Data link control proctocol for 3G wireless system

• US 6,542,490 B1
• Filed: 01/29/1999
• Issued: 04/01/2003
• Est. Priority Date: 01/29/1999
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Wu, Geng, Fong, Mo-Han, Ahmadvand, Nima
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US09/239,545
• Time in Patent Office: 1,523 Days
• Field of Search: 370/328, 370/329, 370/338, 370/401, 370/465, 370/466, 370/349, 370/469, 370/475
• US Class Current: 370/338
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2491 Mapping quality of service [QoS] requirements between different networks
• CPC Class Codes: H04L 47/43 Assembling or disassembling of packets, e.g. segmentation and reassembly [SAR]
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 28/0273 adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/02 Data link layer protocols
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks

Abstract

A Data Link Control protocol for 3G wireless communication system for direct support for network layer protocols, e.g. the Internet Protocol (IP), is provided. The Link Layer disclosed comprises a Link Access Control (LAC) sublayer and a Medium Access Control (MAC) sublayer. At a transmit end of the wireless system, a plurality of Quality of Service (QoS) data planes are created to directly support the IP QoS. Each QoS data plane is optimized to handle QoS requirements for a corresponding Class of Service (CoS). Data packets received at the LAC sublayer are directed to a QoS data plane according to the particular QoS information they contain and processed according to the particular QoS requirement to generate variable size LAC frames. The variable size LAC frames are transmitted to the MAC sublayer for generating radio link protocol data units (RLP PDUs) to be transmitted to a receiving end. A new level of error correction is provided at the LAC sublayer as the size of the LAC PDUs can be dynamically adjusted in response to the conditions of the communication link. A dual mode ARQ is provided at the MAC sublayer to improve the quality of the air transmission for bursty as well as non-bursty traffic conditions.

Claims

1. A Data Link Control (DLC) protocol for direct support of a network layer protocol, comprising:

at a transmit end of a wireless communication system;

a plurality of Quality of Service (QoS) data planes, a QoS data plane for processing a QoS oriented data packet according to a class of service (CoS), and to provide a radio link protocol data unit (RLP PDU);

a QoS processing module for receiving a network layer protocol data packet, converting said network layer protocol data packet into said QoS oriented data packet, and directing said QoS oriented data packet to one of said QoS data planes according to QoS information in said network layer protocol data packet; and

an interface between said DLC and a physical layer for receiving said RLP PDU and transmitting same to said physical layer.

2. A DLC protocol as claimed in claim 1, wherein said network layer protocol is Internet Protocol (IP).

3. A DLC protocol as claimed in claim 1, wherein each said QoS data plane comprises:

a Link Access Control (LAC) protocol instance for receiving said QoS oriented data packet and generating a HDLC-like LAC frame; and

a Medium Access Control (MAC) protocol instance for receiving said LAC frame and generating said RLP PDU.

4. A DLC protocol as claimed in claim 3, wherein said LAC protocol instance comprises:

a segmentation and re-assembly (SAR) module for receiving said service oriented data packet and dividing same into a number of sequence frames; and

a framing and automatic repeat request (ARQ) module for receiving said sequence frames and encapsulating a plurality of said sequence frames into said LAC frame.

5. A DLC protocol as claimed in claim 3, wherein said MAC protocol instance comprises:

a dedicated/common router (DCR) for receiving and routing said LAC frames to be carried over a radio traffic channel; and

a radio link protocol (RLP) for receiving said LAC frames and converting said LAC frames into said RLP PDUs.

6. A DLC protocol as claimed in claim 5, further comprising a MAC control state machine (CSM) for regulating the delivery of said LAC frames to said RLP.

7. A DLC protocol as claimed in claim 5, wherein said RLP comprises an automatic repeat request (ARQ) function for automatic retransmission of said RLP PDUs if received in error at a receiving end of said wireless system.

8. A DLC protocol as claimed in claim 7, wherein said ARQ function has a selective repeat component active during a normal-mode (NM) of operation and a stop and wait (SW) component active during a burst-mode (BM) of operation.

9. A DLC protocol as claimed in claim 4, wherein said LAC frame has a variable size, said size being dynamically optimized based on the conditions of the communication link.

10. A DLC protocol as claimed in claim 9, wherein said size of said LAC frame is automatically reduced when a predetermined number of negative acknowledgments (NAK) are received.

11. A method as claimed in claim 9, wherein said size of said LAC frame is automatically reduced if no acknowledgments are received for a predetermined period of time.

12. A DLC protocol as claimed in claim 1 wherein said interface is a multiplexer for receiving said RLP PDU, and multiplexing same into a physical channel according to the QoS of said RLP PDU, for transmission to a receiving end of said wireless system.

13. A DLC protocol as claimed in claim 1 further comprising a resource control unit for mapping a QoS requirement to a DLC class of service (CoS), and separating said CoS inside the DLC protocol into said QoS data planes.

14. A method for direct processing a network layer protocol data packets for transmission over a wireless communication system, comprising the steps of:

separating the data link layer of the wireless communication system into a plurality of Quality of Service (QoS) data planes, a QoS plane for processing a QoS oriented data packet according to a class of service (CoS), and to provide a radio link protocol data unit (RLP PDU);

processing said network layer protocol data packet by converting said network layer protocol data packet into said QoS oriented data packet and directing said QoS oriented data packet to one of said QoS data planes according to QoS information in said network layer protocol data packet; and

forwarding said RLP PDU to a physical layer according to the QoS of said RLP PDU.

15. A method as claimed in claim 14, wherein said network layer protocol is Internet Protocol (IP).

16. A method as claimed in claim 14, wherein said step of separating comprises:

providing a plurality of QoS oriented Link Access Control (LAC) protocol instances, a LAC protocol instance for each said QoS data plane, said LAC protocol instance for receiving said service oriented data packet and generating a HDLC-like LAC frame; and

providing a plurality of QoS oriented Medium Access Control (MAC) protocol instances, a MAC protocol instance for each QoS data plane, said MAC protocol instance for receiving said LAC frames and generating said radio link protocol data unit (RLP PDU).

17. A method as claimed in claim 16, wherein said step of generating a HDLC-like LAC frame comprises dividing said QoS oriented data packet into a number of sequence frames and encapsulating a plurality of said sequence frames into said LAC frame.

18. A method as claimed in claim 16, wherein said step of generating said RLP PDU comprises receiving said LAC frames and converting said LAC frames into said RLP PDUs.

19. A method as claimed in claim 18, further comprising regulating the delivery of said LAC frames to said RLP.

20. A method as claimed in claim 16, further comprising an automatic repeat request (ARQ) function for automatic retransmission of said RLP PDUs if received in error at a receiving end of said wireless system.

21. A DLC protocol as claimed in claim 20, wherein said ARQ function operates in a normal-mode (NM) of operation to selectively repeat (SR) any said RLP PDU received in error, and in a burst-mode (BM) of operation to stop and wait (SW) for an acknowledgment of receipt of said RLP PDU.

22. A method as claimed in claim 21, wherein said ARQ function assumes said BM of operation at activation, without any handshake initiation procedures.

23. A method as claimed in claim 21, wherein said ARQ function transits from said BM of operation to said NM of operation whenever an implementation specific condition is met.

24. A method as claimed in claim 23, wherein implementation specific condition is the size of said RLP PDUs.

25. A method as claimed in claim 23, further comprising a handshake initiation sequence for commencing transmission in said NM of operation.

26. A method as claimed in claim 17, wherein said step of encapsulating also provides a dynamic optimization of the size of said LAC frame based on the conditions of the communication link, for enhancing the quality of the air transmission.

27. A method as claimed in claim 26, wherein said size of said LAC frames is automatically reduced when a predetermined number of negative acknowledgments (NAK) are received.

28. A method as claimed in claim 26, wherein said size of said LAC frames is automatically reduced if no acknowledgments are received for a predetermined period of time.

29. A method as claimed in claim 17, wherein said sequence frame comprises a beginning of frame field and a sequence number field.

30. A method as claimed in claim 14, wherein said step of processing comprises mapping a QoS requirement to a DLC class of service (CoS), and separating said CoS inside the DLC protocol into said QoS data planes.

31. A method as claimed in claim 30, wherein said step of processing further comprises adding a length indicator to said network layer protocol data packet.