A macro-cell apparatus configured to operate within a wireless network and configured to connect to at least one subordinate transmission node, the macro-cell apparatus comprising: a wireless transceiver configured to transmit and receive wireless signals; a processor; and a non-transitory computer-readable medium comprising one or more computer program instructions which are configured to, when executed by the processor, cause the macro-cell apparatus to: transmit one or more first scrambled reference signals, the one or more first scrambled reference signals scrambled with a first cell-specific scrambling sequence that is unique to the macro-cell, wherein the one or more first cell-specific scrambling sequence is selected from a first set of cell-specific scrambling sequences associated with macro-cells; and assign at least one or more second scrambling sequences to the at least one subordinate transmission node, wherein the at least one or more second cell-specific scrambling sequence is selected from a second set of cell-specific scrambling sequences associated with subordinate nodes, where the assignment of the at least one or more second scrambling sequences causes the at least one subordinate transmission node to scramble one or more transmissions with the assigned one or more second scrambling sequences, wherein the identification of the at least one subordinate transmission node is determined from the at least one or more second scrambling sequence, wherein the at least one or more second cell-specific scrambling sequence is assigned to the at least one subordinate transmission node by the macro-cell, and characterised wherein the first set of cell-specific scrambling sequences and the second set of cell-specific scrambling sequences are generated from a same scrambling sequence generation scheme which is divided into the first and second set of cell-specific scrambling sequences. a wireless transceiver configured to transmit and receive wireless signals; a processor; and a non-transitory computer-readable medium comprising one or more computer program instructions which are configured to, when executed by the processor, cause the macro-cell apparatus to: transmit one or more first scrambled reference signals, the one or more first scrambled reference signals scrambled with a first cell-specific scrambling sequence that is unique to the macro-cell, wherein the one or more first cell-specific scrambling sequence is selected from a first set of cell-specific scrambling sequences associated with macro-cells; and assign at least one or more second scrambling sequences to the at least one subordinate transmission node, wherein the at least one or more second cell-specific scrambling sequence is selected from a second set of cell-specific scrambling sequences associated with subordinate nodes, where the assignment of the at least one or more second scrambling sequences causes the at least one subordinate transmission node to scramble one or more transmissions with the assigned one or more second scrambling sequences, wherein the identification of the at least one subordinate transmission node is determined from the at least one or more second scrambling sequence, wherein the at least one or more second cell-specific scrambling sequence is assigned to the at least one subordinate transmission node by the macro-cell, and characterised wherein the first set of cell-specific scrambling sequences and the second set of cell-specific scrambling sequences are generated from a same scrambling sequence generation scheme which is divided into the first and second set of cell-specific scrambling sequences. transmit one or more first scrambled reference signals, the one or more first scrambled reference signals scrambled with a first cell-specific scrambling sequence that is unique to the macro-cell, wherein the one or more first cell-specific scrambling sequence is selected from a first set of cell-specific scrambling sequences associated with macro-cells; and assign at least one or more second scrambling sequences to the at least one subordinate transmission node, wherein the at least one or more second cell-specific scrambling sequence is selected from a second set of cell-specific scrambling sequences associated with subordinate nodes, where the assignment of the at least one or more second scrambling sequences causes the at least one subordinate transmission node to scramble one or more transmissions with the assigned one or more second scrambling sequences, wherein the identification of the at least one subordinate transmission node is determined from the at least one or more second scrambling sequence, wherein the at least one or more second cell-specific scrambling sequence is assigned to the at least one subordinate transmission node by the macro-cell, and characterised wherein the first set of cell-specific scrambling sequences and the second set of cell-specific scrambling sequences are generated from a same scrambling sequence generation scheme which is divided into the first and second set of cell-specific scrambling sequences.