Random access in dynamic and shared spectrums

Patent metadata

Field	Value
Publication number	US-2016249384-A1
Application number	US-201615147274-A
Country	US
Kind code	A1
Filing date	May 5, 2016
Priority date	Feb 24, 2012
Publication date	Aug 25, 2016
Grant date	—

Abstract

Systems and methods for using a communication system in a spectrum are provided. For example, a random access or RACH procedure may be performed where the random access or RACH procedure may be configured to reduce secondary interference and/or to be used in a pixel-based environment. The random access or RACH procedure may include selecting a RACH preamble; sending a RACH preamble and/or format information; determining a transmission power of the RACH preamble and/or the format information; determining a random access radio network temporary identifier (RA-RNTI) and preamble ID associated with the RACH preamble; and/or selecting a physical RACH (PRACH).

First claim

What is claimed:

1 . A method for configuring a random access channel (RACH) procedure used by a wireless transmit/receive unit (WTRU) in a communication system, the method comprising:
determining whether a secondary user is present in an operating channel; and performing a RACH procedure based on the determination, wherein based on a determination that the secondary user is absent in the operating channel of the communication system, a first RACH procedure is performed, and based on a determination that the secondary user is present in the operating channel of the communication system, a second RACH procedure different from the first RACH procedure is performed.

2 . The method of claim 1 , wherein the second RACH procedure is based on a type of the secondary user.

3 . The method of claim 1 , wherein the second RACH procedure is configured by an eNB.

4 . The method of claim 1 , further comprising receiving information relating to whether the secondary user is present in the operating channel, wherein the determining is based on the received information.

5 . The method of claim 4 , wherein the information relating to whether the secondary user is present in the operating channel is received from an eNB, and the eNB uses a feature detection to determine whether the secondary user is present in the operating channel.

6 . The method of claim 4 , wherein the information relating to whether the secondary user is present or absent in the operating channel of the communication system is received via an RRC configuration message.

7 . The method of claim 1 , wherein the WTRU sends a preamble at a power level higher than a default power level if the secondary user is present in the operating channel of the communication system.

8 . A method for sending a random access channel (RACH) from a wireless transmit/receive unit (WTRU), the method comprising:
determining whether a communication channel is available during a RACH resource based on sensing on the communication channel; and determining a timing for sending a RACH preamble based on whether the communication channel is available during the RACH resource, wherein the RACH preamble is determined to be sent during the RACH resource when the communication channel is available during the RACH resource, and the RACH preamble is determined to be sent during a subsequent RACH resource when the communication channel is unavailable during the RACH resource.

9 . The method of claim 8 , further comprising sending the RACH preamble from the WTRU during an immediately subsequent RACH resource without increasing a power of the RACH preamble when the communication channel is unavailable during the RACH resource.

10 . The method of claim 8 , further comprising sending the RACH preamble from the WTRU during an immediately subsequent RACH resource with an increased power during the subsequent RACH resource when the communication channel is unavailable during the RACH resource.

11 . The method of claim 8 , further comprising sending the RACH preamble over multiple consecutive RACH resources when the multiple consecutive RACH resources are available.

12 . The method of claim 8 , further comprising when multiple consecutive RACH resources are available and the communication channel is unavailable during an entire RACH resource, sending the RACH preamble with an increased power during the subsequent RACH resource of the multiple consecutive RACH resources.

13 . The method of claim 8 , further comprising:
adjusting power level for sending the RACH preamble based on whether the communication channel is available, wherein a default power level is used when the communication channel is available, and an increased power relative to the default power level is used when the communication channel is unavailable.

14 . The method of claim 8 , further comprising sensing the communication channel by performing at least one of an energy detection or a feature detection.

15 . The method of claim 14 , wherein the feature detection is used to determine whether the communication channel is occupied by a WiFi system, the method further comprising sending the RACH preamble when the communication channel is not occupied by the WiFi system.

16 . The method of claim 8 , further comprising reducing a length of the RACH preamble.

17 . The method of claim 16 , further comprising sending the reduced-length RACH preamble once following a Listen Before Talk (LBT) time of the WTRU.

18 . The method of claim 16 , further comprising sending the reduced-length RACH preamble multiple times before an end of the RACH resource.

19 . The method of claim 16 , further comprising sending the reduced-length RACH preamble once at a random time during the RACH resource.

20 . The method of claim 19 , wherein sending the reduced-length RACH preamble once at a random time during the RACH resource comprises:
selecting a random time for the WTRU to perform a Listen Before Talk (LBT) procedure; and performing the LBT procedure the selected time and sending the RACH preamble based on whether the communication channel is available, wherein, the RACH preamble is sent when the communication channel is available for the entire time of the LBT procedure, and the LBT procedure is repeated when the communication channel is unavailable during the LBT procedure.

21 . A method for using a communication system comprising a wireless transmit/receive unit (WTRU) in a spectrum, the method comprising:
selecting a random access channel (RACH) procedure as a function of a presence or an absence of a secondary user in an operating channel of the communication system; and performing the selected random access channel (RACH) procedure.

22 . The method of claim 21 , further comprising configuring the RACH procedure to reduce secondary interference.

23 . The method of claim 21 , wherein performing the selected RACH procedure comprises sending at least one of a RACH preamble and format information.

24 . The method of claim 23 , wherein performing the selected RACH procedure comprises determining a transmission power for at least one of the RACH preamble and the format information.

25 . A method for configuring a random access channel (RACH) procedure used by a wireless transmit/receive unit (WTRU) in a communication system, the method comprising:
determining, at an eNB, whether a secondary user is present in an operating channel of the communication system; and configuring the RACH procedure at the WTRU based on whether the secondary user is present in the operating channel of the communication system.

26 . The method of claim 25 , further comprising reducing a length of a RACH preamble.

27 . The method of claim 26 , further comprising sending the reduced-length RACH preamble multiple times before an end of a RACH resource.

28 . The method of claim 26 , further comprising sending the reduced-length RACH preamble once at a random time during a RACH resource.

29 . The method of claim 25 , further comprising:
receiving, at a WTRU in a pixel-based environment, an indication of a first maximum transmit power defined for a group of pixels of the pixel-based environment; sending a RACH preamble with the first maximum transmit power; receiving, at the WTRU in the pixel-based environment, an indication of a second maximum transmit po

Assignees

• Interdigital Patent Holdings Inc

Inventors

• Di Girolamo Rocco
• Freda Martino M
• Gauvreau Jean-Louis
• Laughlin Scott

Classifications

• H04W74/0808 Primary

  using carrier sensing, e.g. carrier sense multiple access [CSMA] · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04W16/14

  Spectrum sharing arrangements {between different networks} · CPC title