If you are from Mexico, it's unnecessary to write your post on English, you are right now on the Samsung Members Community of México, so, talking on English will low your probabilities of having answers with your question.
Regarding your question, it's not uncommon for upload speeds to be slower than downloading speeds, actually, it's very frequent on many ISP's. However, if you are experiencing extremely low uploading speeds, you can try this:
1. Rebooting your phone 2. Forgetting the network and trying to connect to it again. 3. Rebooting your router.
The scenarios of this problem, can occur if:
1. Your network is experiencing congestion, to resolve this, you can try to change the network channel in your router settings page (accessing with the IP address on a browser).
2. A poor signal strength also can produce this problem.
