Institute for Information Industry

Tsinghua University

Whai-En Chen

Chin-Liang Wang

Phone Lin

Chun-Yen Hsu

Chia-Peng Lee

Chun-Chieh Chiu

Chiu-Wen Chen

Chih-Wei Su

Bo-En Chen

A network address translation traversal system and method for real-time communications are provided. The network address translation traversal system includes a user terminal equipment, a network address translation device, a signaling control system and a peer terminal. The user terminal equipment is in a private network, while the signaling control system and the peer terminal are in a public network. The signaling control system is configured to instruct the network address translation device to create a network address translation mapping for a real-time communication connection. The peer terminal is configured to create the real-time communication connection with the user terminal equipment via the network address translation device directly according to the network address translation mapping.

Network address translation traversal system and method for real-time communications

A communication network system, a calling terminal and a voice call establishing method thereof are provided. The communication network system comprises a called terminal, the calling terminal and a session initiation protocol (SIP) server. The calling terminal generates and transmits an invite message including IPv4 connection information and IPv6 connection information of the calling terminal. The SIP server is communicatively connected to the calling terminal and the called terminal. The SIP server receives the invite message from the calling terminal and forwards the invite message to the called terminal. The called terminal establishes a voice call with the calling terminal according to one of the IPv4 connection information and the IPv6 connection information of the calling terminal.

Communication network system, calling terminal and voice call establishing method thereof

A transmission system and a transmission method for network address translation traversal are provided. The transmission system includes a private network device, a network address record device, a public network device and a network address translation server. The network address record device records an inner network address of the private network device and an outer network address corresponding to the inner network address. The public network device inquires the inner network address of the private network device and the outer network address corresponding to the inner network address from the network address record device, and generates a packet according to the inner network address and the outer network address corresponding to the inner network address. The network address translation server receives the packet from the public network device, and transmits the packet to the public network device.

Transmission system and method for network address translation traversal

A method for reducing the handover frequency by a communication device in femtocell networks includes the steps: measuring the radio signal strength by a communication device and storing the information of the serving base station into a cache memory; checking whether the stored information in the cache memory is classified as 'femtocell' or not; if so, deleting the macrocell's information from the measurement report by the communication device and transmitting this to the serving base station; when the radio link failure occurred, checking whether the stored information in the cache memory is classified as 'femtocell' or not; if so, initiating a timer; detecting an available femtocell before the timer expires; transmitting a call reestablishment request message to the available femtocell for rebuilding the link.

Method for reducing the handover frequency by a communication device in femtocell networks

A method for reducing the handover frequency by a femto gateway in femtocell networks includes the steps: receiving a measurement report from a communication device by an initial femtocell; transmitting a relocation required message to a femto gateway by the initial femtocell if the signal strength thereof is below a threshold; ignoring the relocation required message and enabling the timer by the femto gateway after receiving the relocation required message; determining whether the cell ID included in the call reestablishment request message is classified as 'femtocell' or not by the femto gateway before the timer expires; if so, rebuilding the link to the femtocell in response to the cell ID by the femto gateway.

Growing community of inventors

Yilan, Taiwan

Whai-En Chen