APPARATUS AND METHOD FOR CONNECTION ADMISSION CONTROL IN BROADBAND WIRELESS ACCESS SYSTEM

• US 20090116384A1
• Filed: 11/06/2008
• Published: 05/07/2009
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Ki-Back, PARK, Eun-Chan
• Granted Patent: US 7,864,804 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 47/824 Applicable to portable or mobile terminals
• CPC Class Codes: H04L 47/83 based on usage prediction

Abstract

An apparatus and method for Connection Admission Control (CAC) in a Broadband Wireless Access (BWA) system are provided. In the method, a QoS class of a call requesting connection admission is detected and an application layer required bandwidth is determined using the QoS parameters of a service flow of the detected QoS class. A required bandwidth weight of the QoS class is determined in consideration of a packet header overhead. Per-slot available bandwidths of a reference QoS class and the QoS class are determined using the determined application layer required bandwidth, and a required bandwidth conversion ratio of a corresponding QoS class is determined using the determined per-slot available bandwidths. An equivalent MAC layer required bandwidth is determined using the determined application layer required bandwidth, the required bandwidth weight, and the required bandwidth conversion ratio.

Claims

1. A method for Connection Admission Control (CAC) in a Broadband Wireless Access (BWA) system, the method comprising:

detecting a QoS class of a call requesting connection admission;

determining an application layer required bandwidth by using the QoS parameters of a service flow of the detected QoS class;

determining a required bandwidth weight of the QoS class in consideration of a packet header overhead;

determining per-slot available bandwidths of a reference QoS class and the QoS class by using the determined application layer required bandwidth;

determining a required bandwidth conversion ratio of a corresponding QoS class by using the determined per-slot available bandwidths; and

determining an equivalent MAC layer required bandwidth by using the determined application layer required bandwidth, the required bandwidth weight, and the required bandwidth conversion ratio.

2. The method of claim 1, wherein the determining of the application layer required bandwidth comprises:

if the QoS class is Unsolicited Grant Service (UGS), determining the application layer required bandwidth by using the Maximum Sustained Traffic Rate among the QoS parameters of the corresponding QoS class;

if the QoS class is extended real-time Polling Service (ertPS), determining the application layer required bandwidth by using at least one of the Maximum Sustained Traffic Rate and the Minimum Reserved Traffic Rate among the QoS parameters of the corresponding QoS class; and

if the QoS class is real-time Polling Service (rtPS) or non-real-time Polling Service (nrtPS), determining the application layer required bandwidth by using the Minimum Reserved Traffic Rate among the QoS parameters of the corresponding QoS class.

3. The method of claim 1, wherein the packet header overhead comprises at least one of Generic MAC Header (GMH), Cyclic Redundancy Check (CRC), Packing Sub-Header (PSH), Fragmentation Sub-Header (FSH), and Traffic Encryption Key (TEK).

4. The method of claim 1, wherein the required bandwidth weight is determined using at least one of the packet header overhead, characteristics of the QoS class, the application layer required bandwidth, and a padding-caused overhead.

5. The method of claim 1, wherein the per-slot available bandwidth of the QoS class is determined using the following equation:

6. The method of claim 5, wherein the required bandwidth conversion ratio is determined using the following equation:

7. The method of claim 6, wherein the equivalent required bandwidth is determined using the following equation:

C_eq=BW_req*(1+α

(application SF))/β

(QoS_class)

where C_eq denotes the equivalent required bandwidth, BW_req denotes the application layer required bandwidth, α

(application SF) denotes the required bandwidth weight of the QoS class, which is greater than 0, and β

(QoS_class) denotes the required bandwidth conversion ratio of the QoS class.

8. The method of claim 1, wherein the reference QoS class comprises Unsolicited Grant Service (UGS).

9. The method of claim 1, wherein determining of the signal overhead of the QoS class comprises:

determining an available bandwidth by excluding, from the entire slots, a slot allocated to the determined signal overhead and a slot allocated to a data burst of all the QoS SFs except Best Effort (BE);

determining an equivalent available bandwidth by using the determined available bandwidth and the per-slot available bandwidth of the reference QoS class; and

performing a CAC operation by comparing the determined equivalent required bandwidth and the equivalent available bandwidth.

10. The method of claim 9, wherein the signal overhead comprises at least one of a Multicast and Broadcast Service (MBS) supporting overhead, a sleep or idle mode user supporting overhead, a preamble, DL/UL MAP, a broadcasting message, a UL control channel, a bandwidth allocation request, Dynamic Service Add (DSA)/Dynamic Service Change (DSC)/Dynamic Service Deletion (DSD), RObust Header Compression (ROHC) feedback signals, and ARQ ACK.

11. The method of claim 9, wherein the equivalent available bandwidth is determined using the following equation:

C_a=N_a*Δ

C(reference QoS_class)

where C_a denotes the equivalent available bandwidth, N_a denotes the available bandwidth, and Δ

C(reference QoS_class) denotes the per-slot available bandwidth of the reference QoS class.

12. The method of claim 9, wherein the determined equivalent required bandwidth and the equivalent available bandwidth are compared using the following equation:

C_eq<

KC_a

where C_eq denotes the equivalent required bandwidth, C_a denotes the equivalent available bandwidth, and K is a constant value smaller than 1, which is set differently depending on the QoS class of a corresponding call and whether the corresponding call is a new call or a handover call.

13. An apparatus for Connection Admission Control (CAC) in a Broadband Wireless Access (BWA) system, the apparatus comprising:

a controller for determining whether there is a call requesting connection admission; and

a CAC processor for detecting a QoS class of the call requesting connection admission and for determining an application layer required bandwidth by using the QoS parameters of a service flow of the detected QoS class.

14. The apparatus of claim 13, wherein the CAC processor determines a required bandwidth weight of the QoS class in consideration of a packet header overhead, determines per-slot available bandwidths of a reference QoS class and the QoS class by using the determined application layer required bandwidth, determines a required bandwidth conversion ratio of a corresponding QoS class by using the determined per-slot available bandwidths, and determines an equivalent MAC layer required bandwidth by using the determined application layer required bandwidth, the required bandwidth weight, and the required bandwidth conversion ratio.

15. The apparatus of claim 13, wherein the CAC processor determines, if the QoS class is Unsolicited Grant Service (UGS), the application layer required bandwidth by using the Maximum Sustained Traffic Rate among the QoS parameters of the corresponding QoS class, determines, if the QoS class is extended real-time Polling Service (ertPS), the application layer required bandwidth by using at least one of the Maximum Sustained Traffic Rate and the Minimum Reserved Traffic Rate among the QoS parameters of the corresponding QoS class and determines, if the QoS class is real-time Polling Service (rtPS) or non-real-time Polling Service (nrtPS), the application layer required bandwidth by using the Minimum Reserved Traffic Rate among the QoS parameters of the corresponding QoS class.

16. The apparatus of claim 13, wherein the packet header overhead comprises at least one of Generic MAC Header (GMH), Cyclic Redundancy Check (CRC), Packing Sub-Header (PSH), Fragmentation Sub-Header (FSH), and Traffic Encryption Key (TEK).

17. The apparatus of claim 13, wherein the required bandwidth weight is determined using at least one of the packet header overhead, characteristics of the QoS class, the application layer required bandwidth, and a padding-caused overhead.

18. The apparatus of claim 13, wherein the per-slot available bandwidth of the QoS class is determined using the following equation:

19. The apparatus of claim 18, wherein the required bandwidth conversion ratio is determined using the following equation:

20. The apparatus of claim 19, wherein the equivalent required bandwidth is determined using the following equation:

C_eq=BW_req*(1+α

(application SF))/β

(QoS_class)

where C_eq denotes the equivalent required bandwidth, BW_req denotes the application layer required bandwidth, α

(application SF) denotes the required bandwidth weight of the QoS class, which is greater than 0, and β

(QoS_class) denotes the required bandwidth conversion ratio of the QoS class.

21. The apparatus of claim 13, wherein the reference QoS class comprises Unsolicited Grant Service (UGS).

22. The apparatus of claim 13, wherein the CAC processor determines an available bandwidth by excluding, from the entire slots, a slot allocated to the determined signal overhead and a slot allocated to a data burst of all the QoS SFs except Best Effort (BE), determines an equivalent available bandwidth by using the determined available bandwidth and the per-slot available bandwidth of the reference QoS class and performs a CAC operation by comparing the determined equivalent required bandwidth and the equivalent available bandwidth.

23. The apparatus of claim 22, wherein the signal overhead comprises at least one of a Multicast and Broadcast Service (MBS) supporting overhead, a sleep or idle mode user supporting overhead, a preamble, DL/UL MAP, a broadcasting message, a UL control channel, a bandwidth allocation request, Dynamic Service Add (DSA)/Dynamic Service Change (DSC)/Dynamic Service Deletion (DSD), RObust Header Compression (ROHC) feedback signals, and ARQ ACK.

24. The apparatus of claim 22, wherein the equivalent available bandwidth is determined using the following equation:

C_a=N_a*Δ

C(reference QoS_class)

where C_a denotes the equivalent available bandwidth, Na denotes the available bandwidth, and Δ

C(reference QoS_class) denotes the per-slot available bandwidth of the reference QoS class.

25. The apparatus of claim 22, wherein the determined equivalent required bandwidth and the equivalent available bandwidth are compared using the following equation:

C_eq<

KC_a

where C_eq denotes the equivalent required bandwidth, C_a denotes the equivalent available bandwidth, and K is a constant value smaller than 1, which is set differently depending on the QoS class of a corresponding call and whether the corresponding call is a new call or a handover call.