US 9,426,828 B1Granted

Variation of RACH preamble grouping

AssigneeSprint Spectrum L.P.

InventorsJasinder P. Singh, Siddharth S. Oroskar, Maulik K. Shah

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Abstract

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.

Claims17

Dependent claims

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.

3 more elements

A method comprising:

providing, by a cellular base station, 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;
receiving, by the cellular base station, a preamble transmitted from a given mobile terminal in a particular RACH instance of the first group of RACH instances or the second group of RACH instances;
determining, by the cellular base station, whether the particular RACH instance is in the first group of RACH instances or rather is in the second group of RACH instances;
based on the determination of whether the particular RACH instance is in the first group of RACH instances or rather is in the second group of RACH instances, making, by the cellular base station, a decision of whether to determine a characteristic of the mobile terminal based at least in part on the received preamble;
and
if the cellular base station decides to determine the characteristic of the mobile terminal, then the cellular base station determining the characteristic of the mobile terminal based on which preamble the received preamble is, but if the cellular base station decides not to determine the characteristic of the mobile terminal, then the cellular base station not determining the 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.

4 more elements

A method comprising:

detecting, by a mobile terminal, coverage of a base station, wherein the base station provides 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,
making, by the mobile terminal, a decision of whether to designate a characteristic of the mobile terminal when seeking access to the base station;
and
if the decision is to designate the characteristic of the mobile terminal when seeking access to the base station, then the mobile terminal selecting a preamble based at least in part on the characteristic of the mobile terminal and transmitting the selected preamble in a RACH instance of the first group of RACH instances rather than in a RACH instance of the second group of RACH instances, but if the decision is not to designate the characteristic of the mobile terminal, then the mobile terminal transmitting any preamble in a RACH instance of the second group of RACH instances,
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 selecting the preamble based at least in part on the characteristic of the mobile terminal comprises:
based on a value of the characteristic of the mobile terminal, selecting one of the multiple groups of preambles, and
selecting the preamble from the preambles of the selected group of preambles.

5 more elements

Dependencies are inferred from the claim text.