In the method of estimating a signal-to-interference+noise ratio, either the polarities or bit values of a plurality of received data symbol samples are estimated. A first padding layer is positioned at the first side of the core and comprises a foam material having contoured surface facing away from the core. The local caching device is operable to retrieve a requested resource from at least one of the plurality of caching devices, deliver the requested resource to the client device over the local network, and store the requested resource for future requests by other client devices.