Nowadays I don't even consider it serialized.
There's some serialized material, but mostly DS9's approach is more of a "landscape" storytelling style, a bit like Marvel comics has used in recent years. The background and setting evolve over time, with occasional momentous events. Some of the stories then contribute to the ongoing plot, but others just take advantage of the new "landscape" without really altering it.
At Marvel, it's been something like...
Event: Civil War
Resulting Landscape: Enforcement of Registration Act
Event: Secret Invasion
Resulting Landscape: Dark Reign
Event: Siege
Resulting Landscape: Heroic Age
With DS9, it's something like...
Event: Federation arrives on DS9, Wormhole discovered
Landscape: Political unrest on Bajor, exploration of the Gamma Quadrant
Event: First Contact with the Dominion
Landscape: Looming threat of war
Event: Political unrest due to changeling infiltration, Klingons invade Cardassia
Landscape: Tension and skirmishes with the Klingons, paranoia throughout the quadrant
Event: Dominion Invasion of the Alpha Quadrant
Landscape: Dominion War
I don't know if this approach has an official name, and I can't think of any other good examples of this style right off the top of my head, but it's a better description of DS9's approach than serialized storytelling, which the show really doesn't spend much time on overall.