In general, handover means a technology in which when a mobile node that is engaged passes a cell boundary of a corresponding base station and moves to a cell boundary of a neighboring base station, the mobile node automatically tunes with a new traffic channel of the neighboring base station and provides service, and the service is continuously maintained without being stopped even if the mobile node in a corresponding network region enters another network region at a different location.
Accordingly, in order to improve the quality of handover, packet loss needs to be maximally prevented, and the handover needs to be performed as fast as possible to minimize time in which the service is stopped.
The related art discloses handover being performed without an Internet protocol (IP) address when a mobile node moves between sub-nets, and service is continuously provided to the mobile node without performing an additional operation through a mobile Internet protocol (Mobile IPv4).
All network access devices are connected to one central router, which provides an access point with an external network. Accordingly, when the mobile node moves between the sub-nets, all new paths of packets toward the mobile node are controlled by the central router, and the mobile node is provided with service without a separate protocol even after the handover is performed. Since the mobile Internet protocol is not used, it is possible to reduce the delay that occurs due to the utilization of the Internet protocol, which continuously provides service to the mobile node.
Meanwhile, as another example of the related art relates to a method of performing handover of a portable access terminal having mobility in a portable Internet network, in which access information of the portable access terminal in a first base station access device and a first packet access router connected to each other is transmitted to a second packet access router and a second base station access device where the handover of the mobile node is performed. A tunnel is generated between the first packet access router and the second packet access router. Non-transmitted packets in the first base station access device are forwarded to the first packet access router, and are then forwarded to the second base station access device through the tunnel. The second base station access device forwards the received packets to the portable access terminal.
During the handover process, since the data transmission path is changed, data packets may be lost during the path change process. Different from a circuit-based voice service, in some cases packet loss in a packet system causes time delay due to re-transmission when a session is broken, or when a protocol such as a TCP having a re-transmission mechanism is used. As a result, service interruption time is lengthened.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
USPTO Backgrounds
USPTO Backgrounds