Yes, U.S. and Canadian stations and operations near the border are protected as stated in Section 17 of DBS-01 -White Space Database Specifications which is excerpted below for your convenience:
17. Operation Near the Canada-U.S. Border
The bands 54-60 MHz, 76-88 MHz, 174-216 MHz, 470-608 MHz and 614-698 MHz are currently covered by theAgreement Between the Government of Canada and the Government of the United States of America Related to the TV Broadcasting Service and the Associated Working Arrangement(the Agreement), theLetter of Understanding (LOU),Footnote5which covers areas within 400 km of the border, and theInterim Agreement Between Canada and the United States Concerning Digital Television (DTV)(the Interim Agreement).
These three agreements and working arrangements deal with the sharing and use of the bands by broadcasting services operating in the United States and in Canada. In addition, the LOU specifies that new (non-broadcasting) services shall not claim protection from DTV stations or analog TV stations in either country.
The LOU does not deal with non-broadcasting versus non-broadcasting operations in the border area. Therefore, until such time as a new Agreement can be reached between Canada and the United States, any authorization issued for non-broadcasting use in Canada within 400 km of the border area must be on a no-interference, no-protection basis with respect to broadcasting services in the United States.
17.2 Protection Criteria for U.S. Stations
Operating U.S. broadcasting stations, protected receive sites and LPA are to be protected according to the same criteria specified for Canadian stations above, with the exception that protected contours and/or operational areas will be assumed to stop at the Canada/U.S. border. The required separation distances extend within Canada.