Patent ID: 7315750

Claim:
An access network selecting method, which selects one from multiple access networks in a heterogeneous network environment for a mobile device capable of connecting with different access networks to accordingly establish a connection with a selected access network, the method comprising: a setup step, which records user configuration information including a requested bandwidth, a required signal quality for each access network and a weight that is set based on user preference for each access network in the mobile device; a collecting step, wherein the mobile device collects and records current status information including a signal quality and an available bandwidth of each access network; a stability coefficient determining step, wherein the mobile device determines a network stability coefficient for each access network based on the requested bandwidth, the required signal quality, the weight, the signal quality and the available bandwidth, such that the stability coefficient is zero when the available bandwidth is smaller than the requested bandwidth or the signal quality is smaller than the required signal quality, and otherwise the stability coefficient equals the weight; and an access network selecting step, wherein the mobile device selects an access network with a maximum network stability coefficient to thus establish a connection with the access network selected, wherein in the stability coefficient determining step, the network stability coefficient is determined as S(N i )=w i *s(N i ), where i is an integer from one to a total of access networks in the heterogeneous network environment, N i indicates i-th access network, w i indicates the weight of the access network N i , and s(N i ) indicates whether or not the access network N i meets user requirement that is defined as: s ⁡ ( N i ) = { 0 , if ⁢ ⁢ ( ( SNR ⁡ ( N i ) < SNR req ⁡ ( N i ) ) ⋁ ( BW res ⁡ ( N i ) < BW req ) ) 1 , otherwise , where SNR(N i ) indicates the signal quality of the access network N i , SNR req (N i ) indicates the requested signal quality of the access network N i , BW req indicates the requested bandwidth, and BW res (N i ) indicates the available bandwidth in the access network N i .