Yeah it’s a bit of a unique situation with the inability for private institutions to establish police forces. I remember in the 90s there was even talk of a special bill in Sacrament to authorize such, and I recall were only 2 such exceptions in the state that were grandfathered in already.
Anyhow the USC Dept of Public Safety is split into two – Safety Officers which are armed and with uniforms similar to the Sheriff Dept, patrol the campus and adjacent streets. Their vehicles have white light bars with “Public Safety” lettering. Second is the non-armed Community Service Officers which do things like monitors CCTV feeds, manage facility access, etc.. Additionally few years back USC contracted for supplemental guard services known as ‘Security Ambassadors’. Currently Contemporary Services Corporation has the contract (that 452.3875 frequency) and provides high visibility patrols and fixed post guards in bright yellow jackets around the campus and periphery.
For anyone that monitors LAPD Southwest frequency, you can sometimes hear DPS Safety Officers pop on using "USC" callsign to do things like requesting LAPD to meet them, or even running wants/warrant on people.