Dynamic PCI assignment in two‐tier networks based on cell activity prediction

Abstract

Physical cell identity (PCI) is used to identify each cell. However, with the introduction of femtocells, 8 bytes allocation for PCI cannot accommodate a large number of femtocells. The current solution in 3GPP Release 9 is to use cell global identity associated with PCI to resolve this problem. However, this solution may incur higher inbound handover failure. A dynamic PCI assignment based on cell activity level prediction is proposed. The system level simulation showed that the approach outperforms the existing approaches.

On minimum-collisions assignment in heterogeneous self-organizing networks

“…The algorithm proposed in [10], is decentralized and depends on BSs exchanging neighbor relation tables as opposed to the algorithm in [11], which is centralized and makes use of messages from UEs to build the neighbor relation tables and PCI assignment. In [12], a dynamic PCI assignment algorithm is proposed. The algorithm categorizes the BSs according to activity level and assigns a unique PCI to busy cells while cells with lower activity obtains a reused PCI.…”

Fuzzy layered physical cell identities assignment in heterogeneous and small cell networks

“…Either passive or proactive method is from the perspective of avoiding PCI conflicts and confusions. In [7], a dynamic PCI assignment algorithm for user quality of service is proposed to assign unique PCIs to busy cells as a matter of priority, and then the inactive cells will reuse the rest of the PCIs. However, the intervals of busy cells may be contented with PCI reuse distance, and the distribution threshold between unique and reused PCIs is not discussed as well.…”

“…For each layer ranked by cell activities from high to low, assign unique PCI to co-existed cells and reused PCIs to separate cells successively. Thus, the proposed algorithm can guarantee the system performance with preferential PCI allocation as [7], while improving the assignment efficiency by reusing PCIs in each clustered layer.…”

“…Generally, t w is valued with one day as a cycle. To illustrate the advantage of the proposed algorithm, the optimal and completely dynamic PCI assignment methods [5,7] are introduced as comparisons. The following two figures have presented the performance of PCI allocations, where 'optimal' represents the algorithm in [5], 'dynamic' represents the one in [7], and 'proposed' is the layered PCI assignment in this Letter.…”

“…It is obvious that the optimal method of PCI assignment demonstrates the best PCI reuse performance, and the proposed algorithm with a compromise still shows a better performance compared to the dynamic one. Since it is fast consumption with mainly unique allocations of PCIs adopted by Zhang et al [7]. Fig.…”