Wireless should be avoided when possible, wired is always best and more solid setup, however there are some good wireless solutions and the technology has improved a lot over recent years.
But unless some solar solution is setup, wireless still needs a wire for power, therefore it's not fully wireless and sometimes better to just do a data cable instead of just power.
However there are sometimes special setups that require wireless and can benefit from it, wireless does require good wireless router to have good signal, most wireless cameras don't have very strong wireless adapters although so wireless router should be strong.
