Pub Date : 1996-10-15DOI: 10.1109/PIMRC.1996.567485
M. Nofal, M. El-Rabeey
A real-time object-oriented expert system is developed for mobile radio networks. The goals, facts, procedural and heuristic rules related to the mobile radio environment are stored in the knowledge base. This knowledge is put together with an inference mechanism and a pruning structure to develop the expert system. The proposed expert system sorts out a variety of parameters existing in mobile radio environment and tailors its real-time response to an intelligent channel assignment and handover management.
{"title":"A real-time object-oriented expert system for mobile radio networks","authors":"M. Nofal, M. El-Rabeey","doi":"10.1109/PIMRC.1996.567485","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567485","url":null,"abstract":"A real-time object-oriented expert system is developed for mobile radio networks. The goals, facts, procedural and heuristic rules related to the mobile radio environment are stored in the knowledge base. This knowledge is put together with an inference mechanism and a pruning structure to develop the expert system. The proposed expert system sorts out a variety of parameters existing in mobile radio environment and tailors its real-time response to an intelligent channel assignment and handover management.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"285 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114260219","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567412
Ruey-yi Wei, M. Lin
We derive a new upper bound on the pairwise error probability for MPSK sequences over the Rayleigh fading channel when channel state information (CSI) is not available. This is obtained by adding weight factors in calculating the symbol metrics. Simulation shows that the weight factors which optimize the upper bound are likely to optimize the error rate too. We also design multilevel coded MPSK schemes which are suitable for the Rayleigh fading channel. These schemes are basically in the form of block coded modulation with interblock memory (BCMIM), which was originally designed for an additive white Gaussian noise (AWGN) channel. The added weight factors are found to be effective in improving the error performance of these BCMIM schemes in case that CSI is not available.
{"title":"On multilevel coded MPSK for the Rayleigh fading channel","authors":"Ruey-yi Wei, M. Lin","doi":"10.1109/PIMRC.1996.567412","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567412","url":null,"abstract":"We derive a new upper bound on the pairwise error probability for MPSK sequences over the Rayleigh fading channel when channel state information (CSI) is not available. This is obtained by adding weight factors in calculating the symbol metrics. Simulation shows that the weight factors which optimize the upper bound are likely to optimize the error rate too. We also design multilevel coded MPSK schemes which are suitable for the Rayleigh fading channel. These schemes are basically in the form of block coded modulation with interblock memory (BCMIM), which was originally designed for an additive white Gaussian noise (AWGN) channel. The added weight factors are found to be effective in improving the error performance of these BCMIM schemes in case that CSI is not available.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115180163","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567489
A. Liou, Shih-Fang Wong
Current researches on PDA are emphasizing the technical issues such as the hardware organization or language for remote communication. However, the details of the wireless PDA services are yet to be defined. We need to know what kind of services can be conducted and what data should be transmitted in what manner in order to complete the service. This research provides a practical application layer design which examines the possible categories of wireless PDA services and, for each category, the necessary data formats designed for conducting the service. The aim is to figure out an organized and feasible application scheme which, when being employed, makes the wireless PDA services viable.
{"title":"The design of PDA application schemes for wireless communication services","authors":"A. Liou, Shih-Fang Wong","doi":"10.1109/PIMRC.1996.567489","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567489","url":null,"abstract":"Current researches on PDA are emphasizing the technical issues such as the hardware organization or language for remote communication. However, the details of the wireless PDA services are yet to be defined. We need to know what kind of services can be conducted and what data should be transmitted in what manner in order to complete the service. This research provides a practical application layer design which examines the possible categories of wireless PDA services and, for each category, the necessary data formats designed for conducting the service. The aim is to figure out an organized and feasible application scheme which, when being employed, makes the wireless PDA services viable.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125453238","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567428
M. You, Cheng-Shang Chang
The well known problem among most random access protocols in wireless networks is that the throughput drops rapidly in heavy loads. To cope with this problem, one has to control to the load offered to a network. Unlike the traditional backoff policy in Ethernet where backoff occurs after collision, we propose various control schemes based on the new idea of resampling, where carrier sensing ability is used to determine whether a backoff command should be issued or not. We show from various experiments that our schemes are capable of controlling the offer load to the optimal offer load. As a result, the throughputs of these schemes are kept close to the network capacity in heavy loads.
{"title":"Resampling for wireless access","authors":"M. You, Cheng-Shang Chang","doi":"10.1109/PIMRC.1996.567428","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567428","url":null,"abstract":"The well known problem among most random access protocols in wireless networks is that the throughput drops rapidly in heavy loads. To cope with this problem, one has to control to the load offered to a network. Unlike the traditional backoff policy in Ethernet where backoff occurs after collision, we propose various control schemes based on the new idea of resampling, where carrier sensing ability is used to determine whether a backoff command should be issued or not. We show from various experiments that our schemes are capable of controlling the offer load to the optimal offer load. As a result, the throughputs of these schemes are kept close to the network capacity in heavy loads.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125484661","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567466
D. Kim, Seung Joon Lee, D. Choi, D. Sung
To accommodate multimedia and broadband mobile services, future mobile communication networks are likely to be integrated with broadband fixed networks. Previous MAN-based architectures may be rather complex to provide various isochronous/non-isochronous services due to complicated slot generation processings. We propose a broadband personal communication network (BPCN) architecture based on B-ISDN/ATM. We employ simple cell based add-drop multiplexers (ADMs) instead of rather complex medium access control systems. We also suggest a ring management scheme. After describing call processing procedures, we calculate and compare the signaling processing loads at the various nodes and the signaling loads on the various links for six types of configurations according to the locations of basestation controller (BSC), visitor location register (VLR), and mobile switching center (MSC). These results may be utilized in designing BPCNs in the given conditions, such as PCN subscriber environments and the capabilities of network entities. A 150 Mbps-dual ring can support the maximum carried traffic load of about 5,500 on-off voice traffic in the case that 300 connections are supported in the ring node (RN). This ring capacity corresponds to covering approximately 180 cells, if we assume 30 connections per cell.
{"title":"An architecture of broadband personal communication network","authors":"D. Kim, Seung Joon Lee, D. Choi, D. Sung","doi":"10.1109/PIMRC.1996.567466","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567466","url":null,"abstract":"To accommodate multimedia and broadband mobile services, future mobile communication networks are likely to be integrated with broadband fixed networks. Previous MAN-based architectures may be rather complex to provide various isochronous/non-isochronous services due to complicated slot generation processings. We propose a broadband personal communication network (BPCN) architecture based on B-ISDN/ATM. We employ simple cell based add-drop multiplexers (ADMs) instead of rather complex medium access control systems. We also suggest a ring management scheme. After describing call processing procedures, we calculate and compare the signaling processing loads at the various nodes and the signaling loads on the various links for six types of configurations according to the locations of basestation controller (BSC), visitor location register (VLR), and mobile switching center (MSC). These results may be utilized in designing BPCNs in the given conditions, such as PCN subscriber environments and the capabilities of network entities. A 150 Mbps-dual ring can support the maximum carried traffic load of about 5,500 on-off voice traffic in the case that 300 connections are supported in the ring node (RN). This ring capacity corresponds to covering approximately 180 cells, if we assume 30 connections per cell.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126136836","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568467
M. Cheng, L. Chang
System capacity of PACS (personal access communications system) is determined by two factors: (1) blocking due to insufficient servers at the radio port being accessed and (2) blocking due to insufficient signal quality of the radio link being accessed. The Erlang traffic capacity can be enhanced by access re-routing, i.e., a user is allowed to access other available radio ports immediately if it fails in a previous attempt. However, the signal quality would be degraded due to re-routing if the cell size is relatively large. The signal quality performance can be improved by reducing the cell size but the cell size cannot be too small for economic and technical reasons. This study is to investigate the effects of both cell size reduction and access re-routing on the overall system performance of PACS and to examine the tradeoffs between different system parameters. It is found that with cell size reduction and access re-routing together, the overall system performance is greatly improved. At a reasonably high normalized offered traffic of 60%, the overall call blocking probability is reduced from 11.5% to 3.5% by changing a port-to-port separation of 2000 ft. (i.e., a cell radius of 1000 ft.) without re-routing to 1000 ft. with re-routing. A number of 3 or 4 re-routing attempts out of a maximum of 16 is sufficient to provide a good result. In addition, more than 90% of the successful calls are admitted in the first attempt and therefore, the additional access delay and system overhead due to re-routing is insignificant.
{"title":"Effect of cell size reduction and access re-routing on PACS system capacity","authors":"M. Cheng, L. Chang","doi":"10.1109/PIMRC.1996.568467","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568467","url":null,"abstract":"System capacity of PACS (personal access communications system) is determined by two factors: (1) blocking due to insufficient servers at the radio port being accessed and (2) blocking due to insufficient signal quality of the radio link being accessed. The Erlang traffic capacity can be enhanced by access re-routing, i.e., a user is allowed to access other available radio ports immediately if it fails in a previous attempt. However, the signal quality would be degraded due to re-routing if the cell size is relatively large. The signal quality performance can be improved by reducing the cell size but the cell size cannot be too small for economic and technical reasons. This study is to investigate the effects of both cell size reduction and access re-routing on the overall system performance of PACS and to examine the tradeoffs between different system parameters. It is found that with cell size reduction and access re-routing together, the overall system performance is greatly improved. At a reasonably high normalized offered traffic of 60%, the overall call blocking probability is reduced from 11.5% to 3.5% by changing a port-to-port separation of 2000 ft. (i.e., a cell radius of 1000 ft.) without re-routing to 1000 ft. with re-routing. A number of 3 or 4 re-routing attempts out of a maximum of 16 is sufficient to provide a good result. In addition, more than 90% of the successful calls are admitted in the first attempt and therefore, the additional access delay and system overhead due to re-routing is insignificant.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128041083","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567525
M. Saito, Hiraku Okada, Takahide Sato, T. Yamazato, M. Katayama, A. Ogawa
In this paper, we present the throughput performance of CDMA slotted ALOHA systems with modified channel load sensing protocol (MCLSP). In MCLSP, a hub station continuously senses channel load for a certain number of slots, and computes the probability with which each user station should transmit its packet, then broadcasts the computed value. As the access control is based on this probability, we can apply it to slotted system. We show that MCLSP can achieve significant improvement in throughput performance of CDMA slotted ALOHA systems even in large offered load. One of the issues in such a protocol is the access timing delay, which is the sum of process time and propagation time for the packet access control. We also show the effect of the access timing delay on the throughput performance.
{"title":"Throughput improvement of CDMA slotted ALOHA system by modified channel load sensing protocol","authors":"M. Saito, Hiraku Okada, Takahide Sato, T. Yamazato, M. Katayama, A. Ogawa","doi":"10.1109/PIMRC.1996.567525","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567525","url":null,"abstract":"In this paper, we present the throughput performance of CDMA slotted ALOHA systems with modified channel load sensing protocol (MCLSP). In MCLSP, a hub station continuously senses channel load for a certain number of slots, and computes the probability with which each user station should transmit its packet, then broadcasts the computed value. As the access control is based on this probability, we can apply it to slotted system. We show that MCLSP can achieve significant improvement in throughput performance of CDMA slotted ALOHA systems even in large offered load. One of the issues in such a protocol is the access timing delay, which is the sum of process time and propagation time for the packet access control. We also show the effect of the access timing delay on the throughput performance.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128191309","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568419
T. Shimizu, H. Ohtsuka
This paper presents the design and performance of a trial fiber-oriented wireless access system with a small packaged optical interface. Signal extraction and frequency arrangement (SEFA) technology is proposed in the trial system to improve the input dynamic range. The designed 40-cc optical interface performance is discussed with respect to an optical loss of 5 and 15 dB. The overall performance of the system, to which the designed optical interface and SEFA technology are implemented, is presented using an /spl pi//4-QPSK signal with a transmission rate of 384 kb/s. It is shown that the receiver sensitivity reaches 8 dB/spl mu/V even if the optical loss is 15 dB.
{"title":"Design and performance of fiber-oriented wireless access system","authors":"T. Shimizu, H. Ohtsuka","doi":"10.1109/PIMRC.1996.568419","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568419","url":null,"abstract":"This paper presents the design and performance of a trial fiber-oriented wireless access system with a small packaged optical interface. Signal extraction and frequency arrangement (SEFA) technology is proposed in the trial system to improve the input dynamic range. The designed 40-cc optical interface performance is discussed with respect to an optical loss of 5 and 15 dB. The overall performance of the system, to which the designed optical interface and SEFA technology are implemented, is presented using an /spl pi//4-QPSK signal with a transmission rate of 384 kb/s. It is shown that the receiver sensitivity reaches 8 dB/spl mu/V even if the optical loss is 15 dB.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123684516","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568411
M. Chiani, A. Volta
The problem of error control strategies in wireless multimedia networks adopting the ATM protocol is addressed. In particular, we investigate the performance attainable by using a hybrid combination of automatic repeat request (ARQ) techniques and forward error correcting (FEC) codes for class C, connection oriented, non-delay critical and variable bit-rate services. To mitigate the wireless channel impairments we propose an adaptive error control scheme that chooses the control technique for each connection according to its requirements described by the connection specific parameters (e.g. maximum delay and cell loss ratio). The analysis is carried out for an OFDM/QPSK modulation format over a typical indoor radio channel.
{"title":"Hybrid ARQ/FEC techniques for wireless ATM local area networks","authors":"M. Chiani, A. Volta","doi":"10.1109/PIMRC.1996.568411","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568411","url":null,"abstract":"The problem of error control strategies in wireless multimedia networks adopting the ATM protocol is addressed. In particular, we investigate the performance attainable by using a hybrid combination of automatic repeat request (ARQ) techniques and forward error correcting (FEC) codes for class C, connection oriented, non-delay critical and variable bit-rate services. To mitigate the wireless channel impairments we propose an adaptive error control scheme that chooses the control technique for each connection according to its requirements described by the connection specific parameters (e.g. maximum delay and cell loss ratio). The analysis is carried out for an OFDM/QPSK modulation format over a typical indoor radio channel.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121793524","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568400
Meng-Han Hsieh, Che-Ho Wei
This paper derives a frequency acquisition algorithm for orthogonal frequency division multiplexing (OFDM) systems. This frequency acquisition algorithm is a modification of the frequency tracking algorithm introduced by Moose (see IEEE Trans. Commun., vol.42, no.10, p.2908-14, 1994), which uses a repeated data symbol and a maximum likelihood estimation (MLE) algorithm to estimate the frequency offset. The estimate is extremely accurate but the acquisition range is limited to /spl plusmn/1/2 of the intercarrier spacing. With some modifications of the frequency tracking scheme and an assumption of a multipath channel, the frequency acquisition can be converted to an analogous PN sequence acquisition problem. Therefore, a partial-sum correlator with an appropriate threshold can be used to acquire the frequency offset.
{"title":"A frequency acquisition scheme for OFDM systems","authors":"Meng-Han Hsieh, Che-Ho Wei","doi":"10.1109/PIMRC.1996.568400","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568400","url":null,"abstract":"This paper derives a frequency acquisition algorithm for orthogonal frequency division multiplexing (OFDM) systems. This frequency acquisition algorithm is a modification of the frequency tracking algorithm introduced by Moose (see IEEE Trans. Commun., vol.42, no.10, p.2908-14, 1994), which uses a repeated data symbol and a maximum likelihood estimation (MLE) algorithm to estimate the frequency offset. The estimate is extremely accurate but the acquisition range is limited to /spl plusmn/1/2 of the intercarrier spacing. With some modifications of the frequency tracking scheme and an assumption of a multipath channel, the frequency acquisition can be converted to an analogous PN sequence acquisition problem. Therefore, a partial-sum correlator with an appropriate threshold can be used to acquire the frequency offset.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124748756","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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