User equipment, network node and methods therein for handling preamble transmissions on a random access channel in a radio communications network

Patent metadata

Field	Value
Publication number	US-11711845-B2
Application number	US-202016951607-A
Country	US
Kind code	B2
Filing date	Nov 18, 2020
Priority date	Feb 10, 2014
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

The embodiments herein relate to a user equipment (121) and a method performed by the UE (121) for performing preamble transmissions, on a random access channel, to a network node (110). The method comprising: determining (801) a starting subframe for the preamble transmissions based on at least a system frame number (SFN), a number of times (R) the preamble transmissions is to be repeated and a random access channel configuration, and transmitting (802), to the network node (121) the preamble repeatedly starting in the determined starting subframe. The embodiments herein also relate to a network node (110) and a method performed by the network node (110).

First claim

The invention claimed is:

1. A method performed by a user equipment for performing preamble transmissions on a random access channel to a network node, the method comprising:
receiving a system frame number, SFN, from the network node;
receiving a random access channel configuration from the network node, wherein the random access channel configuration comprises a first offset value indicating positions of subframes that are available for transmission and an average number of subframes, N, comprising at least one random access channel source;
determining, from a System Information Block, SIB, received from the network node, a cell identifier associated with a cell to which the network and the user equipment belong;
determining a number of times, R, a preamble transmission is to be repeated;
determining a starting subframe for the preamble transmission(s) based at least on the received SFN, the received random access channel configuration, the cell identifier, and the determined number of times, R, the preamble transmission is to be repeated, such that a different starting subframe is determined for corresponding cells based on respective cell identifiers, wherein the starting subframe is offset by a second offset value being a cell-specific value associated with the cell, wherein the second offset value is different from the cell identifier; and
transmitting, to the network node, the preamble repeatedly starting in the determined starting subframe.

2. The method according to claim 1 , wherein the SFN is received from the network node in a Master Information Block, MIB.

3. The method according to claim 1 , wherein the random access channel configuration is received from the network node in a System Information Block, SIB.

4. The method according to claim 1 , wherein the starting subframe is further determined based on an offset.

5. The method according to claim 4 , wherein the offset depends on the received random access channel configuration.

6. A user equipment for performing preamble transmissions on a random access channel to a network node, the user equipment being configured to:
receive a system frame number, SFN, from the network node;
receive a random access channel configuration from the network node, wherein the random access channel configuration comprises a first offset value indicating positions of subframes that are available for transmission and an average number of subframes, N, comprising at least one random access channel source;
determine, from a System Information Block, SIB, received from the network node, a cell identifier associated with a cell to which the network and the user equipment belong;
determine a number of times, R, a preamble transmission is to be repeated;
determine a starting subframe for the preamble transmission(s) based at least on the received SFN, the received random access channel configuration, the cell identifier, and the determined number of times, R, the preamble transmission is to be repeated, such that a different starting subframe is determined for corresponding cells based on respective cell identifiers, wherein the starting subframe is offset by a second offset value being a cell-specific value associated with the cell, wherein the second offset value is different from the cell identifier; and
transmit, to the network node, the preamble repeatedly starting in the determined starting subframe.

7. The user equipment according to claim 6 , wherein the SFN is received from the network node in a Master Information Block, MIB.

8. The user equipment according to claim 6 , wherein the random access channel configuration is received from the network node in a System Information Block, SIB.

9. The user equipment according to claim 6 , wherein the user equipment is configured to further determine the starting subframe based on an offset.

10. The user equipment according to claim 9 , wherein the offset depends on the received random access channel configuration.

11. A method performed by a network node for receiving preamble transmission(s) from a user equipment on a random access channel, the method comprising:
transmitting, to the user equipment, a system frame number, SFN;
transmitting, to the user equipment, a random access channel configuration, wherein the random access channel configuration comprises a first offset value indicating positions of subframes that are available for transmission and an average number of subframes, N, comprising at least one random access channel source;
determining, from a System Information Block, SIB, received from the network node, a cell identifier associated with a cell to which the network and the user equipment belong;
determining a number of times, R, a preamble transmission is to be repeated;
determining a starting subframe for the preamble transmission(s) based at least on the SFN, the random access channel configuration, the cell identifier, and the determined number of times, R, the preamble transmission is to be repeated, such that a different starting subframe is determined for corresponding cells based on respective cell identifiers, wherein the starting subframe is offset by a second offset value being a cell-specific value associated with the cell, wherein the second offset value is different from the cell identifier; and
receiving, from the user equipment, the preamble transmission repeatedly starting in the determined starting subframe.

12. The method according to claim 11 , wherein the SFN is transmitted to the user equipment in a Master Information Block, MIB.

13. The method according to claim 11 , wherein the random access channel configuration is transmitted to the user equipment in a System Information Block, SIB.

14. The method according to claim 11 , wherein the starting subframe is further determined based on an offset.

15. The method according to claim 14 , wherein the offset depends on the transmitted random access channel configuration.

16. A network node for receiving preamble transmission(s) from a user equipment on a random access channel, the network node being configured to:
transmit, to the user equipment, a system frame number, SFN;
transmit, to the user equipment, a random access channel configuration, wherein the random access channel configuration comprises a first offset value indicating positions of subframes that are available for transmission and an average number of subframes, N, comprising at least one random access channel source;
determine, from a System Information Block, SIB, received from the network node, a cell identifier associated with a cell to which the network and the user equipment belong;
determine a number of times, R, a preamble transmission is to be repeated;
determine a starting subframe for the preamble transmission(s) based at least on the SFN, the random access channel configuration, the cell identifier, and the determined number of times, R, the preamble transmission is to be repeated, such that a different starting subframe is determined for corresponding cells based on respective cell identifiers, wherein the starting subframe is offset by a second offset value being a cell-specific value associated with the cell, wherein the second offset value is different from the cell identifier; and
receive, from the user equipment, the preamble transmission repeatedly starting in the determined starting subframe.

17. The network node according to claim 16 , wherein the SFN is transmitted to the user equipment in a Master Information Block, MIB.

18. The network node according to claim 16 , wherein the rando

Assignees

• Ericsson Telefon Ab L M

Inventors

• Frenne Mattias
• Bergman Johan
• Eriksson Erik
• Gunnarsson Fredrik
• Wallen Anders

Classifications

• H04W74/0838

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

• H04W74/0833

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

• H04W74/004 Primary

  in the uplink, i.e. towards network · CPC title

• H04W56/001

  Synchronization between nodes · CPC title

• H04W72/02

  Selection of wireless resources by user or terminal · CPC title