Pub Date : 1991-11-04DOI: 10.1109/MILCOM.1991.258413
M. Rafter
The author discusses some of the issues associated with establishing a multimedia communications network architecture, primarily relying on the use of a multiparameter routing metric developed for use in the media resource controller program. Improvements to the previously published multi-media communications model (MMCM) are discussed and simulation performance results are presented.<>
{"title":"Architectural considerations for the improvement of multimedia communications network performance","authors":"M. Rafter","doi":"10.1109/MILCOM.1991.258413","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258413","url":null,"abstract":"The author discusses some of the issues associated with establishing a multimedia communications network architecture, primarily relying on the use of a multiparameter routing metric developed for use in the media resource controller program. Improvements to the previously published multi-media communications model (MMCM) are discussed and simulation performance results are presented.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129687807","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258323
S. An
A scheme is proposed to generate a soft metric based on L hard decision diversity outputs. The performance of this scheme is studied and compared with existing schemes. The target system used for investigation is a slow frequency-hopped differential phase shift keying (FH/DPSK) system in the presence of partial band noise jamming (PBNJ). It is shown that a significant improvement in L-diversity hard decision systems can be achieved. It is demonstrated that, by using the proposed soft metric, the almost ideal performance can be achieved for FH/DPSK systems in the presence of PBNJ without relying on any jammer state information; nor is optimization for quantization step size or threshold needed in order to achieve a satisfactory performance.<>
{"title":"A new soft metric for FH/DPSK systems with coding and diversity in the presence of partial-band noise jamming","authors":"S. An","doi":"10.1109/MILCOM.1991.258323","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258323","url":null,"abstract":"A scheme is proposed to generate a soft metric based on L hard decision diversity outputs. The performance of this scheme is studied and compared with existing schemes. The target system used for investigation is a slow frequency-hopped differential phase shift keying (FH/DPSK) system in the presence of partial band noise jamming (PBNJ). It is shown that a significant improvement in L-diversity hard decision systems can be achieved. It is demonstrated that, by using the proposed soft metric, the almost ideal performance can be achieved for FH/DPSK systems in the presence of PBNJ without relying on any jammer state information; nor is optimization for quantization step size or threshold needed in order to achieve a satisfactory performance.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"15 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130910847","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258300
K. Parsa, D. Schilling
A necessary step in the design of high-speed adaptive meteor burst (MB) systems is to determine how the channel distorts the phase of the meteor signal. This aspect of the meteor burst channels is characterized. An enhanced MB channel model is developed. This is achieved by characterizing the MB Doppler spread, Doppler rate, head-echo induced phase jitter, and deriving simple mathematical expressions for them.<>
{"title":"Phase characterization of the meteor burst channel","authors":"K. Parsa, D. Schilling","doi":"10.1109/MILCOM.1991.258300","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258300","url":null,"abstract":"A necessary step in the design of high-speed adaptive meteor burst (MB) systems is to determine how the channel distorts the phase of the meteor signal. This aspect of the meteor burst channels is characterized. An enhanced MB channel model is developed. This is achieved by characterizing the MB Doppler spread, Doppler rate, head-echo induced phase jitter, and deriving simple mathematical expressions for them.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125510150","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258277
L. Garth, R. Vijayan, H. Poor
The nonlinear filter derived by H.V. Poor and R. Vijayan (1988, 1990) is generalized to the case of channels corrupted by impulsive noise. The class of impulsive channels considered includes the Gaussian channel as a special case. The authors exploit the binary nature of the direct-sequence signals to obtain performance using nonlinear filters. A nonlinear modification of the transversal filter, with the coefficients being updated using the least mean square algorithm, is seen to perform significantly better than the standard adaptive linear filter. Further nonlinear modifications of the prediction filters are found for a variety of impulsive channel distribution shapes. It was found that the filters designed for the Gaussian channel perform as well as those tailored to the specific impulsive channels. As a result, the impulsive channels can be approximated by a Gaussian one with no loss in performance.<>
{"title":"A new approach to interference suppression in spread-spectrum systems","authors":"L. Garth, R. Vijayan, H. Poor","doi":"10.1109/MILCOM.1991.258277","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258277","url":null,"abstract":"The nonlinear filter derived by H.V. Poor and R. Vijayan (1988, 1990) is generalized to the case of channels corrupted by impulsive noise. The class of impulsive channels considered includes the Gaussian channel as a special case. The authors exploit the binary nature of the direct-sequence signals to obtain performance using nonlinear filters. A nonlinear modification of the transversal filter, with the coefficients being updated using the least mean square algorithm, is seen to perform significantly better than the standard adaptive linear filter. Further nonlinear modifications of the prediction filters are found for a variety of impulsive channel distribution shapes. It was found that the filters designed for the Gaussian channel perform as well as those tailored to the specific impulsive channels. As a result, the impulsive channels can be approximated by a Gaussian one with no loss in performance.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"366 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125622479","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258422
A. Michelson, G. Rosen
Severely punctured versions of the well-known rate-1/2, constraint-length-seven convolutional code are considered. Severely punctured means that exactly half of the data normally transmitted is deleted, specifically, the entire output of one parity circuit or the other. Redundancy is conveyed only by the code tail. It is shown that, for maximum likelihood decoding of short to moderately long messages, significant coding gains can be achieved, 2 to 3.8 dB. Both simulation and analytical results are given. It is also shown that less severely punctured codes have minimum distance two, and, for one of the generators, the punctured codes are cyclic for certain message lengths.<>
{"title":"A severely punctured convolutional code-its performance and structure","authors":"A. Michelson, G. Rosen","doi":"10.1109/MILCOM.1991.258422","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258422","url":null,"abstract":"Severely punctured versions of the well-known rate-1/2, constraint-length-seven convolutional code are considered. Severely punctured means that exactly half of the data normally transmitted is deleted, specifically, the entire output of one parity circuit or the other. Redundancy is conveyed only by the code tail. It is shown that, for maximum likelihood decoding of short to moderately long messages, significant coding gains can be achieved, 2 to 3.8 dB. Both simulation and analytical results are given. It is also shown that less severely punctured codes have minimum distance two, and, for one of the generators, the punctured codes are cyclic for certain message lengths.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125847656","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258454
R. Fang
The concept of a fully meshed network of a briefcase-sized terminals is presented for personal and thin-route communications over Ku-band satellite transponders. In this concept, undesirable double-hop delays are avoided for voice communications. The bandwidth and power resources of the transponder are efficiently shared by users in a simple demand-assigned manner via code-division multiple access (CDMA). Voice, data, and facsimile are statistically multiplexed at each terminal. In order to minimize terminal costs, frequency-precorrected and level-preadjusted continuous-wave tones are sent from the central network control station in each beam so that the terminals in each downlink beam can use these pilots as references for antenna acquisition and tracking, as reliable frequency sources, and as indicators of signal fade for uplink power control (ULPC). The potential CDMA near-far problem due to uplink fades is mitigated by using ULPC. Quasi-burst mode transmission is used to minimize the potential of clock and pseudorandom number code synchronization.<>
{"title":"Personal and thin-route communications via K-band satellite transponders","authors":"R. Fang","doi":"10.1109/MILCOM.1991.258454","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258454","url":null,"abstract":"The concept of a fully meshed network of a briefcase-sized terminals is presented for personal and thin-route communications over Ku-band satellite transponders. In this concept, undesirable double-hop delays are avoided for voice communications. The bandwidth and power resources of the transponder are efficiently shared by users in a simple demand-assigned manner via code-division multiple access (CDMA). Voice, data, and facsimile are statistically multiplexed at each terminal. In order to minimize terminal costs, frequency-precorrected and level-preadjusted continuous-wave tones are sent from the central network control station in each beam so that the terminals in each downlink beam can use these pilots as references for antenna acquisition and tracking, as reliable frequency sources, and as indicators of signal fade for uplink power control (ULPC). The potential CDMA near-far problem due to uplink fades is mitigated by using ULPC. Quasi-burst mode transmission is used to minimize the potential of clock and pseudorandom number code synchronization.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114151903","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258418
W. G. Hartung, F. Ogden, A. Moylan
It is pointed out that to fully utilize the benefits of automated writer-to-reader messaging to be provided by the Defense Message System (DMS) the Department of Defense (DoD) end users must be prepared to accept new responsibilities and adapt to a different, but user-friendly, way of doing business. In the evolution to the DMS, the DoD organizational and individual messaging users will make the transition to a common environment in which the functions currently centralized and performed by a large unseen cadre of communications experts will be automated and distributed. These end users will assume both more control over and responsibility for messaging. Thus, it is imperative that they learn, adapt, and become pro-active participants in the DMS implementation process. The baseline is described, and the three phases of the transition to the DMS are reviewed.<>
{"title":"The impact of automated writer-to-reader messaging on the DoD end user","authors":"W. G. Hartung, F. Ogden, A. Moylan","doi":"10.1109/MILCOM.1991.258418","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258418","url":null,"abstract":"It is pointed out that to fully utilize the benefits of automated writer-to-reader messaging to be provided by the Defense Message System (DMS) the Department of Defense (DoD) end users must be prepared to accept new responsibilities and adapt to a different, but user-friendly, way of doing business. In the evolution to the DMS, the DoD organizational and individual messaging users will make the transition to a common environment in which the functions currently centralized and performed by a large unseen cadre of communications experts will be automated and distributed. These end users will assume both more control over and responsibility for messaging. Thus, it is imperative that they learn, adapt, and become pro-active participants in the DMS implementation process. The baseline is described, and the three phases of the transition to the DMS are reviewed.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114570766","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258229
R. Wilder
The author focuses on experiments and simulations designed to examine the difficulties in providing a fair communication service in an internet carrying traffic from the transport control protocol (TCP) and open systems interconnection (OSI) applications. Fairness between connections that compete for resources is a goal of congestion control schemes that have been developed for both protocol suites. The slow start congestion control mechanism is now fairly standard for TCP, and the DEC-bit approach to congestion avoidance is widely accepted for OSI networks with a connectionless network layer. Unfortunately, these two approaches have evolved independently and are not designed to provide fairness between protocol suites. The network experiments and simulations reported examined the extent of fairness problems to be expected in a mixed TCP/OSI environment and the effects of a simple router-based measure to limit unfairness between protocol suites.<>
{"title":"Fairness issues for mixed TCP/OSI internets","authors":"R. Wilder","doi":"10.1109/MILCOM.1991.258229","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258229","url":null,"abstract":"The author focuses on experiments and simulations designed to examine the difficulties in providing a fair communication service in an internet carrying traffic from the transport control protocol (TCP) and open systems interconnection (OSI) applications. Fairness between connections that compete for resources is a goal of congestion control schemes that have been developed for both protocol suites. The slow start congestion control mechanism is now fairly standard for TCP, and the DEC-bit approach to congestion avoidance is widely accepted for OSI networks with a connectionless network layer. Unfortunately, these two approaches have evolved independently and are not designed to provide fairness between protocol suites. The network experiments and simulations reported examined the extent of fairness problems to be expected in a mixed TCP/OSI environment and the effects of a simple router-based measure to limit unfairness between protocol suites.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114239727","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258393
Patrick Hosein, D. Schmidt
The authors describe the broadcast algorithm used in the Survivable Signaling Network (SSN). SSN provides the Nationwide Emergency Telecommunications System (NETS) a highly survivable and robust network for national security emergency preparedness calls being set up over AT&T Switched Network. SSN achieves this high survivability and robustness through the application of broadcast algorithms to disseminate network status and to ultimately determine the routing of signaling traffic. The SSN broadcast algorithm is based on the Arpanet broadcast algorithm. However, the long node and link recovery times inherent in the Arpanet algorithm are intolerable in telephone signaling. The SSN algorithm extends the Arpanet algorithm to provide a rapid recovery from node and link crashes. It accomplishes this in a simple fashion consistent with the Arpanet algorithm.<>
{"title":"Broadcasting topology information in the Survivable Signaling Network","authors":"Patrick Hosein, D. Schmidt","doi":"10.1109/MILCOM.1991.258393","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258393","url":null,"abstract":"The authors describe the broadcast algorithm used in the Survivable Signaling Network (SSN). SSN provides the Nationwide Emergency Telecommunications System (NETS) a highly survivable and robust network for national security emergency preparedness calls being set up over AT&T Switched Network. SSN achieves this high survivability and robustness through the application of broadcast algorithms to disseminate network status and to ultimately determine the routing of signaling traffic. The SSN broadcast algorithm is based on the Arpanet broadcast algorithm. However, the long node and link recovery times inherent in the Arpanet algorithm are intolerable in telephone signaling. The SSN algorithm extends the Arpanet algorithm to provide a rapid recovery from node and link crashes. It accomplishes this in a simple fashion consistent with the Arpanet algorithm.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126832804","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 : 1991-11-04DOI: 10.1109/MILCOM.1991.258193
S. Pupolin, G. Guidotti
The authors have set up a simulation program to evaluate the throughput of a packet radio network (PRN) by comparing different routing strategies in both the static and dynamic PRN topology. They compare link access protocol efficiency of a system with spread spectrum modulation, forward error correction coding with an Aloha like protocol in a multihop network versus Aloha. Code division multiple access (CDMA) and conventional Aloha access techniques are compared, showing that CDMA gives a more reliable and higher throughput. Different routing strategies are compared with static and dynamic networks enabling the understanding of why some of them result in network congestion at lower throughput than others. A result is that for a 16 node network with a grid connectivity, the throughput is increased as soon as the network connectivity was reduced up to an optimum value.<>
{"title":"Throughput analysis in multihop packet radio networks","authors":"S. Pupolin, G. Guidotti","doi":"10.1109/MILCOM.1991.258193","DOIUrl":"https://doi.org/10.1109/MILCOM.1991.258193","url":null,"abstract":"The authors have set up a simulation program to evaluate the throughput of a packet radio network (PRN) by comparing different routing strategies in both the static and dynamic PRN topology. They compare link access protocol efficiency of a system with spread spectrum modulation, forward error correction coding with an Aloha like protocol in a multihop network versus Aloha. Code division multiple access (CDMA) and conventional Aloha access techniques are compared, showing that CDMA gives a more reliable and higher throughput. Different routing strategies are compared with static and dynamic networks enabling the understanding of why some of them result in network congestion at lower throughput than others. A result is that for a 16 node network with a grid connectivity, the throughput is increased as soon as the network connectivity was reduced up to an optimum value.<<ETX>>","PeriodicalId":212388,"journal":{"name":"MILCOM 91 - Conference record","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127761712","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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