By the load definition of cluster, the request is regarded as granularity to compute load and implement the load balancing in cache cluster. First, the processing power of cache-node is studied from four aspects: netw...By the load definition of cluster, the request is regarded as granularity to compute load and implement the load balancing in cache cluster. First, the processing power of cache-node is studied from four aspects: network bandwidth, memory capacity, disk access rate and CPU usage. Then, the weighted load of cache-node is customized. Based on this, a load-balancing algorithm that can be applied to the cache cluster is proposed. Finally, Polygraph is used as a benchmarking tool to test the cache cluster possessing the load-balancing algorithm and the cache cluster with cache array routing protocol respectively. The results show the load-balancing algorithm can improve the performance of the cache cluster.展开更多
Two adaptive power and bit loading algorithms to maximize the throughput of MIMO-OFDM systems in frequency selective fading environment are proposed. The two algorithms allocate bit based on maximizing the overall thr...Two adaptive power and bit loading algorithms to maximize the throughput of MIMO-OFDM systems in frequency selective fading environment are proposed. The two algorithms allocate bit based on maximizing the overall throughput. One algorithm allocates power based on guaranteeing that the bit error rate （BER） of each sub-carrier and the total allocated power remain below a target BER threshold and a power threshold, respectively; another one allocates power based on guaranteeing that the mean BER of sub-carriers and the total allocated power remain below a target BER threshold and a power threshold, respectively. The simulation results show that the proposed algorithms can achieve faster throughput with lower computational complexity, which indicates that the proposed algorithms are effective when compared to some existing algorithms.展开更多
Fog radio access network(F-RAN) is one of the key technology that brings cloud computing benefit to the future of wireless communications for handling massive access and high volume of data traffic. The high fronthaul...Fog radio access network(F-RAN) is one of the key technology that brings cloud computing benefit to the future of wireless communications for handling massive access and high volume of data traffic. The high fronthaul burden of a typical cellular system can be partially diminished by utilizing the storage and signal processing capabilities of the F-RANs, which is still not desirable as user throughput requirement is in the increasing trend with the increment of the internet of things(IoT) devices. This paper proposes an efficient scheduling scheme that minimizes the fronthaul load of F-RAN system optimally to improve user experience, and minimize latency. The scheduling scheme is modeled in a way that the scheduler which provides the lower fronthaul load while fulfilling the minimum user throughput requirement is selected for the data transmission process. Simulation results in terms of user selection fairness, outage probability, and fronthaul load for a different portion of user equipments(UEs) contents in fog access point(F-AP) are shown and compared with the most common scheduling scheme such as round robin(RR) scheme to validate the proposed method.展开更多
In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is inv...In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is investigated in terms of channel throughput under perfect and slow Rayleigh fading channels. It is shown that the proposed model gives better insight into the operation of DCF.展开更多
Although small cell offloading technology can alleviate the congestion in macrocell, aggressively offloading data traffic from macrocell to small cell can also degrade the performance of small cell due to the heavy lo...Although small cell offloading technology can alleviate the congestion in macrocell, aggressively offloading data traffic from macrocell to small cell can also degrade the performance of small cell due to the heavy load. Because of collision and backoff, the degradation is significant especially in network with contention-based channel access, and finally decreases throughput of the whole network. To find an optimal fraction of traffic to be offloaded in heterogeneous network, we combine Markov chain with the Poisson point process model to analyze contention-based throughput in irregularly deployment networks. Then we derive the close-form solution of the throughput and find that it is a function of the transmit power and density of base stations.Based on this, we propose the load-aware offloading strategies via power control and base station density adjustment. The numerical results verify our analysis and show a great performance gain compared with non-load-aware offloading.展开更多
文摘By the load definition of cluster, the request is regarded as granularity to compute load and implement the load balancing in cache cluster. First, the processing power of cache-node is studied from four aspects: network bandwidth, memory capacity, disk access rate and CPU usage. Then, the weighted load of cache-node is customized. Based on this, a load-balancing algorithm that can be applied to the cache cluster is proposed. Finally, Polygraph is used as a benchmarking tool to test the cache cluster possessing the load-balancing algorithm and the cache cluster with cache array routing protocol respectively. The results show the load-balancing algorithm can improve the performance of the cache cluster.
基金the National Natural Science Foundation of China (60496313).
文摘Two adaptive power and bit loading algorithms to maximize the throughput of MIMO-OFDM systems in frequency selective fading environment are proposed. The two algorithms allocate bit based on maximizing the overall throughput. One algorithm allocates power based on guaranteeing that the bit error rate （BER） of each sub-carrier and the total allocated power remain below a target BER threshold and a power threshold, respectively; another one allocates power based on guaranteeing that the mean BER of sub-carriers and the total allocated power remain below a target BER threshold and a power threshold, respectively. The simulation results show that the proposed algorithms can achieve faster throughput with lower computational complexity, which indicates that the proposed algorithms are effective when compared to some existing algorithms.
基金supported by Incheon National University(International Cooperative)Research Grant in 2015
文摘Fog radio access network(F-RAN) is one of the key technology that brings cloud computing benefit to the future of wireless communications for handling massive access and high volume of data traffic. The high fronthaul burden of a typical cellular system can be partially diminished by utilizing the storage and signal processing capabilities of the F-RANs, which is still not desirable as user throughput requirement is in the increasing trend with the increment of the internet of things(IoT) devices. This paper proposes an efficient scheduling scheme that minimizes the fronthaul load of F-RAN system optimally to improve user experience, and minimize latency. The scheduling scheme is modeled in a way that the scheduler which provides the lower fronthaul load while fulfilling the minimum user throughput requirement is selected for the data transmission process. Simulation results in terms of user selection fairness, outage probability, and fronthaul load for a different portion of user equipments(UEs) contents in fog access point(F-AP) are shown and compared with the most common scheduling scheme such as round robin(RR) scheme to validate the proposed method.
文摘In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is investigated in terms of channel throughput under perfect and slow Rayleigh fading channels. It is shown that the proposed model gives better insight into the operation of DCF.
基金supported by the National High-Tech R&D Program (863 Program) under grant No. 2015AA01A705Beijing Municipal Science and Technology Commission research fund project under grant No. D151100000115002+1 种基金China Scholarship Council under grant No. 201406470038BUPT youth scientific research innovation program under grant No. 500401238
文摘Although small cell offloading technology can alleviate the congestion in macrocell, aggressively offloading data traffic from macrocell to small cell can also degrade the performance of small cell due to the heavy load. Because of collision and backoff, the degradation is significant especially in network with contention-based channel access, and finally decreases throughput of the whole network. To find an optimal fraction of traffic to be offloaded in heterogeneous network, we combine Markov chain with the Poisson point process model to analyze contention-based throughput in irregularly deployment networks. Then we derive the close-form solution of the throughput and find that it is a function of the transmit power and density of base stations.Based on this, we propose the load-aware offloading strategies via power control and base station density adjustment. The numerical results verify our analysis and show a great performance gain compared with non-load-aware offloading.
