To minimize interference in LTE networks, several inter-cell interference coordination (ICIC) techniques have been introduced. Among them, semi-static ICIC offers a balanced trade-off between applicability and system performance. The power allocation per resource block and cell is adapted in the range of seconds according to the load in the system. An open issue in the literature is the question how fast the adaptation should be performed. This leads basically to a trade-off between system performance and feasible computation times of the associated power allocation problems. In this work, we close this open issue by studying the impact that different durations of update times of semi-static ICIC have on the system performance. We conduct our study on realistic scenarios considering also the mobility of mobile terminals. Secondly, we also consider the implementation aspects of a semi-static ICIC. We introduce a very efficient implementation on general purpose graphic processing units, harnessing the parallel computing capability of such devices. We show that the update periods have a significant impact on the performance of cell edge terminals. Additionally, we present a graphic processing unit (GPU) based implementation which speeds up existing implementations up to a factor of 92x.
Parruca, Donald and Aizaz, Fahad and Chantaraskul, Soamsiri and Gross, James. “Semi-static Interference Coordination in OFDMA/LTE Networks: Evaluation of Practical Aspects. In Proceedings of the 17th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems, pp 87-94 2014.
We present PacketShader, a high-performance software router framework for general packet processing with Graphics Processing Unit (GPU) acceleration. PacketShader exploits the massively-parallel processing power of GPU to address the CPU bottleneck in current software routers. Combined with our high-performance packet I/O engine, PacketShader outperforms existing software routers by more than a factor of four, forwarding 64B IPv4 packets at 39 Gbps on a single commodity PC. We have implemented IPv4 and IPv6 forwarding, OpenFlow switching, and IPsec tunneling to demonstrate the flexibility and performance advantage of PacketShader. The evaluation results show that GPU brings significantly higher throughput over the CPU-only implementation, confirming the effectiveness of GPU for computation and memory-intensive operations in packet processing.
(Sangjin Han, Keon Jang, KyoungSoo Park and Sue Moon: “PacketShader: A GPU-accelerated Software Router”, Proceedings of ACM SIGCOMM 2010, Delhi, India, September 2010. Project webpage. DOI)
From a press release:
New Software Solution Reduces Dependency on CPUs
PORTLAND, Ore.- SC09-Nov. 18, 2009- NVIDIA Corporation (Nasdaq: NVDA) and Mellanox Technologies Ltd. today introduced new software that will increase cluster application performance by as much as 30% by reducing the latency that occurs when communicating over Mellanox InfiniBand to servers equipped with NVIDIA Tesla™ GPUs.
The system architecture of a GPU-CPU server requires the CPU to initiate and manage memory transfers between the GPU and the InfiniBand network. The new software solution will enable Tesla GPUs to transfer data to pinned system memory that a Mellanox InfiniBand solution is able to read and transmit over the network. The result is increased overall system performance and efficiency.
“NVIDIA Tesla GPUs deliver large increases in performance across each node in a cluster, but in our production runs on TSUBAME 1 we have found that network communication becomes a bottleneck when using multiple GPUs,” said Prof. Satoshi Matsuoka from Tokyo Institute of Technology. “Reducing the dependency on the CPU by using InfiniBand will deliver a major boost in performance in high performance GPU clusters, thanks to the work of NVIDIA and Mellanox, and will further enhance the architectural advances we will make in TSUBAME2.0.” Read the rest of this entry »