In order to achieve the service integration of audio/video stream to the EPA control bus, we proposed a communication scheduling application algorithm based on EPA, according to the transmission characteristics of audio/video stream, and with the realtime requirement of control data transmission and block stream’s constraints. This algorithm defines audio/video stream as “block stream”, meanwhile giving its mathematical model, and considers block stream as period data, takes the control data’s delay, block’s period and delay jitter requirements as constraints to schedule the width of micro-cycle; and schedules the time slice to divide the same block to multi micro cycles, in order to fully utilize the bandwidth. This algorithm can ensure the stability of EPA network and control’s real-time, and can satisfy the fluency of block stream. In a practical complex transmission application of control data and video, the delay jitter of video met the requirement, with no disturbance to control data meanwhile, thus the validity of this algorithm is examined.
[1] BRACKNELL D R. The MILSTD1553B data bus: What does the future hold? [J]. The Aeronautical Journal, 2007,111(1118):231-246.
[2] IEC 6178425. Industrial communication networks Part 2: Additional fieldbus profiles for realtime networks based on ISO/IEC 88023[S]. Switzerland: International Electrotechnical Commission, 2009.
[3] IEC 6178421. Industrial communication networks Part 2: Additional fieldbus profiles for realtime networks based on ISO/IEC 88023[S]. Switzerland: International Electrotechnical Commission, 2009.
[4] IEC 61784212. Industrial communication networks Part 2: Additional fieldbus profiles for realtime networks based on ISO/IEC 88023[S]. Switzerland: International Electrotechnical Commission, 2009.
[5] IEC 61784216. Industrial communication networks Part 2: Additional fieldbus profiles for realtime networks based on ISO/IEC 88023[S]. Switzerland: International Electrotechnical Commission, 2009.
[6] HONG S H. Bandwidth allocation scheme for cyclicservice fieldbus networks [J]. IEEE/ASME Transactions on Mechatronics. 2001,2(6):197-204.
[7] IETF RFC3550STD0064. RTP: A transport protocol for realtime applications [S]. [S. l.]:The Internet Society (ISOC),2003.
[8] IEC 61784214. Industrial communication networks Part 2: Additional fieldbus profiles for realtime networks based on ISO/IEC 88023[S]. Switzerland: International Electrotechnical Commission, 2009.
[9] 鲁立,冯冬芹,禇健,等. 用于EPA网络的实时调度方案[J]. 东南大学学报:自然科学版. 2009,39(s1):210-214.
LU Li, FENG Dongqin, CHU Jian, et al. A realtime scheduling scheme for EPA networks [J]. Journal of Southeast University :Natural Science Edition,2009,39(s1):210-214.