 © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology 5th Percentile User Throughput 350000 300000 250000 200000 150000 100000 50000 Average Number of Users per Cell No ICIC Mean User Throughput 700000 600000 500000 400000 300000 200000 100000 Average Number of Users per Cell No ICIC Figure 4.13 System simulation results on uplink intercell interference coordina- tion; full buffer-peak rate limited traffic scenario. the same resource blocks for its cell edge UEs. This way the proactive scheme allows neighbor eNode Bs to reduce the probabilities of "exterior-exterior" (i.e., cell edge) UEs simultaneously taking into use the same resource blocks. The avoidance of such exterior-exterior collisions has been found useful by system- level simulations. An important part of the proactive scheme is the identification of cell edge UEs. The 3GPP currently studies the use of UE measurement report- ing (similar but not identical to that used for handovers) for this purpose (see references 43-48); these proposals are expected to be discussed more at future 3GPP meetings. © 2009 by Taylor & Francis Group, LLC CDF Comparison 5th Percentile User Throughput (bps) 25000 20000 15000 10000 Number of Users in the System UE Power (dBm) No ICIC No ICIC Histogram of the SINR Histogram of the Effective Number of Bits per RB -24 -19 -14 -8.5 -3.5 1.5 6.5 11.5 16.5 21.5 26.5 31.5 36.5 SINR (dB) Effective Number of Bits per RB No ICIC No ICIC Figure 4.14 System simulation results on uplink intercell interference coordination; nonfull buffer-non-peak rate limited traffic scenario. C 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology In addition, the 3GPP discusses the use of the overload indicator (OI) originally proposed for intercell power control purposes. It is currently agreed in 3GPP that the OI also carries information at the resource block granularity. As opposed to the proactive scheme, the overload indication is a reactive scheme that indicates