Decision-For-Network-Access-Control
(1)  
(2)  
(3)  If is bad then
(4) If is high then
(5)  If is unstable then
(6)   Find another WiFi
(7)  End if
(8) Else if is normal then
(9)  If is stable then
(10)   If then
(11)   Find another WiFi
(12)   Else
(13)    Find another WiFi and then migrate to the WiFi
(14)   End if
(15)  Else
(16)   If then
(17)    Use cellular and WiFi simultaneously until the buffer meets THRD_M
(18)   Else
(19)    Use cellular and WiFi simultaneously until the buffer meets THRD_H
(20)   End if
(21)  End if
(22) Else if is low then
(23)  If is stable then
(24)   If then
(25)    Use cellular and WiFi simultaneously until the buffer meets THRD_H
(26)   Else
(27)    Find another WiFi and then migrate to the WiFi
(28)    Or transfer to cellular
(29)   End if
(30)  Else
(31)   If then
(32)    Find another WiFi and then migrate to the WiFi
(33)    Or transfer to cellular
(34)   Else
(35)    Transfer to cellular
(36)   End if
(37)  End if
(38) End if
(39)  End if
Algorithm 2: Decision algorithm for network access control: bad WiFi status.