Uplink and downlink in lte full#

Radio-Electronics, LTE FDD, TDD, TD-LTE Duplex Schemes,, Available:

LTE-U Forum, 'LTE-U Technical Report Coexistence Study for LTE-U SDL', LTE-U Forum Companies, V1.0, Feb. 3GPP TSG, 'Evolved Universal Terrestrial Radio Access User Equipment radio transmission and reception (Release 14)', 3GPP, Valbonne, France, 3GPP TS 36.101 V14.1.0, Sept. 2016. The below table lists Time Division Duplex LTE bands, compiled from 3GPP 36.101 (Rel 14 September 2016). Like all unlicensed band LTE technologies, V2X operates Band 47 only in carrier aggregation with the operator's licensed band. Cellular V2X (C-V2X) may require the use of unlicensed bands to solve regulatory issues related to LTE-Direct, where devices broadcast directly to nearby devices. The increasing asymmetric demand for downlink data has also resulted in the introduction of Band 46, a downlink-only Supplemental DL band operating in the 5 GHz U-NII frequency range.īand 47 has been introduced for applications such as Vehicle to Everything (V2X) communications, which is positioned in the U-NII-3 5 GHz unlicensed band. The below table lists Frequency Division Duplex LTE bands, compiled from 3GPP 36.101 (Rel. Supplemental DL bands 252 and 255 have been included as part of the LTE-U expansion into unlicensed 5 GHz bands U-NII-1 and U-NII-3, respectively. The continuing evolution of carrier aggregation has resulted in several new bands added, including B29, B32, B67, and B69 used for downlink-only carrier aggregation, termed Supplemental DL bands. However, transmission timing must be synchronised between base stations, introducing complexity, along with guard periods being required between DL and UL subframes, which reduces capacity. UL/DL capacity can also be dynamically adjusted to match demand simply by devoting more airtime to one over the other. By comparison, deploying TDD requires less spectrum as well as eliminating then need for guard bands permitting a more efficient stacking of spectrum. While less efficient and more electrically complex to deploy, FDD tends to be more commonly deployed by operators due to refarming of existing 3G spectrum arrangements.

Uplink and downlink in lte full#

In order to achieve high data rates, LTE operates full duplex whereby both downlink (DL) and uplink (UL) communication takes place simultaneously by separating DL and UL traffic either by frequency (i.e., FDD), or time periods (i.e., TDD). LTE has been developed to operate on paired spectrum for Frequency Division Duplex (FDD), and unpaired spectrum for Time Division Duplex (TDD).įor an LTE radio system to facilitate bidirectional communication, it is necessary to implement a duplex scheme so that a device may transmit and receive without collision.