Abstract
A system and method of Random-Access Response RAR messaging when a base station employs narrow beamforming. Multiple RAR messages are successively transmitted from the base station to a User Equipment UE before any response to a RAR message is received from the UE. Thus despite any calibration mismatch between Uplink UL and Downlink DL beams in the beamformed system a RAR message is not only received by the UE but is received over the most-suitable DL beam for that UE. Each RAR message may contain a message-specific scheduling-delay indicator in the UL grant carried in the RAR message to provide an adjustable time delay for the UEs uplink transmission scheduled by the UL grant. Multiple RAR transmissions can schedule a single UL transmission at a specific time instance or different UL transmissions at different time intervals. The UE may report to the base station the best DL RAR transmission detected by the UE.
Technologies
Resource configuration Random access Beamforming
Product
User Equipment (UE/Terminal)Base Station (eNB/gNB)AntennaAccess point
Use Cases
Wireless communication
Services
Transmitting/receiving data in uplink
Claim
1. A method of transmitting a Random-Access Response (RAR) from a network entity to a User Equipment (UE) when the network entity employs narrow beamforming, wherein the method comprises performing the following by the network entity:
generating a plurality of RAR messages, wherein each RAR message carries a respective Uplink (UL) grant for the UE to enable the UE to respond to the RAR message;
for each RAR message, providing a RAR message-specific time-delay indicator in the respective UL grant carried by the RAR message;
configuring each RAR message-specific time-delay indicator to provide to the UE an indication of a time interval in which the UE is scheduled to transmit in the UL to respond to a respective RAR message; and
successively transmitting the plurality of RAR messages to the UE before any response from the UE is received by the network entity in the UL.
2. The method of claim 1, wherein one of the following applies:
the time interval is the same for each RAR message regardless of which of the plurality of RAR messages the UE is responding to; and
the time interval is different for at least two of the plurality of RAR messages.
3. The method of claim 1, wherein the indication is one of the following:
a first time delay value relative to a timing of the respective RAR message carrying the indication; and
a second time delay value relative to a timing of a UL message from the UE received by the network entity, wherein the plurality of RAR messages is transmitted by the network entity in response to the UL message.
4. The method of claim 3, wherein configuring each RAR message-specific time-delay indicator includes performing one of the following by the network entity:
when the indication is the first time-delay value, representing the first time-delay value in terms of a first number of subframes measured from a subframe of the respective RAR message carrying the indication; and
when the indication is the second time-delay value, representing the second time-delay value in terms of a second number of subframes measured from a subframe of the UL message.
5. The method of claim 4, further comprising performing the following by the network entity:
using one or more bits in the respective RAR message carrying the indication to indicate one of the following:
the first number of subframes; and
the second number of subframes.
6. The method of claim 1, wherein the RAR message-specific time-delay indicator is a bit field.
7. The method of claim 1, further comprising performing the following by the network entity:
for each RAR message, using the following parameters to calculate the time interval in which the UE is scheduled to transmit in the UL:
a first number identifying a radio subframe of the RAR message carrying the RAR message-specific time-delay indicator;
a second number indicating a fixed minimum delay of a pre-determined number of radio subframes; and
a third number representing at least one of the following:
a time delay value in terms of radio subframes relative to the first number, and
said indication of the time interval in which the UE is scheduled to transmit in the UL.
8. The method of claim 1, wherein the time interval is a radio subframe.
9. The method of claim 1, further comprising performing the following by the network entity:
receiving a response from the UE in the UL, wherein the response indicates which of the plurality of RAR messages the UE is responding to.
10. The method of claim 1, wherein configuring each RAR message-specific time-delay indicator includes performing one of the following by the network entity when the time interval to be indicated by a RAR message-specific time-delay indicator happens to be a reserved subframe:
re-configuring the RAR message-specific time-delay indicator to refer to another radio subframe that occurs before the reserved subframe; and
re-configuring the RAR message-specific time-delay indicator to refer to another radio subframe that occurs after the reserved subframe.
11. The method of claim 1, wherein successively transmitting the plurality of RAR messages includes performing at least one of the following by the network entity:
transmitting at least two of the plurality of RAR messages at different times; and
transmitting at least two of the plurality of RAR messages using different radio beams.
12. A method of processing a Random-Access Response (RAR) received by a User Equipment (UE) from a network entity when the network entity employs narrow beamforming, wherein the method comprises performing the following by the UE:
receiving a plurality of RAR messages from the network entity, wherein each RAR message includes a RAR message-specific time-delay indicator in a respective Uplink (UL) grant for the UE carried by the RAR message, wherein each RAR message-specific time-delay indicator specifies a UL time interval in which the UE is scheduled to transmit in the UL to the network entity, and wherein one of the following applies:
the UL time interval is the same for each RAR message, and
the UL time interval is different for at least two of the plurality of RAR messages;
selecting at least one of the plurality of RAR messages; and
sending a response to the selected at least one RAR message during the UL time interval specified by the selected at least one RAR message, wherein the response identifies the selected at least one RAR message to the network entity.
13. The method of claim 12, further comprising performing the following by the UE as part of sending the response:
processing the RAR message-specific time-delay indicator associated with the selected at least one RAR message to determine the UL time interval specified by the selected at least one RAR message in which the UE is scheduled to transmit to the network entity.
14. The method of claim 13, wherein processing the RAR message-specific time-delay indicator includes performing the following by the UE:
using the RAR message-specific time-delay indicator associated with the selected at least one RAR message in a pre-defined formula to determine the UL time interval specified by the selected at least one RAR message.
15. The method of claim 12, wherein selecting at least one of the plurality of RAR messages includes performing one of the following by the UE:
from the received plurality of RAR messages, choosing a RAR message having the largest received power as the selected at least one RAR message;
from the received plurality of RAR messages, choosing a successfully-received RAR message as the selected at least one RAR message; and
from the received plurality of RAR messages, choosing the selected at least one RAR message based on a pre-defined criterion.
16. The method of claim 12, wherein sending the response to the selected at least one RAR message includes performing one of the following by the UE when the UL time interval specified by the selected at least one RAR message happens to be a reserved subframe:
send the response using another radio subframe that occurs before the reserved subframe; and
send the response using another radio subframe that occurs after the reserved subframe.
17. A network entity in a cellular network for transmitting a Random-Access Response (RAR) to a mobile device, wherein the network entity employs narrow beamforming, and wherein the network entity comprises:
a transceiver for transmitting a plurality of RAR messages to the mobile device;
a scheduler for generating the plurality of RAR messages before they are transmitted to the mobile device, wherein the scheduler is operative to perform the following:
include a respective Uplink (UL) grant in each RAR message to enable the mobile device to respond to the RAR message,
for each RAR message, provide a RAR message-specific time-delay indicator in the respective UL grant carried by the RAR message, and
configure each RAR message-specific time-delay indicator to provide to the mobile device an indication of a time interval in which the mobile device is scheduled to transmit in the UL to respond to a respective RAR message; and
a processor coupled to the transceiver and the scheduler, wherein the processor is operative to facilitate successive transmission by the transceiver of the plurality of RAR messages generated by the scheduler, and wherein the processor is operative to facilitate the successive transmission before any response from the mobile device is received by the network entity in the UL.
18. The network entity of claim 17, wherein the network entity is one of the following:
a Radio Base Station (RBS);
a Base Station Controller (BSC);
a Radio Network Controller (RNC);
an evolved Node B (eNodeB); and
a group of base stations.
19. The network entity of claim 17, wherein the indication is one of the following:
a first time delay value relative to a timing of the respective RAR message carrying the indication; and
a second time delay value relative to a timing of a UL message from the mobile received by the transceiver, wherein the plurality of RAR messages is transmitted in response to the UL message.
20. The network entity of claim 19, wherein the scheduler is operative to perform the following as part of configuring each RAR message-specific time-delay indicator:
when the indication is the first time-delay value, specify the first time-delay value in terms of a first number of subframes measured from a subframe of the respective RAR message carrying the indication; and
when the indication is the second time-delay value, specify the second time-delay value in terms of a second number of subframes measured from a subframe of the UL message.
21. The network entity of claim 17, wherein the RAR message-specific time-delay indicator is a bit field.
22. The network entity of claim 17, wherein the scheduler is operative to further perform the following:
for each RAR message, use the following parameters to calculate the time interval in which the mobile device is scheduled to transmit in the UL:
a first number identifying a radio subframe of the RAR message carrying the RAR message-specific time-delay indicator;
a second number indicating a fixed minimum delay of a pre-determined number of radio subframes; and
a third number representing at least one of the following:
a time-delay value in terms of radio subframes relative to the first number, and
said indication of the time interval in which the mobile device is scheduled to transmit in the UL.
23. The network entity of claim 17, wherein the processor is operative to configure the transceiver to successively transmit the plurality of RAR messages in at least one of the following ways:
transmit at least two of the plurality of RAR messages at different times; and
transmit at least two of the plurality of RAR messages using different radio beams.
24. The network entity of claim 17, wherein one of the following applies:
the time interval is the same for each RAR message regardless of which of the plurality of RAR messages the mobile device is responding to; and
the time interval is different for at least two of the plurality of RAR messages.
25. A method of transmitting a Random-Access Response (RAR) from a network entity to a User Equipment (UE) when the network entity employs narrow beamforming, wherein the method comprises performing the following by the network entity:
generating an RAR message, wherein the RAR message carries an Uplink (UL) grant for the UE to enable the UE to respond to the RAR message;
providing a RAR message-specific time-delay indicator in the UL grant;
configuring the RAR message-specific time-delay indicator to provide to the UE an indication of a time interval in which the UE is scheduled to transmit in the UL to respond to the RAR message;
further providing a flag bit in the RAR message, wherein the flag bit instructs the UE to transmit a plurality of messages in the UL when responding to the RAR message as scheduled by the time interval; and
transmitting the RAR message to the UE.
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The information in blue was extracted from the third parties (Standard Setting Organisation, Espacenet)
The information in grey was provided by the patent holder
The information in purple was extracted from the FrandAvenue
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