RA41215EN30GLA0 Bearer Management 1 RA41215EN30GLA0 Bearer Management 4 RA41215EN30GLA0 Bearer Management 5 RA41215EN30GLA0 Bearer Management 6 RA41215EN30GLA0 Bearer Management 7 RA41215EN30GLA0 Bearer Management 8 RA41215EN30GLA0 Bearer Management 9 RA41215EN30GLA0 Bearer Management 10 RA41215EN30GLA0 Bearer Management 11 RA41215EN30GLA0 Bearer Management 12 RA41215EN30GLA0 Bearer Management 13 RA41215EN30GLA0 Bearer Management 14 RA41215EN30GLA0 Bearer Management 15 "Signalling Radio Bearers" (SRBs) are defined as Radio Bearers (RB) that are used only for the transmission of RRC and NAS messages. More specifically, the following three SRBs are defined: -SRB0 is for RRC messages using the CCCH logical channel; -SRB1 is for RRC messages (which may include a piggybacked NAS message) as well as for NAS messages prior to the establishment of SRB2, all using DCCH logical channel; -SRB2 is for NAS messages, using DCCH logical channel. SRB2 has a lower-priority than SRB1 and is always configured by E-UTRAN after security activation. Default bearer is created at attach > fast access to services Additional default bearers may be created when simultaneous access toservices available via multiple APNs is needed Creation of an additional dedicated bearer is initiated by UE -> max 1 DRB per UE supported in RL10 Default bearers are always non-GBR bearers Dedicated bearers (non-GBR or GBR) are created for QoS differentiationpurposes The IP address allocated for the default bearer is used for the dedicated bearers within the same PDN connection Creation of a dedicated bearer is initiated by network RL10 only non-GBR dedicated bearers For each EPS bearer (default and dedicated), QoS support is based onQoS parameters Available in subscriber profile Controllable by the network RA41215EN30GLA0 Bearer Management 16 Default bearer is created at attach > fast access to services Additional default bearers may be created when simultaneous access toservices available via multiple APNs is needed Creation of an additional dedicated bearer is initiated by UE -> max 1 DRB per UE supported in RL10 Default bearers are always non-GBR bearers Dedicated bearers (non-GBR or GBR) are created for QoS differentiationpurposes The IP address allocated for the default bearer is used for the dedicated bearers within the same PDN connection Creation of a dedicated bearer is initiated by network RL10 only non-GBR dedicated bearers For each EPS bearer (default and dedicated), QoS support is based onQoS parameters Available in subscriber profile Controllable by the network RA41215EN30GLA0 Bearer Management 17 RA41215EN30GLA0 Bearer Management 18 qciSupp in structure qciTab9 must be set to 'ENABLED' if actNonGbrServiceDiff is set to 'false' RA41215EN30GLA0 Bearer Management 19 RA41215EN30GLA0 Bearer Management 20 RA41215EN30GLA0 Bearer Management 21 RA41215EN30GLA0 Bearer Management 22 The support of EPS bearers with QCI=1 can be enabled / disabled per eNB via O&M. RA41215EN30GLA0 Bearer Management 23 RA41215EN30GLA0 Bearer Management 24 RA41215EN30GLA0 Bearer Management 25 RA41215EN30GLA0 Bearer Management 26 RA41215EN30GLA0 Bearer Management 27 RA41215EN30GLA0 Bearer Management 28 RA41215EN30GLA0 Bearer Management 29 RA41215EN30GLA0 Bearer Management 30 RA41215EN30GLA0 Bearer Management 31 RA41215EN30GLA0 Bearer Management 32 RA41215EN30GLA0 Bearer Management 33 For details regarding the context see RFC 4164 - RObust Header Compression (ROHC): Context Replication Base context. A base context is a context that has been validated by both the compressor and the decompressor. The compressor can use a base context as the reference when building a new context using replication. Base CID (BCID) The Base Context Identifier is the CID used to identify the base context, from which information needed for context replication can be extracted. Context replication Context replication is the mechanism that initializes a new context based on another already existing context (a base context). Context replication allows some header fields, such as the IP source and/or destination addresses (16 octets each for IPv6), to be omitted within the special Initiation and Refresh (IR) packet type specifically defined for replication. It also allows other fields, such as source and/or destination ports, to be either omitted or sent in a compressed form from the very first packet of the header compressed flow. The compressor performs context replication by reusing or creating a copy of an existing context, i.e., a base context, to create the replicated context. The replicated context is then updated to match the header fields of the new flow. The compressor then sends to the decompressor a packet that contains a reference to the selected base context, along with some data for the fields that need to be updated when creating the replicated context. Finally, the decompressor creates the replicated context based on the reference to the base context along with the uncompressed and compressed data from the received packet.