Everybody is currently talking about the upcoming 5G era but during this race to get to 5G, we should not forget about the evolution of LTE that’s taking place. One of the main reasons for this is the potential 5G requirement to have tight integration with the evolved LTE. With Rel-13 of 3GPP standards getting frozen a new step has been taken in the evolution of LTE, under the name of “LTE-Advanced Pro”.
LTE-Advanced Pro: What is it?
LTE-Advanced Pro is a new marker for LTE starting with Rel-13 onwards. According to 3GPP, “the new term is intended to mark the point in time where the LTE platform has been dramatically enhanced to address new markets as well as adding functionality to improve efficiency” . Some of the main features for initial LTE-Advanced Pro release are summarized below.
LTE-Advanced Pro Rel-13 features
The first release of LTE-Advanced Pro was frozen in March 2016. It was brought to reality with quite extensive set of new functionalities as compared to LTE-Advanced. They are summarized below.
Massive CA - extends carrier aggregation towards higher number of aggregated bands and towards the use of unlicensed spectrum for mobile networking. Massive CA enables up to 32CCs and thus theoretically provides up to 640MHz of aggregated bandwidth for a single device, while still fulfilling backwards compatibility with LTE Rel-8 channel bandwidths.
Dual Connectivity (DC) – spectrum aggregation in inter-site scenario, where a macro-cell serves as a mobility anchor, whereas the additional radio link provided by Small Cell acts as a local capacity booster. DC enables to switch User Plane links among available SCs, whereas the user’s context is maintained by the overlay macro-cell. In contrary to CA, DC scheme, instead of aggregating MAC layer transport blocks, the PDCP Packet Data Units are combined, thus omitting the requirement for low latency and allowing non-ideal backhaul for Small Cell connectivity.
Indoor positioning – improvements for location performance (especially for emergency calls) using WiFi, collaborative positioning and beacon systems.
LTE-WLAN Aggregation (LWA) - the Carrier Wi-Fi serves as a capacity booster, using radio level integration for uniform user experience provisioning over the Wi-Fi radio. In LWA, UE is configured by the eNB to utilize radio resources of both, LTE and WLAN.
Licensed Assisted Access (LAA) - aggregates the licensed LTE carrier (serving as a mobility and signaling anchor - PCell) with SCell using the new LTE frame format over the unlicensed 5GHz ISM band.
Device-to-device (D2D) - direct communication between devices assisted by network utilizing sidelink using new
transport and physical channels.
MTC enhancements – addressing low complexity MTC with focus to define a low complexity UE category type that supports reduced bandwidth (operation with 1.4MHz), reduced transmit power, reduced support for downlink transmission modes, ultra-long battery life via power consumption reduction techniques and extended coverage operation (up to 15dB). Additionally, NB-IoT has been specified as a modified LTE interface for even lower channel bandwidth for the operation in 180kHz spectrum chunks.
3D/Full Dimension-MIMO - allows to use elevation beamforming enhancing the horizontal beam steering, and using up to 64 antenna ports with further outlook towards high frequencies for 5G.
You can also learn more on Grandmetric's blog and in the recent book from Moe Rahnema and Marcin Dryjanski: