Simplified PRACH procedure using speculative random access response

Patent metadata

Field	Value
Publication number	US-9549417-B2
Application number	US-201214406051-A
Country	US
Kind code	B2
Filing date	Jun 21, 2012
Priority date	Jun 21, 2012
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

The present invention relates to method and arrangement in cellular mobile communication systems, in particular for handling of a physical random access channel for example in a Long Term Evolution communication network. By sending to at least one user equipment, UE, in a communication network cell an un-solicited speculative random access response, RAR, message comprising information relating to at least one of pre-amble identifier, allocated UE identifier, and uplink resource allocation data for L2/L3 message, it is possible to reduce the complexity of the access node, e.g. an eNodeB.

First claim

The invention claimed is:

1. A network infrastructure access device in a wireless telecommunications network serving a wireless communication cell, wherein the device comprises:
at least one processor;
at least one receiving unit; and
at least one transmitting unit, wherein the at least one processor is arranged to:
send, using the transmitting unit, to at least one UE in the cell, a speculative random access response (RAR) message comprising a preamble identifier based on detection of a presence of the preamble from a signal on a physical random access channel (PRACH) signal received using the receiving unit from the at least one UE, wherein the preamble identifier is determined independent of an identity of a preamble transmitted by the at least one UE to the network infrastructure access device; and
receive, using the receiving unit, an L2/L3 message from the at least one UE comprising an allocated UE identifier and an UE identity.

2. The device according to claim 1 , where the at least one processor is further arranged to send the speculative RAR message with some periodicity.

3. The device according to claim 1 , wherein the at least one processor is further arranged to handle a collision event in relation to receiving L2/L3 messages from several UEs.

4. The device according to claim 1 , wherein the device is arranged to operate in a communication cell with a range radius of less than 500 m.

5. The device according to claim 1 , wherein the device is arranged to handle less than 100 UEs at the same time in the cell.

6. The device according to claim 1 , further comprising a PRACH detector arranged to detect a PRACH message on the communication interface.

7. The device according to claim 6 , wherein the PRACH detector comprise a fast Fourier transform unit operating on a sub-set of available antenna signal data for extracting a received PRACH data set and further comprising an energy detector for detecting energy content in the received PRACH data set for detecting a presence of at least one PRACH message in a communication message received from at least one UE.

8. The device according to claim 1 , wherein the device is arranged to only detect a PRACH signal irrespective of sending UE and transmit response message to at least one UE in the cell.

9. The device according to claim 1 , wherein the allocated UE identifier is a Cell Radio Network Temporary Identifier (C-RNTI).

10. The device according to claim 1 , wherein the RAR message is part of a Media Access Control (MAC) payload message.

11. The device according to claim 9 , wherein the MAC payload comprise a plurality of RAR messages.

12. A method in a wireless telecommunications network serving a wireless communication cell, the method comprising steps of:
sending, using the transmitting unit, to at least one UE in the cell, a speculative random access response (RAR) message comprising a preamble identifier based on detection of a presence of the preamble from a signal on a physical random access channel (PRACH) signal received using the receiving unit from the at least one UE, wherein the preamble identifier is determined independent of an identity of a preamble transmitted by the at least one UE to the network infrastructure access device; and
receiving, using the receiving unit, an L2/L3 message from the at least one UE comprising an allocated UE identifier and an UE identity.

13. The method according to claim 12 , wherein the step of detecting comprise using a sub-set of received antenna data for detecting energy content in PRACH.

14. The method according to claim 12 , further comprising a step of handling collision events in relation to receiving L2/L3 messages from several UEs.

15. The method according to claim 12 , wherein the step of sending the RAR message comprise sending the RAR message in a Media Access Control (MAC) payload message.

16. The method according to claim 12 , wherein the allocated UE identifier is a Cell Radio Network Temporary Identifier (C-RNTI).

Assignees

• Olsson Thomas
• Brauer Peter
• Carlsson Anders
• Carlsson Roland
• Engdal David
• Sahlin Henrik
• Svensson Jim
• Ericsson Telefon Ab L M

Inventors

• Olsson Thomas
• Brauer Peter
• Carlsson Anders
• Carlsson Roland
• Engdal David
• Sahlin Henrik
• Svensson Jim

Classifications

• H04W74/002 Primary

  Transmission of channel access control information · CPC title

• H04W74/0833 Primary

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

• H04W72/04 Primary

  Wireless resource allocation · CPC title