METHOD AND APPARATUS FOR CONTROLLING CROSS LINK ESTABLISHMENT

• US 20140321416A1
• Filed: 12/07/2012
• Published: 10/30/2014
• Est. Priority Date: 12/08/2011
• Status: Abandoned Application

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Pragada, Ravikumar V., Deng, Tao, Raghothaman, Balaji, Deng, Zhuorong, Sternberg, Gregory S., Vanganuru, Kiran K.
• Application Number:
  US14/363,460
• Publication Number:
  US 20140321416A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 76/25 Maintenance of established connections
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A method and apparatus for controlling crosslink (XL) establishment are disclosed. In the method and apparatus, the XL between a terminal wireless transmit/receive unit (T-WTRU) and a helper WTRU (H-WTRU) is controlled, whereby the T-WTRU and the H-WTRU may be in a radio resource control (RRC) Idle mode and may perform discontinuous reception (DRX). Further, the T-WTRU may transition between infrastructure coverage mode and WTRU-to-WTRU (W2W) coverage mode. Additionally, neighbor discovery and H-WTRU selection are performed and association between the T-WTRU and H-WTRU is established and maintained.

Claims

1. A terminal wireless transmit/receive unit (T-WTRU) for establishing a cross link (XL) with a helper WTRU (H-WTRU), the T-WTRU comprising:

a receiver configured to receive basic system information from the H-WTRU; and

a processor configured to determine whether to establish a XL with the H-WTRU based on the basic system information, wherein on a condition that the T-WTRU determines to establish a XL with the H-WTRU, the T-WTRU further comprises;

a transmitter configured to transmit a selected as H-WTRU message to the H-WTRU.

2. The T-WTRU of claim 1, wherein the basic system information includes a public land mobile network (PLMN) Identity List, a tracking area code, or a cell identity associated with the H-WTRU.

3. The T-WTRU of claim 2, wherein the processor determines not to establish the XL with the H-WTRU on a condition that the T-WTRU is barred from the cell associated with the H-WTRU.

4. The T-WTRU of claim 2, wherein the processor determines to establish the XL with the H-WTRU on a condition that the T-WTRU requires the XL for an emergency call.

5. The T-WTRU of claim 2, wherein the processor determines not to establish the XL with the H-WTRU on a condition that the PLMN is not a preferred PLMN.

6. The T-WTRU of claim 1, wherein on a condition that the T-WTRU determines not to establish the XL with the H-WTRU, the transmitted is further configured to transmit an association message to a neighbor present WTRU (NP-WTRU).

7. A terminal wireless transmit/receive unit (T-WTRU) for maintaining association with a helper WTRU (H-WTRU), the T-WTRU comprising:

a receiver configured to receive a first keep live message from the H-WTRU during a wake up period in discontinuous reception (DRX); and

a transmitter configured to transmit a second keep alive message to the H-WTRU, the second keep alive indicates the T-WTRU seeks to maintain the association with the H-WTRU.

8. The T-WTRU of claim 7, wherein the T-WTRU performs reselection evaluation based on a signal strength of the first keep alive message, and wherein on a condition that the signal of the first keep alive message is less than the threshold, the T-WTRU foregoes transmitting the second keep alive message.

9. The T-WTRU of claim 7, wherein a DRX cycle length cycle length of the T-WTRU is equal to or an integer multiple of the DRX cycle length of the H-WTRU.

10. The T-WTRU of claim 7, wherein a paging occasion of the T-WTRU is offset by a predetermined number of paging occasions from the H-WTRU.

11. The T-WTRU of claim 7, wherein the H-WTRU determines whether the page associated with the T-WTRU is received from a base station, and wherein the H-WTRU.

12. A base station for controlling helper wireless transmit/receive unit (H-WTRU) selection, the base station comprising:

a receiver configured to receive a first message from a first neighbor present WTRU (NP-WTRU), the first message indicating receipt of a neighbor discovery initiation transmission (NDIT) from a neighbor seeking WTRU (NS-WTRU);

a processor configured to start a timer;

the processor further configured to select a H-WTRU upon expiration of the timer; and

a transmitter configured to transmit a neighbor discovery response message to the H-WTRU, the neighbor discovery response message indicating selection of the H-WTRU to relay cross link (XL) data associated with NS-WTRU.

13. The base station of claim 12, wherein the receiver is further configured to receive a second message from a second NP-WTRU, the second message indicating receipt of the neighbor discovery initiation transmission (NDIT) from the neighbor seeking WTRU (NS-WTRU) and the second message being received before the timer expires.

14. The base station of claim 13, wherein the H-WTRU is the first NP-WTRU or the second NP-WTRU.

15. The base station of claim 13, wherein the first NP-WTRU transitions to the RRC-CONNECTED state upon receiving the NDIT and the second NP-WTRU transitions to the RRC-CONNECTED state upon receiving the NDIT.