LTE: Bearer Resource Modification Request

·        The purpose of the UE requested bearer resource modification procedure is for a UE to request a modification or release of bearer resources for a traffic flow aggregate or modification of a traffic flow aggregate by replacing or adding packet filters.

·        When requesting a modification of bearer resources for a traffic flow aggregate or a modification of a traffic flow aggregate, the UE can modify the existing GBR.

·        If the network accepts this procedure, it invokes a dedicated EPS bearer context activation, an EPS bearer context modification, or an EPS bearer context deactivation procedure.

·        If there is a PDN connection for emergency bearer services established, the UE shall not request a modification of bearer resources for this PDN connection.

·        In order to request the modification of bearer resources for one traffic flow aggregate, the UE shall send a BEARER RESOURCE MODIFICATION REQUEST message to the MME

·        The UE shall include the EPS bearer identity of the EPS bearer associated with the traffic flow aggregate in the EPS bearer identity for packet filter IE.

·        To request a change of the GBR without changing the packet filter(s), the UE shall set the TFT operation code in the Traffic flow aggregate IE to "no TFT operation" and include the packet filter identifier(s) to which the change of the GBR applies in the Packet filter identifier parameter in the parameters list.

·        The UE shall indicate the new GBR requested for the EPS bearer context in the Required traffic flow QoS IE.

·        To request a modification of a traffic flow aggregate, the UE shall set the TFT operation code in the Traffic flow aggregate IE to "Replace packet filters in existing TFT" or "Add packet filters to existing TFT".

·        If the TFT operation code is set to "Add packet filters to existing TFT", the UE shall include the existing packet filter identifier(s) to which the newly added packet filter(s) is linked in the parameters list.

·        To request a release of bearer resources, the UE shall set the TFT operation code in the Traffic flow aggregate IE to "Delete packet filters from existing TFT".

·     If the UE includes the Required Traffic Flow QoS IE, the UE shall set the QCI to the current QCI value of the EPS bearer context.

·        If the bearer resource modification requested is accepted by the network, the MME shall send ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST, MODIFY EPS BEARER CONTEXT REQUEST or DEACTIVATE EPS BEARER CONTEXT REQUEST message with a PTI which matches the value used for the BEARER RESOURCE MODIFICATION REQUEST message.

·        If the bearer resource modification requested cannot be accepted by the network, the MME shall send a BEARER RESOURCE MODIFICATION REJECT message to the UE.

Reference 3GPP TS 24.301

Example:  BEARER RESOURCE MODIFICATION REQUEST message