- PRACH optimization
is the pseudo-random sequence random code (preamble code). Optimization goal is to reduce the collision between the code and the code
Base station broadcasts a pseudo-random sequence code (e.g., 64), the selection of a transmission terminal. Different users use the same one yard will produce collisions. Co-frequency networking, the pseudo-random sequence code of the neighboring cell is the same, it will further increase the probability of collision. Random access indicators will be more poor.
- Initial contention based random access network
Preamble transmission code sent Shihai RA-RNTI (different channels have different RA-RNTI, for a few to several business, for several to several signaling protocol are clearly defined) random code, the base station returning a response and incidental under RA-RNTI to the UE, UE match the RA-RNTI is not their own.
3: code collision conflict resolution
4: code collision conflict resolution
- Non-contention based random access - dedicated preamble switch
The base station, Preamble codes assigned to the terminal directly, and other terminals do not need to grab.