Apparatus and Method for Scheduling of High-Speed Portable Internet System

• US 20080186909A1
• Filed: 06/27/2006
• Published: 08/07/2008
• Est. Priority Date: 06/27/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute, KT Corporation, Samsung Electronics Co. Ltd., Hanaro Telecom., Inc. (SK Telecom Co., Ltd.), SK Telecom Co., Ltd.
• Original Assignee: KT Corporation, KT Freetel Co., Ltd. (KT Corporation), Samsung Electronics Co. Ltd., Hanaro Telecom., Inc. (SK Telecom Co., Ltd.), SK Telecom Co., Ltd.
• Inventors: Kim, Kyung-Soo, Kim, Ju-Hee, Lee, Sook-Jin
• Granted Patent: US 8,792,415 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/1273 of downlink data flows

Abstract

The present invention relates to a scheduling apparatus and a method thereof in an HPi system. A scheduling algorithm is applied appropriate to a characteristic of each multimedia service (e.g., real-time service, non real-time service, best-effort service, etc.) and a transmission order of the IP packets transmitted from a network is determined such that a transmit wait queue is generated. Radio resource allocation is performed in accordance with the order of the data items queued in the transmit wait queue, the size of transmittable data is determined such that a PDU is generated. In addition, frame data formed of bursts of PDUs is generated and transmitted to a physical layer. Therefore, a scheduling algorithm can be applied appropriate to characteristics of each multimedia service. In addition, packet scheduling is performed in two steps in order to schedule traffic corresponding to radio frames such that packets can be efficiently processed.

Claims

1. A method for scheduling a packet transmitted to a user terminal from a base station, the base station supporting a wireless access and a network connection of the user terminal, the method comprising:

a) determining multimedia service types provided by the base station, selecting a given scheduling algorithm corresponding to the respective the multimedia service types, determining a transmission order of packets by applying the selected scheduling algorithm to the packets received through the network, and forming a transmit wait queue; and

b) allocating radio resources to the packets queued in the transmit wait queue, determining the size of transmittable data, generating a protocol data unit (PDU) based on the size of the transmittable data, and generating frame data formed of a plurality of PDU bursts.

2. The method of claim 1, wherein a) comprises:

determining an amount of data allocation for each service available in a current frame in consideration of data service rates for the respective multimedia service types and a total number of packets queued for each service; and

selecting packets corresponding to the determined amount of data allocation for each service according to a scheduling algorithm applied for each service and storing packet information in the transmit wait queue.

3. The method of claim 1, wherein a) further comprises:

before applying the scheduling algorithm, receiving a packet from the network, generating Internet protocol (IP) packet information by performing packet determination for determining the corresponding user, a connection identifier, and priority, collecting scheduling information containing the IP packet information and channel quality information transmitted from the user terminal, and calculating importance of the corresponding service, and

wherein the transmit wait queue is formed of data items including at least one of packet information to be serviced, the corresponding connection identifier, importance, and channel quality information when generating the transmit wait queue, the data items being in a linked list.

4. The method of claim 1, wherein b) comprises:

extracting a data item from the transmit wait queue and determining a modulation and coding scheme (MCS) level according to channel quality information stored in the data item;

calculating the number of subchannels in a radio frame for transmission of data to be serviced when the MCS level is determined;

calculating the size of a service data transmittable through a currently available subchannel when the calculated number of subchannels in the radio frame is greater than the number of subchannels left in the current frame;

allocating an amount of data corresponding to the calculated transmittable service data size to the available subchannel, and processing remaining data to be serviced in the next frame; and

generating a PDU for wireless network transmission of the data allocated to the available subchannel.

5. The method of claim 4,

wherein the number of subchannels in the radio frame is calculated in accordance with adaptive modulation and coding information determined by the size of the data allocated to the corresponding user within the frame and radio channel quality, and

wherein the PDU is generated for a packet selected within the calculated number of subchannels at every frame.

6. The method of claim 4,

wherein data failed to be transmitted in the current frame is transmitted in the next frame according to the transmission order in the transmit wait queue;

and

wherein in a), a total number of packets waiting to be serviced for each service is determined in accordance with a total number of packets left in the transmit wait queue when the packets queued in the transmit wait queue are failed to be transmitted in the current frame.

7. The method of claim 1, wherein, when a hybrid automatic repeat request (HARQ) is applied, b) comprises allocating a radio resource for a PDU burst waiting for retransmission, allocating a radio resource for the packet left in the transmit wait queue, and generating a PDU and frame data.

8. A scheduling apparatus scheduling packets transmitted to a user terminal from a base station that supports wireless access and network connection of the user terminal, the scheduling apparatus comprising:

a scheduler comprising;

a packet classifier analyzing a packet header transmitted from the network and classifying the packet;

a storing unit storing the packet transmitted from the packet classifier;

a first scheduling process module selecting a scheduling algorithm appropriate for a multimedia service type provided from the base station, performing the selected scheduling algorithm, determining a packet transmission order, and forming a transmit wait queue; and

a second scheduling process module allocating a radio resource for packet queued in the transmit wait queue, selecting data to be transmitted at every frame, and generating the corresponding generation information; and

a protocol data unit (PDU) generator generating a PDU according to the generation information provided by the scheduler.

9. The scheduling apparatus of claim 8, wherein the first scheduling process module comprises:

a scheduling packet collector collecting scheduling information containing IP packet information and channel quality information according to a result of the packet determination;

an algorithm performer performing a scheduling algorithm predetermined for the corresponding service type and determining a packet transmission order based on the scheduling information; and

a wait queue generator generating a transmit wait queue based on the packets with the determined transmission order.

10. The scheduling apparatus of claim 8, wherein the second scheduling process module comprises:

a resource allocator allocating a radio resource for a packet according to the order of data items queued in the transmit wait queue, the data items including at least one of packet information to be serviced, the corresponding connection identifier, priority, and importance; and

an information generator selecting data to be transmitted at every frame, determining a transmittable data size, generating PDU generation information, and transmitting the PDU generation information to the PDU generator.