P. Agrawal, A. Asthana, M. Cravatts, E. Hyden, P. Krzyzanowski, P. Mishra, B. Narendran, M. Srivastava, J. Trotter
The rapid deployment of wireless access technology, along with the emergence of high speed integrated service networks, promises to provide users with ubiquitous access to multimedia information in the near future. We are building an experimental testbed system, SWAN (Seamless Wireless ATM Network), to mimic this emerging networking environment. Our wireless access network is organized according to a nanocellular design with base stations serving as a gateway for communication between the wired network and the mobile hosts in a cell. Normally, a mobile host sends and receives traffic through the base station in its current cell. But SWAN also supports direct ephemeral networking between a limited number of cooperating mobile hosts within a small domain. The heart of the testbed is a networking subsystem, FAWN (Flexible Adapter for Wireless Networking) that interfaces the standard PCMCIA bus to an RF modem. The FAWN interface is used with a PC or workstation connected to a wired backbone network or a portable device such as a laptop or palmtop computer. In addition, a user interface consisting of an LCD display, audio I/O, and a bar code reader has been built. When interfaced with FAWN this results in a portable wireless multimedia terminal.
{"title":"A testbed for mobile networked computing","authors":"P. Agrawal, A. Asthana, M. Cravatts, E. Hyden, P. Krzyzanowski, P. Mishra, B. Narendran, M. Srivastava, J. Trotter","doi":"10.1109/ICC.1995.525203","DOIUrl":"https://doi.org/10.1109/ICC.1995.525203","url":null,"abstract":"The rapid deployment of wireless access technology, along with the emergence of high speed integrated service networks, promises to provide users with ubiquitous access to multimedia information in the near future. We are building an experimental testbed system, SWAN (Seamless Wireless ATM Network), to mimic this emerging networking environment. Our wireless access network is organized according to a nanocellular design with base stations serving as a gateway for communication between the wired network and the mobile hosts in a cell. Normally, a mobile host sends and receives traffic through the base station in its current cell. But SWAN also supports direct ephemeral networking between a limited number of cooperating mobile hosts within a small domain. The heart of the testbed is a networking subsystem, FAWN (Flexible Adapter for Wireless Networking) that interfaces the standard PCMCIA bus to an RF modem. The FAWN interface is used with a PC or workstation connected to a wired backbone network or a portable device such as a laptop or palmtop computer. In addition, a user interface consisting of an LCD display, audio I/O, and a bar code reader has been built. When interfaced with FAWN this results in a portable wireless multimedia terminal.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116141230","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}
ATM interconnection of computers and supercomputers offers exciting prospects for building both LANs and WANs because of the expected economies of scale, wide penetration of ATM, and future scalability to higher bandwidths. The ATM trial discussed was developed in Boulder, Colorado by US WEST to determine the feasibility of using ATM for high-end computing applications. We describe the Boulder ATM trial and report performance measurements for three types of applications: communication between workstations, communication between supercomputers, and access rates from computers to mass storage. In each case we found that the ATM WAN provided an efficient and effective transport mechanism, and limiting bandwidth effects were invariably within the computers and mass storage systems.
{"title":"Experiences with ATM: the Boulder perspective","authors":"R.G. Foldvik, O. McBryan","doi":"10.1109/ICC.1995.525154","DOIUrl":"https://doi.org/10.1109/ICC.1995.525154","url":null,"abstract":"ATM interconnection of computers and supercomputers offers exciting prospects for building both LANs and WANs because of the expected economies of scale, wide penetration of ATM, and future scalability to higher bandwidths. The ATM trial discussed was developed in Boulder, Colorado by US WEST to determine the feasibility of using ATM for high-end computing applications. We describe the Boulder ATM trial and report performance measurements for three types of applications: communication between workstations, communication between supercomputers, and access rates from computers to mass storage. In each case we found that the ATM WAN provided an efficient and effective transport mechanism, and limiting bandwidth effects were invariably within the computers and mass storage systems.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115302186","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}
A major advantage of spread-spectrum communication systems is their ability to exploit the multipath structure of the received signal. A standard RAKE receiver estimates the time delay, attenuation, and angle of arrival of each path and uses a maximum-ratio combiner to recombine different path signals. Antenna array structures were proposed to mitigate the effects of multipath by separating the paths in both time and spatial domains. New techniques for estimating the spatio-temporal characteristics of the channel for coherent direct-sequence spread-spectrum systems are proposed. The simulation results present the performance of such a multichannel estimator.
{"title":"Spatio-temporal channel estimation techniques for multiple access spread spectrum systems with antenna arrays","authors":"B. Khalaj, A. Paulraj, T. Kailath","doi":"10.1109/ICC.1995.524456","DOIUrl":"https://doi.org/10.1109/ICC.1995.524456","url":null,"abstract":"A major advantage of spread-spectrum communication systems is their ability to exploit the multipath structure of the received signal. A standard RAKE receiver estimates the time delay, attenuation, and angle of arrival of each path and uses a maximum-ratio combiner to recombine different path signals. Antenna array structures were proposed to mitigate the effects of multipath by separating the paths in both time and spatial domains. New techniques for estimating the spatio-temporal characteristics of the channel for coherent direct-sequence spread-spectrum systems are proposed. The simulation results present the performance of such a multichannel estimator.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"3 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113937672","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}
A problem has been identified with the handling of information tones by the full-rate GSM voice activity detector (VAD). The paper describes the modifications made in the half-rate GSM VAD which significantly improve the transmission of information tones, thus enabling the implementation of discontinuous transmission (DTX) in the GSM down-link. The modification consists of the addition of a tone detection algorithm to the basic full-rate GSM VAD architecture. The underlying assumptions behind the tone detector are discussed and the potential performance limitations identified. The half-rate GSM VAD successfully detects almost all tones that are likely to be encountered in networks across the world.
{"title":"Information tone handling in the half-rate GSM voice activity detector","authors":"P. A. Barrett","doi":"10.1109/ICC.1995.525141","DOIUrl":"https://doi.org/10.1109/ICC.1995.525141","url":null,"abstract":"A problem has been identified with the handling of information tones by the full-rate GSM voice activity detector (VAD). The paper describes the modifications made in the half-rate GSM VAD which significantly improve the transmission of information tones, thus enabling the implementation of discontinuous transmission (DTX) in the GSM down-link. The modification consists of the addition of a tone detection algorithm to the basic full-rate GSM VAD architecture. The underlying assumptions behind the tone detector are discussed and the potential performance limitations identified. The half-rate GSM VAD successfully detects almost all tones that are likely to be encountered in networks across the world.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123828658","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}
A method is proposed for forming an adaptive phased array transmission beam pattern at a base station without any knowledge of array geometry, path angles or mobile feedback. Estimates of receive vector channels are used to form a transmit weight vector optimization problem. The authors provide closed form solutions for both the single user case and the multiple user case. They show through simulation of a multiple user cellular network that the cooperative transmission network algorithm is capable of improving network frequency re-use capacity by a factor of 5 to 8.
{"title":"A blind adaptive transmit antenna algorithm for wireless communication","authors":"G. Raleigh, S. Diggavi, V. K. Jones, A. Paulraj","doi":"10.1109/ICC.1995.524451","DOIUrl":"https://doi.org/10.1109/ICC.1995.524451","url":null,"abstract":"A method is proposed for forming an adaptive phased array transmission beam pattern at a base station without any knowledge of array geometry, path angles or mobile feedback. Estimates of receive vector channels are used to form a transmit weight vector optimization problem. The authors provide closed form solutions for both the single user case and the multiple user case. They show through simulation of a multiple user cellular network that the cooperative transmission network algorithm is capable of improving network frequency re-use capacity by a factor of 5 to 8.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121366214","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}
A real-time call admission control algorithm is developed for admitting real time traffic streams with quality of service (QoS) constraints in high-speed networks operating in a packet-switched mode under a fixed routing strategy. The theory developed is based on a calculus for network delay at each network node with general traffic arrival process at the network edge. The authors give the necessary and sufficient conditions for the schedulability of real-time connections at each network node under non-preemptive earliest-due date scheduling policy for deterministic QoS guarantees. These necessary and sufficient conditions form the mathematical basis for the deterministic QoS guarantees in real-time communication services. The manner in which the end-to-end delay bound is to be divided into local delay bounds which together satisfy the end-to-end QoS requirements is finally proposed.
{"title":"A real-time call admission control algorithm in high-speed networks","authors":"Shanzeng Guo, N. Georganas","doi":"10.1109/ICC.1995.525181","DOIUrl":"https://doi.org/10.1109/ICC.1995.525181","url":null,"abstract":"A real-time call admission control algorithm is developed for admitting real time traffic streams with quality of service (QoS) constraints in high-speed networks operating in a packet-switched mode under a fixed routing strategy. The theory developed is based on a calculus for network delay at each network node with general traffic arrival process at the network edge. The authors give the necessary and sufficient conditions for the schedulability of real-time connections at each network node under non-preemptive earliest-due date scheduling policy for deterministic QoS guarantees. These necessary and sufficient conditions form the mathematical basis for the deterministic QoS guarantees in real-time communication services. The manner in which the end-to-end delay bound is to be divided into local delay bounds which together satisfy the end-to-end QoS requirements is finally proposed.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125140684","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}
Rainbow is a prototype optical metropolitan area network (MAN) developed at IBM. It employs wavelength division multiplexing (WDM) on a fiber-optic passive-star network topology, with each station equipped with a laser, which is fixed tuned to its own unique wavelength, and a Fabry-Perot filter, which is tunable across all wavelengths. The paper presents a model and analysis of the protocol used in the Rainbow prototype using the equilibrium point analysis (EPA) technique. The authors examine the system's throughput and how it is affected by various system parameters such as message arrival rate, message length, and timeout duration. They show that, for a given arrival rate, there is a timeout duration that will yield the optimal throughput. The analytical results are verified by simulation.
{"title":"Performance analysis of the Rainbow WDM optical network prototype","authors":"J. Jue, M. Borella, B. Mukherjee","doi":"10.1109/ICC.1995.525179","DOIUrl":"https://doi.org/10.1109/ICC.1995.525179","url":null,"abstract":"Rainbow is a prototype optical metropolitan area network (MAN) developed at IBM. It employs wavelength division multiplexing (WDM) on a fiber-optic passive-star network topology, with each station equipped with a laser, which is fixed tuned to its own unique wavelength, and a Fabry-Perot filter, which is tunable across all wavelengths. The paper presents a model and analysis of the protocol used in the Rainbow prototype using the equilibrium point analysis (EPA) technique. The authors examine the system's throughput and how it is affected by various system parameters such as message arrival rate, message length, and timeout duration. They show that, for a given arrival rate, there is a timeout duration that will yield the optimal throughput. The analytical results are verified by simulation.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"26 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113973269","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}
There are many radio access standards contending for attention in the world-wide cellular marketplace. Practical estimator methods and sequences are introduced for the reference symbol based DS-CDMA radio (denoted "RC"). It is a physical layer scheme involving insertion of a known training sequence into the coded, interleaved bit stream for an IS-95-like CDMA reverse channel. This paper presents the principle estimators needed for implementation of an RC receiver, and frame error rate (FER) results for a flat fading channel. The frame error rate or Eb/No required for a 1% FER is given for both idealized and realistic conditions concerning time varying carrier frequency offset and delay slew of the received timing. A comparison to IS-95 shows a 2 dB improvement.
{"title":"Implementation of a coherent reverse channel 900 MHz CDMA receiver with reference symbols","authors":"T. Sexton, F. Ling","doi":"10.1109/ICC.1995.524256","DOIUrl":"https://doi.org/10.1109/ICC.1995.524256","url":null,"abstract":"There are many radio access standards contending for attention in the world-wide cellular marketplace. Practical estimator methods and sequences are introduced for the reference symbol based DS-CDMA radio (denoted \"RC\"). It is a physical layer scheme involving insertion of a known training sequence into the coded, interleaved bit stream for an IS-95-like CDMA reverse channel. This paper presents the principle estimators needed for implementation of an RC receiver, and frame error rate (FER) results for a flat fading channel. The frame error rate or Eb/No required for a 1% FER is given for both idealized and realistic conditions concerning time varying carrier frequency offset and delay slew of the received timing. A comparison to IS-95 shows a 2 dB improvement.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122874160","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}
J. Solé-Pareta, D. Sarkar, J. Liebeherr, I. Akyildiz
We address the problem of routing connectionless traffic in an ATM network and propose an adaptive multipath routing scheme that enhances the routing methods employed at the inter-working units (IWUs). We present a scheme that distributes packets among multiple virtual paths (VPs) according to the utilization of the links of these VPs. The utilization of the VPs is determined by a feedback mechanism. We present simulation studies to show the effectiveness of the proposed adaptive multipath routing scheme.
{"title":"Adaptive multipath routing of connectionless traffic in an ATM network","authors":"J. Solé-Pareta, D. Sarkar, J. Liebeherr, I. Akyildiz","doi":"10.1109/ICC.1995.524476","DOIUrl":"https://doi.org/10.1109/ICC.1995.524476","url":null,"abstract":"We address the problem of routing connectionless traffic in an ATM network and propose an adaptive multipath routing scheme that enhances the routing methods employed at the inter-working units (IWUs). We present a scheme that distributes packets among multiple virtual paths (VPs) according to the utilization of the links of these VPs. The utilization of the VPs is determined by a feedback mechanism. We present simulation studies to show the effectiveness of the proposed adaptive multipath routing scheme.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134583730","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}
A new ATM switch called wrapped around multiple (WAM) banyan network is proposed. A. WAM banyan switch is constructed using 2d/spl times/2d switch elements. It consists of K parallel banyan switch planes and a packet is allowed to switch/overflow from one switch plane to another when packet contention occurs. This degree of freedom is provided by connecting the d logically equivalent output links from a switch element to d logically equivalent switch elements in the next stage, one in each plane. To further enhance the performance of this switch design, packet broadcasting is used together with priority switching. It is found that under full loading, a WAM banyan switch with K=R=d=3 can have a packet loss probability P/sub loss//spl les/10/sup -6/ for a switch with size up to 4096/spl times/4096. Changing the loading from /spl lambda/=1.0 to 0.8 can give about one order of magnitude further improvement in P/sub loss/.
{"title":"A new ATM switch design using wrapped around multiple (WAM) banyan network","authors":"K. Yeung","doi":"10.1109/ICC.1995.525224","DOIUrl":"https://doi.org/10.1109/ICC.1995.525224","url":null,"abstract":"A new ATM switch called wrapped around multiple (WAM) banyan network is proposed. A. WAM banyan switch is constructed using 2d/spl times/2d switch elements. It consists of K parallel banyan switch planes and a packet is allowed to switch/overflow from one switch plane to another when packet contention occurs. This degree of freedom is provided by connecting the d logically equivalent output links from a switch element to d logically equivalent switch elements in the next stage, one in each plane. To further enhance the performance of this switch design, packet broadcasting is used together with priority switching. It is found that under full loading, a WAM banyan switch with K=R=d=3 can have a packet loss probability P/sub loss//spl les/10/sup -6/ for a switch with size up to 4096/spl times/4096. Changing the loading from /spl lambda/=1.0 to 0.8 can give about one order of magnitude further improvement in P/sub loss/.","PeriodicalId":241383,"journal":{"name":"Proceedings IEEE International Conference on Communications ICC '95","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114404510","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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