enhanced prach for standalone contention-based communications including unlicensed spectrum

摘要

These are additional improvements in the design of enhanced eprach channel access procedures for communication systems having a contention-based shared spectrum including unlicensed frequency bands. Additional improvements relate to transmission uncertainty in pre-check (lbt) -based communication and cooperation with other radio access technologies competing for the same frequency spectrum. an evaluation of extended free channels in multiple subframes is performed by the eu, during which, in particular, the presence of channel reserve signals, such as cubs, is monitored. In the event of ecca / cca success, the type 2 random access preamble is transmitted before the subframe resynchronization threshold or the next subframe if it is no longer appropriate.