PBS programming and other content is distributed by the originating station in the subnetwork to other full-power stations that serve as satellites as well as any low-power translators in other areas of the state. Some states may be served by such a regional network and simultaneously have PBS member stations in a certain city (such as the case with secondary member KBDI-TV in Denver, which is not related to Colorado member network Rocky Mountain PBS and its flagship station and primary Denver PBS member, KRMA-TV) that operate autonomously from the regional member network. As opposed to the present commercial broadcasting model in which network programs are often carried exclusively on one television station in a given market, PBS may maintain more than one member station in certain markets, which may be owned by the licensee of the market's primary PBS member station or owned by a separate licensee (as a prime example, KOCE-TV, KLCS and KVCR-DT—which are all individually owned—serve as PBS stations for the Los Angeles market; KCET served as the market's primary PBS member until it left the service in January 2011, at which time it was replaced by KOCE). KCET rejoined PBS in 2019, thus giving the Los Angeles area four different member stations. For these cases, PBS utilizes the Program Differentiation Plan, which divides by percentage the number of programs distributed by the service that each member can carry on their schedule; often, this assigns a larger proportion of PBS-distributed programming to the primary member station, with the secondary members being allowed to carry a lesser number of program offerings from the service's schedule. Unlike public broadcasters in most other countries, PBS cannot own any of the stations that broadcasts its programming; therefore it is one of the few television programming bodies that does not have any owned-and-operated stations. This is partly due to the origins of the PBS stations themselves, and partly due to historical broadcast license issues. Participating stations Most PBS member stations have produced at least some nationally distributed programs. Current regularly scheduled programming on the PBS national feed is produced by a smaller group of stations, including: WGBH-TV (Arthur, NOVA, Masterpiece, Frontline, Martha Speaks, Peep and the Big Wide World, Curious George, Lidia's Kitchen, Design Squad, Jamie Oliver, etc.) WNET (Nature, PBS NewsHour Weekend, Cyberchase, Amanpour & Company, Wishbone etc.) Previously Connecticut Public Television and now WNET (Barney & Friends, Bob the