Video　transmission　bandwidth　can　be　substantially　increased　by　concurrent　transmission　through　multiple　radio　interfaces　introduced　by　heterogeneous　wireless　networks.　However,　delivering　high-quality　real-time　videos　with　stringent　end-to-end　delay　constraints　is　still　challenging　due　to　the　time-varying　multipath　channel　status.　Thus,　to　integrate　available　multipath　bandwidth　and　guarantee　low　end-to-end　delay,　this　paper　investigates　a　real-time　concurrent　multipath　video　transmission　scheme　in　heterogeneous　access　networks.　First,　we　present　a　multipath　buffer　analysis　model　(MBAM)　to　derive　the　lower　and　upper　bounds　of　the　target　video　frame　bits.　Second,　given　the　low-latency　and　received　video　quality　smoothness,　we　propose　a　buffer-driven　rate　control　and　packet　distribution　(BRCPD)　algorithm　aided　by　frame-level　rate　control　and　multipath　transmission　buffer　awareness　based　on　MBAM.　Finally,　we　implement　the　proposed　application-layer　solution　BRCPD　algorithm　in　a　real-world　testbed.　The　experiment　results　verify　that　different　from　existing　multipath　video　transmission　schemes,　the　proposed　algorithm　is　able　to　leverage　the　MBAM-based　frame-level　rate　control　to　guarantee　the　target　low　end-to-end　delay.　In　particular,　the　BRCPD　algorithm　is　able　to　guarantee　an　overdue　loss　rate　of　less　than　5%　under　strictly　limited　delay　constraints　(250　ms)　in　the　real-world　testbed.