How Many WiFi Cameras per Router?

The first four cameras worked, but since the customer added three more, clips stutter, live view times out and the family’s video calls freeze. How many WiFi cameras per router a network can carry has no single answer, because the limit is not the camera count. It is capacity: how many clients the router accepts, how much airtime its radio has, and how much video the internet uplink can send. This guide shows how to work it out and what to do when a network runs short.

The four limits that decide camera count

A WiFi camera network runs out of room at whichever of these it hits first:

• Client limit: the number of devices the router or access point will associate at once, set by its maker. Phones, TVs, speakers and plugs count too.
• Airtime: the share of time each radio channel can carry traffic. Every device on a channel takes turns.
• Local throughput: what actually reaches the recorder or the router from each camera at its real signal level.
• Internet upload: what leaves the building, which matters when cameras record to the cloud or when owners watch remotely.

Coverage is a separate question. If a camera has weak signal at its mount, start with our guide to extending WiFi to an outdoor camera, then come back to capacity.

Airtime on 2.4 GHz is the usual bottleneck

WiFi is a shared medium: on one channel, only one device transmits at a time and the rest wait their turn. That makes a slow device expensive. A paper presented at IEEE INFOCOM 2003, Performance anomaly of 802.11b, showed that a host transmitting at 1 Mb/s cut the throughput of every other host on the network, including those at 11 Mb/s, to below 1 Mb/s. The cause is the channel access method itself, which gives each device a roughly equal chance to send, so a slow sender holds the channel longest.

Cameras make this worse in three ways:

1. They are often mounted at the edge of coverage, outdoors or behind brick, so they drop to their slowest data rates.
2. Many budget cameras only use the 2.4 GHz band, which is crowded with neighbors’ networks and household devices.
3. They stream continuously or upload on every event, so their demand never pauses the way a phone’s does.

The practical rule: one camera with a poor signal can slow a network more than three cameras with a strong one.

Work out WiFi camera bandwidth

Read each camera’s bitrate from its settings page or from the recorder’s stream statistics, not from the box. Bitrate changes with resolution, frame rate, codec and how busy the scene is. Then add them up. As a worked example, with assumed figures you should replace with your own:

• Six cameras, each set to an assumed 2 Mbps main stream: 6 x 2 = 12 Mbps of steady traffic.
• Add 25 percent headroom, an installer’s margin rather than a standard: 12 x 1.25 = 15 Mbps.
• Compare that with what the radio delivers at the cameras’ real signal levels, measured with a speed test at the mount, not the router’s advertised rate.

The same bitrate figures drive recording storage; our guide to how much storage for security cameras uses the same arithmetic.

Cloud vs local recording and upload speed

Where the video goes changes which limit you hit.

For continuous cloud recording, compare the bandwidth total with the measured upload speed of the internet service, which is often far lower than its download speed, and leave room for everything else in the building. Recording locally keeps camera traffic off the internet link; our guide to viewing an NVR remotely covers access from outside.

Signs of too many devices on a WiFi network

Capacity problems look different from coverage problems. Typical symptoms:

• Cameras that worked alone start dropping or buffering when others are added.
• Recordings show gaps or frozen frames at busy times, such as evenings, when the household is also streaming.
• New devices fail to join, or one device joining knocks another off, which points to the client limit.
• Live view loads slowly from outside, but fine on the local network, which points to upload speed.

Check the router’s client list and per-device signal level first. A camera showing a weak signal and a low link rate is the one to fix before adding anything else.

Fixes: give cameras their own radio or a wire

Work through these in order of effect:

1. Wire the busiest or weakest cameras. Each camera moved to Ethernet frees airtime for the rest. Our wired vs wireless security cameras guide covers the trade-off per location, and PoE injector vs PoE switch covers power.
2. Add a separate access point for cameras on its own channel. A second SSID on the same radio only separates the traffic logically; it shares the same airtime. A separate radio on a different channel adds real capacity. See WiFi access point placement and mesh WiFi vs access points.
3. Move cameras that support it to 5 GHz, which has more channels than 2.4 GHz and usually less interference, where signal at the mount allows.
4. Lower bitrate where detail is not needed, using a lower frame rate or the substream for live view.
5. Record locally if upload speed is the limit.

Where to find wireless cameras and network gear

The wireless cameras category sits in the Security, Surveillance and Control division, and access points are in the wireless access point category. For pricing and availability, ask your sales representative through the Bursma contact page or the Columbus, Ohio branch, or open a Bursma dealer account.

Frequently asked questions