Method for detecting radio link failure for transmission over enhanced dedicated channel in a CELL—FACH state

Patent metadata

Field	Value
Publication number	US-9749877-B2
Application number	US-201213729136-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Oct 29, 2007
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A method and apparatus are used for detecting a radio link (RL) failure and a post verification process. A quality of a downlink fractional dedicated physical channel (F-DPCH) is monitored once a transmission on an enhanced dedicated channel (E-DCH) has begun. It is determined whether the quality of the downlink F-DPCH is below a predefined threshold. If the quality is below the predefined threshold, then an occurrence of an RL failure is declared and a transmission over the E-DCH in a cell forward access channel (CELL_FACH) state is terminated. In a case of the post verification failure, E-DCH resources are released.

First claim

What is claimed is:

1. A method implemented in a wireless transmit receive unit (WTRU) for handling a radio link (RL) failure, the method comprising:
determining that a criterion for RL failure is met when operating in a cell forward access channel (CELL FACH) state; and
upon determining that the criterion for RL failure is met, releasing enhanced dedicated channel (E-DCH) resource and performing a backoff procedure prior to attempting another random uplink (UL) access, the backoff procedure comprising:
waiting a predefined amount of time prior to starting a timer; and
while the timer is running, checking whether a cell reselection criterion is met, wherein upon determining that the cell reselection criterion is met, cell reselection is performed and the timer is stopped, and wherein upon expiry of the timer the cell reselection criterion is not met, a new random UL access is attempted without performing the cell reselection.

2. The method of claim 1 wherein the timer is a backoff timer.

3. The method of claim 1 , wherein the new random UL access is attempted on a current cell.

4. A wireless transmit receive unit (WTRU), the WTRU comprising:
a processor; and
a memory comprising instructions that when executed by the processor cause the WTRU to:
determine that a criterion for radio link (RL) failure is met when operating in a cell forward access channel (CELL FACH) state; and
upon determining that the criterion for RL failure is met, release enhanced dedicated channel (E-DCH) resource and perform a backoff procedure prior to attempting another random uplink (UL) access, the backoff procedure comprising:
waiting a predefined amount of time prior to starting a timer; and
while the timer is running, checking whether a cell reselection criterion is met, wherein upon determining that the cell reselection criterion is met, cell reselection is performed and the timer is stopped, and wherein upon expiry of the timer the cell reselection criterion is not met, a new random UL access is attempted without performing the cell reselection.

5. The WTRU of claim 4 , wherein the timer is a backoff timer.

6. The WTRU of claim 4 , wherein the new random UL access is attempted on a current cell.

Assignees

• Interdigital Patent Holdings Inc

Inventors

• Cave Christopher
• Kim In H
• Pelletier Benoit
• Marinier Paul
• Pani Diana

Classifications

• H04W24/00 Primary

  Supervisory, monitoring or testing arrangements · CPC title

• H04W36/30

  by measured or perceived connection quality data · CPC title

• H04W76/028

  Electricity · mapped topic

• H04W36/305 Primary

  Handover due to radio link failure (control signalling for hand-off failure H04W36/0079) · CPC title

• H04W76/19 Primary

  Connection re-establishment · CPC title