COMMUNICATION CHARACTERISTIC MEASURING DEVICE ADAPTED TO WIRELESS TERMINAL

• US 20100165864A1
• Filed: 12/22/2009
• Published: 07/01/2010
• Est. Priority Date: 12/25/2008
• Status: Active Grant

• Current Assignee: KDDI R&D Laboratories Inc. (KDDI Corporation)
• Original Assignee: KDDI R&D Laboratories Inc. (KDDI Corporation)
• Inventors: Fujimoto, Takashi, Takeuchi, Kazunori, Kashiki, Kanshiro, YAMAGUCHI, Akira
• Granted Patent: US 8,391,170 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A cognitive terminal includes different types of radio modules suiting to different types radio media employed by a cognitive base station in the radio communication system. The radio module of the cognitive terminal counts the number of times it receives/transmits ACK/NACK in each unit time. A radio environment cognition unit of the cognitive terminal performs calculations using the count number(s) in consideration of the packet transmission time interval or the time required for repeating a single data packet, thus measuring characteristics of delay time variations in uplink/downlink communication with respect to each radio media. Thus, it is possible for the cognitive terminal to switch over radio media based on ACK/NACK in uplink/downlink communication.

Claims

1. A communication characteristic measuring device adapted to a wireless terminal performing communication using a plurality of radio media via a base station in a radio communication system, comprising:

a plurality of radio modules, each of which obtains reception acknowledgement information regarding a data packet transmitted to or received from a counterpart wireless terminal in a prescribed communication range independently with respect to each radio media; and

a radio environment cognition unit that generates delay time variation data representing characteristics of delay time variations based on the reception acknowledgement information independently with respect to each radio media and each direction of communication.

2. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

B”

representing the number of times it receives ACK in a unit time “

A”

, wherein the radio environment cognition unit calculates “

C”

representing an average reception time interval by way of an equation of C=A÷

B, and wherein the radio environment cognition unit calculates “

E”

representing an uplink average packet arrival time error by way of an equation of E=D−

C where D denotes a packet transmission time interval, thus measuring distribution characteristics of the uplink average packet arrival time error as the delay time variation data in uplink communication.

3. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

Bd”

representing the number of times it transmits ACK in a unit time “

A”

, wherein the radio environment cognition unit calculates “

Cd”

representing an average reception time interval by way of an equation of Cd=A÷

Bd, and wherein the radio environment cognition unit calculates “

Ed”

representing a downlink average packet arrival time error by way of an equation of Ed=D−

Cd where D denotes a packet transmission time interval, thus measuring distribution characteristics of the downlink average packet arrival time error as the delay time variation data in downlink communication.

4. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

G”

representing the number of times it receive NACK in a unit time “

A”

, and wherein the radio environment cognition unit calculates “

I”

representing an uplink average accumulated delay time by way of an equation of I=G×

H where H denotes a time required for repeating a single data packet, thus measuring distribution characteristics of the uplink average accumulated delay time as the delay time variation data in uplink communication.

5. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

Gd”

representing the number of times it transmits NACK in a unit time “

A”

, and wherein the radio environment cognition unit calculates “

Id”

representing a downlink average accumulated delay time by way of an equation of Id=Gd×

H where H denotes a time required for repeating a single data packet, thus measuring distribution characteristics of the downlink average accumulated delay time as the delay time variation data in downlink communication.

6. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

B”

representing the number of times it receives ACK in a unit time A and “

G”

representing the number of times it receives NACK in the unit time A, and wherein the radio environment cognition unit calculates “

K”

representing an uplink average packet repeat delay time by way of an equation of K=G÷

B×

H where H denotes a time required for repeating a single data packet, thus measuring distribution characteristics of the uplink average packet repeat delay time as the delay time variation data in uplink communication.

7. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module counts “

Bd”

representing the number of times it transmits ACK in a unit time A and “

Gd”

representing the number of times it transmits NACK in the unit time A, and wherein the radio environment cognition unit calculates “

Kd”

representing an downlink average packet repeat delay time by way of an equation of Kd=Gd÷

Bd×

H where H denotes a time required for repeating a single data packet, thus measuring distribution characteristics of the downlink average packet repeat delay time as the delay time variation data in downlink communication.

8. The communication characteristic measuring device adapted to a wireless terminal according to claim 1, wherein the radio module records a first reception time “

R1”

for receiving a data packet in a unit time “

A” and

a second reception time “

R2”

for acknowledging success of reception with respect to the data packet, and wherein the radio environment cognition unit calculates “

M”

representing a downlink average packet delay time by way of an equation of M=R2−

R1, thus measuring distribution characteristics of the downlink average packet delay time as the delay time variation data in downlink communication.