Method and apparatus for reporting buffer status

Abstract

A method, a user equipment (UE), and communications system for reporting buffer status are provided. A UE selects, from a plurality of available transport blocks (TBs) in a single transmission time interval (TTI), a TB that meets a buffer status report (BSR) transmission condition to report BSR information about at least one logical channel group (LCG) of the UE via the selected TB. In instances where there is more than one TB that meets the BSR transmission condition, only one TB is selected by the UE to report the BSR information. In this way, the UE can make full use of the padding bits of the TB, and report the buffer status flexibly via the selected TB.

What is claimed is: 
     
         1 . A user equipment (UE) comprising:
 a processor configured to select, from a plurality of transport blocks (TBs) available within a single transmission time interval (TTI), a TB meeting a buffer status report (BSR) transmission condition, wherein in instances where there is more than one TB that meets the BSR transmission condition, only one TB is selected; and   a transmitter configured to transmit, within the TTI, a BSR of at least one logical channel group (LCG) of the UE and a control element (CE) sub-header corresponding to the BSR via the selected one TB.   
     
     
         2 . The UE of  claim 1 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate the BSRs of all LCGs of the UE plus a CE sub-header corresponding to the BSRs of all the LCGs, and
 the transmitter is configured to transmit, via the selected one TB, the BSRs of all the LCGs and the CE sub-header corresponding to the BSRs of all the LCGs.   
     
     
         3 . The UE of  claim 1 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate the BSR of one or more LCGs of the UE plus a first CE sub-header corresponding the BSR of the one or more LCGs, but insufficient to accommodate BSRs of all the LCGs of the UE plus a second CE sub-header corresponding to the BSRs of all the LCGs, and
 the transmitter is configured to transmit, via the selected one TB, a truncated BSR and a third CE sub-header corresponding to the truncated BSR, wherein a total size of the truncated BSR plus the corresponding third CE sub-header is not less than a size of the BSR of a single LCG plus a CE sub-header corresponding to the BSR of the single LCG, and is not greater than a size of the padding bits of the selected TB.   
     
     
         4 . The UE of  claim 3 , wherein the truncated BSR is the BSR of the LCG having the highest priority among all the LCGs of the UE. 
     
     
         5 . The UE of  claim 1 , wherein the CE sub-header is configured to include indication information about BSR length. 
     
     
         6 . The UE of  claim 1 , wherein the processor is configured to set a buffer value to zero or to a null value for a BSR of the LCG containing no logical channel. 
     
     
         7 . A communications system comprising:
 a user equipment (UE) configured to be communicatively connectable to a network equipment, wherein the UE is further configured to:   select, from a plurality of transport blocks (TBs) available within a single transmission time interval (TTI), a TB meeting a buffer status report (BSR) transmission condition, wherein in instances where there is more than one TB that meets the BSR transmission condition, only one TB is selected; and   transmit, within the TTI, a BSR of at least one logical channel group (LCG) of the UE and a control element (CE) sub-header corresponding to the BSR via the selected one TB.   
     
     
         8 . The communications system of  claim 7 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate the BSRs of all LCGs of the UE plus a CE sub-header corresponding to the BSRs of all the LCGs, and
 wherein the UE is configured to transmit, via the selected one TB, the BSRs of all the LCGs and the CE sub-header corresponding to the BSRs of all the LCGs.   
     
     
         9 . The communications system of  claim 7 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate a BSR of one or more LCGs of the UE plus a first CE sub-header corresponding the BSR of the one or more LCGs, but insufficient to accommodate BSRs of all the LCGs of the UE plus a second CE sub-header corresponding to the BSRs of all the LCGs, and
 the UE is configured to transmit, via the selected one TB, a truncated BSR and a third CE sub-header corresponding to the truncated BSR, wherein a total size of the truncated BSR plus the corresponding third CE sub-header is not less than a size of a BSR of a single LCG plus a CE sub-header corresponding to the BSR of the single LCG, and is not greater than a size of the padding bits of the selected TB.   
     
     
         10 . The communications system of  claim 9 , wherein the truncated BSR is the BSR of the LCG having the highest priority among all the LCGs of the UE. 
     
     
         11 . The communications system of  claim 7 , wherein the CE sub-header is configured to include indication information about BSR length. 
     
     
         12 . The communications system of  claim 7 , wherein the UE is further configured to set a buffer value to zero or to a null value for a BSR of the LCG containing no logical channel. 
     
     
         13 . A method of buffer status reporting (BSR), comprising:
 selecting, by a user equipment (UE), a transport block (TB) meeting a BSR transmission condition from a plurality of TBs available within a single transmission time interval (TTI), wherein in instances where there is more than one TB that meets the BSR transmission condition, only one TB is selected; and   reporting, by the UE, via the selected one TB within the TTI, a BSR of at least one logical channel group (LCG) of the UE and a control element (CE) sub-header corresponding to the BSR.   
     
     
         14 . The method of  claim 13 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate the BSRs of all LCGs of the UE plus a CE sub-header corresponding to the BSRs of all the LCGs, and
 the reporting step provides for transmission of the BSRs of all the LCGs and the CE sub-header corresponding to the BSRs of all the LCGs via the selected one TB.   
     
     
         15 . The method of  claim 13 , wherein the BSR transmission condition indicates that padding bits of a single TB are sufficient to accommodate BSR of one or more LCGs of the UE plus a first CE sub-header corresponding the BSR of the one or more LCGs, but insufficient to accommodate BSRs of all the LCGs of the UE plus a second CE sub-header corresponding to the BSRs of all the LCGs, and
 the reporting step provides for transmission of a truncated BSR and a third CE sub-header corresponding to the truncated BSR via the selected one TB,   wherein a total size of the truncated BSR plus the corresponding third CE sub-header is not less than a size of the BSR of a single LCG plus a CE sub-header corresponding to the BSR of the single LCG, and is not greater than a size of the padding bits of the selected TB.   
     
     
         16 . The method of  claim 15 , wherein the truncated BSR is the BSR of the LCG having the highest priority among all the LCGs of the UE. 
     
     
         17 . The method of  claim 15 , wherein the CE sub-header includes indication information about BSR length. 
     
     
         18 . The method of  claim 13 , further comprising:
 setting a buffer value to zero or to a null value for the BSR of the LCG containing no logical channel.