It will also ensure that the downlink from the reader to the tag is the same for all systems. When the reader opens up a line of communications, the on-board device will know what type of reader it is and whether or not the tag needs to respond. The standard will ensure that even if you have a tag and reader that support different technologies, at least the tag will know the reader's type and function. I understand that several large toll road authorities were represented at the meeting, and that they expressed concern if any new standard made their current systems obsolete. These standards support a gradual migration strategy.
Agencies can continue to deploy their current technologies until a new standard is in place.
When the new standard is approved, they'll replace their existing readers and tags in the normal course of events when these devices wear out. As soon as the standard is complete, I envision they'll stop buying their old tags and start buying new ones. On average, tags need to be replaced every 5 to 7 years. Readers have a longer lifetime. Interoperability requires much more than just a DSRC standard.