1. An apparatus comprising: one or more processors; and one or more memories including computer program code, the one or more memories and the computer program code configured, with the one or more processors, to cause the apparatus to perform at least the following: monitoring a first parameter comprising an information when an original search space of a downlink control channel of an orthogonal frequency division multiplex technology is redefined; checking whether or not the first parameter indicates the original search space is redefined; and searching an entry at a search entry of the redefined search space.