A transmission window is a window of time in which certain file transfers are expected or allowed to occur.
Transmission windows typically reoccur on a regular basis, such as every day, on all weekdays, on a particular day of the week, or on the first or last day of the month or quarter.
Most transmission windows are contiguous and set on hourly boundaries (e.g., from 3:00pm to 11:00pm) but can also contain breaks (e.g., 3-6pm and 7-9pm) and start/end on minute/second boundaries (e.g., from 3:05:30pm to 7:54:29).
Files received outside of transmission windows are not immediately processed or forwarded by file transfer systems. Instead, they are typically stored or queued, and are usually processed when the transmission window opens back up. (e.g., a file received at 7:58am for an 8am-2pm transmission window would be processed today at 8:00am, however a file received at 2:02pm would be processed tomorrow at 8:00am.)
When transmission windows are coupled with specific types of file transfers, service level agreements (SLAs) can be written to lock down expectations and reduce variability.
See also: cut-off time.
BEST PRACTICE: When possible, select file transfer scheduling technology that allows you to maintain transmission windows separate from your defined workflows. For example, if you want to change the transmission window for a particular type of file across 50 customer workflows, make sure you can do so by only changing one window definition, not 50 workflow definitions. Also look for technology that allows you to see and control the contents of queued files received outside of transmission windows. Your operators may want to allow, roll over or simply delete some of the files received outside any particular transmission window.