This is a very difficult problem, unless you are willing to plant something other than roses. Deer view roses as the equivalent of chocolates. That being said, there are some measures that you can take.
For starters, it will help to understand a little bit about deer natural history if you wish to develop an effective strategy to deter them. They live in herds (usually segregated by gender and by age). Aggregating in herds affords them some protection from predators (when there were predators that actively hunted them and not just vehicles) as they have many pairs of eyes and ears as well as noses constantly on the alert for predators. Each deer eats, on average, 5-15 pounds of browse (plant material taken from trees and shrubs) each day. If the deer herd where you live is large enough and food is scarce enough the deer will eat just about anything they can get to.
Actions that you can take to dissuade deer from browsing on your roses can be broken into 4 general categories.
Oregon State University has a publication, “Reduce deer damage in your yard,” that may also give you some ideas to consider.
Another possibility is a dog in your yard. Deer will avoid areas where they are likely to encounter potential predators. A barking dog, actively chasing the deer will soon dissuade them from feeding in your yard. However, as with mechanical deterrents, if the dog is in the yard in a predictable pattern, and you have a large hungry herd of deer, the deer will habituate to the presence of the dog and enter the yard at times they have learned that the dog is not present.
A local source of information and help is Fairfield County Extension Center.
The University of Connecticut IPM (Integrated Pest Management) program web site also has a number of excellent suggestions. The most cogent piece of advice they may have is:
"The size of the deer population in a particular season, the availability of alternative food sources, the system chosen for keeping deer away and the location can all affect your success at keeping deer out of the garden. It may be best to alternate with different garden protection methods until you find what works in your particular location."