{"title":"Tandem voice communications: digital cellular, VoIP, and voice over Wi-Fi","authors":"J. Gibson, B. Wei","doi":"10.1109/GLOCOM.2004.1378036","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378036","url":null,"abstract":"We consider the problems of voice over wireless LANs and voice communications over heterogeneous asynchronous tandem networks, including digital cellular, VoIP, and voice over Wi-Fi. For voice over Wi-Fi, we minimize retransmissions by combining new packetization methods and packet loss concealment approaches. We demonstrate that tandem network connections can suffer significant loss in voice quality, even with ideal channels. We present a particular example of a VoIP network in tandem with voice over Wi-Fi and study end-to-end performance for different voice codecs, bit error rates, packet loss rates, and packet loss concealment methods.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123903386","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}
{"title":"Indoor field measurements with a configurable multi-antenna testbed","authors":"R. Rao, S. Lang, B. Daneshrad","doi":"10.1109/GLOCOM.2004.1379109","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1379109","url":null,"abstract":"This paper reports the development of a configurable, non-real-time, 2/spl times/2 multi-antenna testbed operating at 5.25 GHz with a bandwidth of 25 MHz.. MIMO-OFDM modulation and demodulation are performed offline. The unit is fully calibrated and was used in extensive indoor wireless measurements at UCLA. The paper reports measurements for SISO, SIMO 1/spl times/2 and MIMO 2/spl times/2 setups in line of sight and nonline of sight channels. These measurements show that LOS channels are not necessarily detrimental for MIMO performance. Further experiments show that with -3 dBm of transmit power uncoded data rates of 140 Mbit/s are achievable.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123967031","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}
{"title":"Design of multiple reverse spanning trees in next generation of Ethernet-VPNs","authors":"A. Kolarov, B. Sengupta, A. Iwata","doi":"10.1109/GLOCOM.2004.1378212","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378212","url":null,"abstract":"Recently, a new global open Ethernet (GOE) architecture was proposed as a cost-effective scalable solution for the next generation of VPNs over an optical network infrastructure. In this paper, we present a traffic engineering design for networks that support the GOE architecture. The current extensions of the spanning tree protocol (STP), such as rapid spanning tree (RST) and multiple spanning tree (MST), use a link cost metric which is inversely proportional to the link capacity. In order to achieve a better load balancing in the network, we propose to use the link cost metric which is a function of the current link load. The traffic engineering algorithms presented in this paper use two different link cost functions. We comment on the performance of those heuristic algorithms for various network topologies and under several traffic scenarios. Our results demonstrate a significant improvement in the network utilization when the link cost metric is a function of the link load compared to the case when it is inversely proportional to the link capacity.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123971278","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}
{"title":"A reverse channel call admission control scheme based on total received power for CDMA systems supporting integrated voice/data services","authors":"Wei Li, D. Agrawal","doi":"10.1108/17427370780000145","DOIUrl":"https://doi.org/10.1108/17427370780000145","url":null,"abstract":"In code-division multiple-access (CDMA) systems, the number of users that each cell can support is limited by the total received power or interference received at each base station and can vary with time. The total received power can be used as an indicator of traffic load in call admission control. In this paper, we develop an algorithm to estimate the updated total received power due to a new call based on the current measure of the received power. Using this algorithm, we propose a call admission control (CAC) scheme with the purpose of maximizing the resource utilization and guaranteeing a minimum amount of resources for each type of traffic when congestion occurs. We model the system by a multi-dimensional Markov chain to evaluate the system performance.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124017235","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}
{"title":"Real mechanisms for mobile networks modeling and engineering","authors":"H. Khedher, F. Valois, S. Tabbane","doi":"10.1109/GLOCOM.2004.1378388","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378388","url":null,"abstract":"As mobile networks are growing fast in size and complexity, radio network resource planning needs to be optimized to cope with both increased traffic demand and spectrum scarcity. Although many studies have been reported in the area of mobile network planning in terms of traffic distribution analysis and mobility modeling, relatively few studies have been achieved regarding network planning based on real-world data and measurements. A realistic model has been developed in order to evaluate the performance of a real GSM network providing a voice service in an urban area. In this framework, our contribution addresses an important issue: how to monitor the performance measurements collected in the operations and maintenance centre (OMC) to propose a complete study including a realistic mobility model and a qualitative and quantitative traffic characterization that constitute a generic planning model which can be customized by any operator for mobile network deployment.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123343428","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}
{"title":"Performance of the delay diversity receiver in asynchronous CDMA channels","authors":"Wan Choi, J. Andrews","doi":"10.1109/GLOCOM.2004.1378485","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378485","url":null,"abstract":"In this paper, the performance of the delay diversity receiver is analyzed in asynchronous CDMA channels. The outage probability and the bit error probability of the delay diversity receiver are accurately derived and compared with those of the conventional diversity receiver. From the analytical and numerical results, it is confirmed that the delay diversity receiver achieves a remarkable diversity gain with reasonable cost and complexity in asynchronous CDMA channels. Specifically, for roughly the same hardware complexity, the delay diversity receiver achieves nearly twice the diversity order of the conventional receiver.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"19 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120916012","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}
{"title":"The effect of router buffer size on HighSpeed TCP performance","authors":"D. Barman, Georgios Smaragdakis, I. Matta","doi":"10.1109/GLOCOM.2004.1378255","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378255","url":null,"abstract":"We study the effect of the IP router buffer size on the throughput of HighSpeed TCP (HSTCP). We are motivated by the fact that, in high speed routers, the buffer size is important, as a large buffer size might be a constraint. We first derive an analytical model for HighSpeed TCP and we show that for a small buffer size, equal to 10% of the bandwidth-delay product, HighSpeed TCP can achieve more than 90% of the bottleneck capacity. We also show that setting the buffer size equal to 20% can increase the utilization of HighSpeed TCP up to 98%. On the contrary, setting the buffer size to less than 10% of the bandwidth-delay product can decrease HighSpeed TCP's throughput significantly. We also study the performance effects under both DropTail and RED AQM (active queue management). Analytical results obtained using a fixed-point approach are compared to those obtained by simulation.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121213859","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}
{"title":"Next step in MAC evolution: battery awareness?","authors":"S. Jayashree, B. S. Manoj, C. Murthy","doi":"10.1109/GLOCOM.2004.1378862","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378862","url":null,"abstract":"A major issue in the energy-constrained ad hoc wireless networks is to find ways that increase their lifetime. The communication protocols for these networks have to be designed such that they are aware of the state of the batteries. In this paper, we propose a novel battery aware medium access control (BAMAC(k)) protocol that takes benefit of the chemical properties of the batteries and provides a longer life for the mobile nodes' battery. The proposed protocol extends the battery lifetime and consumes lesser percentage nominal capacity of the battery per packet transmission compared to the IEEE 802.11 and the DWOP (distributed wireless ordering protocol), respectively. A discrete chain Markov model is used to theoretically analyze the protocol, the correctness of which is verified through a detailed simulation study. The performance results show that BAMAC(k) outperforms IEEE 802.11 and DWOP MAC protocols, in terms of power consumption, fairness, and lifetime of the nodes.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114207911","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}
{"title":"Maintaining useful server throughput under load attacks using active NIC portals","authors":"O. Demir, K. Ghose","doi":"10.1109/GLOCOM.2004.1378389","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1378389","url":null,"abstract":"The paper presents a solution to denial-of-service (DoS) attacks on servers where. the server resources are saturated by repeated request for execution of scripts or download requests for large files. Existing solutions for coping with DoS attacks, which are primarily based on limiting the traffic rates, are incapable of providing any protection against load attacks, as these attacks do not manifest themselves as heavy bursts of traffic. We present an intelligent gateway based solution for maintaining the useful throughput of the servers under load attacks that uses specific information from the servers to perform dynamic load balancing and dynamic packet filtering. The intelligent gateway is implemented using a dual-ported active network card (NIC). Clients are classified according to their request history, and rate limits are imposed at the gateway for each class according to the level and duration of the attack. Results for a prototype implementation indicate our solution to be an effective deterrent against load attacks.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114349750","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}
{"title":"Bi-truncation for simplified MIMO signal detection","authors":"Wen Jiang, Xingxing Yu, Geoffrey Y. Li","doi":"10.1109/GLOCOM.2004.1377978","DOIUrl":"https://doi.org/10.1109/GLOCOM.2004.1377978","url":null,"abstract":"The joint maximum-likelihood (JML) detector may be used in memoryless multiple input multiple output (MIMO) systems to obtain optimal detection performance. However the JML detector needs an exhaustive search and causes prohibitively large decoding complexity. To reduce the complexity of MIMO signal detection, the minimum mean-square-error (MMSE) linear detector (LD), decision-feedback detector (DFD) and sphere detector (SD) may be used. In this paper we develop bi-truncation based approaches for MIMO signal detection. The new approaches have low-complexity, and computer simulation results show that they outperform MMSE-LD and MMSE-DFD.","PeriodicalId":162046,"journal":{"name":"IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116248020","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}