Wireless Network's at the moment are not as reliable as Ethernet connections, there are many reasons why a wireless connection may fail and then reconnect, examples: microwave disruption (as you pointed out), where you are in the house. Wall, ceiling thickness between you and router causing signal dropout. Other local wireless connection's interfering with your's. Weather conditions, the list is almost endless. At the moment I believe we are using the 2.4GHz frequency range and now there are talks of using 5GHz range. Whatever range we use there will be interference.