Systems and methods schedule periodic and non-periodic transactions in a multi-speed bus environment that includes in a downstream hub a data forwarding component, such as a USB transaction translator, which accommodates communication speed shifts at the hub. The method may comprise receiving a split packet request defining a transaction with a device, tagging the request with an identifier allocated to the data forwarding component, storing the request in a transaction list associated with the identifier, initiating transfer of payload data, and updating a counter associated with the identifier to reflect an amount of payload data for which transfer was initiated. The identifier may have associated therewith a counter for tracking a number of bytes-in-progress to the data forwarding component and one or more transaction lists configured to store a plurality of split packet requests awaiting execution and state information regarding an execution status of the requests.