| 摘要 |
A contention-free activation/deactivation mechanism in PRACH, which allows dynamic allocation of the contention-free and contention-based preambles. This allows contention-free preambles which have been allocated to a UE to be revoked once contention-free operation is no longer needed, or cannot be supported due to a shortage of preambles. In one embodiment, a terminal is configured (S12) with a contention-free preamble by specific signalling, and thereafter monitors periodic broadcasts (S14) indicating the set of contention-free preambles; if the configured preamble is within the set (S16, "Y"), the preamble is activated for contention-free operation (S18); otherwise (S16, "N"), the preamble is deactivated and the terminal should follow the contention-based procedure (S20). |
