Wireless lan with enhanced capture provision

• US 5,987,033 A
• Filed: 09/08/1997
• Issued: 11/16/1999
• Est. Priority Date: 09/08/1997
• Status: Expired due to Term

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Diepstraten, Wilhelmus Josephus, Kopmeiners, Robert John, Boer, Jan, Kamerman, Adriaan, van Driest, Hans, van Bokhorst, Hendrik, Mud, Rienk
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Pezzlo, John
• Application Number:
  US08/925,416
• Time in Patent Office: 799 Days
• Field of Search: 370/338, 370/445, 370/447, 370/448, 370/461, 370/462, 370/332, 370/313, 370/349
• US Class Current: 370/445
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A receiver, and a method for operating the receiver, for a station in a wireless local area network using a common wireless communication channel and employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol includes various modes. In normal mode, the receiver follows typical states in order to detect a message and demodulate data from the message properly. Meanwhile, a process implements a message-in-message (MIM) mode when an energy increase above a specified level is detected. While in the MIM mode, if a carrier is detected, the energy increase is caused by a new message; otherwise, the energy increase is caused by an interfering station. If the carrier is detected, the receiver begins retraining so that it can start receiving the new message as soon as the first message ends. If no carrier is detected, the receiver waits a specified time to detect a carrier or for the end of the first message, after which the receiver returns to the beginning of the normal mode. While in the normal mode, if a message is detected that is not addressed to the station, the receiver enters a hunt mode. While in the hunt mode, the receiver waits for the current message to finish. At the same time, a process implements retraining when both an energy increase above a specified level and a carrier are detected. If no carrier is detected within a specified time, or if the energy level decreases below the specified level, the receiver returns to the beginning of the normal mode.

Claims

1. A method for operating a receiver of a station in a wireless local area network using a common wireless communication channel and employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol, comprising the steps of:

detecting a message;

determining when said message is addressed to said station;

demodulating said message when said message is addressed to said station;

detecting a first energy increase above a first specified level when said message is being demodulated;

detecting a carrier upon detection of said first energy increase;

retraining upon detection of said carrier;

detecting a second energy increase above a second specified level;

detecting said carrier when said second energy increase is detected; and

retraining upon detection of said second energy increase and detection of said carrier,

wherein there is no transmission of a collision detect signal either after detecting said first energy increase or after detecting said second energy increase.

2. A method according to claim 1, further comprising:

determining said first specified level; and

determining said second specified level.

3. A receiver for a station in a wireless local area network using a common wireless communication channel and employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol, comprising:

first detecting means for detecting a message;

means for determining when said message is addressed to said station;

means for demodulating said message when said message is addressed to said station;

second detecting means for detecting a first energy increase above a first specified level when said message is being demodulated;

third detecting means for detecting a carrier upon detection of said first energy increase;

first retraining means for retraining upon detection of said carrier;

fourth detecting means for detecting a second energy increase above a second specified level;

fifth detecting means for detecting said carrier when said second energy increase is detected; and

second retraining means for retraining upon detection of said second energy increase and detection of said carrier,

wherein the receiver does not include means for transmitting a collision detect signal after detecting either said first or said second increase in energy.

4. A receiver according to claim 3, further comprising:

first determining means for determining said first specified level; and

second determining means for determining said second specified level.