Gamma-level simulations were a caste of artificial intelligence programs common among all human factions. Used for countless tasks where precision -- but never creativity -- was required, they excelled at everything from piloting ships along routine routes to conducting customs interviews.
Different gamma-level personas may or may not be capable of simulating consciousness, but they were never actually self-aware. A gamma-level intended to portray (vaguely) sentient behavioral quirks was always based on a fictitious personality, rather than an actual person like a beta-level simulation.
RS Glossary entry
Gamma-level: Simulation of a fictitious personality. Turing-compliance not necessary. Extralegal agents operating in near-Yellowstone airspace during the Conjoiner-Demarchist war.
- description from the official RS glossary 
- Revelation Space universe - RS Glossary - G, AlastairReynolds.com, the official website of Alastair Reynolds