On minimum-collisions assignment in heterogeneous self-organizing networks

Abstract

Minimum-collisions assignment, in a wireless network, is the distribution of a finite resource set, such that the number of neighbor cells which receive common elements is minimized. In classical operator deployed networks, resources are assigned centrally. Heterogeneous networks contain user deployed cells, therefore centralized assignment is problematic. This paper examines the minimum-collisions assignment problem in the context of physical cell identity (PCI) allocation. Minimumcollisions assignment is NP-complete, therefore a potential-gametheoretic model is proposed as a distributed solution. The players of the game are the cells, actions are the set of PCIs and the utility of a cell is the number of neighbor cells in collision. The price of anarchy and price of stability are derived. Moreover the paper adapts a randomized-distributed-synchronous-update algorithm, for the case, when the number of PCIs is higher than the maximum degree of the neighbor relations graph. It is proven that the algorithm converges to a optimal pure strategy Nash equilibrium in finite time and it is robust to node addition. Simulation results demonstrate that the algorithm is sub-linear in the size of the input graph, thus outperforms best response dynamics.

BiSON: A Bioinspired Self‐Organizing Network for Dynamic Auto‐Configuration in 5G Wireless

“…Table 1 shows the summary of major existing works on SON and bioinspired approaches in wireless networks. Geolocation based allocation [8,9], game-theory based minimum collision assignment [7], and graph coloring optimization [3,4] [13,15]. Bioinspired solutions have been used in wireless networks for scheduling and resource allocation [16,17], optimal cell planning [18], BS deployment [18], and load balancing [19].…”

“…In order to analyze the convergence speed of BiSON, we first state the definition of a minorization condition [33] Referring to (7) and (8) from Section 6.1, we can have the following relation:…”

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

“…Nevertheless, some proactive algorithms to assign PCI before error detections are proposed in [5, 6]. In [5], it considers PCI assignment as a graph colouring problem and Goonewardena et al [6] analyse the problem with the potential‐game theory further. However, proactive methods of optimising the PCI assignment are time consuming, and sometimes they are not quite applicable to large‐scale, multi‐radio access and random on–off deployment scenarios of small cells.…”

“…Some passive methods are presented in [3,4] to detect PCI conflicts and confusions via cell measurements. Nevertheless, some proactive algorithms to assign PCI before error detections are proposed in [5,6]. In [5], it considers PCI assignment as a graph colouring problem and Goonewardena et al [6] analyse the problem with the potential-game theory further.…”

“…Then the optimal λ can be expressed in (6), where α = 0.05 , all the BSs are allocated to corresponding fuzzy layers, and the layers are ordered based on cell activity level, in which containing the biggest observing data indicates the highest level and vice versa. For each layer, the clusters of BSs are considered as a new graph.…”