Methods, apparatuses and computer program product for pdu formatting according to sdu segmentation

Abstract

An example method includes determining, for a protocol data unit (PDU) to be provided to a receiver entity, whether a segment of a service data unit (SDU) is to be included in the PDU and, if so, determining a position of the segment relative to the SDU. The PDU comprises a header part and a data field part. The method includes determining whether to include information in the header part in dependence on the determining whether the segment of the SDU is to be included in the PDU, and, if so, determining the content of the information in the header part in dependence on the position of the segment relative to the SDU. The method also includes providing the PDU to a receiver entity.

What is claimed is: 
     
         1 . A method comprising
 determining, for a SDU to be included in a PDU, whether a segment of the SDU is to be included in the PDU and, if so, determining the position of the segment relative to the SDU, the PDU comprising a header part and a data field part;   determining whether to include information in the header part in dependence of the first determining, and, if so, determining the content of the information in dependence on the first determining; and   providing the PDU to a receiver entity.   
     
     
         2 . A method according to  claim 1 , comprising determining that a segment of the SDU is the first segment of the SDU and that the content of the information indicates the SDU length. 
     
     
         3 . A method according to  claim 1 , comprising determining that a segment of the SDU is a segment between the first segment and the last segment of the SDU and that the content of the information indicates segment offset. 
     
     
         4 . A method according to  claim 1 , comprising determining that a segment of the SDU is the last segment of the SDU and that the content of the information indicates the SDU segment length. 
     
     
         5 . A method according to  claim 1 , comprising determining that a segment of the SDU is the last segment of the SDU and fills the PDU, and determining not to include the information in the header part. 
     
     
         6 . A method according to  claim 1 , wherein the information comprises a length indicator field. 
     
     
         7 . A method according to  claim 1 , wherein the header part comprises framing information, the framing information comprising a first bit indicative of whether the first byte of the data field corresponds to the first byte of a SDU and a second bit indicative of whether the last byte of the data field corresponds to the last byte of a SDU. 
     
     
         8 . A method according to  claim 7 , wherein the header part comprises data field element information, the data field element indicative of the number of data field elements in the data field and comprising providing data field element information after the second bit of the framing information and before the first bit of the framing information. 
     
     
         9 . A method according to  claim 1 , wherein the receiver entity is a radio link control entity. 
     
     
         10 . A method according to  claim 1 , wherein the header part comprises a sequence number and the sequence number corresponds to the sequence number of the first SDU included in the PDU. 
     
     
         11 . A method comprising:
 receiving a PDU from a transmission entity, the PDU comprising a header part and a data field part;   determining whether a segment of a SDU is present in the PDU and, if so, determining the position of the segment relative to the SDU; and   determining whether information is present in the header part and, if so, using said information in dependence on the first determining.   
     
     
         12 . A method according to  claim 11 , comprising determining that a segment of the SDU is the first segment of the SDU and wherein the content of the information indicates the SDU length. 
     
     
         13 . A method according to  claim 11 , comprising determining that a segment of the SDU is a segment between the first segment and the last segment of the SDU and wherein the content of the information indicates segment offset. 
     
     
         14 . A method according to  claim 11 , comprising determining that a segment of the SDU is the last segment of the SDU and wherein the content of the information indicates the SDU segment length. 
     
     
         15 . A method according to  claim 11 , wherein the first information comprises a length indicator field. 
     
     
         16 . A method according to  claim 11 , wherein the header part comprises framing information, the framing information comprising a first bit indicative of whether the first byte of the data field corresponds to the first byte of a SDU and a second bit indicative of whether the last byte of the data field corresponds to the last byte of a SDU.