This story takes place in the year 2011, in an alternate history from 1913 on. Ill give you a crash-course on technology.
Vehicles are about at the Vietnam era, minus the Jets, which do not exist yet. Primitive personal drop-pods have been invented as a faster way to get soldiers into the battle than parachuting. These pods are typically found in groups of 9-12 on specialized airplanes.
Weapons are still at about the same level as they were in WWII. There have been some advances, but very few. The Atomic Bomb was never invented.
No form of body armor exists yet that didnt at the start of the war.
Efficiant forms of communication have been invented for the armies (ie personal comms).
A few side notes:
Due to nearly a century of straight war, the environment has suffered a bit. Snow can be expected during the winter months in any area more than 10 degrees from the equator. World-wide, the skies are filled with thick grey clouds 24/7, making it dim even during mid-day.
The Empire changed from a Fascist society to a democracy after the death of Adolf Hitler in 1966. The use of the Swastika as the symbol of the empire is also discontinued in this year, and is replaced by a white X.
Thats about all i can think of right now. I may edit later.