Packet scheduling method using cumulative distribution function

• US 20050163072A1
• Filed: 12/02/2004
• Published: 07/28/2005
• Est. Priority Date: 12/05/2003
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Original Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Inventors: Seo, Han-Byul, Cho, Sung-Hyun, Yun, Sang-Boh, Park, Dae-Young, Kwon, Ho-Joong, Park, Won-Hyoung, Lee, Byeong-Gi
• Application Number:
  US11/002,026
• Publication Number:
  US 20050163072A1
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 47/626 channel conditions
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 72/535 based on resource usage policies
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

A packet scheduling method using a cumulative distribution function. The scheduling method for use in a communication system including a plurality of MSs (Mobile Stations) and a central controller for assigning resources to individual MSs on the basis of a transmission rate associated with downlink channels fed back from the MSs, includes the steps of generating a uniform random variable of transmission rates of individual MSs; converting the uniform random variable into a scheduling priority; comparing the scheduling priority of each MS with each other; and assigning resources to a MS having the highest scheduling priority.

Claims

1. A scheduling method for use in a communication system including a plurality of MSs (Mobile Stations) and a central controller for assigning resources to the MSs on the basis of transmission rates of downlink channels, the transmission rates being fed back from the MSs, comprising the steps of:

generating a uniform random variable of the transmission rates for each MS;

converting the uniform random variable into a scheduling priority;

comparing the scheduling priority of each MS with each other; and

assigning resources to a MS having the highest scheduling priority.

2. The method of claim 1, wherein the uniform random variable is a cumulative distribution function of transmission rates of the MS.

3. The method of claim 1, wherein the step of generating the uniform random variable, further includes the steps of:

periodically receiving the transmission rates fed back from the MSs;

generating a cumulative distribution function based on the received transmission rates; and

generating a uniform random variable using the cumulative distribution function.

4. A scheduling method for use in a wireless communication system including a plurality of Mobile Stations (MSs) and a Base Station (BS) for assigning specific resources to the MSs on the basis of transmission rate indicators associated with downlink channels, the transmission rate indicators being fed back from the MSs, comprising:

generating uniform random variables based on the transmission rate indicators;

converting the uniform random variables into scheduling priorities;

comparing the scheduling priorities of the MSs with each other; and

assigning a timeslot to a MS having a highest scheduling priorities.

5. The method of claim 4, wherein the uniform random variable is a cumulative distribution function of the transmission rate indicators fed back from each MS.

6. A scheduling method for use in a wireless communication system including a plurality of Mobile Stations (MSs) and a Base Station (BS) for assigning an n-th timeslot to a MS on the basis of transmission rate indicators of downlink channels, comprising the steps of:

generating a uniform random variable based on transmission rates corresponding to the transmission rate indicators from each MS;

converting the uniform random variable into scheduling priorities;

comparing scheduling priorities of the MSs with each other; and

assigning the n-th timeslot to an MS having the highest scheduling priorities.

7. The method of claim 6, wherein the uniform random variable is a cumulative distribution function of the transmission rates represented by the transmission rate indicators fed back from each MS.

8. A scheduling method for use in a wireless communication system including k Mobile Stations (MSs) and a Base Station (BS) which selects one MS for assigning an n-th timeslot on the basis of transmission rate information m_k(n) of downlink channels fed back from the MSs, comprising the step of:

generating a uniform random variable U_k(n) using the transmission rate information received from each MS;

converting the uniform random variable U_k(n) into a scheduling priority U_k(n)^1/wk;

comparing the scheduling priority U_k(n)^1/wk of each MSs with each other; and

assigning the n-th timeslot to a MS having a highest scheduling priority U_k(n)^1/wk where,

$\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br>w_m=1.$

9. The method of claim 8, wherein the uniform random variable U_k(n) is a cumulative distribution function F_Rk(r) of transmission rates R_k(n) corresponding to the transmission rate information m_k(n).

10. The method of claim 8, further comprising the step of updating the cumulative distribution function F_Rk(r).

11. The method of claim 10, wherein the cumulative distribution function F_Rk(r) update is based on a probability density function of the transmission rates.

12. The method of claim 11, wherein the cumulative distribution function F_Rk(r) update includes the step of updating the probability density function.

13. The method of claim 12, wherein the probability density function P_k,m is updated based on:

p_k,m←

λ

p_k,m+(1−

λ

)1_m=mk(n), where, λ

is 0<

λ

<

1, A represents the condition m=m_k(n), and 1_A is an indicator which is ‘

1’

when the condition ‘

A’

is satisfied or is ‘

0’

when the condition ‘

A’

is not satisfied, if the probability density function is set to p_k,m≡

Pr(R_k(n)=r_k,m) and the cumulative distribution function q_k,m is set to

14. The method of claim 8, wherein the uniform random variable U_k(n) is a cumulative distribution function F_Rk(r) of the transmission rate information m_k(n).

15. The method of claim 14, wherein updating the probability density function is carried out using a probability density function of the transmission rate.

16. The method of claim 14, wherein the cumulative distribution function is updated using a probability density function of the transmission rate.

17. The method of claim 15, wherein the probability density function is updated based on:

p_k,m←

λ

p_k,m+(1−

λ

)1_m=mk(n), where, λ

is 0<

λ

<

1, A represents the condition m=m_k(n), and 1_A is an indicator which is ‘

1’

when the condition ‘

A’

is satisfied or is ‘

0’

when the condition ‘

A’

is not satisfied, if the probability density function is set to p_k,m≡

Pr(R_k(n)=r_k,m) and the cumulative distribution function q_k,m is set to