A method and apparatus is provided for interleaving and de-interleaving frame symbols using a single memory buffer. Communications capabilities of the communications service provider are sliced into a plurality of virtual slices and each of the plurality of virtual slices is configured for a different service provider from among the one or more service providers. The score assists users in focusing any manual verification efforts on data that may actually contain incorrect category assignments, thereby making the verification process more efficient. Moreover, external system of natural cooling has a condenser that is located in the open air and connected to the evaporator with the help of vapor lines and condensed vapor lines. A stud with a pivot joint on one end is interposed between the walls. In the optical waveguide device which includes a core and a cladding layer formed around the core and has one end formed to be inclined so as to refract input and output signals, the core includes therein a diffraction portion for diffracting an optical signal incident through the cladding layer to propagate straight through the core.