Pub Date : 2005-10-17DOI: 10.1109/MILCOM.2005.1606090
A. Snow, P. Rastogi, G. Weckman
Critical infrastructures such as wireless network systems demand dependability. Dependability attributes addressed in this paper include availability, reliability, maintainability and survivability. This research uses computer simulation and artificial intelligence to introduce a new approach to assess dependability of wireless networks. The new approach is based on the development of a neural network, which is trained to investigate availability, reliability, maintainability, and survivability attributes (ARMS) of a wireless network. In this work, given a variety of reliability and maintainability attribute scenarios for a wireless infrastructure, the resulting impact on network availability and survivability are determined. Component mean time to failure (MTTF) is used to model reliability, while the mean time to restore (MTR) is used for maintainability. Here, unavailability, the complement of availability, is defined as the fraction of time the entire network system is down, while survivability is the fraction of network user capacity up over time. Both availability and survivability can be instantaneous or averaged over some period. The data set, which is used to train the neural network, is obtained from simulation experiments with a range of component MTTF and MTTR. In addition, the number of times a new regulatory outage reporting threshold is surpassed is also determined. This research also focuses on the relative performance of neural network modeling compared to analytical and simulation techniques for assessing the ARMS attributes of a wireless network, and the additional insights that can be obtained from NN modeling.
{"title":"Assessing dependability of wireless networks using neural networks","authors":"A. Snow, P. Rastogi, G. Weckman","doi":"10.1109/MILCOM.2005.1606090","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1606090","url":null,"abstract":"Critical infrastructures such as wireless network systems demand dependability. Dependability attributes addressed in this paper include availability, reliability, maintainability and survivability. This research uses computer simulation and artificial intelligence to introduce a new approach to assess dependability of wireless networks. The new approach is based on the development of a neural network, which is trained to investigate availability, reliability, maintainability, and survivability attributes (ARMS) of a wireless network. In this work, given a variety of reliability and maintainability attribute scenarios for a wireless infrastructure, the resulting impact on network availability and survivability are determined. Component mean time to failure (MTTF) is used to model reliability, while the mean time to restore (MTR) is used for maintainability. Here, unavailability, the complement of availability, is defined as the fraction of time the entire network system is down, while survivability is the fraction of network user capacity up over time. Both availability and survivability can be instantaneous or averaged over some period. The data set, which is used to train the neural network, is obtained from simulation experiments with a range of component MTTF and MTTR. In addition, the number of times a new regulatory outage reporting threshold is surpassed is also determined. This research also focuses on the relative performance of neural network modeling compared to analytical and simulation techniques for assessing the ARMS attributes of a wireless network, and the additional insights that can be obtained from NN modeling.","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115843734","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1606008
D. Green
In this paper, we describe our efforts to build a working IPv6 transition architecture for Stryker Brigade Combat Team (SBCT) tactical radio networks and test the efficiency of the architecture via an OPNET M&S study. Our engineers determined that the previous study Macintyre, L. of IPv6 over advanced tactical radio networks did not experiment with some key technologies that are now emerging such as robust IP header compression Bormann, et al., scalable link-state (proactive) MANET routing protocols with scoped routing areas [Baker, et al. (2003), Spagnolo, et al. (2004), Chandra, et al. (2004)], or "dual stacked" routing protocols where a single protocol instance is capable of advertising both IPv4 and IPv6 addresses on a single link Mirtarobi, et al. (2004). The models also were lacking an accurate low-level model of tactical radio link and physical layers, and did not use an accurate traffic model of military tactical data communications like the PCS traffic model that the CERDEC team has developed through our experience with PCS and DARPA M&S work. By injecting these key technologies into our SBCT radio model, we have created architecture, extensible to other net-centric forces like PCS, for transitioning tactical radios networks to IPv6. Our study found that with proper engineering, tactical networks could reap the benefits of IPv6 and operate with efficiency equal to or greater than current IPv4 networks
{"title":"Stryker Brigade Combat Team IPv6 transition modeling and simulation study","authors":"D. Green","doi":"10.1109/MILCOM.2005.1606008","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1606008","url":null,"abstract":"In this paper, we describe our efforts to build a working IPv6 transition architecture for Stryker Brigade Combat Team (SBCT) tactical radio networks and test the efficiency of the architecture via an OPNET M&S study. Our engineers determined that the previous study Macintyre, L. of IPv6 over advanced tactical radio networks did not experiment with some key technologies that are now emerging such as robust IP header compression Bormann, et al., scalable link-state (proactive) MANET routing protocols with scoped routing areas [Baker, et al. (2003), Spagnolo, et al. (2004), Chandra, et al. (2004)], or \"dual stacked\" routing protocols where a single protocol instance is capable of advertising both IPv4 and IPv6 addresses on a single link Mirtarobi, et al. (2004). The models also were lacking an accurate low-level model of tactical radio link and physical layers, and did not use an accurate traffic model of military tactical data communications like the PCS traffic model that the CERDEC team has developed through our experience with PCS and DARPA M&S work. By injecting these key technologies into our SBCT radio model, we have created architecture, extensible to other net-centric forces like PCS, for transitioning tactical radios networks to IPv6. Our study found that with proper engineering, tactical networks could reap the benefits of IPv6 and operate with efficiency equal to or greater than current IPv4 networks","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115971515","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1605774
Yun Zhou, Yuguang Fang
Sensor networks are vulnerable to many active attacks due to the defects of the network protocols that are not designed carefully to involve security defenses at the beginning. Most of the attacks try to cause topological distortion by spoofing or replaying routing information. This paper proposes to use a location-based naming (LBN) mechanism for sensor nodes, in which location information is embedded into node identifier and acts as an inherent node characteristic to provide authentication service in local access control. When LBN is enforced, the impacts of many attacks to sensor network topology can be limited in a small area. A link layer authentication (LLA) scheme is also proposed to further decrease the impacts of those attacks. Our LBN and LLA can be combined and act as an efficient solution against a wide range of topological attacks in sensor networks
{"title":"Defend against topological attacks in sensor networks","authors":"Yun Zhou, Yuguang Fang","doi":"10.1109/MILCOM.2005.1605774","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1605774","url":null,"abstract":"Sensor networks are vulnerable to many active attacks due to the defects of the network protocols that are not designed carefully to involve security defenses at the beginning. Most of the attacks try to cause topological distortion by spoofing or replaying routing information. This paper proposes to use a location-based naming (LBN) mechanism for sensor nodes, in which location information is embedded into node identifier and acts as an inherent node characteristic to provide authentication service in local access control. When LBN is enforced, the impacts of many attacks to sensor network topology can be limited in a small area. A link layer authentication (LLA) scheme is also proposed to further decrease the impacts of those attacks. Our LBN and LLA can be combined and act as an efficient solution against a wide range of topological attacks in sensor networks","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131382043","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1605811
T. X. Lai, A. Sesay
The iterative multiuser detection methods are proposed for time hoping impulse radio (TH-IR) communications systems by drawing the similarity between the digital PAM IR and the conventional spread spectrum systems, i.e. DS-CDMA. These iterative multiuser receivers overcome the problem of pulse collisions in the IR system that causes the collapse of the conventional receiver. Two different receiver structures are proposed and their performance is studied and compared with the single user case. It is shown that the performance of these iterative receivers approach that of the single user receiver after only a few (two or three) iterations
{"title":"On the iterative multiuser receivers for time hoping impulse radio communication systems","authors":"T. X. Lai, A. Sesay","doi":"10.1109/MILCOM.2005.1605811","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1605811","url":null,"abstract":"The iterative multiuser detection methods are proposed for time hoping impulse radio (TH-IR) communications systems by drawing the similarity between the digital PAM IR and the conventional spread spectrum systems, i.e. DS-CDMA. These iterative multiuser receivers overcome the problem of pulse collisions in the IR system that causes the collapse of the conventional receiver. Two different receiver structures are proposed and their performance is studied and compared with the single user case. It is shown that the performance of these iterative receivers approach that of the single user receiver after only a few (two or three) iterations","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"258 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131954214","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1605750
M. Bansal, E. S. Pynadath, L. Kondi, J. Matyjas, M. Medley, S. Reichhart, K. Turck
In this work, we demonstrate the interference mitigation capabilities of the auxiliary vector (AV) receiver for scalable video transmission over direct-sequence code division multiple access (DS-CDMA) systems using a hardware testbed. The proposed receiver design is also compared to the conventional RAKE matched-filter (RAKE-MF) and minimum variance distortionless response (MVDR) receivers. The DS-CDMA video data stream is transmitted over an RF channel under ''real world'' Rayleigh-faded multipath channel conditions, emulating open and/or urban battlefield environments. The state-of-the-art Agilent E4438C vector signal generator and baseband studio fader is used to provide a configurable "real time" RF channel. In this work, the "foreman" video sequence is source encoded using an MPEG-4 compatible video codec and channel-coded using rate-compatible punctured convolutional (RCPC) codes. After spreading and modulating, the resultant bitstream is transmitted over a user-defined Agilent wireless channel emulation. Upon chip-matched filtering and sampling at the chip-rate on a hardware testbed, the received data are despread/demodulated using the AV, RAKE-MF and MVDR receivers and, subsequently, channel and source decoded. The resultant video clips exemplify that the AV receiver outperforms the MVDR and the RAKE-MF receiver counterparts under a wide range of rates and channel conditions
{"title":"Interference resistant scalable video transmission over DS-CDMA channels","authors":"M. Bansal, E. S. Pynadath, L. Kondi, J. Matyjas, M. Medley, S. Reichhart, K. Turck","doi":"10.1109/MILCOM.2005.1605750","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1605750","url":null,"abstract":"In this work, we demonstrate the interference mitigation capabilities of the auxiliary vector (AV) receiver for scalable video transmission over direct-sequence code division multiple access (DS-CDMA) systems using a hardware testbed. The proposed receiver design is also compared to the conventional RAKE matched-filter (RAKE-MF) and minimum variance distortionless response (MVDR) receivers. The DS-CDMA video data stream is transmitted over an RF channel under ''real world'' Rayleigh-faded multipath channel conditions, emulating open and/or urban battlefield environments. The state-of-the-art Agilent E4438C vector signal generator and baseband studio fader is used to provide a configurable \"real time\" RF channel. In this work, the \"foreman\" video sequence is source encoded using an MPEG-4 compatible video codec and channel-coded using rate-compatible punctured convolutional (RCPC) codes. After spreading and modulating, the resultant bitstream is transmitted over a user-defined Agilent wireless channel emulation. Upon chip-matched filtering and sampling at the chip-rate on a hardware testbed, the received data are despread/demodulated using the AV, RAKE-MF and MVDR receivers and, subsequently, channel and source decoded. The resultant video clips exemplify that the AV receiver outperforms the MVDR and the RAKE-MF receiver counterparts under a wide range of rates and channel conditions","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132487826","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1605777
J. Heissler, J. Marshall, R.M. Piccola, R. Sonalkar, J. Zeng
The role of satellite communications (SATCOM) in support of the deployed warfighter has increased in recent years. With this increased reliance on SATCOM, the importance for a Department of Defense (DoD) wide strategy to efficiently procure and utilize the limited set of commercial DoD space assets has been emphasized. A step in the migration towards this strategy will be the development of a standard, multi-access, packet-based protocol that provides bandwidth on demand to the Joint warfighter. The digital video broadcast (DVB) standard chosen for this waveform leverages existing commercial modem technologies and offers a mature standard base which minimizes the development burden on the DoD. Of key interest for the tactical warfighter is the ability of the DVB family of standards to support certain functional capabilities: 1) to support robust communications while on-the-move (COTM), 2) to support a full mesh architecture, 3) to support a mix of non-real time, and real time traffic, and, 4) a capability to scale to large number of users and very efficiently share bandwidth. This paper provides a summary of a set of analyses that was performed to quantify the performance of the DVB standards to meet the four capabilities highlighted above. The analysis also inherently provides some insight on the challenges of applying commercial modem technologies to the battlefield
{"title":"A performance analysis on the application of commercial standards for IP SATCOM modems","authors":"J. Heissler, J. Marshall, R.M. Piccola, R. Sonalkar, J. Zeng","doi":"10.1109/MILCOM.2005.1605777","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1605777","url":null,"abstract":"The role of satellite communications (SATCOM) in support of the deployed warfighter has increased in recent years. With this increased reliance on SATCOM, the importance for a Department of Defense (DoD) wide strategy to efficiently procure and utilize the limited set of commercial DoD space assets has been emphasized. A step in the migration towards this strategy will be the development of a standard, multi-access, packet-based protocol that provides bandwidth on demand to the Joint warfighter. The digital video broadcast (DVB) standard chosen for this waveform leverages existing commercial modem technologies and offers a mature standard base which minimizes the development burden on the DoD. Of key interest for the tactical warfighter is the ability of the DVB family of standards to support certain functional capabilities: 1) to support robust communications while on-the-move (COTM), 2) to support a full mesh architecture, 3) to support a mix of non-real time, and real time traffic, and, 4) a capability to scale to large number of users and very efficiently share bandwidth. This paper provides a summary of a set of analyses that was performed to quantify the performance of the DVB standards to meet the four capabilities highlighted above. The analysis also inherently provides some insight on the challenges of applying commercial modem technologies to the battlefield","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134443985","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1605872
H. Çelebi, H. Arslan
The detection issues of UWB signals depend on the type of modulation scheme used during the transmission. The cross-modulation interference (CMI) for pulse position modulated (PPM) UWB signaling is introduced. The effects of CMI on the detection mechanism of selective-Rake (SRake), transmitted-reference (TR) and energy detector (ED) receivers are analyzed. The bit-error-rate (BER) performance of all three receivers in the presence and absence of CMI are studied through computer simulations. The results show that the CMI amount varies according to the modulation index and the performance degradation due to CMI can be extremely severe depending on the modulation index for all three receivers. The validity of the conventional optimal and orthogonal PPM criteria are checked considering the CMI effects. The results demonstrate that the conventional orthogonal PPM for all three receivers and the conventional optimal PPM criterion for N-SRake and TR receivers can be used in the presence of CMI. On the other hand, the BER performance of ED receivers using the conventional optimal PPM criterion result in error floor and this criterion is not valid to be used for ED receivers
{"title":"Cross-modulation interference for pulse position modulated UWB signals","authors":"H. Çelebi, H. Arslan","doi":"10.1109/MILCOM.2005.1605872","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1605872","url":null,"abstract":"The detection issues of UWB signals depend on the type of modulation scheme used during the transmission. The cross-modulation interference (CMI) for pulse position modulated (PPM) UWB signaling is introduced. The effects of CMI on the detection mechanism of selective-Rake (SRake), transmitted-reference (TR) and energy detector (ED) receivers are analyzed. The bit-error-rate (BER) performance of all three receivers in the presence and absence of CMI are studied through computer simulations. The results show that the CMI amount varies according to the modulation index and the performance degradation due to CMI can be extremely severe depending on the modulation index for all three receivers. The validity of the conventional optimal and orthogonal PPM criteria are checked considering the CMI effects. The results demonstrate that the conventional orthogonal PPM for all three receivers and the conventional optimal PPM criterion for N-SRake and TR receivers can be used in the presence of CMI. On the other hand, the BER performance of ED receivers using the conventional optimal PPM criterion result in error floor and this criterion is not valid to be used for ED receivers","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131553235","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1606041
R. Ramirez
The envisioned Air Force airborne network (AF AN) circa 2020 will most likely consist of a backbone network and many edge networks. The backbone nodes are expected to experience semi-permanent connectivity whereas the edge network nodes may experience rapidly changing connectivity in an ad-hoc manner. In addition, nodes may join and leave any edge network at fairly rapid rates. In this environment there is a need to manage link connectivity, node membership and the overall network topology in such a way as to minimize the impact of rapidly-changing connectivity and node network membership on the performance of user information transfers. This rapid detection/response management of links, nodes and the overall topology is defined as link management (LM), This paper describes the LM approach being taken for the AF AN circa 2020. The following topics are addressed: (a) high level LM functions from a network perspective, (b) LM architecture alternatives based on the extent of centralization/decentralization employed, and (c) a proposed LM functional allocation between platform and terminal equipment. Finally, this paper identifies sample issues pertaining to the successful development of an AN LM system, along with possible methods to resolve these issues.
{"title":"Link management in the Air Force airborne network","authors":"R. Ramirez","doi":"10.1109/MILCOM.2005.1606041","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1606041","url":null,"abstract":"The envisioned Air Force airborne network (AF AN) circa 2020 will most likely consist of a backbone network and many edge networks. The backbone nodes are expected to experience semi-permanent connectivity whereas the edge network nodes may experience rapidly changing connectivity in an ad-hoc manner. In addition, nodes may join and leave any edge network at fairly rapid rates. In this environment there is a need to manage link connectivity, node membership and the overall network topology in such a way as to minimize the impact of rapidly-changing connectivity and node network membership on the performance of user information transfers. This rapid detection/response management of links, nodes and the overall topology is defined as link management (LM), This paper describes the LM approach being taken for the AF AN circa 2020. The following topics are addressed: (a) high level LM functions from a network perspective, (b) LM architecture alternatives based on the extent of centralization/decentralization employed, and (c) a proposed LM functional allocation between platform and terminal equipment. Finally, this paper identifies sample issues pertaining to the successful development of an AN LM system, along with possible methods to resolve these issues.","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"13 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131750478","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1606136
R. Nagarajan, S. Parekh, G. Atkinson, Xiangpeng Jing
Networks emerging as increasingly significant to US DoD visions comprise dynamic, heterogeneous terrestrial, airborne, and/or space-based nodes, some of whose links are directional, variable performance, and inherently unstable. Our work investigates an approach for maintaining TCP performance over such ad hoc networks with free-space optical (FSO) links. We focus on a mechanism to differentiate random link error losses from congestion losses. Our simulations show that the end-to-end TCP response time improves significantly as compared to the standard TCP implementation over a variety of scenarios relevant to FSO networks.
{"title":"Architectural enhancements for improving TCP performance over FSO networks","authors":"R. Nagarajan, S. Parekh, G. Atkinson, Xiangpeng Jing","doi":"10.1109/MILCOM.2005.1606136","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1606136","url":null,"abstract":"Networks emerging as increasingly significant to US DoD visions comprise dynamic, heterogeneous terrestrial, airborne, and/or space-based nodes, some of whose links are directional, variable performance, and inherently unstable. Our work investigates an approach for maintaining TCP performance over such ad hoc networks with free-space optical (FSO) links. We focus on a mechanism to differentiate random link error losses from congestion losses. Our simulations show that the end-to-end TCP response time improves significantly as compared to the standard TCP implementation over a variety of scenarios relevant to FSO networks.","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127633116","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 : 2005-10-17DOI: 10.1109/MILCOM.2005.1606068
Yingming Tsai, Guodong Zhang, Jung-Lin Pan
Constant envelope OFDM with phase modulation (CE-OFDM-PM) was proposed. The motivation of the CE-OFDM-PM system is to alleviate the high peak-to-average power ratio of conventional OFDM systems. In this paper, we explore more details of CE-OFDM-PM systems regarding bandwidth efficiency and performance under AWGN and multipath channels. A theoretical approach instead of Carson's rule to analyze bandwidth is proposed. It indicates that bandwidth requirement is determined by factors such as input data variance and modulation index. The analytical results show that the CE-OFDM-PM systems require the same bandwidth as conventional OFDM system when appropriate (low) modulation index is applied in CE-OFDM-PM system. Under the same multipath channel and bandwidth, the performance of CE-OFDM-PM systems is compared to conventional OFDM system with one tap equalizer. The uncoded BER performance of CE-OFDM-PM is getting close when OFDM applies clipping, but power efficiency of CE-OFDM-PM still outperforms OFDM since clipping cannot eliminate PAPR issue
{"title":"Orthogonal frequency division multiplexing with phase modulation and constant envelope design","authors":"Yingming Tsai, Guodong Zhang, Jung-Lin Pan","doi":"10.1109/MILCOM.2005.1606068","DOIUrl":"https://doi.org/10.1109/MILCOM.2005.1606068","url":null,"abstract":"Constant envelope OFDM with phase modulation (CE-OFDM-PM) was proposed. The motivation of the CE-OFDM-PM system is to alleviate the high peak-to-average power ratio of conventional OFDM systems. In this paper, we explore more details of CE-OFDM-PM systems regarding bandwidth efficiency and performance under AWGN and multipath channels. A theoretical approach instead of Carson's rule to analyze bandwidth is proposed. It indicates that bandwidth requirement is determined by factors such as input data variance and modulation index. The analytical results show that the CE-OFDM-PM systems require the same bandwidth as conventional OFDM system when appropriate (low) modulation index is applied in CE-OFDM-PM system. Under the same multipath channel and bandwidth, the performance of CE-OFDM-PM systems is compared to conventional OFDM system with one tap equalizer. The uncoded BER performance of CE-OFDM-PM is getting close when OFDM applies clipping, but power efficiency of CE-OFDM-PM still outperforms OFDM since clipping cannot eliminate PAPR issue","PeriodicalId":223742,"journal":{"name":"MILCOM 2005 - 2005 IEEE Military Communications Conference","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129395739","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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