Wireless access point apparatus and method for testing signal reception sensitivity

• US 10,182,359 B2
• Filed: 10/17/2011
• Issued: 01/15/2019
• Est. Priority Date: 04/15/2011
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Chung, Jae Ho, Rho, Wi Sang, Ji, Yung Ha, Han, Kyu Jeong
• Primary Examiner(s): Divito, Walter J
• Assistant Examiner(s): Luo, Anthony
• Application Number:
  US14/111,992
• Publication Number:
  US 20140036715A1
• Time in Patent Office: 2,647 Days
• CPC Class Codes: H04B 17/0085 using test signal generators
• CPC Class Codes: H04B 17/29 Performance testing
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

A method and apparatus for testing signal reception sensitivity of a wireless access point are provided. The apparatus includes a receiver which is configured to receive a test start request signal, a transmission power level change request signal and a test packet retransmission request signal from a neighboring access point apparatus; a test signal generator which is configured to generate a test packet signal to be transmitted to the neighboring access point apparatus; a transmission power level adjuster which is configured to adjust a transmission power level of the test packet signal; a transmitter which is configured to transmit the test packet signal to the neighboring access point apparatus with a power having a level adjusted by the transmission power level adjuster; and a test executor which is configured to execute a test program having a predetermined sequence for testing a signal reception sensitivity of the neighboring access point apparatus.

Claims

1. A method for testing a signal reception sensitivity of a wireless access point apparatus, comprising operations of:

(a) transmitting a test packet from a first access point apparatus, as a transmission access point (AP), to a second access point apparatus, as a reception AP, the test packet being transmitted at a predetermined first transmission power level;

(b) measuring a packet error rate of the test packet and writing a Modulation and Coding Scheme (MCS) level applied to the test packet, the packet error rate being measured and the MCS level being written by the second access point apparatus;

(c) transmitting a request for changing a transmission power level by increasing the transmission power level for retransmitting the test packet from the second access point apparatus to the first access point apparatus, in response to a completion of the measuring and the writing in operation (b);

(d) retransmitting the test packet at a changed transmission power level from the first access point apparatus to the second access point apparatus;

(e) repeating operations (b) to (d) until the changed transmission power level reaches a predetermined second transmission power level; and

(f) transmitting a test target AP switching request signal from the second access point apparatus to the first access point apparatus after operations (a) to (e), and in response to the test target AP switching request signal, repeating operations (a) to (e) with respect to the second access point apparatus as the transmission AP and the first access point apparatus as the reception AP.

2. The method of claim 1, wherein the repeating operations (a) to (e) with respect to the second access point apparatus as the transmission AP and the first access point apparatus as the reception AP comprises operations:

(g) transmitting the test packet from the second access point apparatus to the first access point apparatus at a predetermined third transmission power level after transmitting the test target AP switching request signal;

(h) measuring the packet error rate of the test packet transmitted in operation (g) and writing the Modulation and Coding Scheme (MCS) level applied to the test packet transmitted in the operation (g), the packet error rate being measured and the MCS level being written by the first access point apparatus;

(i) transmitting the request for changing the transmission power level for retransmitting the test packet from the first access point apparatus to the second access point apparatus;

(j) retransmitting the test packet at the changed transmission power level from the second access point apparatus to the first access point apparatus; and

(k) repeating operations (h) to (j) until the changed transmission power level reaches a predetermined fourth transmission power level.

3. The method of claim 2, wherein operation (h) further comprises:

measuring a reception power after receiving the test packet transmitted in said operation (g), the reception power being measured by the first access point apparatus; and

evaluating a signal reception sensitivity of the first access point apparatus based on whether the packet error rate of the test packet of the received MCS level is smaller than or equal to a predetermined reference value for the measured reception power, the signal reception sensitivity being evaluated by the first access point apparatus.

4. The method of claim 3, wherein the operation (h) further comprises:

checking for a variable MCS level in the measured reception power level based on a pre-stored MCS table if the packet error rate of the test packet received by the first access point apparatus is smaller than or equal to the predetermined reference value, the variable MCS level being checked for by the first access point apparatus,

wherein operation (i) further comprises transmitting information on the variable MCS level from the first access point apparatus to the second access point apparatus, and

wherein operation (j) further comprises changing an MCS level to apply to the test packet based on the received information on the MCS level, the MCS level being changed by the second access point apparatus.

5. The method of claim 1, wherein said operation (b) further comprises:

measuring a reception power after receiving the test packet, the reception power being measured by the second access point apparatus; and

evaluating a signal reception sensitivity of the second access point apparatus based on whether the packet error rate of the test packet of the MCS level is smaller than or equal to a predetermined reference value for the measured reception power.

6. The method of claim 5, wherein said operation (b) further comprises checking for a variable MCS level in the measured reception power level based on a pre-stored MCS table if the packet error rate is smaller than or equal to the predetermined reference value, the variable MCS level being checked for by the second access point apparatus,

wherein operation (c) comprises transmitting information on the variable MCS level from the second access point apparatus to the first access point apparatus, and

wherein operation (d) comprises changing an MCS level to apply to the test packet based on the received information on the MCS level, the MCS level being changed by the first access point apparatus.

7. The method of claim 1, wherein the first access point apparatus and the second access point apparatus are configured to communicate wirelessly and are connected by a wired network.

8. The method of claim 7, wherein the first access point apparatus and the second access point apparatus are connected by a wireless local area network.

9. The method of claim 8, wherein the first access point apparatus and the second access point apparatus are adjacent to each other.

10. The method of claim 7, further comprising, prior to the transmitting the test packet from the first access point apparatus to the second access point apparatus, transmitting a switching request signal from the first access point apparatus to the second access point apparatus.

11. The method of claim 10, wherein the transmitting the test packet from the first access point apparatus to the second access point apparatus is performed in response to the transmitting the switching request signal from the first access point apparatus to the second access point apparatus.

12. The method of claim 7, further comprising, prior to the transmitting the test packet from the first access point apparatus to the second access point apparatus, transmitting a test start request signal from the second access point apparatus to the first access point apparatus.

13. The method of claim 12, wherein the transmitting the test packet from the first access point apparatus to the second access point apparatus is in response to the transmitting the test start request signal from the second access point apparatus to the first access point apparatus.

14. The method of claim 1, wherein the retransmitting the test packet is performed independent from the packet error rate measured by the second access point apparatus.

15. A wireless access point apparatus, comprising:

a receiver which is configured to, in a transmission mode of the wireless access point apparatus, receive a test start request signal, a transmission power level change request signal and a test packet retransmission request signal from a neighboring access point apparatus;

a non-transitory computer readable medium configured to store instructions that, when executed by a processor, cause the processor to;

generate a test packet signal to be transmitted to the neighboring access point apparatus; and

adjust a transmission power level of the test packet signal; and

a transmitter which is configured to, in the transmission mode, transmit the test packet signal to the neighboring access point apparatus at the adjusted transmission power level;

wherein the receiver, the transmitter, and the processor are configured to, in the transmission mode, execute a test program having a test sequence for testing a signal reception sensitivity of the neighboring access point apparatus, the test sequence comprising;

controlling the transmitter to transmit a test packet to the neighboring access point apparatus at power having a predetermined first transmission power level in response to receiving the test start request signal; and

changing the transmission power level of the test packet by increasing the transmission power level based on the test program and retransmitting the test packet having the changed transmission power level to the neighboring access point apparatus, in response to receiving the transmission power level change request signal and the test packet retransmission request signal from the neighboring access point apparatus which previously received the test packet,

wherein the wireless access point apparatus switches from the transmission mode to a reception mode in response to receiving a test target AP switching request signal from the neighboring access point apparatus,

wherein, in the reception mode, the transmitter transmits the test start request signal, the transmission power level change request signal and the test packet retransmission request signal to the neighboring access point apparatus, and the receiver receives the test packet signal from the neighboring access point apparatus.

16. The wireless access point apparatus of claim 15, wherein the non-transitory computer readable medium is further configured to store instructions that, when executed by the processor, cause the processor to:

measure a reception power after receiving the test packet and measure a packet error rate of the test packet if the receiver receives the test packet from the neighboring access point apparatus;

record a Modulation and Coding Scheme (MCS) level applied to the test packet; and

evaluate a signal reception sensitivity based on whether the packet error rate of the test packet of the MCS level is smaller than or equal to a predetermined reference value for the measured reception power.

17. The wireless access point apparatus of claim 16, wherein, in case the packet error rate has a value that is smaller than or equal to the predetermined reference value, the non-transitory computer readable medium is further configured to store instructions, when executed by the processor, cause the processor to check for a variable MCS level that is applicable for the measured reception power level, based on a pre-stored MCS table.

18. The wireless access point apparatus of claim 17, wherein the non-transitory computer readable medium is further configured to instructions to store instructions, when executed by the processor, cause the processor to control the transmitter to transmit information on the variable MCS level to the neighboring access point apparatus.

19. The wireless access point apparatus of claim 15, wherein the processor comprises at least one hardware component.

20. A method for testing a signal reception sensitivity of a wireless access point apparatus, comprising operations:

(a) transmitting a test packet from a first access point apparatus to a second access point apparatus, the test packet being transmitted at a predetermined first transmission power level;

(b) measuring a packet error rate of the test packet and writing a Modulation and Coding Scheme (MCS) level applied to the test packet, the packet error rate being measured and the MCS level being written by the second access point apparatus;

(c) transmitting a request for changing a transmission power level for retransmitting the test packet from the second access point apparatus to the first access point apparatus in response to the measuring and the writing in operation (b) being completed;

(d) retransmitting the test packet at a changed transmission power level from the first access point apparatus to the second access point apparatus; and

(e) repeating operations (b) to (d) until the changed transmission power level reaches a predetermined second transmission power level,

wherein after operations (a) to (e), the method further comprises;

(f) transmitting a test target access point (AP) switching request signal from the second access point apparatus to the first access point apparatus;

(g) transmitting the test packet from the second access point apparatus to the first access point apparatus at a predetermined third transmission power level after transmitting the test target AP switching request signal;

(h) measuring the packet error rate of the test packet transmitted in operation (g) and writing an MCS level applied to the test packet transmitted in the operation (g), the packet error rate being measured and the MCS level being written by the first access point apparatus;

(i) transmitting the request for changing the transmission power level for retransmitting the test packet from the first access point apparatus to the second access point apparatus;

(j) retransmitting the test packet at the changed transmission power level from the second access point apparatus to the first access point apparatus; and

(k) repeating operations (h) to (j) until the changed transmission power level reaches a predetermined fourth transmission power level.