TERMINAL DEVICE, BASE STATION DEVICE, WIRELESS COMMUNICATION SYSTEM, AND WIRELESS COMMUNICATION METHOD

• US 20180255579A1
• Filed: 05/01/2018
• Published: 09/06/2018
• Est. Priority Date: 11/12/2015
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shimomura, Tsuyoshi, TANAKA, YOSHINORI
• Granted Patent: US 10,966,244 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A terminal device includes a processor and a memory connected to the processor, wherein the processor executes a process including: receiving a resource specifying signal that specifies a random access resource used to transmit a preamble for random access; selecting one preamble from a plurality of preamble candidates previously acquired; and transmitting the selected preamble by using a random access resource arranged in timing based on a reception timing of the resource specifying signal.

Claims

1. A terminal device comprising:

a processor; and

a memory connected to the processor, wherein

the processor executes a process comprising;

receiving a resource specifying signal that specifies a random access resource used to transmit a preamble for random access;

selecting one preamble from a plurality of preamble candidates previously acquired; and

transmitting the preamble selected by using a random access resource arranged in timing based on a reception timing of the resource specifying signal.

2. The terminal device according to claim 1, wherein

the receiving includes receiving the resource specifying signal including resource information indicating a time from reception timing of the resource specifying signal to timing of the random access resource and a frequency of the random access resource, and

the transmitting includes transmitting the preamble selected by using the random access resource indicated by the resource information.

3. The terminal device according to claim 2, wherein

the receiving includes receiving the resource specifying signal including the resource information indicating a maximum allowable delay that is allowed when a preamble is transmitted by using the random access resource, and

the transmitting includes:

determining whether a frequency band that is targeted for random access is occupiable by a wireless communication system to which the terminal device belongs; and

transmitting the preamble selected when it is determined that the frequency band is occupiable before the maximum allowable delay elapses after the timing of the random access resource.

4. The terminal device according to claim 3, wherein

the transmitting includes:

when it is determined that the frequency band is not occupiable, determining whether the random access is started by using a request for adjustment of transmission timing by the terminal device as a trigger; and

when it is determined that the request for adjustment of transmission timing is a trigger, cancelling transmission of the preamble selected and, when it is determined that the request for adjustment of transmission timing is not a trigger, repeatedly determining whether the frequency band is occupiable until the maximum allowable delay has elapsed.

5. The terminal device according to claim 2, wherein

the receiving includes receiving the resource specifying signal including the resource information on a plurality of random access resources that are arranged at an identical time and that have different frequencies, and

the transmitting includes:

determining whether there is a response to a preamble previously transmitted by using the random access resource; and

when it is determined that there is no response, transmitting the preamble selected by using more random access resources than previously used random access resources.

6. The terminal device according to claim 1, wherein

the receiving includes receiving the resource specifying signal that is transmitted when it is determined that a frequency band targeted for random access is occupiable by a wireless communication system to which the terminal device and a counterpart device belong as a result of determination made by the counterpart device, and

the transmitting includes transmitting the preamble selected within a predetermined time after timing in which the resource specifying signal is received.

7. A base station device comprising:

a processor; and

a memory connected to the processor, wherein

the processor executes a process comprising;

generating a resource specifying signal that specifies a random access resource used to transmit a preamble for random access and that is transmitted in timing that is a basis for timing in which the random access resource is arranged; and

transmitting the resource specifying signal generated.

8. The base station device according to claim 7, wherein the generating includes generating the resource specifying signal including resource information indicating a time from transmission timing of the resource specifying signal to timing of the random access resource and a frequency of the random access resource.

9. The base station device according to claim 7, wherein

the transmitting includes:

determining whether a frequency band targeted for random access is occupiable by a wireless communication system to which the base station device and a counterpart device belong; and

transmitting the resource specifying signal generated when it is determined that the frequency band is occupiable.

10. A wireless communication system comprising:

a base station device; and

a terminal device, wherein

the base station device includes a first processor and a first memory connected to the first processor,

the first processor executes a process comprising;

generating a resource specifying signal that specifies a random access resource used to transmit a preamble for random access and that is transmitted in timing that is a basis for timing in which the random access resource is arranged; and

transmitting the resource specifying signal generated,

the terminal device includes a second processor and a second memory connected to the second processor,

the second processor executes a process comprising;

receiving the resource specifying signal;

selecting one preamble from a plurality of preamble candidates previously acquired; and

transmitting the preamble selected by using a random access resource arranged in timing based on a reception timing of the resource specifying signal.

11. A wireless communication method comprising:

receiving a resource specifying signal that specifies a random access resource used to transmit a preamble for random access;

selecting one preamble from a plurality of preamble candidates previously acquired; and

transmitting the preamble selected by using a random access resource arranged in timing based on a reception timing of the resource specifying signal.

12. A wireless communication method comprising:

generating a resource specifying signal that specifies a random access resource used to transmit a preamble for random access and that is transmitted in timing that is a basis for timing in which the random access resource is arranged; and

transmitting the resource specifying signal generated.