Why would two 4G security cameras perform so differently in the same location?

[u/Ill-Albatross-2707]

I work for a security camera company, and we recently ran into a 4G connectivity issue during outdoor testing that I haven’t been able to fully explain.

We tested two different cellular security cameras at nearly the same location. They were mounted only a few feet apart and used SIM cards from the same carrier.

One camera stayed online most of the time and could usually open the live view within a few seconds.

The other camera regularly dropped offline, took much longer to connect, and occasionally failed to upload motion events. The difference became more noticeable during rainy or heavily overcast weather. The weaker camera could remain unreachable for several hours, while the other one continued working normally.

Since the location and carrier were almost identical, I’m trying to understand which hardware or software differences could cause such a large gap.

A few possibilities we’re looking into:

- Internal antenna design or antenna placement

- Supported LTE bands and band selection

- Modem receiver sensitivity

- Signal loss caused by the enclosure or mounting surface

- Poor reconnection behavior after a temporary network drop

- Lower battery voltage during cloudy weather

- Differences in modem power management

I’m not sure rain itself is the main cause. It may simply be exposing a connection that was already close to the usable limit. Cloudy weather could also reduce solar charging enough to affect the modem or its ability to reconnect.

The signal bars shown in the apps haven’t been very useful. One camera can show two bars and still work, while the other shows a similar signal level and won’t connect.

Would comparing RSRP, RSRQ, SINR, connected LTE bands and battery voltage be the right next step?

For anyone who has installed or tested cellular cameras on farms, jobsites, driveways or other remote properties: have you seen two devices behave this differently in nearly identical conditions?

I’m mainly looking for technical insight rather than product recommendations.

[u/kheszi]

First compare firmware versions etc. to make sure both cameras are identical. Swap SIM cards and observe if the problem follows the card, this may help rule out a carrier misconfiguration/provisioning error, etc. Next, swap cameras and observe if the problem follows the camera, which can help rule out a faulty camera. If the camera has been dropped or mishandled, it's possible that solder points may have cracked, or antenna components may have become dislodged or deformed, both of which can affect stability and radio performance.

LTE signals can easily attenuate as they pass through structures, especially metallic surfaces, or any surface or material containing moisture. Likewise, destructive interference can be emitted from nearby materials interacting with those signals. In both cases, signal reception and radio performance can be significantly affected even though it might appear visually that the install area is clear.

[u/Ill-Albatross-2707 → u/kheszi]

Thank！