Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863087
Jun-woo Kim, Jang-won Moon, Young-Jin Moon, Gosan Noh, Youn-Ok Park
In this paper, we propose a latency reduction scheme for an Orthogonal Frequency Division Multiplexing (OFDM) modulator and apply it to a 3GPP LTE transmitter. In the OFDM modulator, latency is composed of the latencies of inverse fast Fourier transform (IFFT), re-ordering and cyclic prefix (CP) addition. The proposed scheme reduces this latency by adding a phase pre-rotator to the IFFT input part and implementing IFFT with decimation in time (DIT) structure. Since this makes the output of IFFT be in-order and contain the cyclic prefix, the OFDM modulation latency is reduced by half compared to the conventional design. Implemented in VHDL, the operation of the proposed OFDM modulator is successfully verified for the three different types of cyclic prefixes in LTE.
{"title":"A research on fast OFDM modulation for 3GPP LTE transmitter","authors":"Jun-woo Kim, Jang-won Moon, Young-Jin Moon, Gosan Noh, Youn-Ok Park","doi":"10.1109/TENCONSPRING.2014.6863087","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863087","url":null,"abstract":"In this paper, we propose a latency reduction scheme for an Orthogonal Frequency Division Multiplexing (OFDM) modulator and apply it to a 3GPP LTE transmitter. In the OFDM modulator, latency is composed of the latencies of inverse fast Fourier transform (IFFT), re-ordering and cyclic prefix (CP) addition. The proposed scheme reduces this latency by adding a phase pre-rotator to the IFFT input part and implementing IFFT with decimation in time (DIT) structure. Since this makes the output of IFFT be in-order and contain the cyclic prefix, the OFDM modulation latency is reduced by half compared to the conventional design. Implemented in VHDL, the operation of the proposed OFDM modulator is successfully verified for the three different types of cyclic prefixes in LTE.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115861212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863051
R. Yadav, Sunil Kumar, S. Kulkarni
In multi-element coupled lines, the effect of junction discontinuity is unavoidable. These are found prominent in the high power coupled lines for HF and VHF applications because of larger structural dimensions. For the development of a 200kW tandem 3±0.2dB ultra-wideband hybrid coupler, design and simulation of a 3-elements 8.34±0.2dB coupled section is performed. In simulation results, coupling and output parameters of the designed coupled section are found significantly deteriorated from the theoretical prediction. The problem is investigated and found associated to the effect junction discontinuity. Junctions that are employed to join the elements produce undesirable reactive effect known as junction discontinuity effect. An analysis of the junction discontinuity effect in multi-element coupled lines and its compensation using novel approach is presented.
{"title":"Junction discontinuity effect in multi-element coupled lines and its compensation","authors":"R. Yadav, Sunil Kumar, S. Kulkarni","doi":"10.1109/TENCONSPRING.2014.6863051","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863051","url":null,"abstract":"In multi-element coupled lines, the effect of junction discontinuity is unavoidable. These are found prominent in the high power coupled lines for HF and VHF applications because of larger structural dimensions. For the development of a 200kW tandem 3±0.2dB ultra-wideband hybrid coupler, design and simulation of a 3-elements 8.34±0.2dB coupled section is performed. In simulation results, coupling and output parameters of the designed coupled section are found significantly deteriorated from the theoretical prediction. The problem is investigated and found associated to the effect junction discontinuity. Junctions that are employed to join the elements produce undesirable reactive effect known as junction discontinuity effect. An analysis of the junction discontinuity effect in multi-element coupled lines and its compensation using novel approach is presented.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131943776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863091
K. S. Dash, N. Puhan, G. Panda
Unconstrained handwritten character recognition is a major research area where there is a lot of scope for improving accuracy. There are many statistical, structural feature extraction techniques being proposed for different languages. Many classifier models are combined with these features to obtain high recognition rates. There still exists a gap between the recognition accuracy of printed characters and unconstrained handwritten scripts. Odia is a popular and classical language of the eastern part of India. Though the research in Optical Character Recognition (OCR) has advanced in other Indian languages such as Devanagari and Bangla, not much attention has been given to Odia character recognition. We propose a hybrid feature extraction technique using Kirsch gradient operator and curvature properties of handwritten numerals, followed by a feature dimension reduction using Principal Component Analysis (PCA). We use Modified Quadratic Discriminant Function (MQDF), Discriminative Learning Quadratic Discriminant Function (DLQDF) classifiers as they provide high accuracy of recognition and compare both the classifier performances. We verify our results using the Odia numerals database of ISI Kolkata. The recognition accuracy for Odia numerals with our proposed approach is found to be 98.5%.
{"title":"A hybrid feature and discriminant classifier for high accuracy handwritten Odia numeral recognition","authors":"K. S. Dash, N. Puhan, G. Panda","doi":"10.1109/TENCONSPRING.2014.6863091","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863091","url":null,"abstract":"Unconstrained handwritten character recognition is a major research area where there is a lot of scope for improving accuracy. There are many statistical, structural feature extraction techniques being proposed for different languages. Many classifier models are combined with these features to obtain high recognition rates. There still exists a gap between the recognition accuracy of printed characters and unconstrained handwritten scripts. Odia is a popular and classical language of the eastern part of India. Though the research in Optical Character Recognition (OCR) has advanced in other Indian languages such as Devanagari and Bangla, not much attention has been given to Odia character recognition. We propose a hybrid feature extraction technique using Kirsch gradient operator and curvature properties of handwritten numerals, followed by a feature dimension reduction using Principal Component Analysis (PCA). We use Modified Quadratic Discriminant Function (MQDF), Discriminative Learning Quadratic Discriminant Function (DLQDF) classifiers as they provide high accuracy of recognition and compare both the classifier performances. We verify our results using the Odia numerals database of ISI Kolkata. The recognition accuracy for Odia numerals with our proposed approach is found to be 98.5%.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132070320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863026
M. Hamedi, S. Salleh, A. M. Noor, Iman Mohammad-Rezazadeh
Many studies have reported the usefulness of motor imagery (MI) electroencephalogram (EEG) signals for Brain Computer Interface (BCI) systems. MI has been broadly characterized by the average of event-related changes of brain activity at specific frequency bands; but, temporal features of EEG have rarely been considered to identify different mental states of BCIs' users. Additionally, complex classification techniques may have been proposed to enhance the accuracy of system but they may cause a notable delay during online applications. This paper investigated the application of neural network-based algorithms to classify three-class MIs by utilizing EEG time-domain features. Integrated EEG (IEEG) and Root Mean Square (RMS) features were extracted from EEG signals. Then, Multilayer Perceptron and Radial Basis Function Neural Networks were employed to classify the features. The discrimination ratio of such features were examined and compared through different classifiers. Moreover, the robustness of classifiers was investigated and compared. The results of this study indicated that RMS was more capable than IEEG for characterizing MI movements and RBF was more accurate and faster than MLP. The effectiveness of IEEG and RMS features and the performance of MLP and RBF classifiers were compared with Willison Amplitude (WAMP) feature and support vector machine (SVM) classifier respectively. This study proved that WAMP and SVM were more efficient for classification of MI tasks in both terms of accuracy (88.96%) and training time (0.5 second); however, considerable difference was not observed since RBF performed as fast as SVM with only about 3% less accuracy.
{"title":"Neural network-based three-class motor imagery classification using time-domain features for BCI applications","authors":"M. Hamedi, S. Salleh, A. M. Noor, Iman Mohammad-Rezazadeh","doi":"10.1109/TENCONSPRING.2014.6863026","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863026","url":null,"abstract":"Many studies have reported the usefulness of motor imagery (MI) electroencephalogram (EEG) signals for Brain Computer Interface (BCI) systems. MI has been broadly characterized by the average of event-related changes of brain activity at specific frequency bands; but, temporal features of EEG have rarely been considered to identify different mental states of BCIs' users. Additionally, complex classification techniques may have been proposed to enhance the accuracy of system but they may cause a notable delay during online applications. This paper investigated the application of neural network-based algorithms to classify three-class MIs by utilizing EEG time-domain features. Integrated EEG (IEEG) and Root Mean Square (RMS) features were extracted from EEG signals. Then, Multilayer Perceptron and Radial Basis Function Neural Networks were employed to classify the features. The discrimination ratio of such features were examined and compared through different classifiers. Moreover, the robustness of classifiers was investigated and compared. The results of this study indicated that RMS was more capable than IEEG for characterizing MI movements and RBF was more accurate and faster than MLP. The effectiveness of IEEG and RMS features and the performance of MLP and RBF classifiers were compared with Willison Amplitude (WAMP) feature and support vector machine (SVM) classifier respectively. This study proved that WAMP and SVM were more efficient for classification of MI tasks in both terms of accuracy (88.96%) and training time (0.5 second); however, considerable difference was not observed since RBF performed as fast as SVM with only about 3% less accuracy.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133780269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863114
R. Kodali, Nisheeth Rawat, Lakshmi Boppana
The application of technology in the field of agriculture has increased the effectiveness and efficiency of the farmers. The application of Wireless Sensor Network (WSN) in precision agriculture assists the farmers to know about their fields in statistical manner, which helps them in making better and accurate decisions. There are various type of sensors that can be used to calculate the statistical parameters of an agricultural fields, which convert the event or a phenomenon into an electrical or measurable quantity. This paper provides an elaboration of the basic principles of some of the sensors and their related specifications of few commercial products.
{"title":"WSN sensors for precision agriculture","authors":"R. Kodali, Nisheeth Rawat, Lakshmi Boppana","doi":"10.1109/TENCONSPRING.2014.6863114","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863114","url":null,"abstract":"The application of technology in the field of agriculture has increased the effectiveness and efficiency of the farmers. The application of Wireless Sensor Network (WSN) in precision agriculture assists the farmers to know about their fields in statistical manner, which helps them in making better and accurate decisions. There are various type of sensors that can be used to calculate the statistical parameters of an agricultural fields, which convert the event or a phenomenon into an electrical or measurable quantity. This paper provides an elaboration of the basic principles of some of the sensors and their related specifications of few commercial products.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"40 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114121705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863088
Bhupendra Gupta, S. S. Lamba
The internodal distance is an important characteristic of ad-hoc wireless networks and sensor networks. Some important properties like propagation delay, like capacity etc. are depending on the internodal distance. In this paper we consider a d-dimensional binomial point process (BPP) having N points distributed uniformly over a compact space S ⊂ Rd. Here we prove that the kth nearest neighbor distance in binomial point process converges weakly to the nth nearest neighbor distance in Poisson point process, which follows a generalize gamma density.
{"title":"On k-th nearest neighbor distance distribution of random ad-hoc network","authors":"Bhupendra Gupta, S. S. Lamba","doi":"10.1109/TENCONSPRING.2014.6863088","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863088","url":null,"abstract":"The internodal distance is an important characteristic of ad-hoc wireless networks and sensor networks. Some important properties like propagation delay, like capacity etc. are depending on the internodal distance. In this paper we consider a d-dimensional binomial point process (BPP) having N points distributed uniformly over a compact space S ⊂ Rd. Here we prove that the kth nearest neighbor distance in binomial point process converges weakly to the nth nearest neighbor distance in Poisson point process, which follows a generalize gamma density.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114173973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863075
M. Ahmed, Nor Ashidi Mat Isa
The proposed structural fuzzy classification system (SFCS) is an online self-organizing method and automatically identifies the prominent distinct data in the output domain for the new fuzzy rule. Thus, SFCS always tends from higher to lower error region. Both evolving error and rule creation are dynamically realized from the past and current knowledge. Therefore, effective rule-base is the balanced fuzzy model of the approximated system. This effective rule-base might be applied to engineering application to depict the prominent distinction on the output space.
{"title":"Structural fuzzy classification system, evolves and its engineering application","authors":"M. Ahmed, Nor Ashidi Mat Isa","doi":"10.1109/TENCONSPRING.2014.6863075","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863075","url":null,"abstract":"The proposed structural fuzzy classification system (SFCS) is an online self-organizing method and automatically identifies the prominent distinct data in the output domain for the new fuzzy rule. Thus, SFCS always tends from higher to lower error region. Both evolving error and rule creation are dynamically realized from the past and current knowledge. Therefore, effective rule-base is the balanced fuzzy model of the approximated system. This effective rule-base might be applied to engineering application to depict the prominent distinction on the output space.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114157457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6862988
M. Rao, Neha Oraon, P. Sravani
The wireless transmission circuit consists of power amplifier and heatsinks which is a 3D structure. Heatsinks are normally designed to be near power amplifier circuit. The heatsink radiations are undesirable for some applications and should be minimized to reduce electromagnetic interference (EMI). However in certain applications the design of heatsinks are unavoidable. The use of heatsink as a radiating or receiving electromagnetic radiation will be of significant value if heatsink is designed as an antenna. The fabrication of 3D antennas depends on the designed resonant frequency. As the antennas are made smaller physically, their resonant frequency increases, so building millimeter-wave capable antennas using conventional semiconductor processing techniques becomes feasible. The fabrication of on-chip antenna heatsinks for high frequency radiations can be visualized using a novel self assembly process. The self assembly(SA) technique is driven by surface tension property to pull the 2D metal patterns into 3D structures. The SA method involves conventional semiconductor steps with an additional dip soldering and reflow steps to develop 3D antennas. In our previous paper we have investigated antenna properties of 3D structures as an antenna for two different frequencies: low (2.4 GHz) and high (23.78 GHz) frequencies. This paper provides the simulation of truncated square pyramid (TSP) 3D structures which has high fabrication yield among all other structures. The simulation of TSP structures as an antenna is also demonstrated.
{"title":"Self assembly based high frequency 3D heatsink antenna","authors":"M. Rao, Neha Oraon, P. Sravani","doi":"10.1109/TENCONSPRING.2014.6862988","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6862988","url":null,"abstract":"The wireless transmission circuit consists of power amplifier and heatsinks which is a 3D structure. Heatsinks are normally designed to be near power amplifier circuit. The heatsink radiations are undesirable for some applications and should be minimized to reduce electromagnetic interference (EMI). However in certain applications the design of heatsinks are unavoidable. The use of heatsink as a radiating or receiving electromagnetic radiation will be of significant value if heatsink is designed as an antenna. The fabrication of 3D antennas depends on the designed resonant frequency. As the antennas are made smaller physically, their resonant frequency increases, so building millimeter-wave capable antennas using conventional semiconductor processing techniques becomes feasible. The fabrication of on-chip antenna heatsinks for high frequency radiations can be visualized using a novel self assembly process. The self assembly(SA) technique is driven by surface tension property to pull the 2D metal patterns into 3D structures. The SA method involves conventional semiconductor steps with an additional dip soldering and reflow steps to develop 3D antennas. In our previous paper we have investigated antenna properties of 3D structures as an antenna for two different frequencies: low (2.4 GHz) and high (23.78 GHz) frequencies. This paper provides the simulation of truncated square pyramid (TSP) 3D structures which has high fabrication yield among all other structures. The simulation of TSP structures as an antenna is also demonstrated.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117003392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863069
H. Singh, G. Pandey, P. K. Bharti, M. K. Meshram
A low profile ultrawide band (UWB) planar inverted-F antenna (PIFA) for multiple input multiple output (MIMO) applications is studied. This antenna consists of rectangular monopole as a feed plate and top loaded rectangular plate. The assembly of feed plate and top loaded rectangular monopole is grounded through shorting wall. The size of top loaded rectangular plate and rectangular feed plate are chosen 20 × 10 mm2 and 14 × 6.75 mm2 respectively. The proposed antenna covers the frequency range from 3.0-10.8 GHz with impedance bandwidth of 113 % and isolation between antenna elements is obtained less than -15 dB without any isolation improvement techniques. The diversity performances is analyzed for evaluation of diversity antenna. Antenna is also characterized by S-parameters, far field radiation patterns, efficiency, and peak realized gain. Fidelity factor for proposed antenna is calculated to characterize time domain behaviour. The optimized structure is fabricated and tested. The acceptable agreement is obtained between simulated and measured results.
{"title":"Design of low profile ultra wideband PIFA for MIMO applications","authors":"H. Singh, G. Pandey, P. K. Bharti, M. K. Meshram","doi":"10.1109/TENCONSPRING.2014.6863069","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863069","url":null,"abstract":"A low profile ultrawide band (UWB) planar inverted-F antenna (PIFA) for multiple input multiple output (MIMO) applications is studied. This antenna consists of rectangular monopole as a feed plate and top loaded rectangular plate. The assembly of feed plate and top loaded rectangular monopole is grounded through shorting wall. The size of top loaded rectangular plate and rectangular feed plate are chosen 20 × 10 mm2 and 14 × 6.75 mm2 respectively. The proposed antenna covers the frequency range from 3.0-10.8 GHz with impedance bandwidth of 113 % and isolation between antenna elements is obtained less than -15 dB without any isolation improvement techniques. The diversity performances is analyzed for evaluation of diversity antenna. Antenna is also characterized by S-parameters, far field radiation patterns, efficiency, and peak realized gain. Fidelity factor for proposed antenna is calculated to characterize time domain behaviour. The optimized structure is fabricated and tested. The acceptable agreement is obtained between simulated and measured results.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128103529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-14DOI: 10.1109/TENCONSPRING.2014.6863002
Wang Hui, Y. Fukushima, T. Yokohira
Split-connection type proxies have been proposed to improve TCP (Transmission Control Protocol) throughput in network environment with wireless LANs. A proxy is placed at the boundary of a wireless LAN (WLAN) and a wired network and it splits a TCP connection into two virtual TCP connections. We proposed a split-connection type proxy called MDA-Proxy (Modified Decreasing-ACK Proxy), which increases throughput of upflows (flows from wireless hosts to wired hosts) by decreasing the number of ACKs in a WLAN. MDA-Proxy uses two parameters, ack_stock and delay_timer, for each connection. The former controls the number of ACKs sent to a WLAN and the latter is used to recover from losses and delays of ACKs in a wired network. However, it is assumed that MDA-Proxy uses fixed values of the two parameters and their automatic tuning in response to network situation remains to be future work. In this paper, we propose a new type of proxy called ASA-Proxy (Ack_Stock Autotunning Proxy), which automatically tunes the two parameters in MDA-Proxy. Ack_stock is tuned comparing throughputs before and after its changing so that throughput of the connection becomes large, and delay_timer is replaced by the normal TCP retransmission timer because it is better than a fixed value of delay_timer for the inference of losses and delays of ACKs in a wired network. Extensive simulation runs show that ASA-Proxy is superior to MDA-Proxy.
为了提高无线局域网环境下TCP (Transmission Control Protocol，传输控制协议)的吞吐量，提出了分离连接型代理。代理被放置在无线局域网(WLAN)和有线网络的边界，它将一个TCP连接分割成两个虚拟的TCP连接。我们提出了一种分离连接类型的代理，称为MDA-Proxy (Modified递减ack proxy)，它通过减少WLAN中的ack数量来增加上行流(从无线主机到有线主机的流量)的吞吐量。MDA-Proxy对每个连接使用两个参数ack_stock和delay_timer。前者控制发送到WLAN的ack数量，后者用于从有线网络中的ack丢失和延迟中恢复。但是，假设MDA-Proxy使用两个参数的固定值，它们根据网络情况的自动调优仍然是未来的工作。在本文中，我们提出了一种新的代理，称为ASA-Proxy (Ack_Stock Autotunning proxy)，它可以自动调整MDA-Proxy中的两个参数。对Ack_stock进行调优，比较其变化前后的吞吐量，使连接的吞吐量变得很大，并且将delay_timer替换为普通的TCP重传计时器，因为它比固定值的delay_timer更好地推断有线网络中ack的损失和延迟。大量的仿真运行表明ASA-Proxy优于MDA-Proxy。
{"title":"Throughput improvement of TCP proxies in network environment with wireless LANs","authors":"Wang Hui, Y. Fukushima, T. Yokohira","doi":"10.1109/TENCONSPRING.2014.6863002","DOIUrl":"https://doi.org/10.1109/TENCONSPRING.2014.6863002","url":null,"abstract":"Split-connection type proxies have been proposed to improve TCP (Transmission Control Protocol) throughput in network environment with wireless LANs. A proxy is placed at the boundary of a wireless LAN (WLAN) and a wired network and it splits a TCP connection into two virtual TCP connections. We proposed a split-connection type proxy called MDA-Proxy (Modified Decreasing-ACK Proxy), which increases throughput of upflows (flows from wireless hosts to wired hosts) by decreasing the number of ACKs in a WLAN. MDA-Proxy uses two parameters, ack_stock and delay_timer, for each connection. The former controls the number of ACKs sent to a WLAN and the latter is used to recover from losses and delays of ACKs in a wired network. However, it is assumed that MDA-Proxy uses fixed values of the two parameters and their automatic tuning in response to network situation remains to be future work. In this paper, we propose a new type of proxy called ASA-Proxy (Ack_Stock Autotunning Proxy), which automatically tunes the two parameters in MDA-Proxy. Ack_stock is tuned comparing throughputs before and after its changing so that throughput of the connection becomes large, and delay_timer is replaced by the normal TCP retransmission timer because it is better than a fixed value of delay_timer for the inference of losses and delays of ACKs in a wired network. Extensive simulation runs show that ASA-Proxy is superior to MDA-Proxy.","PeriodicalId":270495,"journal":{"name":"2014 IEEE REGION 10 SYMPOSIUM","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129602376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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