Packet forwarding device and wireless communication system

A packet forwarding device that performs forwarding of a packet between first and second wireless communication networks to which different identifiers are attached, the packet forwarding device comprising:

• a relay network that is interposed between the first and second wireless communication networks;
• a first processing unit that is connected to the first wireless communication network, the first processing unit performing first routing control by using first routing information in which the first wireless communication network and the relay network are defined as outgoing interfaces;
• and
• a second processing unit that is connected to the second wireless communication network, the second processing unit performing second routing control by using second routing information in which the second wireless communication network and the relay network are defined as outgoing interfaces.