it really does not matter how long you have been a permanent resident if you have been deported.  Once you have been deported the options are the same regardless of whether you have been a permanent resident for 1 year or for 40 years.  Once you satisfy the conditions of your deportation order you can apply for a visa to return to the US.  If you are deemed ineligible to return to the US, if that is a permanent bar then you are permanently barred from the US.  If you have to be outside the US for a requisite period of time, you need to find out what that time period is.