Random Access Procedure

Patent metadata

Field	Value
Publication number	US-2023180302-A1
Application number	US-202318101658-A
Country	US
Kind code	A1
Filing date	Jan 26, 2023
Priority date	Feb 15, 2018
Publication date	Jun 8, 2023
Grant date	—

Abstract

Embodiments include methods performed by a wireless device for random access to a wireless communications network. Such methods include transmitting a random access preamble in a first uplink (UL) bandwidth part (BWP) of a carrier and selecting a first downlink (DL) BWP of the carrier based on an association between the first UL BWP and the first DL BWP. Such methods include monitoring the first DL BWP for a random access response from the wireless communication network to the transmitted random access preamble. Other embodiments include complementary methods for a base station configured to support random access by wireless devices, as well as wireless devices and base stations configured to perform such methods.

First claim

1 . A method performed by a wireless device for random access to a wireless communications network, the method comprising:
transmitting a random access preamble in a first uplink (UL) bandwidth part (BWP) of a carrier; selecting a first downlink (DL) BWP of the carrier based on an association between the first UL BWP and the first DL BWP; and monitoring the first DL BWP for a random access response from the wireless communication network to the transmitted random access preamble.

2 . The method of claim 1 , wherein the first DL BWP is selected based on both the first UL BWP and the first DL BWP being associated with a first index.

3 . The method of claim 2 , wherein the first index identifies one or more DL BWPs, including the first DL BWP, on which a random access response will be transmitted by the wireless communication network in response to receiving a random access preamble transmitted using one or more of the following identified by the first index: a physical random access channel (PRACH) configuration, and random access resources.

4 . The method of claim 2 , wherein the first UL BWP is associated with a physical random access channel (PRACH) configuration identified by the first index.

5 . The method of claim 2 , wherein the random access preamble is transmitted using random access resources that are identified by the first index and that are in the first UL BWP.

6 . The method of claim 2 , wherein the random access preamble is included in a set of using random access preambles that are identified by the first index.

7 . The method of claim 1 , wherein:
the random access preamble is transmitted in random access resources that are associated with a plurality of UL BWPs, including the first UL BWP; and the method further comprises receiving the random access response in the first DL BWP based on the monitoring, wherein the random access response includes a plurality of grants of uplink resources in the respective plurality of UL BWPs.

8 . The method of claim 1 , wherein selecting the first DL BWP of the carrier is further based on one or more of the following:
the first DL BWP being an active DL BWP that the wireless device is configured to monitor for data reception; bandwidth capability of the wireless device; and random selection from among a plurality of DL BWPs associated with the first UL BWP.

9 . The method of claim 1 , further comprising, after monitoring the first DL BWP for a predetermined time period without receiving a random access response, selecting a second DL BWP of the carrier and monitoring the selected second DL BWP for a random access response from the wireless communication network, wherein the second DL BWP is selected based on one of the following:
an association between the first UL BWP and the second DL BWP, or the second DL BWP being an active DL BWP that the wireless device is configured to monitor for data reception.

10 . The method of claim 1 , further comprising monitoring an active DL BWP for data reception while monitoring the first DL BWP for the random access response.

11 . A wireless device configured for random access to a wireless communications network, the wireless device comprising:
transceiver circuitry configured to communicate with the wireless communications network; and processing circuitry operably coupled to the transceiver circuitry, whereby the processing circuitry and the transceiver circuitry are configured to perform operations corresponding to the method of claim 1 .

12 . A method performed by a base station of a wireless communication network to support random access by wireless devices to the wireless communication network, the method comprising:
receiving a random access preamble from a wireless device in a first uplink (UL) bandwidth part (BWP) of a carrier; selecting one or more downlink (DL) BWPs of the carrier based on an association between the first UL BWP and the one or more DL BWPs; and transmitting respective one or more random access responses to the wireless device in the one or more DL BWPs.

13 . The method of claim 12 , wherein the one or more DL BWPs are selected based on both the first UL BWP and the one or more DL BWPs being associated with a first index.

14 . The method of claim 13 , wherein the first index identifies one or more DL BWPs on which a random access response will be transmitted by the base station in response to receiving a random access preamble transmitted by a wireless device using one or more of the following identified by the first index: a physical random access channel (PRACH) configuration, and random access resources.

15 . The method of claim 13 , wherein the first UL BWP is associated with a physical random access channel (PRACH) configuration identified by the first index.

16 . The method of claim 13 , wherein the random access preamble is transmitted using random access resources that are identified by the first index and that are in the first UL BWP.

17 . The method of claim 13 , wherein the random access preamble is included in a set of using random access preambles that are identified by the first index.

18 . The method of claim 12 , wherein:
the random access preamble is received in random access resources that are associated with a plurality of UL BWPs, including the first UL BWP; and each particular random access response, transmitted in a particular DL BWP, includes a plurality of grants of uplink resources in the respective plurality of UL BWPs.

19 . The method of claim 12 , wherein receiving the random access preamble from the wireless device in the first UL BWP of the carrier comprises:
receiving, via beamforming, the random access preamble in a beam associated with a coverage area; and determining that the random access preamble was transmitted by the wireless device in the first UL BWP based on an association between the coverage area and the UL BWP.

20 . A base station configured to support random access by wireless devices to a wireless communication network, the base station comprising:
transceiver circuitry configured to communicate with the wireless devices; and processing circuitry operably coupled to the transceiver circuitry, whereby the processing circuitry and the transceiver circuitry are configured to perform operations corresponding to the method of claim 12 .

Assignees

• Ericsson Telefon Ab L M

Inventors

• Hofström Björn
• Christoffersson Jan
• Wang Min

Classifications

• H04W24/08 Primary

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04W72/542

  using measured or perceived quality · CPC title

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04W74/0838

  using contention-free random access [CFRA] · CPC title

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title