Network connection control method and apparatus of mobile terminal

Abstract

A network connection control method and apparatus of a mobile terminal maintains or releases connection to a wireless network based on the existence of downlink traffic from the wireless network. The method preferably includes connecting to a wireless network transmitting a signal greater than a predetermined value in strength when an Internet access request is detected; requesting the connected wireless network for traffic; determining whether the traffic is received from the connected wireless network; and releasing the connection to the wireless network by determining the wireless network as an idle wireless network when no traffic is received. The determination as to whether to maintain or release the connection to the currently connected WLAN based on whether actual traffic is received from the WLAN. When the mobile terminal is connected to an Access Point not coupled to the Internet, the mobile terminal immediately switches the connection to a cellular network.

What is claimed is: 
     
         1 . A network connection control method of a mobile terminal, comprising:
 detecting, by the mobile terminal, a request to access the Internet and connecting to a wireless network via an external device;   requesting a traffic to the external device;   determining whether the traffic is received from the external device; and   releasing the connection to the wireless network if no traffic is received within a predetermined amount of time.   
     
     
         2 . The network connection control method of  claim 1 , wherein the releasing steps comprises:
 determining the wireless network as an idle network; and   registering an identifier of the idle network with an idle network list.   
     
     
         3 . The network connection control method of  claim 2 , wherein the connecting to the wireless network comprises:
 selecting for connection a candidate wireless network having a highest received signal strength by measuring received signal strengths of discovered wireless networks;   determining whether the candidate wireless network is contained in the idle network list; and   stopping connection to the candidate wireless network, if the candidate wireless network is contained in the idle network list.   
     
     
         4 . The network connection control method of  claim 2 , wherein a network connection controller of the mobile terminal attempts connection to a candidate wireless network prior to the mobile terminal determining that the candidate wireless network is contained in the idle network list, and stopping attempted connection to the candidate wireless network when the mobile terminal determines the candidate wireless network is not on the idle network list. 
     
     
         5 . The network connection control method of  claim 4 , further comprising beginning connection to another candidate network having next highest received signal strength after stopping connection to the candidate wireless network. 
     
     
         6 . The network connection control method of  claim 1 , wherein determining comprises:
 determining, when a signal strength received from the connected wireless network is equal to or greater than a predetermined signal strength, that the wireless network comprises an active network coupled to the Internet and maintaining the connection to the wireless network.   
     
     
         7 . The network connection control method of  claim 6 , wherein determining comprises:
 measuring a time duration until traffic is received from the connected wireless network when a signal strength received from the wireless network is less than a predetermined signal strength; and   determining the wireless network as an active network connected to the Internet and maintaining the connection to the wireless network, when the measured time duration is less than a predetermined time.   
     
     
         8 . The network connection control method of  claim 7 , wherein determining comprises:
 measuring a data rate of payload of Internet Protocol (IP) packets in Transmission Control Protocol/Internet Protocol (TCP/IP) level, when the measured time duration is equal to or greater than a predetermined time; and   determining the wireless network as an active network connected to the Internet and maintaining the connection to the wireless network, when the measured data rate is equal to or greater than a predetermined value.   
     
     
         9 . The network connection control method of  claim 8 , wherein determining comprises:
 determining the wireless network as an idle network not connected to the Internet and releasing the connection to the wireless network, when the measured data rate is less than a predetermined value.   
     
     
         10 . The network connection control method of  claim 2 , further comprising discovering another wireless network and connecting to said another wireless network after releasing the connection to the idle network. 
     
     
         11 . A mobile terminal comprising:
 a wireless network unit for discovering wireless networks and connecting to a wireless network via an external device, if an Internet access request is input; and   a control unit configured to:   send a traffic request;   determine whether the traffic is received from the external device; and   release, if no traffic is received within a predetermined amount of time, the connected wireless network.   
     
     
         12 . The mobile terminal of  claim 12 , wherein the control unit determines the connected wireless network comprises an idle network. 
     
     
         13 . The mobile terminal of  claim 12 , further comprising a storage unit which stores an idle network list containing identifiers of the idle networks. 
     
     
         14 . The mobile terminal of  claim 13 , wherein the control unit controls the storage unit to store an identifier for each of the idle network. 
     
     
         15 . The mobile terminal of  claim 13 , wherein the control unit selects a candidate wireless network having a highest received signal strength by comparing received signal strengths of discovered wireless networks, determining whether the candidate wireless network is contained in the idle network list, and stops one of connection with the candidate wireless network or a connection process to the candidate wireless network, if the candidate wireless network is contained in the idle network list. 
     
     
         16 . The mobile terminal of  claim 12 , wherein the control unit determines, when a signal strength received from the connected wireless network is equal to or greater than a predetermined signal strength, that the wireless network is an active network coupled to the Internet and maintains the connection to the wireless network. 
     
     
         17 . The mobile terminal of  claim 16 , wherein the control unit measures, when a signal strength received from the connected wireless network is less than a predetermined signal strength, a time duration until traffic is received from the connected wireless network; and determines, when the measured time duration is less than a predetermined time, that the wireless network is an active wireless network coupled to the Internet and maintains the connection to the wireless network. 
     
     
         18 . The mobile terminal of  claim 17 , wherein the control unit measures, when the measured time duration is equal to or greater than a predetermined time, a data rate of payload of Internet Protocol (IP) packets in Transmission Control Protocol/Internet Protocol (TCP/IP) level; and determines, when the measured data rate is equal to or greater than a predetermined value, that the wireless network is an active network connected to the Internet and maintains the connection to the wireless network. 
     
     
         19 . The mobile terminal of  claim 18 , further comprising a cellular network module for supporting connection to a cellular network, wherein the control unit determines, if the measured data rate is less than a predetermined value, that the wireless network is an idle network not connected to the Internet and releases the connection to the wireless network.