Cell isolation or the inter-cell interference is an important characteristic of radio networks. The cell isolation together with link performance limits the achievable user throughput and the capacity for a 1-reuse link adaptive packet access systems such as LTE. In this paper, cell isolation is measured as geometry factors and assessed through UE measurements in two different networks utilizing different access techniques, LTE and GSM. The use of UE measurements are beneficial in the sense that the mobile position is always known, making it possible to distinguish between indoor and outdoor positions. It is found that the geometry factor is higher indoor than outdoor. The GSM measurements provide better accuracy because of the sparse frequency reuse and more mature mobiles detecting a large set of neighbor cells. These GSM measurements also confirm previous system measurements on commercial traffic in the same area.