An apparatus comprising: an encoder configured to: determine a set of search space candidates of an enhanced - physical downlink control channel, E-PDCCH, based on an aggregation level of downlink control information, DCI, predetermined spacing between adjacent search space candidates, and a number of virtual resource blocks, VRBs, of the E-PDCCH, the set of search space candidates to be potential bearers of DCI; select one or more VRBs from the set of search space candidates; and encode DCI onto the selected VRBs; and a mapper configured to map the VRBs of the E-PDCCH to physical resource blocks, PBRs, for transmission to a user equipment in a downlink frame, wherein the encoder is configured to select one or more VRBs from the set of search space candidates to be potential bearers of DCI to ensure the lowest index of VRBs for each E-PDCCH transmission is a multiple of 2 based on: η VRB E − PDCCH Λ k = Λ + δ Λ N VRB E − PDCCH ⋅ m + i mod N VRB E − PDCCH, wherein Λ is one of multiple aggregation levels, wherein η VRB E − PDCCH Λ k is an index number of one of the number of VRBs for E-PDCCH transmission associated with the aggregation level Λ at a subframe k, said apparatus characterised in that δ Λ, N VRB E − PDCCH = δ Λ N VRB, Base E − PDCCH + N VRB E − PDCCH − N VRB, Base E − PDCCH M Λ is the VRB spacing between adjacent search space candidates associated with the one of multiple aggregation levels Λ, wherein N VRB E − PDCCH is the number of the VRBs allocated for E-PDCCH transmission, wherein m = 0,..., M(Λ)-1, wherein M is a number of search space candidates to be monitored associated with the one of the multiple aggregation levels Λ, wherein i = 0,..., (Λ-1), wherein N VRB, Base E − PDCCH is a baseline number of VRBs. an encoder configured to: determine a set of search space candidates of an enhanced - physical downlink control channel, E-PDCCH, based on an aggregation level of downlink control information, DCI, predetermined spacing between adjacent search space candidates, and a number of virtual resource blocks, VRBs, of the E-PDCCH, the set of search space candidates to be potential bearers of DCI; select one or more VRBs from the set of search space candidates; and encode DCI onto the selected VRBs; and determine a set of search space candidates of an enhanced - physical downlink control channel, E-PDCCH, based on an aggregation level of downlink control information, DCI, predetermined spacing between adjacent search space candidates, and a number of virtual resource blocks, VRBs, of the E-PDCCH, the set of search space candidates to be potential bearers of DCI; select one or more VRBs from the set of search space candidates; and encode DCI onto the selected VRBs; and a mapper configured to map the VRBs of the E-PDCCH to physical resource blocks, PBRs, for transmission to a user equipment in a downlink frame, wherein the encoder is configured to select one or more VRBs from the set of search space candidates to be potential bearers of DCI to ensure the lowest index of VRBs for each E-PDCCH transmission is a multiple of 2 based on: η VRB E − PDCCH Λ k = Λ + δ Λ N VRB E − PDCCH ⋅ m + i mod N VRB E − PDCCH, wherein Λ is one of multiple aggregation levels, wherein η VRB E − PDCCH Λ k is an index number of one of the number of VRBs for E-PDCCH transmission associated with the aggregation level Λ at a subframe k, said apparatus characterised in that δ Λ, N VRB E − PDCCH = δ Λ N VRB, Base E − PDCCH + N VRB E − PDCCH − N VRB, Base E − PDCCH M Λ is the VRB spacing between adjacent search space candidates associated with the one of multiple aggregation levels Λ, wherein N VRB E − PDCCH is the number of the VRBs allocated for E-PDCCH transmission, wherein m = 0,..., M(Λ)-1, wherein M is a number of search space candidates to be monitored associated with the one of the multiple aggregation levels Λ, wherein i = 0,..., (Λ-1), wherein N VRB, Base E − PDCCH is a baseline number of VRBs. η VRB E − PDCCH Λ k = Λ + δ Λ N VRB E − PDCCH ⋅ m + i mod N VRB E − PDCCH, wherein Λ is one of multiple aggregation levels, wherein η VRB E − PDCCH Λ k is an index number of one of the number of VRBs for E-PDCCH transmission associated with the aggregation level Λ at a subframe k, said apparatus characterised in that δ Λ, N VRB E − PDCCH = δ Λ N VRB, Base E − PDCCH + N VRB E − PDCCH − N VRB, Base E − PDCCH M Λ is the VRB spacing between adjacent search space candidates associated with the one of multiple aggregation levels Λ, wherein N VRB E − PDCCH is the number of the VRBs allocated for E-PDCCH transmission, wherein m = 0,..., M(Λ)-1, wherein M is a number of search space candidates to be monitored associated with the one of the multiple aggregation levels Λ, wherein i = 0,..., (Λ-1), wherein N VRB, Base E − PDCCH is a baseline number of VRBs.