This post is in continuation of part of UE Capabilities post PART 1
In previous post we discussed about LTE UE capabilities with respect to 3GPP release 8, 9 and 10.
- UE capabilities were discussed in the following aspects:
- UE Category Types
- General Capabilities
- PDCP Related Information in UE Capability Information
- Physical Layer Capabilities in UE Capability Information
Now it's time to go further into UE Capability Information message and find out what additional details it contains as information elements
Optional RF Capabilities
The table below presents the RF capabilities included within the 'UE EUTRA Capability' information element.
Looking at the table above we can have the following observation.
- Supported E-UTRA Band List specifies a list of supported FDD and TDD operating bands using a specific numbering scheme. In addition a flag can be included to indicate that only half duple transmission/ reception is supported within a specific operating band. Other, support for full duplex transmission / reception is assumed.
- Supported band combination message structure allows a UE to signal up to 128 different band combinations, and include up to 64 bands within each combination. Each band included within a combination is identified by its band number, ranging from 1 to 64. Each band can have up to 16 sets of uplink parameters and up to 16 sets of downlink parameters.
- Each set of uplink parameters associated with a specific band defines the Carrier Aggregation bandwidth class (bandwidth classes of A,B,C,D,E or F). The uplink MIMO capability is also defined as either 2-layers or 4-layers
- Each set of downlink parameters associated with a specific band defines the Carrier Aggregation bandwidth class ( bandwidth classes of A,B,C,D,E or F). The downlink MIMO capability is also defined as either 2 layers, 4-layers or 8-layers.
Optional Measurement Capabilities
The table below represents measurement capabilities included within the 'UE EUTRA Capability' information element.
Optional Measurement capabilities parameters indicate whether or not the UE requires measurement gaps to be configured when completing inter-frequency or inter-RAT measurements. Measurement gaps may not be necessary if the UE has multiple receivers and is able to measure one RF carrier while receiving on another RF carrier.
- Inter-Frequency need for Gaps is specified for each supported operating band. The operating bands themselves are not listed explicitly as part of this capability information, instead the list of indications are ordered using the same operating band sequence as used for the 'Supported E-UTRA Band List' within the RF capabilities information.
- Inter-RAT Need for Gaps is specified for each supported operating band and for each supported radio access technology. The operating bands themselves are not listed explicitly as part of this capability information, but the list of indications are ordered using the same operating band sequence as provided within the inter-RAT capabilities information.
Release 10 UE also provide inter-frequency and inter-RAT ' need for gaps' information for each supported band combination.
optional inter-rat capabilities
The table below indicates the inter-RAT capabilities included within the 'UE EUTRA Capability' information element.
UE can signal its support for the following technologies
- UTRA FDD
- UTRA TDD 1.28 Mcps
- UTRA TDD 3.84 Mcps
- UTRA TDD 7.68 Mcps
- CDMA2000 HRPD
- CDMA2000 1xRTT
UEs do not use dedicated flags to signal their support for these technologies. Instead, UEs include a list of supported operating bands for each supported technology. This allows eNodeB to deduce which technologies are supported.
- UEs which support FDD or TDD UTRA also support packet switched inter-system handover from LTE to UTRAN.
- UEs which support GERAN use a separate flag to indicate whether or not packet switched inter-system handover from LTE to GERAN is supported.
- UE which support CDMA2000 HRPD or 1xRTT include additional flags to indicate support for either a single transmitter or dual transmitter. UEs equipped with a dual transmitter are able to simultaneously transmit on LTE and CDMA2000. Similarly, UEs which support CDMA2000 include an additional flag to indicate support for either a single receiver or dual receiver. UE equipped with a dual receiver are able to simultaneously receive on LTE and CDMA2000.
- In case of CDMA2000 include, UEs can signal its support for the enhanced CS Fallback procedure. This procedure makes CS fallback relatively seamless and avoids the requirement for an RRC connection release with re-direction. The enhanced CS fallback procedure tunnels handover signalling between the UE and the 1xRTT network. This allows the transition between radio access technologies to be handled as a handover rather than a release with re-direction.
- In case if UE can support CDMA2000 and HRPD simultaneously,then it can signal its support for enhanced CS falback to CDMA2000 1xRTT in combination with a concurrent packet switched handover to CDMA2000 HRPD.
- Enhanced Redirection to UTRA refers to the ability of the UE to receive FDD or TDD UTRA system information within the RRC Connection Release message sent from the LTE network. This avoids the UE having to acquire the system information after synchronising with the UTRA network, i.e. the UE can immediately establish its connection after being re-directed for CS fallback.
- The concept of enhanced-re-direction can also be applied to GERAN, i.e. UE is provided with GERAN system information within the RRC Connection Release message sent from the LTE network. Reference 3GPP TS 36.306
- Dual transfer Mode (DTM) parameter specifies whether or not the UE supports DTM for GERAN. DTM allows simultaneous transfer of CS and PS data on the same GERAN RF carrier
- Enhanced CS Fallback to CDMA200 with Dual Transmitter/Receiver is only applicable if the UE supports dual transmitter and dual receiver. This parameter indicates that UE can complete the enhanced CS fallback procedure using its dual transmitter/receiver.
- Enhanced Redirection to UTRA TDD introduced within release 10 version of 3GPP specificiations allows the LTE network to include a list of UTRA TDD RF carriers within the RRC Connection Release message for re-direction purposes. In addition, system information belonging to each of those UTRA TDD RF carriers can be included.
Optional closed subscriber group (CSG) Proximity capabilities
Table below includes the Closed Subscriber Group (CSG) proximity capabilities included within the ' UE EUTRA Capability ' information element.
- Proximity detection allows the UEs to inform the eNodeB when it enters or leaves the coverage of a CSG cell included within its whitelist. The UE uses a Proximity Indication message to specify the RF carrier belonging to the CSG cell and also to specify whether the UE is entering or leaving the coverage area.
- UEs are able to signal their support for intra-frequency, inter-frequency and UTRAN proximity detection. Support relies upon the UE having the ability to complete autonomous searches for CSG cells in its whitelist.
Optional Neighbor system information acquisition capabilities
Table below presents the neighbor system information acquisition capabilities included within the 'UE EUTRA Capability' information element.
- Neighbor system information acquisition involves the UE generating autonomous gaps to decode the system information from a neighboring cell. If supported, the eNodeB can request the UE to decode and report the Cell Global Identity (CGI) belonging to neighbouring cells. This information can be used when adding neighbor relations.
- UEs are able to signal their support for intra-frequency, inter-frequency and UTRAN system information acquisition.
Optional SON capabilities
Table below presents the Self Organizing Network (SON) capabilities included within the 'UE EUTRA Capability' information element.
- RACH reports can be included within the UE Information Response message. They allow UE to report the number of PRACH preambles transmitted for the most recent successfully completed random access procedure. They also allow the UE to report whether or not contention resolution was successful.
- UEs use a single flag to indicate their support for RACH reporting.
Optional UE based network performance measurement capabilities
Table below presents UE based network performance measurement capabilities included within the 'UE EUTRA Capability' information element.
- Logged measurement Idle capability can be used by the network for Minimisation of Drive Tests ( MDT). If you are not familiar with MDT, in simple words MDT functionality helps to reduce the requirement for drive testing by collecting measurements from the population of subscribers.
- UEs use a single flag to indicate their support for recording measurements in RRC Idle mode. RACH reporting. Remember 3GPP TS 36.306 specifies that UE which support these measurements must have a minimum of 64 kBytes of memory to record the measurements.
- UEs also use a single flag to indicate whether or not they are equipped with a Global Navigation Satellite System (GNSS) receiver that can be used to provide detailed location information when reporting measurements for MDT.
References: 3GPP TS 36.306, TS 36.331, LTE in Bullets