Pub Date : 1997-12-17DOI: 10.1109/ICPWC.1997.655542
S. Madan, K. Bollinger
With the progress in the design of mobile communication systems, nomadic computing is becoming popular. This paper describes databases issues that arise when dealing with nomadic computing. Potential solutions are discussed with an emphasis on the role of artificial intelligence.
{"title":"Nomadic computing and artificial intelligence","authors":"S. Madan, K. Bollinger","doi":"10.1109/ICPWC.1997.655542","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655542","url":null,"abstract":"With the progress in the design of mobile communication systems, nomadic computing is becoming popular. This paper describes databases issues that arise when dealing with nomadic computing. Potential solutions are discussed with an emphasis on the role of artificial intelligence.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127500604","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655532
Zhi-Ming Lin
We present a user friendly Mandarin remote-controlled based database system for the checking and managing of automobile license. The system consists of handheld wireless hardware and remote-controlled database software. The hardware set is carried with the user. The software is designed in a personal computer located at a local traffic monitoring center. The system provides a convenient way of checking and managing of automobiles.
{"title":"A Mandarin remote-controlled based database system for the checking and managing of automobile license","authors":"Zhi-Ming Lin","doi":"10.1109/ICPWC.1997.655532","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655532","url":null,"abstract":"We present a user friendly Mandarin remote-controlled based database system for the checking and managing of automobile license. The system consists of handheld wireless hardware and remote-controlled database software. The hardware set is carried with the user. The software is designed in a personal computer located at a local traffic monitoring center. The system provides a convenient way of checking and managing of automobiles.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132648984","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655507
A. Chandra, P. Chandra
The performance of indoor communication services offering the transfer of voice and data inside a building is severely affected by the presence of a large number of scatterers/reflectors. The paper reports the results of propagation measurements at 900 MHz and 1.35 GHz conducted inside a room on a floor of a office-cum-laboratory building. From the measured data, the path loss exponent, standard deviation, RMS time delay and coherence bandwidth are determined.
{"title":"Attenuation of 900 MHz and 1.35 GHz signal inside room of a building","authors":"A. Chandra, P. Chandra","doi":"10.1109/ICPWC.1997.655507","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655507","url":null,"abstract":"The performance of indoor communication services offering the transfer of voice and data inside a building is severely affected by the presence of a large number of scatterers/reflectors. The paper reports the results of propagation measurements at 900 MHz and 1.35 GHz conducted inside a room on a floor of a office-cum-laboratory building. From the measured data, the path loss exponent, standard deviation, RMS time delay and coherence bandwidth are determined.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117230442","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655557
N. Kalyandrug
Cellular telecommunications is one of the fastest growing and most challenging telecommunication applications ever. Today, it represents a large and continuously increasing percentage of new telephone subscribers around the world. In the long term, with the emergence of mobile satellite systems, the cellular digital telephony may, become the universal communication system. The design and development of the cellular systems viz. AMPS, CDMA and GSM etc. started off in parallel. In due course these systems have been standardized. With the advent of ASIC technology, and different cellular systems being standardized, it has become necessary to have an integrated system to enhance the virtual throughput of the network by operating different cellular systems in a single network. This paper touches upon the frequency spectrum issues of different systems and the possible network architecture with respect to the integrated base station (IBS) system. The possible IBS architecture is discussed including the conclusions drawn with respect to the integrated system design concepts.
{"title":"Integrated base station-an approach","authors":"N. Kalyandrug","doi":"10.1109/ICPWC.1997.655557","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655557","url":null,"abstract":"Cellular telecommunications is one of the fastest growing and most challenging telecommunication applications ever. Today, it represents a large and continuously increasing percentage of new telephone subscribers around the world. In the long term, with the emergence of mobile satellite systems, the cellular digital telephony may, become the universal communication system. The design and development of the cellular systems viz. AMPS, CDMA and GSM etc. started off in parallel. In due course these systems have been standardized. With the advent of ASIC technology, and different cellular systems being standardized, it has become necessary to have an integrated system to enhance the virtual throughput of the network by operating different cellular systems in a single network. This paper touches upon the frequency spectrum issues of different systems and the possible network architecture with respect to the integrated base station (IBS) system. The possible IBS architecture is discussed including the conclusions drawn with respect to the integrated system design concepts.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133303823","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655498
A.Z.M. Ekram Hossain, J. Sarker
The throughput of a single channel S-ALOHA protocol is analyzed under the full-load condition with a truncated exponential backoff retransmission control scheme considering the capture effect among packets sent at different power levels. Similar analyses are done for a multichannel S-ALOHA protocol with two proposed exponential backoff retransmission control schemes. The effects of the protocol parameters on the throughput performance are investigated. The analytical results are validated through simulation. Simulation results of the system throughput performance for under-load conditions are also presented.
{"title":"On throughput performance of single and multichannel S-ALOHA with exponential backoff retransmission schemes for packet transmissions in multiple power levels","authors":"A.Z.M. Ekram Hossain, J. Sarker","doi":"10.1109/ICPWC.1997.655498","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655498","url":null,"abstract":"The throughput of a single channel S-ALOHA protocol is analyzed under the full-load condition with a truncated exponential backoff retransmission control scheme considering the capture effect among packets sent at different power levels. Similar analyses are done for a multichannel S-ALOHA protocol with two proposed exponential backoff retransmission control schemes. The effects of the protocol parameters on the throughput performance are investigated. The analytical results are validated through simulation. Simulation results of the system throughput performance for under-load conditions are also presented.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124925449","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655475
T. Korhonen, S. Haggman
This paper presents novel instantaneous, radio channel modeling algorithm. It is based on deconvolution and has four basic modules that are: (1) determination of initial estimate by matched filter deconvolution, (2) suppression of deconvolution noise, (3) selection of signal taps and (4) complex tap amplitude accuracy enhancement. The paper analyzes parameter selection and gives an outline of theoretical and simulated performance. As an example we note that the algorithm can achieve with 6 times oversampled 15 chip maximal length code and 5 Rayleigh channel taps an average amplitude accuracy enhancement of 8 dB to 19 dB compared to uncompensated optimum deconvolution when the channel SNR is 20 to 40 dB respectively.
{"title":"Location of subchip radio channel multipath components from direct sequence sounding data","authors":"T. Korhonen, S. Haggman","doi":"10.1109/ICPWC.1997.655475","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655475","url":null,"abstract":"This paper presents novel instantaneous, radio channel modeling algorithm. It is based on deconvolution and has four basic modules that are: (1) determination of initial estimate by matched filter deconvolution, (2) suppression of deconvolution noise, (3) selection of signal taps and (4) complex tap amplitude accuracy enhancement. The paper analyzes parameter selection and gives an outline of theoretical and simulated performance. As an example we note that the algorithm can achieve with 6 times oversampled 15 chip maximal length code and 5 Rayleigh channel taps an average amplitude accuracy enhancement of 8 dB to 19 dB compared to uncompensated optimum deconvolution when the channel SNR is 20 to 40 dB respectively.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122059314","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655548
F. Graf, H. Ruse, J. Kruger
From various publications the theoretical potential of different capacity enhancement techniques in GSM mobile radio networks is well known. Introduction scenarios for some capacity enhancement techniques in real GSM mobile radio networks are developed with respect to the technical and economical constraints of a network operator. Based on parameters and cell statistics which are typical for a operational country wide GSM mobile radio network, a reference scenario for the future network extension is developed. The comparison of introduction scenarios for different capacity enhancement techniques with this reference scenario allows the evaluation of each technique from the technical and economical points of view. A method for calculating the economic efficiency of the radio part for each scenario is presented.
{"title":"Introduction scenarios for capacity enhancement techniques in GSM mobile radio networks-technical potentials and economic efficiencies","authors":"F. Graf, H. Ruse, J. Kruger","doi":"10.1109/ICPWC.1997.655548","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655548","url":null,"abstract":"From various publications the theoretical potential of different capacity enhancement techniques in GSM mobile radio networks is well known. Introduction scenarios for some capacity enhancement techniques in real GSM mobile radio networks are developed with respect to the technical and economical constraints of a network operator. Based on parameters and cell statistics which are typical for a operational country wide GSM mobile radio network, a reference scenario for the future network extension is developed. The comparison of introduction scenarios for different capacity enhancement techniques with this reference scenario allows the evaluation of each technique from the technical and economical points of view. A method for calculating the economic efficiency of the radio part for each scenario is presented.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131281974","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655564
V. Veeravalli
In a direct sequence code division multiple access (CDMA) system, a fixed bandwidth expansion could be allocated to either error correcting coding or modulation signal spreading. The role of coding in CDMA systems that employ multiuser detection is explored here. A comparison is made between the maximum throughputs (in bits/chip or bits/s/Hz) achievable using multiuser detection and single-user detection, for both "single-cell" and cellular systems. For the single-cell scenario, our results indicate that asynchronous multiuser detection systems employing long (random) spreading sequences and low rate coding, can provide considerable improvements in spectral efficiency over single-user detection systems. However, for cellular systems with universal frequency reuse, the improvement is spectral efficiency (per cell) offered by multiuser detection may not be as significant.
{"title":"The role of coding in CDMA systems with multiuser detection","authors":"V. Veeravalli","doi":"10.1109/ICPWC.1997.655564","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655564","url":null,"abstract":"In a direct sequence code division multiple access (CDMA) system, a fixed bandwidth expansion could be allocated to either error correcting coding or modulation signal spreading. The role of coding in CDMA systems that employ multiuser detection is explored here. A comparison is made between the maximum throughputs (in bits/chip or bits/s/Hz) achievable using multiuser detection and single-user detection, for both \"single-cell\" and cellular systems. For the single-cell scenario, our results indicate that asynchronous multiuser detection systems employing long (random) spreading sequences and low rate coding, can provide considerable improvements in spectral efficiency over single-user detection systems. However, for cellular systems with universal frequency reuse, the improvement is spectral efficiency (per cell) offered by multiuser detection may not be as significant.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131613377","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655530
P. Havinga, G. Smit
The Moby Dick project is a joint European project to develop and define the architecture of a new generation of mobile hand-held computers, called Pocket Companions. The Pocket Companion is a hand-held device that is resource-poor, i.e. small amount of memory, limited battery life, low processing power, and connected with the environment via a network with variable connectivity. Because the battery life is limited and the battery weight is an important factor for the size and the weight of the Pocket Companion, energy management plays a crucial role in the architecture. In our architecture we apply several supplementary power reduction techniques on all levels of the system, including the operating system and applications. The two main themes are: (1) to avoid wasteful activity, and (2) to exploit the locality of the reference. We put considerable effort in reducing the energy consumption of the communication interfaces. There are several ways to reduce the energy consumption: e.g. by system decomposition, using hybrid networking, and by applying power aware MAC protocols.
{"title":"Minimizing energy consumption for wireless computers in Moby Dick","authors":"P. Havinga, G. Smit","doi":"10.1109/ICPWC.1997.655530","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655530","url":null,"abstract":"The Moby Dick project is a joint European project to develop and define the architecture of a new generation of mobile hand-held computers, called Pocket Companions. The Pocket Companion is a hand-held device that is resource-poor, i.e. small amount of memory, limited battery life, low processing power, and connected with the environment via a network with variable connectivity. Because the battery life is limited and the battery weight is an important factor for the size and the weight of the Pocket Companion, energy management plays a crucial role in the architecture. In our architecture we apply several supplementary power reduction techniques on all levels of the system, including the operating system and applications. The two main themes are: (1) to avoid wasteful activity, and (2) to exploit the locality of the reference. We put considerable effort in reducing the energy consumption of the communication interfaces. There are several ways to reduce the energy consumption: e.g. by system decomposition, using hybrid networking, and by applying power aware MAC protocols.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126468899","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655523
R. Westerveld
Now that at least one of the proposed satellite systems for mobile personal communication has almost become a reality (e.g. Iridium has launched almost half of its planned satellites and others are to follow), the high potential of these systems for the developing world is stressed in many places. This paper gives an overview of developments in broadband satellite proposals. It also elaborates on some technical issues and regulatory problems involved with the introduction of these systems in the practical reality of the developing world.
{"title":"Global mobile personal communications by satellite (GMPCS), how will developing countries benefit?","authors":"R. Westerveld","doi":"10.1109/ICPWC.1997.655523","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655523","url":null,"abstract":"Now that at least one of the proposed satellite systems for mobile personal communication has almost become a reality (e.g. Iridium has launched almost half of its planned satellites and others are to follow), the high potential of these systems for the developing world is stressed in many places. This paper gives an overview of developments in broadband satellite proposals. It also elaborates on some technical issues and regulatory problems involved with the introduction of these systems in the practical reality of the developing world.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121084781","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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