I use Roku devices in my house for IP-based television and content; all of the Roku devices in the last five years support streaming from mobile devices in full screen. Most of the newer TVs support it as well, at least for non-Apple stuff (Apple likes their own proprietary casting tech which they license out and not everyone pays for the license.)
I dont wish to display my mobiles screen on the tv I wish to display my computers screen on tv I know I can connect the t.v via a hdmi cable but I'm looking for a wireless solution
if anyones interested my p.c is connected to my router via cat 5 the router has wifi
I remember back in the PS3 days there were online services or apps where they were sending streaming content through DLNA to consoles or TVs from the computer as long as they were connected on the same network. Haven't tried it in years. Is this the same thing?
Back to using a PC to do this work: if you're on a Windows PC and if it has a wireless card, then WiDi is an option. There are inexpensive WiDi HDMI adapters in the wild which work well; I personally own a Microsoft one. Unfortunately the technology is based on point-to-point wireless communication, so a wired PC cannot connect to WiDi adapters even if there's a network route from the wired network to the wireless network.
It isn't specifically for this purpose but you can achieve the same effect via remote game streaming.
If your client (the TV or attached media device) can load a game streaming client (eg. Moonlight) and you run the PC as the server (eg. Sunshine) effectively send over the network (or even the internet if you choose) essentially an encoded video of what is being displayed on the server.