Random access channel access and backoff mechanism

• US 20040160977A1
• Filed: 02/10/2004
• Published: 08/19/2004
• Est. Priority Date: 06/18/1999
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad, Dick, Stephen G.
• Granted Patent: US 6,859,441 B2
• Time in Patent Office: Days
• US Class Current: 370/448
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A user equipment has a transmitter for transmitting an access attempt signal and data packets over a random access channel. The access attempt signal requests a base station to permit the user equipment access to the random access channel. A receiver receives access control signals and access control modification signals transmitted from a base station. A controller is operatively coupled to the receiver and transmitter. The controller determines a wait period based on in part the received access control signals and access control modification signals and delays transmission of a subsequent access attempt signal for the wait period in response to an unsuccessful access attempt to the random access channel.

Claims

1. A user equipment for use in a wireless code division multiple access communication system, the user equipment comprising:

a transmitter for transmitting an access attempt signal and data packets over a random access channel, the access attempt signal requests a base station to permit the user equipment access to the random access channel;

a receiver for receiving access control signals and access control modification signals transmitted from the base station; and

a controller operatively coupled to the receiver and transmitter, the controller for determining a wait period based on in part the received access control signals and access control modification signals and for delaying transmission of a subsequent access attempt signal for the wait period in response to an unsuccessful access attempt to the random access channel.

2. The user equipment of claim 1 wherein the access control modification signals are layer one signals.

3. The user equipment of claim 1 wherein the access control signals comprise backoff parameters and the wait period is a backoff wait period which is based on in part the received backoff parameters modified by the received modification signals.

4. The user equipment of claim 1 wherein the wait period is based on in part a backoff wait period and a probability of sending an access signal during the backoff wait period.

5. The user equipment of claim 4 wherein the access control signals comprise backoff parameters and persistence parameters and the backoff wait period is based on in part the received backoff parameters modified by the received modification signals.

6. The user equipment of claim 4 wherein the access control signals comprise backoff parameters and persistence parameters and the sending access signal probability is based on in part the received persistence parameters modified by the received modification signals.