Random access method and apparatus

Abstract

Embodiments of the present invention provide a random access method and an apparatus. PRACH configuration information of is acquired, and a preamble is sent from a corresponding start PRACH resource. The solution includes: acquiring at least one group of physical random access channel PRACH configuration information carried in system information, parsing the at least one group of PRACH configuration information to obtain a corresponding start PRACH resource; and sending a preamble to a base station starting from the start PRACH resource.

What is claimed is: 
     
         1 . A random access method, comprising:
 acquiring at least one group of physical random access channel (PRACH) configuration information, wherein the at least one group of PRACH configuration information is carried in system information;   acquiring a start PRACH resource according to the at least one group of PRACH configuration information; and   sending a preamble to a base station starting from the start PRACH resource.   
     
     
         2 . The method according to  claim 1 , wherein content of the PRACH configuration information comprises a periodic time and/or a start position. 
     
     
         3 . The method according to  claim 1 , wherein
 each group of PRACH configuration information in the at least one group of PRACH configuration information is corresponding to a coverage enhancement level.   
     
     
         4 . The method according to  claim 3 , further comprises:
 determining corresponding PRACH configuration information according to a matched coverage enhancement level; and   the acquiring the start PRACH resource according to the at least one group of PRACH configuration information comprises:   acquiring the start PRACH resource according to the corresponding PRACH configuration information.   
     
     
         5 . The method according to  claim 4 , further comprises:
 calculating, according to downlink information, a path loss generated in a signal transmission process, and determining the matched coverage enhancement level according to the path loss.   
     
     
         6 . The method according to  claim 1 , further comprises:
 acquiring downlink resource information on a PDCCH according to an random access radio network temporary identifier (RA-RNTI);   receiving a random access response (RAR) according to a channel specified by descrambled downlink resource information; and   sending an msg3 according to a quantity of repetition times corresponding to a repetition times index carried on the RAR.   
     
     
         7 . The method according to  claim 6 , wherein the RA-RNTI satisfies
   RA-RNTI=1 +t _ id +10 *f _ id+X,      wherein, X is an offset that corresponds to a coverage enhancement level, t_id and f_id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent.   
     
     
         8 . The method according to  claim 1 , further comprises:
 quitting sending the preamble to the base station within a preset period of time.   
     
     
         9 . An apparatus, comprising:
 a memory storing program instructions; and   at least one processor coupled to the memory, wherein the program instructions, when executed by the at least one processor, cause the apparatus to:   acquire at least one group of physical random access channel (PRACH) configuration information, wherein the at least one group of PRACH configuration information is carried in system information;   acquire a start PRACH resource according to the at least one group of PRACH configuration information; and   send a preamble to a base station starting from the start PRACH resource.   
     
     
         10 . The apparatus according to  claim 9 , wherein content of the PRACH configuration information comprises a periodic time and/or a start position. 
     
     
         11 . The apparatus according to  claim 9 , wherein
 each group of PRACH configuration information in the at least one group of PRACH configuration information is corresponding to a coverage enhancement level.   
     
     
         12 . The apparatus according to  claim 11 , wherein the program instructions, when executed by the at least one processor, further cause the apparatus to:
 determine corresponding PRACH configuration information according to a matched coverage enhancement level; and   acquire the start PRACH resource according to the corresponding PRACH configuration information.   
     
     
         13 . The apparatus according to  claim 9 , wherein the program instructions, when executed by the at least one processor, further cause the apparatus to:
 acquire downlink resource information on a PDCCH according to an random access radio network temporary identifier (RA-RNTI);   receive a random access response (RAR) according to a channel specified by descrambled downlink resource information; and   send an msg3 according to a quantity of repetition times corresponding to a repetition times index carried on the RAR.   
     
     
         14 . The apparatus according to  claim 13 , wherein the RA-RNTI satisfies
   RA-RNTI=1 +t _ id +10 *f _ id+X,      wherein, X is an offset that corresponds to a coverage enhancement level, t_id and f_id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent.   
     
     
         15 . A non-transitory computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to:
 acquire at least one group of physical random access channel (PRACH) configuration information, wherein the at least one group of PRACH configuration information is carried in system information;   acquire a start PRACH resource according to the at least one group of PRACH configuration information; and   send a preamble to a base station starting from the start PRACH resource.   
     
     
         16 . The non-transitory computer-readable storage medium according to  claim 15 , wherein content of the PRACH configuration information comprises a periodic time and/or a start position. 
     
     
         17 . The non-transitory computer-readable storage medium according to  claim 15 , wherein
 each group of PRACH configuration information in the at least one group of PRACH configuration information is corresponding to a coverage enhancement level.   
     
     
         18 . The non-transitory computer-readable storage medium according to  claim 17 , wherein the instructions, when executed by the computer, further cause the computer to:
 determine corresponding PRACH configuration information according to a matched coverage enhancement level; and   acquire the start PRACH resource according to the corresponding PRACH configuration information.   
     
     
         19 . The non-transitory computer-readable storage medium according to  claim 15 , wherein the instructions, when executed by the computer, further cause the computer to:
 acquire downlink resource information on a PDCCH according to an random access radio network temporary identifier (RA-RNTI);   receive a random access response (RAR) according to a channel specified by descrambled downlink resource information; and   send an msg3 according to a quantity of repetition times corresponding to a repetition times index carried on the RAR.   
     
     
         20 . The non-transitory computer-readable storage medium according to  claim 19 , wherein the RA-RNTI satisfies
   RA-RNTI=1 +t _ id +10 *f _ id+X,      wherein, X is an offset that corresponds to a coverage enhancement level, t_id and f_id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent.