Advanced XGP (XGP standard version 3, revision 2)
XGP Forum has developed XGP version 3, revision 2 (XGP 3.2) in September 2015. XGP 3.2 describes new features based on 3GPP Release 12. It is more evolutional system which support some advanced technology including TDD-FDD Carrier Aggregation (TDD-FDD CA) and other features.
The new features can be categorized into 3 groups: General enhancements, Small cell related enhancements, and Radio service related enhancements. Each group includes some advanced features, which are listed on the following table. Key trend factors in XGP 3.2 are Wider Spectrum, Enhanced Small cells, Enhanced MIMO, Advanced Architecture and Enhanced Radio service.
As for TDD-FDD Carrier Aggregation, it enables joint usage of TDD and FDD spectrum at a UE to greatly improve user experience and system capacity. Two or more component carriers (including at least one TDD component carrier and one FDD component carrier) are aggregated for a UE where either TDD or FDD cell can be configured as PCell (Primary cell).
Fig: Relation between XGP 3.1 and XGP 3.2
Table: New feature list in XGP 3.2
|General enhancements||TDD-FDD Carrier Aggregation (CA)||Joint usage of TDD and FDD spectrum at a UE.
Either TDD or FDD cell can be PCell (Primary cell).
|Further Downlink MIMO Enhancements||Codebook & CSI enhancements to further improve 4TX performance.|
|Small Cell related enhancements||Small cell enhancements (SCE) -physical layer aspects||256QAM, Small cell on/off and discovery, Radio interface-based synchronization (RIBS).|
|Dual Connectivity (DC)||A UE can utilize radio resources in two distinct schedulers.|
|Hetrogeneous Network (HetNet) Mobility Enhancements||Improve the mobility performance in HetNet deployment.|
|Dynamic adaptation of UL:DL configuration (eIMTA)||Dynamically adjust TDD UL-DL configuration according to UL/DL traffic load ratio, interference management schemes.|
|Inter-eNB Coordinated Multipoint (e-CoMP)||Coordinated scheduling for the scenario of multiple eNodeBs with non-ideal backhaul connections.|
|RAN assisted WLAN interworking||E-UTRAN assisted UE based bi-directional traffic steering between E-UTRAN and WLAN for UEs.|
|Radio Service enhancements||ProSe (Proximity-based services)||ProSe Direct Discovery and ProSe Direct Communication between Ues.|
|MBMS Minimum Drive Test (MDT)||UE collects and report MBMS measurement to help the eNB MBMS operation.|
|Low Cost Machine Type Communication (MTC) Ues||Provides cost tailored terminals for the low-end UE market.|