Technology Related Sci Fi at War Series...

[Lambda 00]

Surprised that no-one mentioned:

Orson Scott Card's Enderverse:

First Meetings in the Enderverse
Ender's Game
Speaker for the Dead
Xenocide
Children of the Mind
Ender's Shadow
Shadow of the Hegemon
Shadow Puppets
Shadow of the Giant
There may be others, but I haven't seen any more -.-