There are two companies people often confuse with one another. The first is PPI. Portland Patrol, Inc. also known as "Clean & Safe" is part of the Portland Business Alliance, and they typically patrol the downtown core area around 2nd/3rd/4th/5th/6th avenues as well as the Smart Park parking garages. They have bike and foot patrol officers, some of which are armed.
The second is PPS or Pacific Patrol Services Last time I checked is a "doing business as" name, and the actual name of the company on record is "Portland Patrol Services, Inc". PPS was started as an offshoot of PPI and eventually rebranded their name from Portland Patrol Services to Pacific Patrol Services in order to distance themselves from PPI due to a falling out of some sort between the owners of the two companies (this is all hearsay fyi so take it for what it's worth). PPS has contracts all over downtown including a contract with Portland Parks & Recreation to patrol the parks at night when the rangers are off duty. PPS operates with bike and site officers, all of whom are unarmed.
PPI is on the 800mhz Portland TRS using talkgroup 18032. PPS used Nextel push-to-talk phones, and when that service was discontinued by Nextel, they switched to a similar ptt service using SONIM brand phones, though I'm not sure who the service provider is. Also the last time I had any interaction with PPS was a couple of years ago, so I don't know if they're still using the SONIM ptt phones or if they've gotten something else since then.