What hardware are you using? and why do you need a gateway is your indoor and outdoor transmitter/sensors to far from the receiver/ wifi unit? Do you realize the 433mhz receiver has wifi transceiver? Your post is a little unclear to me.
I’m using SI4432 transceiver to receive the 433MHz signal and control it using Arduino UNO. I want to send the data to my web server after receive it via my UNO using GSM Shield. The weather station used the HOPERF module (RF43B transmitter) and using FSK modulation. I tried manually wire the data from weather station board to my UNO. I actually got the data from it and match with the Payload structure from the manufacturer. You can see the payload format in the attachment below.
But still I can’t get anything while using my SI4432, even it’s frequency is 433MHz.
Ok I have never worked with the SI4432 module but looking at datasheet it is a 3.6 volt max powered chip and can run as low as 1.8v, A lot of uno's opperate at 5v so that could blow your SI4432. There is some info on your module here which says
"Wiring Si4432 with 5v arduino communication needs with a cd4050 level conversion." Now that its a bit clearer what you are trying to achieve, and use, someone may beable to offer more help.
Are you able to even comunicate with the si4432 correctly? what voltage is your uno running?
Sorry I can't be more helpful, I am also trying to solve an issue of my own and it required a lot of googling and research to no avail. So I took a small break to help others but thats the best I can offer to you for now.