Contention-free Access in Wireless Communication System

Patent metadata

Field	Value
Publication number	US-2016183299-A1
Application number	US-201615059729-A
Country	US
Kind code	A1
Filing date	Mar 3, 2016
Priority date	Nov 14, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

A contention-free activation/deactivation mechanism in PRACH, which allows dynamic allocation of the contention-free and contention-based preambles. This allows contention-free preambles which have been allocated to a UE to be revoked once contention-free operation is no longer needed, or cannot be supported due to a shortage of preambles. In one embodiment, a terminal is configured (S 12 ) with a contention-free preamble by specific signalling, and thereafter monitors periodic broadcasts (S 14 ) indicating the set of contention-free preambles; if the configured preamble is within the set (S 16, “ Y”), the preamble is activated for contention-free operation (S 18 ); otherwise (S 16, “ N”), the preamble is deactivated and the terminal should follow the contention-based procedure (S 20 ).

First claim

What is claimed is:

1 . A wireless communication method for use in a wireless communication system comprising a base station communicating with at least one terminal, the method comprising:
the base station configuring said terminal with a preamble signature to be used for transmission of a preamble in a contention-free random access procedure; and the base station, by subsequent signalling, dynamically activating and/or deactivating the use by said terminal of said preamble signature in said contention-free random access procedure.

2 . The wireless communication method according to claim 1 wherein the subsequent signalling comprises a broadcast to all terminals served by the base station.

3 . The wireless communication method according to claim 1 wherein the subsequent signalling includes an indication of the preamble signatures available for contention-based random access.

4 . The wireless communication method according to claim 1 wherein the subsequent signalling includes an indication of the preamble signatures available for contention-free random access.

5 . The wireless communication method according to claim 1 wherein the subsequent signalling includes a bit map representing a set of preamble signatures.

6 . The wireless communication method according to claim 1 wherein the subsequent signalling comprises fast signalling from the base station to the said terminal.

7 . The wireless communication method according to claim 6 wherein the configuring is performed by Radio Resource Control, RRC, signalling and the subsequent signalling comprises MAC, PDCCH or EPDCCH signalling.

8 . The wireless communication method according to claim 1 wherein the said terminal determines whether to perform a contention-free or contention-based random access procedure by checking whether the configured preamble signature is activated or deactivated and if activated, follows the contention-free random access procedure.

9 . The wireless communication method according to claim 8 wherein when the configured preamble signature is deactivated, the terminal follows the contention-based random access procedure.

10 . The wireless communication method according to claim 8 wherein the subsequent signalling identifies a set of all preambles available for contention-based access and the said terminal determines its configured preamble as activated if the configured preamble falls outside the identified set, otherwise determines the configured preamble as deactivated.

11 . The wireless communication method according to claim 1 wherein a preamble signature is characterised by at least one of:
a preamble sequence;
a time domain resource for transmission of said preamble; and
a frequency domain resource for transmission of said preamble.

12 . A wireless communication system comprising a base station and at least one terminal, wherein:
the base station is arranged to configure said terminal with a preamble signature to be used for transmission of a preamble in a contention-free random access procedure, and to transmit subsequent signalling; and said terminal is arranged to receive said configuration, to receive said subsequent signalling, and to determine whether or not to use the configured preamble signature in a contention-free random access procedure in dependence on said subsequent signalling.

13 . A base station for use in a wireless communication system comprising the base station and at least one terminal, wherein:
the base station is arranged to configure said terminal with a preamble signature to be used for transmission of a preamble in a contention-free random access procedure, and to transmit subsequent signalling for dynamically activating and/or deactivating the use by the terminal of said preamble signature in said contention-free random access procedure.

14 . A terminal for use in a wireless communication system comprising the terminal and a base station serving the terminal, wherein the terminal is arranged to be configured by the base station with a preamble signature to be used for transmission of a preamble in a contention-free random access procedure, and to receive subsequent signalling for dynamically activating and/or deactivating the use by the terminal of said preamble signature in said contention-free random access procedure.

15 . Non-transitory computer-readable recording media storing computer-readable instructions which, when executed by a processor of a transceiver device in a wireless communication system, cause the device to provide the base station according to claim 13 .

16 . Non-transitory computer-readable recording media storing computer-readable instructions which, when executed by a processor of a transceiver device in a wireless communication system, cause the device to provide the terminal according to claim 14 .

Assignees

• Fujitsu Ltd

Inventors

• Fang Yiwei
• Moulsley Timothy

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W74/0833

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

• H04W74/0838

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

• H04W74/04 Primary

  Scheduled access (hybrid access H04W74/02) · CPC title

• H04W72/042

  Electricity · mapped topic