About IoT protocols, most commonly HTTP, CoAP and MQTT are used on communication.
HTTP and CoAP are suitable for REST type of client(s) to server communication and MQTT supports publishing and subscribing based multi user communication, where the origin can easily be from server to client, client to server and even client to client.
Answering the question:
Use REST over HTTP or CoAP for one to one communications or MQTT for multi point traffic use.
After the comment below I admit my answer was quite partial, so I examined and found a little more:
Even the communications have this kind of mess of standards, if all calculated:
Source: EU Butler Project - Communication Issues
Also postscapes.com has following list based on different aspects:
1 Infrastructure (ex: 6LowPAN, IPv4/IPv6, RPL)
2 Identification (ex: EPC, uCode, IPv6, URIs)
3 Comms / Transport (ex: Wifi, Bluetooth, LPWAN)
4 Discovery (ex: Physical Web, mDNS, DNS-SD)
5 Data Protocols (ex: MQTT, CoAP, AMQP, Websocket, Node)
6 Device Management (ex: TR-069, OMA-DM)
7 Semantic (ex: JSON-LD, Web Thing Model)
8 Multi-layer Frameworks (ex: Alljoyn, IoTivity, Weave, Homekit)
Like seen in the list of each examples, there are plenty of them and also more custom and proprietary ones surely are there.
You should open that link and read it through, it is mind blowing. I believe you may encounter in your project(s) many of these, at least if the sensors are of heavily packed form, ie. not only components in purest format, but parts of some already existing ecosystem. In those cases you maybe cannot negotiate the way you interface them, you just have to select between ecosystems.
The right issue now seems to be to find correct product set or set of sets (group of product sets) with identical or nearly matching protocol stacks over wifi, as you set the goal (keeping in mind infrared is solution out of this area and there are many other non internet wireless networking solutions, which you may still face).
Criteria would be to identify what all things you may want to do, and how many stacks you may want to learn on that way. By learning I mean you still want to play little with the gadgets and be aware how the certain protocol works under the hood.