| 摘要 |
PURPOSE: A method for generating and managing frame data to furnish reliable communication of a DSRC(Dedicated Short Range Communication) RSU(Road Side Unit) is provided to transmit an MSDU(MAC(Medium Access Control) Service Data Unit) by dividing the MSDU by the slot. CONSTITUTION: If a frame is generated(S100), whether a frame type is an ACTC(Activation Channel) is checked(S200). If so(case-1), the frame is processed, and if not, whether the frame type is a multicast MDC is checked(S210). If so, data are transmitted and whether all data are transmitted is checked(S220). If not(case-3), the data are delivered to an image queue-B(S222), and if all data are transmitted(case-2), SAP information is cleaned(S221). If the frame type is a private MDC, whether the private MDC is for uplink is checked(S230), If not, whether a response is received is checked(S240). If received, whether all data are transmitted is checked(S241). If not(case-12), a frame is allocated for transmitting a next slot in the image queue-B(S245), and if all data are transmitted, whether a request response indicates '1' or '3' is checked(S242). If the request response indicates '1' or '3'(case-9), the data are transmitted to the image queue-B(S243). If the request response indicates neither '1' nor '3'(case-8), the SAP is cleaned(S244). If a response is not received in the step S240, whether a maximum re-transmission frequency is exceeded is checked(S246). If so, the SAP is cleaned(S248), and if not exceeded, the data are delivered to the image queue-B and re-transmitted(S247). If the private MDC is for uplink in the step S230, whether a response is received is checked(S250). If so, whether transmission is successful is checked(S251). If so(case-6), the SAP is cleaned(S253), and if not successful(case-7), the data are delivered to the image queue-B(S252). If a response is not received in the step S250, whether a maximum re-transmission frequency is exceeded is checked(S254). If so(case-4), reception failure is decided and the SAP is cleaned(S255), and if not exceeded(case-5), the data are transmitted to the image queue-B(S256). |
