepay terms say credit expires after a set period and restrict the service to personal use, and Three can withdraw it if it believes it is used commercially. Check the terms of any SIM before it goes into unattended equipment.
The router shows online but I cannot view the cameras. Why?
If the mobile network puts the SIM behind carrier-grade NAT, port forwarding on the router will often not work from outside. Use the recorder maker's cloud service or a VPN, or ask your SIM provider whether a private APN suits your deployment.
Does an ANPR camera need a lot of data?
That depends on what it uploads. A camera that reads plates on the device and sends only events or text records can be light, while image or video uploads use much more.
Questions about connectivity for your equipment? Talk to SimFalcon or ask Engineer Support.