modem to provide a data communication connection to a corresponding type of telephone line as another example communication interface 518 may be a local area network lan card to provide a data communication connection to a compatible lan wireless links may also be implemented in any such implementation communication interface 518 sends and receives electrical electromagnetic or optical signals that carry digital data streams representing various types of information network link 520 typically provides data communication through one or more networks to other data devices for example network link 520 may provide a connection through local network 522 to a host computer 524 or to data equipment operated by an internet service provider isp 526 isp 526 in turn provides data communication services through the worldwide packet data communication network now commonly referred to as the u201c internet u201d 528 local network 522 and internet 528 both use electrical electromagnetic or optical signals that carry digital data streams the signals through the various networks and the signals on network link 520 and through communication interface 518 which carry the digital data to and from wireless device 500 are example forms of carrier waves transporting the information wireless device 500 can send and receive messages through the network s network link 520 and communication interface 518 in the internet example a server 530 might transmit a requested code for an application program through internet 528 isp 526 local network 522 and communication interface 518 the received code may be executed by processor 504 as it is received and.