I hope you're also assuming Ericsson isn't stupid either. Ericsson have several (compounding) advantages: since it's their core-competence, they have more people working on RF tech, they also have been in the game for longer[1] which allowed them to get the low hanging fruits and time to get their tech into more standards. I'd guess Ericson has more cellular patents by at least an order of magnitude; likely more.
1. Ericsson has been in the telecoms business since 1876