Speeding ticket in TX

I am an Illinois resident, but recently recieved a ticket in the great state of Texas. The officer who stopped and cited me was a munipical officer, and i was stopped outside of the city limits. Is the ticket vaild? Or does he have jurisdiction over the whole area?

He did it so it must be legal. Most police departments have pacts with neighboring jurisdictions that allow for crossing the city or county lines. The old theory of crossing the county line to avoid a citation does not apply in most locals anymore.