×

Method and apparatus for random access in communications system

  • US 9,907,093 B2
  • Filed: 12/29/2015
  • Issued: 02/27/2018
  • Est. Priority Date: 12/29/2014
  • Status: Active Grant
First Claim
Patent Images

1. A method for a random access of a terminal in a communications system using at least one beam, the method comprising:

  • determining a random access preamble from a beam based preamble group and a cell based preamble group, respectively;

    if a random access preamble from the beam based preamble group is determined to be used, transmitting the determined random access preamble through a beam among the at least one beam; and

    if a random access response for the random access preamble is not received from a base station for a set interval, transmitting the determined random access preamble from another group through the beam,wherein the cell based preamble group includes random access preambles allocated in each cell, and the beam based preamble group includes random access preambles allocated in each beam,wherein the determining of the random access preamble from one group includes;

    if it does not correspond to any of exception cases, preferentially selecting the random access preamble from the beam based preamble group; and

    if it corresponds to any of the exception cases, selecting the new random access preamble from the cell based preamble group, andwherein the exception cases include;

    exception case 1, if a value of path-loss estimated from a reference signal of the base station is greater than a set reference value,exception case 2, if interference between a beam determined by the terminal and a neighboring beam of the base station is greater than a set reference value, andexception case 3, in the case in which restriction on latency of the terminal is higher than a set reference.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×