Patent ID: 7239890

Claim:
A wireless communication network system comprising: a wireless communication terminal that includes: antenna means for receiving signals based on plural wireless network standards; transmitting/receiving means for receiving the signals from said antenna means; switching means for switching the wireless network standards of the signals received by said transmitting/receiving means to one another; reception level judging means for judging the reception level of each of the signals received by said transmitting/receiving means in the priority order of the wireless network standards from the highest-priority wireless network standard to the lowest-priority wireless network standard in the plural wireless network standards; and control means for judging, on the basis of the judgment result of the reception level by said reception level judging means, whether it is possible to carry out communications based on any one of the plural wireless network standards, and controlling the switching operation of said switching means so that the communications based on the highest-priority wireless network standard can be carried out; and a wireless base station which is capable of making communications based on the plural wireless network standards with said wireless communication terminal, and communicates with said wireless communication terminal on the basis of one of the plural wireless network standards, wherein when a problem occurs in the communications based on one of the plural wireless network standards between said wireless base station and said wireless communication terminal, said wireless base station transmits to said wireless communication terminal a shift command for shifting to communications based on another wireless network standard, and when the problem can be overcome, said wireless base station transmits to said wireless communication terminal a return command for returning to the communications based on the one of wireless network standards.