Method and apparatus for transmitting/receiving packet data using pre-defined length indicator in a mobile communication system

• US 7,675,941 B2
• Filed: 05/04/2006
• Issued: 03/09/2010
• Est. Priority Date: 05/04/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Van Lieshout, Gert-Jan, Van Der Velde, Himke, Kim, Soeng-Hun
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): OVEISSI, DAVID M
• Application Number:
  US11/417,219
• Publication Number:
  US 20070060139A1
• Time in Patent Office: 1,405 Days
• Field of Search: 370/281, 370/295, 370/344, 370/252, 370/349, 370/470, 370/474, 370/469
• US Class Current: 370/473
• CPC Class Codes: H04L 1/1841 Resequencing
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• 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 80/02 Data link layer protocols

Abstract

A method and apparatus for enabling efficient use of radio resources by reducing an RLC PDU size in a mobile communication system supporting voice service over a packet network are provided. An RLC layer constructs an RLC PDU without inserting information indicating the start and end of an SDU or indicating the use or non-use of padding. The RLC layer sets an LI in a header to indicate inclusion of an intermediate SDU segment in the data field of the RLC PDU. Therefore, the resulting decrease of overhead arising from packet transmission facilitates the efficient use of limited radio resources.

Claims

1. A method of transmitting data in a mobile communication system, comprising:

receiving a service data unit (SDU) from a higher layer and determining whether the SDU can be comprised in one protocol data unit (PDU);

if the SDU is not comprised in one PDU, segmenting the SDU into a plurality of segments according to a transmittable PDU size, and constructing one or more PDUs, each PDU comprising a header and a data field,

wherein the data field comprises a segment of the SDU,

wherein the header comprises a serial number (SN) field, a one-bit field indicating that the PDU does not contain an entire SDU in the data field and at least one Length Indicator (LI) field,

wherein if the data field of the PDU contains an intermediate segment of the SDU, the LI field in the PDU contains the intermediate segment of the SDU is set to a predefined value indicating that the PDU contains neither a first segment nor a last segment of the SDU; and

sending the PDUs to a receiver.

2. The method of claim 1, further comprising the step of, if the SDU is comprised in one PDU, constructing one PDU comprising a header and a data field,

wherein the header comprises a SN field, and a one-bit field indicating that the PDU contains the entire SDU in the data field.

3. The method of claim 1, further comprising the step of, if a PDU size except the SN field and the one-bit field for a next transmission interval matches to the size of the SDU, determining the PDU size according to the size of the SDU and a radio channel condition, determining that the SDU can be comprised in one PDU.

4. The method of claim 1, wherein LI fields of PDUs comprising the first and last segments of the SDU in data fields are set to values indicating inclusion of the first segment of the SDU and inclusion of the last segment of the SDU.

5. The method of claim 1, wherein the SDU comprises an internet protocol (IP) packet.

6. A method of receiving data in a mobile communication system, comprising:

receiving a protocol data unit (PDU) from a transmitter and detecting a sequence number (SN) field and a one-bit field indicating whether the PDU contains an entire service data unit (SDU) in its data field from the header;

if the one-bit field indicates that the PDU does not contain an entire SDU in its data field, detecting the following length indicator (LI) field from the header of the PDU, and determining whether the LI field is set to a value indicating that the PDU contains an intermediate segment that is neither a first segment nor a last segment of the SDU;

storing the PDU until the PDU can be assembled with a previous segment and a following segment, if the LI field is set to the predefined value; and

constructing the SDU by combining the intermediate segment from the data field of the PDU with at least one previous segment extracted from a data field of at least one previous PDU and at least one following segment extracted from a data field of at least one following PDU.

7. The method of claim 6, further comprising, if the one-bit field indicates that the PDU contains the entire SDU in its data field, acquiring the entire SDU from the data field of the PDU.

8. The method of claim 6, wherein the storing comprises the steps of storing the PDU in a reception buffer according to the SN field of the PDU.

9. The method of claim 8, wherein the constructing comprises constructing the SDU by combining segments extracted from data fields of a set of PDUs stored in the reception buffer, if the first of the PDUs comprises an LI field indicating inclusion of the first segment of the SDU, if at least one intermediate PDU among the PDUs comprises an LI field set to the value, and if the first LI field of the last of the PDUs indicates the position of the last byte of the SDU.

10. An apparatus for transmitting data in a mobile communication system, comprising:

a transmission buffer for receiving a service data unit (SDU) from a higher layer, determining whether the SDU can be comprised in one protocol data unit (PDU) segmenting the SDU into a plurality of segments according to a transmittable PDU size if the SDU does not be comprised in one PDU, and constructing one or more PDUs;

a header inserter for constructing a header of each PDU, wherein the header comprises a serial number (SN) field, a one-bit field, at least one Length Indicator (LI) field;

a one-bit field setter for setting the one-bit field of the at least one PDU to indicate whether the PDU contains an entire SDU in the data field;

an LI inserter for inserting an LI field after the one-bit field in the at least one PDU if the SDU is not comprised in one PDU, and setting an LI field to a predefined value indicating that the PDU contains neither a first segment nor a last segment of the SDU to contain the intermediate segment of the SDU; and

a transmitter for sending the PDUs to a receiver.

11. The apparatus of claim 10, wherein if the SDU is comprised in one PDU, constructing one PDU comprising a header and a data field,

wherein the header comprises a SN field, and a one-bit field indicating that the PDU contains the entire SDU in the data field.

12. The apparatus of claim 10, wherein if a PDU size except the SN field and the one-bit field for a next transmission interval matches to the size of the SDU, the PDU size being determined according to the size of the SDU and a radio channel condition, the transmission buffer determines that the SDU can be comprised in one PDU.

13. The apparatus of claim 10, wherein the LI inserter sets LI fields of PDUs comprising the first and last segments of the SDU in data fields to values indicating inclusion of the first segment of the SDU and inclusion of the last segment of the SDU.

14. The apparatus of claim 10, wherein the SDU comprises an internet protocol (IP) packet.

15. An apparatus for receiving data in a mobile communication system, comprising:

a reception buffer for receiving a protocol data unit (PDU) from a transmitter and storing the PDU;

a reassembly controller for detecting a sequence number (SN) field and a one-bit field indicating whether the PDU contains an entire service data unit (SDU) in its data field from the header, detecting the following length indicator (LI) field from the header of the PDU and determining whether the LI field is set to a predefined value indicating that the PDU contains an intermediate segment that is neither a first segment nor a last segment of the SDU if the one-bit field indicates that the PDU does not contain an entire SDU in its data field;

a header and LI remover for eliminating the SN field, the one-bit field, and the LI field if the one-bit field indicates that the PDU does not contain the entire SDU in its data field,; and

a reassembler for receiving the intermediate segment from the header and LI remover and constructing the SDU by combining the intermediate segment with at least one previous segment extracted from a data field of at least one previous PDU and at least one following segment extracted from a data field of at least one following PDU.

16. The apparatus of claim 15, wherein the header and LI remover eliminate the SN field and the one-bit field from the PDU and acquire the entire SDU from the data field of the PDU if the one-bit field indicates that the PDU contains the entire SDU in its data field.

17. The apparatus of claim 15, wherein the reception buffer stores the PDU according to the SN field of the PDU.

18. The apparatus of claim 17, wherein the reassembler constructs the SDU by combining segments extracted from data fields of a set of PDUs stored in the reception buffer, if the first of the PDUs comprises an LI field indicating inclusion of the first segment of the SDU, if at least one intermediate PDU among the PDUs comprises an LI field set to the value, and if the first LI field of the last of the PDUs indicates the position of the last byte of the SDU.