Handoff system and method among heterogeneous networks and mobile terminal employing the same

A handoff system among heterogeneous networks, comprising:

• plural access nodes which support wireless communication with a mobile terminal, and comprises first and second access nodes, the mobile terminal being connected to the first access node;
• a crossover node which is connected to the plural access nodes, and reserves resources of the second access node which the crossover node selects from among the plural access nodes for a handoff of the mobile terminal from the first access node if a request signal for the handoff is received from the mobile terminal;
• and
• a mobile terminal configured to generate the handoff request signal for the handoff which initiates selecting of the second access node by the crossover node,
• wherein the mobile terminal creates an access node list comprising accessible access nodes, including the second access node, that are available for the handoff, and send the access node list to the crossover node separately from the handoff request signal or as a part of the handoff request signal,
• wherein the crossover node is configured to select the second access node if the second access node satisfies a predetermined condition,
• wherein the crossover node is further configured to receive from the mobile terminal at least one of an identification (ID) of the mobile terminal and the predetermined condition,
• wherein the predetermined condition comprises at least one of wireless communication quality and a network bandwidth, and
• wherein the crossover node is further configured to select, among the plural access nodes, a third access node to which the handoff of the mobile terminal is to be made from the first access node without sending a selection failure notice to the mobile terminal, if the second access node is determined to be still inappropriate for the handoff.