RADIO COMMUNICATION SYSTEM FOR ASSIGNING A SHORT-LIVED C-RNTI

• US 20150043455A1
• Filed: 01/03/2012
• Published: 02/12/2015
• Est. Priority Date: 01/03/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Mikls, Gyrgy, Eriksson, Erik, Rune, Johan, Sachs, Joachim, Turnyi, Zoltn, Wiberg, Niclas
• Granted Patent: US 9,775,183 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/11 Allocation or use of connection identifiers
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A radio communication system and a method 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 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 C-RNTI to be assigned to a second user equipment. Furthermore, a first user equipment and method for enabling assignment of a short-lived C-RNTI to the first user equipment performing random access and a radio network node and method for assigning a short-lived C-RNTI to a first user equipment performing random access are provided.

Claims

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, wherein the method comprises:

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; and

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; and

after the first time period has elapsed;

maintaining the first user equipment connected to the radio network node; and

allowing the short-lived C-RNTI to be assigned to a second user equipment, thereby enabling use of the short-lived C-RNTI for identification of the second user equipment when connected to the radio network node.

2. The method according to claim 1, further comprising, before the first time period has elapsed:

associating, by the radio network node, a first extended C-RNTI to the first user equipment, wherein the first extended C-RNTI comprises a first set of bits and a second set of bits, wherein number of bits of the first set is equal to number of bits of the short-lived C-RNTI.

3. The method according to claim 2, further comprising, before a transmission between the first user equipment and the radio network node and after the first time period has elapsed:

paging, initiated by the radio network node, the first user equipment, at a paging occasion, while using the first extended C-RNTI for identification of the first user equipment.

4. The method according to claim 3, further comprising:

calculating the paging occasion based on the first extended C-RNTI.

5. The method according to claim 3, 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.

6. The method according to claim 5, 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.

7. The method according to claim 2, 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.

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

9. The method according to claim 7, wherein the DCI message is sent on PDCCH 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.

10. The method according to claim 9, wherein the frame comprises a first and a second set of subframes, wherein the resources are allocated to the first or second sets of subframes, wherein the first and second sets of subframes are indicative of zero and one, respectively, for at least one bit of the second set of bits.

11. The method according to claim 7, wherein the DCI message is sent on resources comprised in a dedicated search space for indicating the second set of bits.

12. The method according to claim 11, 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 number of bits of the third set of bits is equal to 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.

13. The method according to claim 12, 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.

14. The method according to claim 3, 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.

15. 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.

16. A first user equipment for enabling assignment of a short-lived Cell Radio Network Temporary Identifier (C-RNTI) to the first user equipment performing random access to a radio network node, wherein the first user equipment comprises:

a processing circuit adapted to register the first user equipment as connected to the radio network node, wherein the short-lived C-RNTI is assignable to the first user equipment for identification thereof during a first time period, wherein the processing circuit further is adapted to;

maintain the first user equipment connected to the radio network node after the first time period has elapsed; and

refrain from considering the short-lived C-RNTI as assigned to the user equipment after the first time period has elapsed, thereby enabling use of the short-lived C-RNTI for identification of the second user equipment when connected to the radio network node; and

a receiver adapted to receive, from the radio network node, a message for synchronizing the radio network node and the first user equipment with respect to the first time period.

17. The first user equipment according to claim 16, wherein the processing circuit is further adapted to:

before the first time period has elapsed, associate a first extended C-RNTI to the first user equipment, wherein the first extended C-RNTI comprises a first set of bits and a second set of bits, wherein number of bits of the first set is equal to number of bits of the short-lived C-RNTI.

18. A radio network node for assigning a short-lived Cell Radio Network Temporary Identifier (C-RNTI) to a first user equipment performing random access to the radio network node, wherein the radio network node comprises:

a processing circuit adapted to register the first user equipment as connected to the radio network node, wherein the short-lived C-RNTI is assignable to the first user equipment for identification thereof during a first time period, wherein the processing circuit further is adapted to;

maintain the first user equipment connected to the radio network node after the first time period has elapsed, and

allow the short-lived C-RNTI to be assigned to a second user equipment after the first time period has elapsed, thereby enabling use of the short-lived C-RNTI for identification of the second user equipment when connected to the radio network node; and

a transmitter adapted to send, 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.

19. The radio network node according to claim 18 wherein the processing circuit is further adapted to:

before the first time period has elapsed, associate a first extended C-RNTI to the first user equipment, wherein the first extended C-RNTI comprises a first set of bits and a second set of bits, wherein number of bits of the first set is equal to number of bits of the short-lived C-RNTI.

20. 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, wherein the radio communication system comprises:

a first user equipment for enabling assignment of a short-lived Cell Radio Network Temporary Identifier (C-RNTI) to the first user equipment performing random access to a radio network node, wherein the first user equipment comprises;

a processing circuit adapted to register the first user equipment as connected to the radio network node, wherein the short-lived C-RNTI is assignable to the first user equipment for identification thereof during a first time period, and adapted to;

maintain the first user equipment connected to the radio network node after the first time period has elapsed; and

refrain from considering the short-lived C-RNTI as assigned to the user equipment after the first time period has elapsed, thereby enabling use of the short-lived C-RNTI for identification of the second user equipment when connected to the radio network node; and

a receiver adapted to receive, from the radio network node, a message for synchronizing the radio network node and the first user equipment with respect to the first time period; and

the radio network node for assigning a short-lived C-RNTI to the first user equipment performing random access to the radio network node, wherein the radio network node comprises;

a processing circuit adapted to register the first user equipment as connected to the radio network node, wherein the short-lived C-RNTI is assignable to the first user equipment for identification thereof during the first time period, and adapted to;

maintain the first user equipment connected to the radio network node after the first time period has elapsed, and

allow the short-lived C-RNTI to be assigned to the second user equipment after the first time period has elapsed, thereby enabling use of the short-lived C-RNTI for identification of the second user equipment when connected to the radio network node; and

a transmitter adapted to send, to the first user equipment, the message for synchronizing the radio network node and the first user equipment with respect to the first time period.