The wifi built in to cameras is often pretty trashy, only supporting 802.11G or N on 2.4 GHz, and having a poor chipset and antenna, so you can expect it to take a lot of airtime to transmit its video stream to the access point. Then, of course, if you are viewing with a device also on wifi, then the video needs to be transmitted a second time over the same radio frequency before you can view it. In poor enough wifi conditions, just one video stream can bog down the whole wifi network. But chances are, you don't just have one video stream on the network. Other wifi-connected devices often stream video or download updates, etc, so you might only have connectivity problems at times of peak load.
The first thing to try is lowering the bit rate in the camera's video encoding configuration. I would try something around 1-2 Mbps (1000-2000 Kbps) with a frame rate of 10-15 FPS. The lower the bit rate, the more stable the stream should be. Lower frame rates help to preserve video quality at lower bit rates, and they also mask the effect of a very unstable connection because you won't notice brief freezes as much.
A better long-term solution would be to install a second wifi network with a different SSID for the cameras. Something like
could be configured to act as an access point.
Some wifi setup advice:
* When setting up a 2.4 GHz wifi network, you must only choose from channels
1, 6, and 11. This helps achieve the most efficient usage of the radio frequencies. Consider channels
2, 3, 4, 5, 7, 8, 9, 10 to be off-limits. This is because a wifi network does not actually use only one channel. The one you pick is only the center frequency, with the network using several channels to the left and right of it. If everybody follows the 1, 6, 11 rule, then you get three non-overlapping networks. If anyone in the area breaks the rule, then you only get two non-overlapping networks at best, and some of the available frequency at the edges of the spectrum goes to waste.
* When configuring a second access point for cameras, it should be configured to use a different channel than the main network (remember: channels 1, 6, or 11 only).
* Do not trust your access point to choose a channel automatically, as a poorly designed access point may choose one of the off-limits channels.
* Some 2.4 GHz wifi access points can be configured to use 40 MHz of spectrum instead of the usual 20 MHz. If you see such an option in your access point, make sure it is configured to use 20 MHz,
not 40 MHz. This is to reduce the interference caused and received by the network. 40 MHz networks only work well in controlled areas where nothing else is using 2.4 GHz radio frequencies.
* To aid in choosing channels to run your networks on, you can download a wifi scanner app on your phone to get an idea of what other 2.4 GHz wifi networks are active in your area, and see what channels they are on. Note however that such apps are not perfect. They can't detect interference that is not from another wifi network. They can't tell you how "busy" each channel actually is. And typically they show 40 MHz networks as a 20 MHz network. So you really only see part of the picture, but part is better than nothing.
