Lag (online Gaming) - Cloud Gaming

Cloud Gaming

Cloud gaming is a type of online gaming where the entire game is hosted on a game server in a data center, and the user is only running a thin client locally that forwards game controller actions upstream to the game server. The game server then renders the next frame of the game video which is compressed using low-lag video compression and is sent downstream and decompressed by the thin client. For the cloud gaming experience to be acceptable, the round-trip lag of all elements of the cloud gaming system (the thin client, the Internet and/or LAN connection the game server, the game execution on the game server, the video and audio compression and decompression, and the display of the video on a display device) must be low enough that the user perception is that the game is running locally. Because of such tight lag requirements, distance considerations of the speed of light through optical fiber come into play, currently limiting the distance between a user and a cloud gaming game server to approximately 1000 miles, according to OnLive, the only company thus far operating a cloud gaming service. There is also much controversy about the lag associated with cloud gaming. In typical multiplayer games the player's computer renders the game's graphics locally and only information about the player's in-game actions are sent to the server. For example when the player presses a button, the character on-screen instantly performs the corresponding action. However, the consequences of the action such as an enemy being killed are only seen after a short delay due to the time taken for the action to reach the server. This is acceptable since as long as the player's character responds instantly the player still feels in complete control.

With cloud gaming when the player presses a button, nothing appears to happen for a short while. The button press must first be transmitted to the remote server, which takes time. Then the server must start rendering the graphics of the action being performed and stream the video back to the player over the network, which again takes time. Thus the player experiences a noticeable delay between pressing a button and seeing something happen on-screen. Depending on the skill & experience of the player, this can cause disorientation and confusion similar to Delayed Auditory Feedback and hampers navigation & aiming in the game world. When rapidly inputting a long combination move, the on-screen character will not be synchronized with the button presses. This usually causes severe confusion in the player resulting in the failure of the combination move.

The extra input lag can also make it very difficult to play certain single player games. For example, if an enemy takes a swing at the player and the player is expected to block, then by the time the player's screen shows that the enemy has commenced attacking, the enemy would have already struck and killed the player on the server.