Radio communication system for assigning a short-lived C-RNTI

Patent metadata

Field	Value
Publication number	US-9775183-B2
Application number	US-201214370162-A
Country	US
Kind code	B2
Filing date	Jan 3, 2012
Priority date	Jan 3, 2012
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A radio communication system and a method for assigning a short-lived Cell Radio Network Temporary Identifier, “CRNTI”, to a first user equipment performing random access to a radio network node are provided. The radio communication system registers the first user equipment as connected to the radio network node. A message for synchronizing the radio network node and the first user equipment with respect to the first time period is transferred. After the first time period has elapsed, the radio communication system maintains the first user equipment connected to the radio network node, and allows the short-lived CRNTI to be assigned to a second user equipment.

First claim

The invention claimed is:

1. A method in a radio communication system for assigning a short-lived Cell Radio Network Temporary Identifier (C-RNTI) to a first user equipment performing random access to a radio network node, the method comprising:
registering the first user equipment as connected to the radio network node, wherein the short-lived C-RNTI is assigned to the first user equipment for identification thereof during a first time period;
transferring, from the radio network node to the first user equipment, a message for synchronizing the radio network node and the first user equipment with respect to the first time period, wherein the first time period is indicative of time elapsed since a last dedicated transmission between the first user equipment and the radio network node;
determining that the first time period has elapsed; and
in response to the determining that the first time period has elapsed:
maintaining the first user equipment connected to the radio network node, wherein the maintaining comprises the first user equipment continuously remaining connected to the radio network node; and
assigning the short-lived C-RNTI to a second user equipment while the first user equipment is connected to the radio network node;

during the first time period and prior to the first time period elapsing, assigning, by the radio network node, a first extended C-RNTI to the first user equipment for identification during signaling on a Physical Downlink Control Channel (PDCCH), wherein the first extended C-RNTI comprises a greater total number of bits than a total number of bits of the short-lived C-RNTI; and
paging, after the first time period has elapsed, initiated by the radio network node, the first user equipment, at a paging occasion, using the first extended C-RNTI for identification of the first user equipment.

2. The method according to claim 1 ,
wherein the first extended C-RNTI comprises a first set of bits and a second set of bits, wherein a number of bits of the first set is equal to the total number of bits of the short-lived C-RNTI.

3. The method according to claim 1 , further comprising:
calculating the paging occasion based on the first extended C-RNTI.

4. The method according to claim 1 , wherein the paging comprises sending a page message to the first user equipment, wherein the page message comprises an indication of resources to be used for the transmission.

5. The method according to claim 4 , wherein the page message further comprises information about a C-RNTI to be assigned to the first user equipment, whereby the C-RNTI is usable for identification of the first user equipment in the transmission.

6. The method according to claim 1 , further comprising, before a transmission between the first user equipment and the radio network node and after the first time period has elapsed:
transferring, from the radio network node to the first user equipment, a dedicated downlink control information message (DCI message) encoded with the first extended C-RNTI, for assigning resources for the transmission.

7. The method according to claim 6 , wherein the DCI message comprises DCI information including a field comprising the second set of bits.

8. The method according to claim 6 , wherein the DCI message is sent on Physical Downlink Control Channel (PDCCH) resources, which are dedicated on a per frame basis to the first extended C-RNTI, for identification of the first extended C-RNTI and in a frame selected such that a number of bits of a system frame number of the frame is indicative of the second set of bits.

9. The method according to claim 8 ,
wherein the frame comprises a first set of subframes and a second set of subframes, and
wherein the PDCCH resources are allocated to the first set of subframes indicating a value of zero for at least one bit of the second set of bits or to the second set of subframes indicating a value of one for at least one bit of the second set of bits.

10. The method according to claim 6 , wherein the DCI message is sent on resources comprised in a dedicated search space for indicating the second set of bits.

11. The method according to claim 10 , wherein the second user equipment is connected to the radio network node while being assigned a second extended C-RNTI, comprising a third and a fourth set of bits, and the short-lived C-RNTI is available for reuse by a further user equipment, wherein a number of bits of the third set of bits is equal to the total number of bits of the short-lived C-RNTI, wherein the first set of bits of the first extended C-RNTI are identical to the third set of bits of the second extended C-RNTI, wherein the dedicated search space for the first user equipment is at least partly non-overlapping with a second dedicated search space for the second user equipment.

12. The method according to claim 11 , wherein the first user equipment uses the dedicated search space in dedicated periods only, wherein the dedicated periods are determined based on one or more of:
the second set of bits and a system frame number of the dedicated period;
information dynamically provided by signalling for indicating the dedicated periods; and
DRX for the first user equipment such that only the first user equipment uses the dedicated search space in the dedicated periods, wherein DRX active period for the second user equipment is at least partly non-overlapping with DRX active period for the first user equipment.

13. The method according to claim 1 , wherein the transmission is an uplink transmission from the first user equipment to the radio network node or a downlink transmission from the radio network node to the first user equipment.

14. The method according to claim 1 , further comprising, before registering the first user equipment as connected to the radio network node by assigning the short-lived C-RNTI to the first user equipment:
determining to assign the short-lived C-RNTI to the first user equipment upon the registration of the first user equipment as connected, wherein the determining is based on one or more of:
number of available C-RNTIs;
a category of the first user equipment, wherein the category is obtained from one or more of the first user equipment, subscription information and collected statistics about transmissions, and
data about transmissions between the first user equipment and the radio network node and/or one or more other radio network nodes, wherein the data about transmission is obtained from one or more of subscription information and collected statistics about transmissions.

15. The method according to claim 1 ,
wherein the maintaining the first user equipment connected to the radio network node comprises maintaining the first user equipment in an RRC_CONNECTED state.

16. The method according to claim 1 , further comprising:
performing, by the first user equipment, the random access to the radio network node, responsive to the first user equipment not having a valid timing advance.

17. The method according to claim 1 , further comprising:
performing, by the first user equipment, the random access to the radio network node, responsive to the first user equipment not having allocated Physical Uplink Control Channel (PUCCH) resources, but having a valid timing advance.

18. The method according to claim 17 , further comprising:
using the first extended C-RNTI for identification of the first user equipment during the performing the random access,
wherein the using the first extended C-RNTI for identification of the first user equipment during the performing

Assignees

• Miklós György
• Eriksson Erik
• Rune Johan
• Sachs Joachim
• Turányi Zoltán
• Wiberg Niclas
• Ericsson Telefon Ab L M

Inventors

• Miklós György
• Eriksson Erik
• Rune Johan
• Sachs Joachim
• Turányi Zoltán
• Wiberg Niclas

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W74/0833

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

• H04W8/26 Primary

  Network addressing or numbering for mobility support · CPC title

• H04W72/042

  Electricity · mapped topic

• H04W76/021 Primary

  Electricity · mapped topic