Macro Cell Muting Coordination for Non-Uniform Topologies in LTE-A HetNets

Enhanced Inter Cell Interference Coordination (eICIC) for co-channel deployments of pico cells throughout a macro cell layout is studied. In particular, we analyze a scenario where only some macro cells have picos deployed, while other macro cells have no small cells. The challenge for such highly irregular scenarios is how to operate eICIC, and especially how to coordinate macro-cell muting. Our analysis shows that for eICIC to provide gain in such scenarios, it is recommended to use fully time aligned traditional Almost Blank Subframes (ABS) in the macro-cells with picos, while first tier surrounding macro cells shall use low-power ABS. For such cases, user throughput gains of 30%-40% are still achievable. Moreover, it is demonstrated that if macro muting patterns are not fully time aligned, it causes additional interference fluctuations in the network, resulting in less efficient link adaptation and radio-aware packet scheduling.