Method and Test System for Testing Wireless LAN Devices

• US 20150257019A1
• Filed: 03/10/2015
• Published: 09/10/2015
• Est. Priority Date: 03/10/2014
• Status: Active Grant

• Current Assignee: Rohde & Schwarz Asia Pte.Ltd. (Rohde & Schwarz GmbH & Company KG)
• Original Assignee: Rohde & Schwarz Asia Pte.Ltd. (Rohde & Schwarz GmbH & Company KG)
• Inventors: Durai, Rajashekar, Bacor, Gerson, Allwang, Michael
• Granted Patent: US 10,090,970 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

The invention relates to a technique for especially testing an IEEE 802.11 WLAN device, in particular for testing performance compliance of the device. According to a method aspect to be performed by a test system, exchange of an ICMP message pair is initiated between the device under test (DUT) and the test system; and a backoff time selected by the DUT during the message exchange is determined.

Claims

1. A method of testing a device under test DUT, especially an device using standard IEEE 802.11, in a test system, comprising

initiating exchange of an ICMP message pair between the DUT and the test system;

and

determining a backoff time selected by the DUT during the message exchange.

2. The method according to claim 1,

wherein the backoff time is determined from a measured time span between an acknowledgement frame ACK received from the DUT and an ICMP message received from the DUT.

3. The method according to claim 2,

wherein a carrier transmission is performed for delaying the ICMP message from the DUT.

4. The method according to claim 3,

wherein the carrier transmission comprises one or more ICMP messages.

5. The method according to claim 1,

comprising the step of triggering the DUT to perform a retransmission.

6. The method according to claim 5,

wherein the retransmission is triggered by suppressing an acknowledgement frame ACK to be sent to the DUT.

7. The method according to claim 5,

wherein at least a second retransmission is triggered.

8. The method according to claim 7,

wherein triggering a higher order transmission includes inspecting a retry bit of a Frame Control Field of the frame carrying the ICMP message of the DUT.

9. The method according to claim 5, comprising

performing a plurality of message exchanges including initial transmissions and retransmissions;

and

classifying the DUT according to at least one classification criterion related to coverage of contention window in the initial transmissions and/or the retransmissions.

10. The method according to claim 9,

wherein the classification is based on retransmissions of various contention window sizes.

11. The method according to claim 3,

performing a plurality of message exchanges with and/or without triggering a delay in the DUT;

and

classifying the DUT according to at least one classification criterion related to coverage of a contention window in the delayed and/or non-delayed transmissions.

12. The method according to claim 9,

wherein the classification criterion comprises a predefined threshold number representative of backoff slots.

13. The method according to claim 1,

performing a plurality of message exchanges with different levels of Quality of Service;

and

classifying the DUT according to at least one classification criterion related to coverage of a contention window in one or more of the different Quality of Service levels.

14. A computer program comprising program code portions for performing the following steps when the computer program is executed on one or more computing devices:

testing a device under test DUT, especially an device using standard IEEE 802.11, in a test system,

initiating exchange of an ICMP message pair between the DUT and the test system; and

determining a backoff time selected by the DUT during the message exchange.

15. A test system for testing a device under test DUT, especially a device using standard IEEE 802.11, comprising

a component adapted to initiate exchange of an ICMP message pair between the DUT and the test system;

and

a component adapted to determine a backoff time selected by the DUT during the message exchange.