A cognitive wireless system for a mobile node, the mobile node to operate dynamically among heterogeneous networks, the heterogeneous networks comprising: at least a first network with communications characteristics and a second network with different communications characteristics, the cognitive wireless system comprising: (a) the mobile node associated with a user thereof, having a policy to select to use said first network as a default; (b) said mobile node having an associated application with a communications link requirements and traffic to exchange with another node; (c) wherein said mobile node monitors at least one of its contextual factors of (i) link assessment factor associated with said first network and link assessment factor associated with said second network, (ii) (ii) environmental factor, (iii) (iii) application factor, and (iv) (iv) cost factor; characterized in that (d) said mobile node has a link selector that operates in real time on said monitored contextual factor(s), and selects said second network to use as the communications link to exchange traffic on, instead of said first network based on superior characteristic(s) of said monitored contextual factor(s) of said second network compared to those of said first network, according to said policy that relates said contextual factors as a combination of factors that are differentially weighted for optimal performance of said first mobile node among the heterogeneous networks. at least a first network with communications characteristics and a second network with different communications characteristics, the cognitive wireless system comprising: (a) the mobile node associated with a user thereof, having a policy to select to use said first network as a default; (b) said mobile node having an associated application with a communications link requirements and traffic to exchange with another node; (c) wherein said mobile node monitors at least one of its contextual factors of (i) link assessment factor associated with said first network and link assessment factor associated with said second network, (ii) (ii) environmental factor, (iii) (iii) application factor, and (iv) (iv) cost factor; characterized in that (d) said mobile node has a link selector that operates in real time on said monitored contextual factor(s), and selects said second network to use as the communications link to exchange traffic on, instead of said first network based on superior characteristic(s) of said monitored contextual factor(s) of said second network compared to those of said first network, according to said policy that relates said contextual factors as a combination of factors that are differentially weighted for optimal performance of said first mobile node among the heterogeneous networks. (a) the mobile node associated with a user thereof, having a policy to select to use said first network as a default; (b) said mobile node having an associated application with a communications link requirements and traffic to exchange with another node; (c) wherein said mobile node monitors at least one of its contextual factors of (i) link assessment factor associated with said first network and link assessment factor associated with said second network, (ii) (ii) environmental factor, (iii) (iii) application factor, and (iv) (iv) cost factor; (i) link assessment factor associated with said first network and link assessment factor associated with said second network, (ii) (ii) environmental factor, (iii) (iii) application factor, and (iv) (iv) cost factor; (d) said mobile node has a link selector that operates in real time on said monitored contextual factor(s), and selects said second network to use as the communications link to exchange traffic on, instead of said first network based on superior characteristic(s) of said monitored contextual factor(s) of said second network compared to those of said first network, according to said policy that relates said contextual factors as a combination of factors that are differentially weighted for optimal performance of said first mobile node among the heterogeneous networks.