Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783289
H. Nguyen, M. Roughan
In this paper we analyze more than 100 hours of packet traces from Planet-Lab measurements to study the correlation of Internet packet losses. We first apply statistical tests to identify the correlation timescale of the binary loss data. We find that in half of the traces packet losses are far from independent. More significantly, the correlation timescale of packet losses is correlated with the network load. We then examine the loss runs and the success runs of packets. The loss runs are typically short, regardless of the network load. We find that the success runs in the majority of our traces are also uncorrelated. Furthermore, their correlation timescale also does not depend on the network load. All of these results show that the impact of network load on the correlation of packet losses is non-trivial and that loss runs and success runs are better modelled as being independent than the binary losses themselves.
{"title":"On the Correlation of Internet Packet Losses","authors":"H. Nguyen, M. Roughan","doi":"10.1109/ATNAC.2008.4783289","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783289","url":null,"abstract":"In this paper we analyze more than 100 hours of packet traces from Planet-Lab measurements to study the correlation of Internet packet losses. We first apply statistical tests to identify the correlation timescale of the binary loss data. We find that in half of the traces packet losses are far from independent. More significantly, the correlation timescale of packet losses is correlated with the network load. We then examine the loss runs and the success runs of packets. The loss runs are typically short, regardless of the network load. We find that the success runs in the majority of our traces are also uncorrelated. Furthermore, their correlation timescale also does not depend on the network load. All of these results show that the impact of network load on the correlation of packet losses is non-trivial and that loss runs and success runs are better modelled as being independent than the binary losses themselves.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132154530","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783304
X. Wang
A new SIP event package called information-category is proposed based on the SIP event notification framework. With this event package an information sharing service is provided in IMS with SIP signaling. The end user could subscribe to interested information categories with SUBSCRIBE, get information from information sharing application server with NOTIFY, and post information with PUBLISH message. A method is provided to let information-category subscribers share multimedia information. Some basic SIP event notification extensions are analyzed to show the new event package is compliant with the existing event package family. With this new service SIP users could get seamless access to community-based and user-generated content on various devices in IMS network.
{"title":"Categorized Multimedia Information Sharing Service in IMS","authors":"X. Wang","doi":"10.1109/ATNAC.2008.4783304","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783304","url":null,"abstract":"A new SIP event package called information-category is proposed based on the SIP event notification framework. With this event package an information sharing service is provided in IMS with SIP signaling. The end user could subscribe to interested information categories with SUBSCRIBE, get information from information sharing application server with NOTIFY, and post information with PUBLISH message. A method is provided to let information-category subscribers share multimedia information. Some basic SIP event notification extensions are analyzed to show the new event package is compliant with the existing event package family. With this new service SIP users could get seamless access to community-based and user-generated content on various devices in IMS network.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133035158","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783324
H. Myburgh, L. Linde
A maximum likelihood sequence estimation (MLSE) combined equalizer and decoder with soft-decision decoding performance, that has a computational complexity superior to that of conventional MLSE equalization, is proposed. Its performance is compared to a system containing a soft-output Viterbi MLSE equalizer followed by a soft-decision Viterbi MLSE decoder. It is shown via computer simulation that the proposed algorithm's performance matches that of conventional soft-decision decoding, while eliminating the use of a decoder in the receiver, for frequency-selective Rayleigh fading channels.
{"title":"Reduced Complexity Combined Soft-Decision MLSE Equalization and Decoding","authors":"H. Myburgh, L. Linde","doi":"10.1109/ATNAC.2008.4783324","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783324","url":null,"abstract":"A maximum likelihood sequence estimation (MLSE) combined equalizer and decoder with soft-decision decoding performance, that has a computational complexity superior to that of conventional MLSE equalization, is proposed. Its performance is compared to a system containing a soft-output Viterbi MLSE equalizer followed by a soft-decision Viterbi MLSE decoder. It is shown via computer simulation that the proposed algorithm's performance matches that of conventional soft-decision decoding, while eliminating the use of a decoder in the receiver, for frequency-selective Rayleigh fading channels.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116202885","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783336
M. Khan, R. Vesilo, L. Davis, I. Collings
This paper considers a signalling scheme for a multi-user wireless broadcast system where the base station has multiple transmit antennas and users can have multiple receive antennas. Independent data streams are transmitted in this system by allocating different transmit antennas to different selected users where multiple transmit antennas may be allocated to each selected user. The signalling scheme is used to select the particular users to receive data in a transmission block and to allocate transmit antennas to those users. We examine two partial feedback schemes for selecting users: one that we call norm-based and the other that we call SINR-based. We also present a novel transmit-antenna selection scheme for allocating multiple transmit antennas to selected users based on the Gram-Schmidt orthogonalisation algorithm. The signalling scheme presented in this paper reduces the amount of channel information required by the base station. We study the performance of the user selection and transmit-antenna selection schemes when linear receivers are used at the receiver side for decoding the transmitted signal. In particular, we consider zero-forcing (ZF) and minimum mean square-error (MMSE) receivers. We examine the sum capacity performance of the system compared to schemes with no feedback and using random antenna selection. We show that the best performance is achieved with norm-based user selection, Gram-Schmidt antenna selection and MMSE receivers.
{"title":"User and Transmit Antenna Selection for MIMO Broadcast Wireless Channels with Linear Receivers","authors":"M. Khan, R. Vesilo, L. Davis, I. Collings","doi":"10.1109/ATNAC.2008.4783336","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783336","url":null,"abstract":"This paper considers a signalling scheme for a multi-user wireless broadcast system where the base station has multiple transmit antennas and users can have multiple receive antennas. Independent data streams are transmitted in this system by allocating different transmit antennas to different selected users where multiple transmit antennas may be allocated to each selected user. The signalling scheme is used to select the particular users to receive data in a transmission block and to allocate transmit antennas to those users. We examine two partial feedback schemes for selecting users: one that we call norm-based and the other that we call SINR-based. We also present a novel transmit-antenna selection scheme for allocating multiple transmit antennas to selected users based on the Gram-Schmidt orthogonalisation algorithm. The signalling scheme presented in this paper reduces the amount of channel information required by the base station. We study the performance of the user selection and transmit-antenna selection schemes when linear receivers are used at the receiver side for decoding the transmitted signal. In particular, we consider zero-forcing (ZF) and minimum mean square-error (MMSE) receivers. We examine the sum capacity performance of the system compared to schemes with no feedback and using random antenna selection. We show that the best performance is achieved with norm-based user selection, Gram-Schmidt antenna selection and MMSE receivers.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131844932","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783285
J. Ellershaw, J. Riding, A. Tran, L. Guan, T. Smith
We model and compare the deployment costs of three broadband access technologies, namely digital subscriber loops (DSL), passive optical networks (PON), and WiMAX wireless access, in Australian rural and remote areas. The analysis shows that wireless technologies are cheapest for a 20 Mbit/s rate when the number of homes per square kilometer is less than one. For 50+ Mbit/s, passive optical networks are the most economic.
{"title":"Economic Analysis of Broadband Access for Australian Rural and Remote Areas","authors":"J. Ellershaw, J. Riding, A. Tran, L. Guan, T. Smith","doi":"10.1109/ATNAC.2008.4783285","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783285","url":null,"abstract":"We model and compare the deployment costs of three broadband access technologies, namely digital subscriber loops (DSL), passive optical networks (PON), and WiMAX wireless access, in Australian rural and remote areas. The analysis shows that wireless technologies are cheapest for a 20 Mbit/s rate when the number of homes per square kilometer is less than one. For 50+ Mbit/s, passive optical networks are the most economic.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130538538","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783292
Mohsen Toorani
The electronic mail plays an unavoidable role in the humankind communications. With the great interest for the connection via mobile platforms, and the growing number of vulnerabilities and attacks, it is essential to provide suitable security solutions regarding the limitations of resource restricted platforms. Although some solutions such as PGP and S/MIME are currently available for the secure e-mail over the Internet, they are based on traditional public key cryptography that involves huge computational costs. In this paper, a new secure application-layer protocol, called SMEmail, is introduced that provides several security attributes such as confidentiality, integrity, authentication, non-repudiation, and forward secrecy of message confidentiality for the electronic mails. SMEmail offers an elliptic curve-based public key solution that uses public keys for the secure key establishment of a symmetric encryption, and is so suitable for the resource restricted platforms such as mobile phones.
{"title":"SMEmail - A New Protocol for the Secure E-mail in Mobile Environments","authors":"Mohsen Toorani","doi":"10.1109/ATNAC.2008.4783292","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783292","url":null,"abstract":"The electronic mail plays an unavoidable role in the humankind communications. With the great interest for the connection via mobile platforms, and the growing number of vulnerabilities and attacks, it is essential to provide suitable security solutions regarding the limitations of resource restricted platforms. Although some solutions such as PGP and S/MIME are currently available for the secure e-mail over the Internet, they are based on traditional public key cryptography that involves huge computational costs. In this paper, a new secure application-layer protocol, called SMEmail, is introduced that provides several security attributes such as confidentiality, integrity, authentication, non-repudiation, and forward secrecy of message confidentiality for the electronic mails. SMEmail offers an elliptic curve-based public key solution that uses public keys for the secure key establishment of a symmetric encryption, and is so suitable for the resource restricted platforms such as mobile phones.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129744884","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783316
N. Sarkar, Eric Lo
Using indoor propagation measurements, the throughput performance of an IEEE 802.11g wireless local area network (WLAN) under different received signal strength (RSS) values is investigated. By using a pair of wireless laptops and an access point (AP) we conducted several experiments involving IEEE 802.11g computer links, which were carried out in an obstructed office block at the AUT University within the School of Computing and Mathematical Sciences office building. Results obtained show that the link throughput of an IEEE 802.11g is not always increasing with RSS in an obstructed office building.
{"title":"Indoor Propagation Measurements for Performance Evaluation of IEEE 802.11g","authors":"N. Sarkar, Eric Lo","doi":"10.1109/ATNAC.2008.4783316","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783316","url":null,"abstract":"Using indoor propagation measurements, the throughput performance of an IEEE 802.11g wireless local area network (WLAN) under different received signal strength (RSS) values is investigated. By using a pair of wireless laptops and an access point (AP) we conducted several experiments involving IEEE 802.11g computer links, which were carried out in an obstructed office block at the AUT University within the School of Computing and Mathematical Sciences office building. Results obtained show that the link throughput of an IEEE 802.11g is not always increasing with RSS in an obstructed office building.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122571010","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783344
M. David, Cheng Guo, N. Prasad
Since sensor nodes are energy constrained devices, optimizing the energy efficiency of wireless sensor networks (WSNs) is a key issue. In this paper we present a new, simple and easy to implement protocol to reduce the energy consumption of nodes. The purpose of the proposed algorithm is to monitor the transmission power of sensor nodes while communicating. The algorithm has been studied, analyzed and then implemented on the nodes. The quantitative and qualitative analysis present similar results, and with the proposed solution a reduction of 50% of the energy spent in the transmission process compared with the standard specifications has been achieved.
{"title":"Adaptive Emitting Power Control Protocol for Wireless Sensor Networks","authors":"M. David, Cheng Guo, N. Prasad","doi":"10.1109/ATNAC.2008.4783344","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783344","url":null,"abstract":"Since sensor nodes are energy constrained devices, optimizing the energy efficiency of wireless sensor networks (WSNs) is a key issue. In this paper we present a new, simple and easy to implement protocol to reduce the energy consumption of nodes. The purpose of the proposed algorithm is to monitor the transmission power of sensor nodes while communicating. The algorithm has been studied, analyzed and then implemented on the nodes. The quantitative and qualitative analysis present similar results, and with the proposed solution a reduction of 50% of the energy spent in the transmission process compared with the standard specifications has been achieved.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124992082","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783341
A.K.-L. Yau, P. Komisarczuk, Paul D. Teal
Cognitive radio (CR) improves utilization of the overall radio spectrum through dynamic adaptation to local spectrum availability. In CR networks, unlicensed or secondary users (SUs) may operate in underutilized spectrum owned by the licensed or primary users (PUs) conditional upon PU encountering acceptable interference levels. A cognitive wireless ad hoc network (CWAN) is a multihop self-organized and dynamic network that applies CR technology. The research into quality of service (QoS) in CWAN is still in its infancy. To date, no attempt has been made to model a QoS architecture as a unified solution for CWAN and so this is the focus of this paper. We present a novel QoS architecture called C2net for CWAN based on a cross-layer approach. C2net provides service prioritization to different traffic types in the presence of nodal mobility and PUs. The main objective is to provide stable QoS assurance to high priority flows. This is realized by a number of distributed features of C2net including topology management, congestion control, scheduling, and dynamic channel selection. The purpose of this paper is twofold. Firstly, to present the architectural framework based on next steps in signaling (NSIS) for C2net. Secondly, to discuss the challenges and open issues posed by the intrinsic complexities of CWAN to spark new research interests in this field.
{"title":"C2net: A Cross-Layer Quality of Service (QoS) Architecture for Cognitive Wireless Ad Hoc Networks","authors":"A.K.-L. Yau, P. Komisarczuk, Paul D. Teal","doi":"10.1109/ATNAC.2008.4783341","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783341","url":null,"abstract":"Cognitive radio (CR) improves utilization of the overall radio spectrum through dynamic adaptation to local spectrum availability. In CR networks, unlicensed or secondary users (SUs) may operate in underutilized spectrum owned by the licensed or primary users (PUs) conditional upon PU encountering acceptable interference levels. A cognitive wireless ad hoc network (CWAN) is a multihop self-organized and dynamic network that applies CR technology. The research into quality of service (QoS) in CWAN is still in its infancy. To date, no attempt has been made to model a QoS architecture as a unified solution for CWAN and so this is the focus of this paper. We present a novel QoS architecture called C2net for CWAN based on a cross-layer approach. C2net provides service prioritization to different traffic types in the presence of nodal mobility and PUs. The main objective is to provide stable QoS assurance to high priority flows. This is realized by a number of distributed features of C2net including topology management, congestion control, scheduling, and dynamic channel selection. The purpose of this paper is twofold. Firstly, to present the architectural framework based on next steps in signaling (NSIS) for C2net. Secondly, to discuss the challenges and open issues posed by the intrinsic complexities of CWAN to spark new research interests in this field.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130080944","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 : 2008-12-01DOI: 10.1109/ATNAC.2008.4783350
A. Haider, A. Nakao
This paper investigates the stability characteristics of overlay networks performing switching between multiple virtual paths. A global stability condition for switched-control-systems has been applied to overlay path switching frequency, that can be incorporated into design of better routing protocols for overlay networks. Further, NS-2 based simulations have been carried out on an overlay network to evaluate the impact of round-trip-time, packet loss probability and throughput metrics on decisions regarding path selection. Throughput based switching decisions have shown to be resulting in lower number of path changes, which is desirable. Also, it has been observed that delay and loss based metrics can result into a large number of frequent path changes, which can push the overlay routing system into an instable oscillating state for a prolonged period of time.
{"title":"On Path Switching in Overlay Networks","authors":"A. Haider, A. Nakao","doi":"10.1109/ATNAC.2008.4783350","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783350","url":null,"abstract":"This paper investigates the stability characteristics of overlay networks performing switching between multiple virtual paths. A global stability condition for switched-control-systems has been applied to overlay path switching frequency, that can be incorporated into design of better routing protocols for overlay networks. Further, NS-2 based simulations have been carried out on an overlay network to evaluate the impact of round-trip-time, packet loss probability and throughput metrics on decisions regarding path selection. Throughput based switching decisions have shown to be resulting in lower number of path changes, which is desirable. Also, it has been observed that delay and loss based metrics can result into a large number of frequent path changes, which can push the overlay routing system into an instable oscillating state for a prolonged period of time.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129260886","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：