Abstract: A method and apparatus are provided for managing session information of an access terminal (AT) that has moved from a source subnet to a target subnet in a mobile communication system for high-speed data transmission. The AT transmits a message with a prior universal access terminal identifier (UATI) to a target access network (AN) to perform session negotiation with the target AN of the target subnet. The target AN transmits a message with the prior UATI to a target packet control function (PCF) to request retrieval of session information of the AT. The target PCF sends a request for transmission of prior session information for the AT to a source PCF of the source subnet, found using the prior UATI. The target PCF receives the prior session information from the source PCF and retrieves the session information of the AT using the received prior session information.

Abstract: An apparatus and method for optimizing a data rate in a wireless communication system supporting Hybrid Automatic Repeat reQuest (HARQ) are provided. The method includes estimating Channel State Information (CSI) of a signal to be transmitted, by using other CSIs received in a previous cycle; determining an instantaneous data rate, at which the CSI is transmitted with an optimal data rate, and the amount of redundancy information to be retransmitted; and retransmitting the redundancy information of the signal according to the amount of redundancy information and the instantaneous data rate, if a receiving end requests signal retransmission. Accordingly, the packet can be transmitted with the optimal data rate.

Abstract: An apparatus and method for optimizing a data rate in a wireless communication system supporting Hybrid Automatic Repeat reQuest (HARQ) are provided. The method includes estimating Channel State Information (CSI) of a signal to be transmitted, by using other CSIs received in a previous cycle; determining an instantaneous data rate, at which the CSI is transmitted with an optimal data rate, and the amount of redundancy information to be retransmitted; and retransmitting the redundancy information of the signal according to the amount of redundancy information and the instantaneous data rate, if a receiving end requests signal retransmission. Accordingly, the packet can be transmitted with the optimal data rate.

Abstract: A method and apparatus are provided for managing session infonnation of an access tenminal (AT) that has moved from a source subnet to a target subnet in a mobile communication system for high-speed data transmission. The AT transmits a message with a prior universal access terminal identifier (UATI) to a target access network (AN) to perfonm session negotiation with the target AN of the target subnet. The target AN transmits a message with the prior UATI to a target packet control function (PCF) to request retrieval of session infonnation of the AT. The target PCF sends a request for transmission of prior session information for the AT to a source PCF of the source subnet, found using the prior UATI. The target PCF receives the prior session information from the source PCF and retrieves the session information of the AT using the received prior session information.

Abstract: An encryption processing system and method are provided in a mobile communication system having an AT, an AN for sending packet data to the AT on a radio channel, a PCF for controlling the AN, and a PDSN for sending packet data to the AN through the PCF. The AT encrypts a packet generated upon user request and sends the encrypted packet on a radio channel. If it is indicated that the packet received from the AT was encrypted, the AN requests encryption information of the AT to the PCF and decrypts the encryption information received from the PCF. Upon receipt of the request of the encryption information of the AT from the AN, the PCF determines whether the AT is authenticated, extracts the encryption information of the AT if the AT is authenticated, and sends the extracted encryption information to the AN.