Dynamic bandwidth allocation apparatus and method

1. A bandwidth allocation method of adaptively allocating radio channels in a mobile communication system, the bandwidth allocation method being performed by a bandwidth allocation module of a bandwidth allocation apparatus and comprising:

receiving, from a call admission control module of the bandwidth allocation apparatus that has determined to accept a call signal of a mobile station, a bandwidth allocation request for a traffic flow for the mobile station;

associating the traffic flow with a token bucket and a queue, and periodically filling the token bucket with an amount of tokens that corresponds to a requested amount of bandwidth determined by the call admission control module; and

allocating bandwidth to the traffic flow by controlling the amount of tokens in the token bucket;

wherein said allocating comprises

comparing a current queue length and a minimum queue length, the current queue length being measured for a predetermined time interval; and

increasing or decreasing the bandwidth depending on whether the current queue length is greater or less than the minimum queue length.

2. The bandwidth allocation method of claim 1 , wherein said allocating further comprises:

comparing a packet loss rate and a packet loss threshold value , wherein the packet loss rate determines an amount of bandwidth to be allocated for the next time interval; and

adjusting the current bandwidth by different amounts depending on whether the packet loss rate is greater or less than the packet loss threshold value.

3. The bandwidth allocation method of claim 2 , wherein, when the current queue length is less than the minimum queue length, said adjusting comprises:

reducing the current bandwidth by a smaller amount when the packet loss rate is greater than the packet loss threshold value; and reducing the current bandwidth by a larger amount when the packet loss rate is less than the packet loss threshold value.

4. The bandwidth allocation method of claim 3 , wherein, when the current queue length is greater than the minimum queue length, said adjusting comprises:

increasing the current bandwidth by a smaller amount when the packet loss rate is less than the packet loss threshold value; and

increasing the current bandwidth by a larger amount when the packet loss rate is greater than the packet loss threshold value.

5. The bandwidth allocation method of claim 2 , wherein, when the current queue length is greater than the minimum queue length, said adjusting comprises:

increasing the current bandwidth by a smaller amount when the packet loss rate is less than the packet loss threshold value; and

increasing the current bandwidth by a larger amount when the packet loss rate is greater than the packet loss threshold value.

6. The bandwidth allocation method of claim 1 , wherein said allocating further comprises

when the current queue length is less than the minimum queue length, determining whether or not the current queue length is less than the minimum queue length during two consecutive time intervals; and

when the current queue length is greater than the minimum queue length, determining whether or not the current queue length is greater than a maximum queue length.

7. The bandwidth allocation method of claim 6 , wherein said allocating further comprises, when the current queue length is determined to be less than the minimum queue length during two consecutive time intervals,

comparing a packet loss rate and a packet loss threshold value , wherein the packet loss rate determines an amount of bandwidth to be allocated for the next time interval; and

adjusting the current bandwidth by different amounts depending on whether the packet loss rate is greater or less than the packet loss threshold value.

8. The bandwidth allocation method of claim 7 , wherein said adjusting comprises:

reducing the current bandwidth by a smaller amount when the packet loss rate is greater than the packet loss threshold value; and

reducing the current bandwidth by a larger amount when the packet loss rate is less than the packet loss threshold value.

9. The bandwidth allocation method of claim 6 , wherein said allocating further comprises, when the current queue length is determined to be greater than the maximum queue length,

comparing a packet loss rate and a packet loss threshold value, wherein the packet loss rate determines an amount of bandwidth to be allocated for the next time interval; and

adjusting the current bandwidth by different amounts depending on whether the packet loss rate is greater or less than the packet loss threshold value.

10. The bandwidth allocation method of claim 9 , wherein said adjusting comprises:

increasing the current bandwidth by a smaller amount when the packet loss rate is less than the packet loss threshold value; and

increasing the current bandwidth by a larger amount when the packet loss rate is greater than the packet loss threshold value.

11. A bandwidth allocation apparatus for adaptively allocating radio channels in a mobile communication system, the bandwidth allocation apparatus comprising:

a call admission control module for requesting bandwidth allocation when a call signal of a mobile station is accepted;

a packet classification module for classifying received packets on the basis of one of an Internet Protocol address, a port, and an upper layer protocol in use, and transmitting the classified packets;

a buffer module for receiving and storing the classified packets transmitted from the packet classification module;

a packet scheduler module for receiving the classified packet from the buffer module and transmitting the packets to the mobile station through a radio resource link; and

a bandwidth allocation module for forming the buffer module for bandwidth allocation, and processing traffic services by inter-working with the packet scheduler module when the bandwidth allocation is requested by the call admission control module;

wherein the bandwidth allocation module allocates a token bucket for each traffic flow and controls a bandwidth allocated to each traffic flow by controlling the amount of tokens provided in the token bucket.

12. A bandwidth allocation apparatus for adaptively allocating radio channels in a mobile communication system, the bandwidth allocation apparatus comprising:

a call admission control module for requesting bandwidth allocation when a call signal of a mobile station is accepted;

a packet classification module for classifying received packets on the basis of one of an Internet Protocol address, a port, and an upper layer protocol in use, and transmitting the classified packets;

a buffer module for receiving and storing the classified packets transmitted from the packet classification module;

a packet scheduler module for receiving the classified packet from the buffer module and transmitting the packets to the mobile station through a radio resource link; and

a bandwidth allocation module for forming the buffer module for bandwidth allocation, and processing traffic services by inter-working with the packet scheduler module when the bandwidth allocation is requested by the call admission control module;

wherein the bandwidth allocation module increases or decreases bandwidth allocation in accordance with the bandwidth utility.

13. A bandwidth allocation apparatus for adaptively allocating radio channels in a mobile communication system, the bandwidth allocation apparatus comprising:

a call admission control module for requesting bandwidth allocation when a call signal of a mobile station is accepted;

a packet classification module for classifying received packets on the basis of one of an Internet Protocol address, a port, and an upper layer protocol in use, and transmitting the classified packets;

a buffer module for receiving and storing the classified packets transmitted from the packet classification module;

a packet scheduler module for receiving the classified packet from the buffer module and transmitting the packets to the mobile station through a radio resource link; and

a bandwidth allocation module for forming the buffer module for bandwidth allocation, and processing traffic services by inter-working with the packet scheduler module when the bandwidth allocation is requested by the call admission control module;

wherein the bandwidth allocation module controls increase/decrease of the bandwidth allocation depending on a measured communication quality of service (QoS).

14. The bandwidth allocation apparatus of claim 13 , wherein

when the communication QoS violation probability is high, the bandwidth allocation module increases a bandwidth increase rate and reduces a bandwidth decrease rate, and

when the communication QoS violation rate is low, the bandwidth allocation module reduces the bandwidth increase rate and increases the bandwidth decrease rate.

15. A bandwidth allocation apparatus for adaptively allocating radio channels in a mobile communication system, the bandwidth allocation apparatus comprising:

a call admission control module for requesting bandwidth allocation when a call signal of a mobile station is accepted;

a packet classification module for classifying received packets on the basis of one of an Internet Protocol address, a port, and an upper layer protocol in use, and transmitting the classified packets;

a buffer module for receiving and storing the classified packets transmitted from the packet classification module;

a packet scheduler module for receiving the classified packet from the buffer module and transmitting the packets to the mobile station through a radio resource link; and

a bandwidth allocation module for forming the buffer module for bandwidth allocation, and processing traffic services by inter-working with the packet scheduler module when the bandwidth allocation is requested by the call admission control module;

wherein the bandwidth allocation module periodically fills each token bucket with an amount of tokens that corresponds to an amount of bandwidth determined by the call admission control module.

16. A bandwidth allocation method of adaptively allocating radio channels in a mobile communication system, the bandwidth allocation method being performed by a bandwidth allocation apparatus and comprising the following steps in which:

a call admission control module of the bandwidth allocation apparatus requests bandwidth allocation when a call signal of a mobile station is accepted;

a packet classification module of the bandwidth allocation apparatus classifies received packets on the basis of one of an Internet Protocol address, a port, and an upper layer protocol in use, and transmits the classified packets;

a buffer module of the bandwidth allocation apparatus receives and stores the classified packets transmitted from the packet classification module;

a packet scheduler module of the bandwidth allocation apparatus receives the classified packet from the buffer module and transmits the packets to the mobile station through a radio resource link; and

a bandwidth allocation module of the bandwidth allocation apparatus

forms the buffer module for bandwidth allocation,

processes traffic services by inter-working with the packet scheduler module when the bandwidth allocation is requested by the call admission control module, and

controls increase/decrease of the bandwidth allocation depending on a measured communication quality of service (QoS).