Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A method for encoding a status PDU including receiving AMD PDUs, determining whether or not there are missing AMD PDUs, calculating an error-checking range and at least one error-occurrence range if it is determined that there are missing PDUs, calculating a distance ratio using the error checking range and error occurrence range, determining whether or not the distance ratio is greater than or equal to a threshold value, selecting a type of super-field for constituting a status PDU based on a determination result, encoding the status PDU with the type of selected super-field, and sending the encoded status PDU to a sending party.

Abstract: A system and method for performing SRNS relocation in a communications system transmits radio resource information including a ciphering parameter from a source RNC to a target RNC, modifies the ciphering parameter to coincide with a deciphering parameter which a user terminal uses when out-of-sequence data is received, ciphers a data unit based on the modified ciphering parameter, and transmits the ciphered data unit from the target RNC to the user terminal. The method may be modified to operate in UM mode or AM mode and to transmit data over one of several radio bearers. In accordance with another embodiment, the system and method transmits radio resource information from a source RNC to a target RNC and then transmits a data unit from the target RNC to a user terminal. In this case, the data unit including a transmission sequence number which consecutively follows a transmission sequence number of a data unit last transmitted from the source RNC to the user terminal.

Abstract: A method for encoding a status PDU according to the present invention includes receiving AMD PDUs, determining whether or not there are missing AMD PDUs, calculating an error-checking range and at least one error-occurrence range if it is determined that there are missing PDUs, calculating a distance ratio using the error checking range and error occurrence range, determining whether or not the distance ratio is greater than or equal to a threshold value, selecting a type of super-field for constituting a status PDU based on a determination result, encoding the status PDU with the type of selected super-field, and sending the encoded status PDU to a sending party. The super-field constituting a status PDU may be selectively encoded using a LIST or RLIST coding algorithm depending on the type of error-occurrence pattern detected, which may include a blue-noise-type or a white-noise-type pattern.