1. A method of integration of content caching with a mobile network operator for traffic alleviation of a mobile network, the method comprising: in response to determining that a cached element stored in a local cache of a mobile device is invalid, detecting, by an operator proxy of the mobile network operator, a poll from an application on the mobile device which would have been served using the cache element from the local cache on the mobile device if the cache element had not been invalid; forwarding, at the operator proxy, the poll from the application on the mobile device to a mobile network operator; receiving, at the operator proxy, a response to the poll from the mobile network operator and providing the response to the server-side proxy server; and wherein, the response is invalid if the response provided to the server-side proxy server is not the same as a prior response for same or similar content at the server-side proxy server and the server-side proxy server transmits an invalidate message to the mobile device to invalidate the cached element.