Algorithm for Physical Cell Identifier Allocation

An apparatus comprising:

• at least one processor;
• and
• at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:
• provide a modulo 3 grouping and a modulo 30 grouping for physical layer cell identifiers in a cellular communication system, wherein the modulo 3 grouping is associated with first synchronization signal assignments and the modulo 30 grouping is associated with second synchronization signal assignments, and wherein a combination of a first synchronization signal and a second synchronization signal determines a physical layer cell identifier of a cell;
• allocate a modulo 3 group to each of a plurality of cells of the cellular communication system;
• allocate, after the allocation of the modulo 3 groups, a modulo 30 group to each of the plurality of cells of the cellular communication system, wherein the allocation of the modulo 30 groups incorporates the allocated modulo 3 group as a precondition to reduce a search space for the modulo 30 grouping;
• and
• allocate to each cell a first synchronization signal a second synchronization signal on the basis of said allocation of the modulo 30 group.