CHANNEL ACCESSING METHOD AND DEVICE IN WIRELESS COMMUNICATION SYSTEM

• US 20170257780A1
• Filed: 09/15/2015
• Published: 09/07/2017
• Est. Priority Date: 09/15/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ryoo, Sunheui, Jung, Jungsoo, Moon, Jungmin, Nigam, Anshuman, Lee, Sungjin
• Granted Patent: US 10,638,331 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 36/0069 in case of dual connectivity, e.g. decoupled uplink/downlink
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/28 involving a plurality of connections, e.g. multi-call or multi-bearer connections
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

The present invention relates to a channel accessing method and device in a wireless communication system and, particularly, to a channel accessing method and device for a call handover for a terminal in a wireless communication system using a plurality of beams. The method according to an embodiment of the present invention, as a method of controlling a macro cell base station when a terminal that is communicating with the macro cell base station performs channel access with a small cell base station in a wireless network capable of using a plurality of transmitting/receiving beams, may include the steps of: determining whether to request a channel setting for a call for the terminal to the small cell base station when a signal strength measurement report for a channel synchronized with the small cell base station is received from the terminal; providing information including at least one of recommending information on the transmitting/receiving beams of the terminal and position information on the terminal in a request message to the small cell base station when a channel setting request to the small cell base station is decided upon; stopping the transmission of data to the terminal and a set data radio bearer (DRB2) when a response message for accepting the channel setting for the terminal is received from the small cell base station; transmitting a radio resource control access reconfiguration message to the terminal to communicate with the small cell base station; and providing information on data to be transmitted and received by the terminal to the small cell base station.

Claims

1. A channel access method in a wireless communication system for a macro cell eNB to perform control operations, when UE in the process of communication with the macro-cell eNB performs channel-access to a small cell eNB, in a wireless network capable of using a number of transmission/reception beams, the method comprising:

determining whether to request a channel setup for a call of the UE from the small cell eNB when an RSSI measurement report regarding a Synchronization CHannel (SCH) of the small cell eNB is received from the UE;

providing the small cell eNB with a request message which includes recommendation information regarding a transmission/reception beam of the UE and/or location information regarding the UE if a channel setup is requested from the small cell eNB;

stopping the transmission of data to a data radio bearer (DBR2) set up with the UE if a response message for accepting the channel setup with the UE is received from the small cell eNB;

transmitting a radio resource control (RRC) Connection Reconfiguration message to the UE to communicate with the small cell eNB; and

providing the small cell eNB with information related to data to be transmitted to the UE.

2. The method of claim 1, wherein the RRC Connection Reconfiguration message comprises:

best transmission beam direction information when the UE sets up a channel with the small cell eNB.

3. The method of claim 1, further comprising:

transmitting the request message along with a channel setup success history with the small cell eNB from a location identical or similar to that of the UE.

4. The method of claim 1, wherein the location information regarding the UE comprises:

location information which is provided by the UE or location information which is obtained, via triangulation, with other eNBs.

5. A channel access method for a small cell eNB to set up a channel with UE which is in the process of communication with a macro-cell eNB in a wireless network capable of using a number of transmission/reception beams, the method comprising:

receiving a message for requesting the setup of a channel with the UE from the macro-cell eNB, setting up a data radio bearer (DBR2) to communicate with the UE, and transmitting a response (acknowledgement) message to the macro-cell eNB;

receiving, from the macro-cell eNB, information related to data to be transmitted to the UE;

reordering the order of beams to receive a preamble via an RACH from the UE, based on information included in the request message, and scanning the RACH; and

receiving a preamble signal of the UE via the RACH, creating an RACH response signal, transmitting the RACH response signal to the UE, and performing a procedure for setting up a channel.

6. The method of claim 5, wherein receiving a preamble signal of the UE comprises:

receiving a preamble signal which is greater than or equal to a preset threshold.

7. The method of claim 5, wherein the information included in the request message comprises:

recommendation information regarding a transmission beam of the UE or a reception beam of the small cell eNB and/or location information regarding the UE.

8. The method of claim 7, wherein reordering the order of beams comprises:

preferentially reordering and scanning a reception beam with a relatively high probability of success, based on the location information regarding the UE;

or

preferentially reordering and scanning a recommended beam, based on the recommendation information.

9. A channel access method for UE, connected to a first eNB, to access a second eNB, in a wireless communication system capable of using a number of transmission/reception beams, the method comprising:

measuring an RSSI of the second eNB and reporting the RSSI to the first eNB;

receiving, from the first eNB, a radio resource control (RRC) Connection Reconfiguration message for assessing the second eNB, stopping a data radio bearer (DBR2) with the first eNB, and transmitting an RRC Connection Reconfiguration complete message to the second eNB;

transmitting a preamble through an RACH of the second eNB, using a best one of a number of transmission beams, based on the received RRC Connection Reconfiguration message; and

performing a procedure for communicating with the second eNB if an RACH response (RAR) is received from the second eNB.

10. The method of claim 9, further comprising:

checking the validity of the SCH of the second eNB, before transmitting the RRC Connection Reconfiguration complete message.

11. The method of claim 9, wherein:

the RRC Connection Reconfiguration message comprises at least one or more recommendation transmission beams to transmit a preamble to the second eNB via an RACH; and

the method further comprises reordering the use order of transmission beams to perform the transmission by preferentially using the recommendation transmission beam.

12. A channel access apparatus of a macro-cell eNB in a wireless communication system for supporting UE, in the process of communication with the macro-cell eNB, to perform channel-access to a small cell eNB, in a wireless network capable of using a number of transmission/reception beams, the apparatus comprising:

an antenna unit with a number of antennas for creating a number of transmission/reception beams;

a radio frequency (RF) unit with a number of RF modules for communicating with UEs under the macro-cell eNB via the antenna unit;

a data processor for modulating and decoding data to be transmitted to the RF unit and demodulating and decoding data received from the RF unit;

an inter-eNB interface communicating with another eNB, including the small-cell eNB; and

a scheduler for;

determining whether to request a channel setup for a call of the UE from the small cell eNB when an RSSI measurement report regarding a Synchronization CHannel (SCH) of the small cell eNB, transmitted by the UE, is received from the data processor;

providing the small cell eNB with a message for requesting channel access to the UE which includes recommendation information regarding a transmission/reception beam of the UE and/or location information regarding the UE, using the inter-eNB interface, if a channel setup is requested from the small cell eNB;

controlling the RF unit and the data processor to stop the transmission of data to a data radio bearer (DBR2) set up with the UE if a response message for accepting the channel setup with the UE is received from the small cell eNB;

transmitting a radio resource control (RRC) Connection Reconfiguration message to the UE to communicate with the small cell eNB; and

providing the small cell eNB with information related to data to be transmitted to the UE.

13. The apparatus of claim 12, wherein the RRC Connection Reconfiguration message comprises:

best transmission beam direction information when the UE sets up a channel with the small cell eNB.

14. A channel access apparatus of a small-cell eNB in a wireless communication system for supporting UE, in the process of communication with a macro-cell eNB, to perform channel-access to the small cell eNB, in a wireless network capable of using a number of transmission/reception beams, the apparatus comprising:

an antenna unit with a number of antennas for creating a number of transmission/reception beams;

a radio frequency (RF) unit with a number of RF modules for communicating with UEs under the small-cell eNB via the antenna unit;

a data processor for modulating and decoding data to be transmitted to the RF unit and demodulating and decoding data received from the RF unit;

an inter-eNB interface communicating with another eNB, including the macro-cell eNB; and

a scheduler for;

receiving a request message for requesting the setup of a channel with the UE from the macro-cell eNB via the inter-eNB interface, setting up a data radio bearer (DBR2) to communicate with the UE, and transmitting a response (acknowledgement) message to the macro-cell eNB;

receiving, from the macro-cell eNB, information related to data to be transmitted to the UE;

reordering the order of beams to receive a preamble from the UE via an RACH, based on information included in the request message;

controlling the RF unit to scan the RACH according to the order of reordered reception beams;

controlling, when receiving a preamble signal of the UE via the RACH, the data processor and the RF unit to transmit an RACH response signal to the UE; and

performing a procedure for setting up a channel with the UE.

15. The apparatus of claim 14, wherein the information included in the request message comprises:

recommendation information regarding a transmission beam of the UE or a reception beam of the small cell eNB and/or location information regarding the UE.

16. A channel access apparatus for UE, in the process of communication with a macro-cell eNB, to perform channel access to a small-cell eNB in a wireless network capable of using a number of transmission/reception beams, the apparatus comprising:

an antenna unit with a number of antennas for creating a number of transmission/reception beams;

a radio frequency (RF) unit for communicating with two or more eNBs;

a data processor for modulating and decoding data to be transmitted to the RF unit and demodulating and decoding data received from the RF unit; and

a controller for;

controlling the RF unit and the data processor to measure an RSSI of the second eNB in a state where the UE is connected to the first eNB and report the RSSI to the first eNB;

receiving, from the first eNB, a radio resource control (RRC) Connection Reconfiguration message for assessing the second eNB, stopping a data radio bearer (DBR2) with the first eNB, and transmitting an RRC Connection Reconfiguration complete message to the second eNB;

transmitting a preamble through an RACH of the second eNB, using a best one of a number of transmission beams, based on the received RRC Connection Reconfiguration message; and

controlling a procedure for communicating with the second eNB if an RACH response (RAR) is received from the second eNB.

17. The apparatus of claim 16, wherein:

the RRC Connection Reconfiguration message comprises at least one or more recommendation transmission beams to transmit a preamble to the second eNB via an RACH; and

the controller reorders the use order of transmission beams to perform the transmission by preferentially using the recommendation transmission beam.