Method and apparatus for determining a bandwidth of a video signal

• US 6,256,351 B1
• Filed: 07/17/1998
• Issued: 07/03/2001
• Est. Priority Date: 10/24/1997
• Status: Expired due to Term

• Current Assignee: Wi-LAN Inc.
• Original Assignee: Daewoo Electronics (Government of South Korea)
• Inventors: Hong, Seung-Hoon
• Primary Examiner(s): LEE, Y YOUNG
• Application Number:
  US09/116,817
• Time in Patent Office: 1,082 Days
• Field of Search: H04/N.712, 375/240.01, 375/240.18, 375/240.26, 375/240.12
• US Class Current: 375/240.26
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5616 Terminal equipment, e.g. codecs, synch.
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5684 Characteristics of traffic flows
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/64307 ATM
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A method and apparatus for allocating a bandwidth to bit streams of a video signal having variable bit rates, wherein the bit streams are transmitted to an ATM(asynchronous transfer mode) network, encodes the video signal to thereby generate the bit streams of the encoded video signal. If the bit streams are of a time domain, the bit streams are transformed into a frequency domain, and if the bit streams are of the frequency domain, the bit streams are passed on without being transformed. Then, power spectral density S(f) of the bit streams of the frequency domain is calculated, an intermediate parameter I is determined based on the power spectral density S(f), and a Hurst parameter H is evaluated based on the intermediate parameter I. The bit streams are allocted with a bandwidth based on the Hurst parameter H and transmitted to the ATM network based on the allocated bandwidth.

Claims

1. A method for allocating a bandwidth to bit streams of a video signal having variable bit rates, wherein the bit streams are transmitted to an ATM(asynchronous transfer mode) network, comprising the steps of:

(a) encoding the video signal to thereby generate the bit streams of the encoded video signal;

(b) transforming the bit streams into a frequency domain if the bit streams are of a time domain to provide bit streams of the frequency domain and providing the bit streams without transforming them if the bit streams are of the frequency domain;

(c) calculating power spectral density S(f) of the bit streams of the frequency domain;

(d) determining intermediate parameter I based on the power spectral density S(f);

(e) evaluating a Hurst parameter H based on the intermediate parameter I;

(f) allocating a bandwidth to the bit streams based on the Hurst parameter H; and

(g) transmitting the bit streams based on the allocated bandwidth.

2. The method of claim 1, wherein the bit streams of the time domain of the step (b) is transformed into the bit streams of the frequency domain by using the following equation:

$F<br><br>\left(f,T\right)={\int <br><br>}_0^T<br><br>X<br><br>\left(t,T\right)·<br><br>{\mathrm{<br><br>}}^{-j<br><br>\text{\hspace{1em}<br><br>}<br><br>2<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{ft}}<br><br><br><br>t$

wherein X(t, T) is the bit streams of the time domain, T is a time interval during which the bit streams of the time domain is generated, and the F(f, T) is the bit streams of the frequency domain.

3. The method of claim 2, wherein the power spectral density S(f) of the step (c) is calculated by using the following equation:

$S<br><br>\left(f\right)=\underset{T\to <br><br>\mathrm{\infty <br><br>}}{\lim }<br><br>\frac{1}{T}<br><br>{<br><br>F<br><br>\left(t,T\right)<br><br>}^2.$

4. The method of claim 3, wherein the intermediate parameter I of the step (d) is determined by using the following equation:

$S<br><br>\left(f\right)\propto <br><br>\frac{1}{f^I.}$

5. The method of claim 4, wherein the intermediate parameter determining step (d) includes the steps of:

(d1) taking a logarithm on both sides of the equation of claim 4 to generate the following equation;

6. The method of claim 5, wherein the Hurst parameter H of the step (e) is evaluated by using the following equation:

$H=\frac{I-1}{2}.$

7. The method of claim 6, wherein the step (g) includes the step of:

(g1) storing the bit streams; and

(g2) providing the stored bit streams to the ATM network based on the bandwidth allocated at the bandwidth allocating step (f).

8. An apparatus for allocating a bandwidth to bit streams of a video signal having variable bit rates, wherein the bit streams are transmitted to an ATM(asynchronous transfer mode) network, comprising:

means for encoding the video signal to thereby generate the bit streams of the encoded video signal;

means for transforming the bit streams into a frequency domain if the bit streams are of a time domain to provide bit streams of the frequency domain and providing the bit streams without transforming them if the bit streams are of the frequency domain;

means for calculating power spectral density S(f) of the bit streams of the frequency domain;

means for determining intermediate parameter I based on the power spectral density S(f);

means for evaluating a Hurst parameter H based on the intermediate parameter I;

means for allocating a bandwidth to the bit streams based on the Hurst parameter H;

means for storing the bit streams; and

means for transmitting the stored bit streams based on the allocated bandwidth.

9. The apparatus of claim 8, wherein the bit streams of the time domain is transformed by the transforming means by using the following equation:

$F<br><br>\left(f,T\right)={\int <br><br>}_0^T<br><br>X<br><br>\left(t,T\right)·<br><br>{\mathrm{<br><br>}}^{-j<br><br>\text{\hspace{1em}<br><br>}<br><br>2<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{ft}}<br><br><br><br>t$

wherein X(t, T) is the bit streams of the time domain, T is a time interval during which the bit streams of the time domain is generated, and the F(f, T) is the bit streams of the frequency domain.

10. The apparatus of claim 9, wherein the power spectral density S(f) is calculated by the power spectral density calculating means by using the following equation:

$S<br><br>\left(f\right)=\underset{T\to <br><br>\mathrm{\infty <br><br>}}{\lim }<br><br>\frac{1}{T}<br><br>{<br><br>F<br><br>\left(t,T\right)<br><br>}^2.$

11. The apparatus of claim 10, wherein the intermediate parameter I of the intermediate parameter determining means is determined by using the following equation:

$S<br><br>\left(f\right)\propto <br><br>\frac{1}{f^I}.$

12. The apparatus of claim 11, wherein the intermediate parameter determining means includes:

means for taking a logarithm on both sides of the equation of claim 11 to generate the following equation;

13. The apparatus of claim 12, wherein the Hurst parameter H of the Hurst parameter evaluating means is evaluated by using the following equation:

$H=\frac{I-1}{2}.$