in the quality of a cloud gaming service is latency, as the amount of delay between the user's inputs and when they take effect can affect gameplay — especially in fast-paced games dependent on precise inputs (such as first-person shooters and fighting games). Attempts to reduce latency include the use of caching as the cached data can be "stored locally ... and can be retrieved when required." The provider's dedicated hardware can be upgraded over time in order to support higher resolutions and frame rates for the rendering and streams. The Quality of Experience (QoE) that measures the user's general level of satisfaction also needs to be brought into consideration during the development phase of cloud gaming. History Early attempts The first demonstrated approach of cloud gaming technology was by startup G-cluster (short for Game Cluster), which introduced its product at the 2000 E3, and released around 2003. In their initial model around 2005, G-cluster provided PC games that ran on their servers, using video-on-demand service providers, set-top box manufacturers, and middleware software providers to help provide their service to network operators, and then offered the games through portals to end users. By 2010, due to changes in the market, G-cluster changed their model to work through a large server manufacturer to provide their games to the network operators and directly to users. This refocusing was necessitated by the increased available of free-to-play games available for personal computers, drawing them away from G-cluster's service, so G-cluster opted to focus on Internet Protocol television (IPTV) users instead, which had a potential target of about three million users in 2010. French telco SFR launched G-cluster gaming service in 2010 for its end users and Orange followed suit in 2012 offering the gaming service for its customers. Both services have been commercially operational ever since offering cloud gaming for their customers on TV and mobile. In early 2003, another attempt was announced by American company Infinium Labs, which intended to revolutionize the market of home entertainment with their Phantom video game console, a device that was envisioned to be capable of providing an on-demand video game delivery service via monthly online subscription. The Phantom was designed to run PC games, thus making it compatible with hundreds of titles from the start, and was to be sold at a much lower price than high-end PC gaming rigs. A functioning prototype was first presented at