Variation of RACH preamble grouping

摘要

A base station may provide wireless service on an air interface that defines different mutually exclusive groups of random access channel (RACH) instances for different uses. In one example, the air interface may define a first group of RACH instances having groupings of preambles for designating a value of a characteristic, and define a second group of RACH instances that does not have groupings of preambles. As another example, the air interface may define a first group of RACH instances that has groupings of preambles for designating a value of a first characteristic, and define a second group of RACH instances that has groupings of preambles for designating a value of a second characteristic. The base station may then differentially handle random access requests based on whether the base station receives a preamble in a RACH instance of the first group or rather the second group.

主权项

1. A base station comprising:
a processor; and an antenna structure for providing wireless service on an air interface, the air interface defining a plurality of periodically recurring random access channel (RACH) instances for carrying random access requests from mobile terminals to the base station, wherein the plurality of RACH instances includes a first group of RACH instances and a second group of RACH instances, the first group of RACH instances and the second group of RACH instances being mutually exclusive, wherein the base station differentially handles random access requests from the mobile terminals based on whether the base station receives from a mobile terminal a preamble in a RACH instance of the first group of RACH instances or rather in a RACH instance of the second group of RACH instances, wherein: (i) if the base station receives the preamble in a RACH instance of the first group of RACH instances, then, based at least in part on the RACH instance in which the base station received the preamble having been in the first group of RACH instances rather than in the second group of RACH instances, the base station determines a characteristic of the mobile terminal based on which preamble the received preamble is, wherein the first group of RACH instances has multiple mutually exclusive groups of preambles, each group of the multiple groups corresponding with a respective value of the characteristic, and wherein determining the characteristic of the mobile terminal comprises determining a value of the characteristic based on which group of the multiple groups includes the received preamble; but (ii) if the base station receives the preamble in a RACH instance of the second group of RACH instances, then, based at least in part on the RACH instance in which the base station received the preamble having been in the second group of RACH instances rather than in the first group of RACH instances, the base station does not determine the characteristic of the mobile terminal based on which preamble the received preamble is.