Pub Date : 2003-09-21DOI: 10.1109/APCC.2003.1274240
B. Kruekaew, C. Phongcharoenpanich
This paper presents the analysis and design of a simple conical beam antenna using circumferential aperture beside the radial waveguide near the reflector for vertically polarized radiation. The structure of the antenna is composed of two circular plates that are parallelled to each other in horizontal plane. The vector potential approach is used to calculate the radiation properties. The radiation characteristics such as radiation pattern, elevation beam peak, half power beamwidth and maximum directivity of the antenna are analyzed. The contour plot of elevation beam peak and directivity as a function of the radius of the circular plates and the spacing between the radial waveguide and the reflector are illustrated as the guideline for the design criterion of a conical beam antenna using circumferential aperture beside the radial waveguide near the reflector for vertically polarized.
{"title":"Analysis of a circumferential aperture beside the radial waveguide near the reflector","authors":"B. Kruekaew, C. Phongcharoenpanich","doi":"10.1109/APCC.2003.1274240","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274240","url":null,"abstract":"This paper presents the analysis and design of a simple conical beam antenna using circumferential aperture beside the radial waveguide near the reflector for vertically polarized radiation. The structure of the antenna is composed of two circular plates that are parallelled to each other in horizontal plane. The vector potential approach is used to calculate the radiation properties. The radiation characteristics such as radiation pattern, elevation beam peak, half power beamwidth and maximum directivity of the antenna are analyzed. The contour plot of elevation beam peak and directivity as a function of the radius of the circular plates and the spacing between the radial waveguide and the reflector are illustrated as the guideline for the design criterion of a conical beam antenna using circumferential aperture beside the radial waveguide near the reflector for vertically polarized.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116148120","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274346
Sang Woo Lee, Heyungsub Lee, Hyeongho Lee, Daeyoung Kim
As an investment in metro area network which connects the access network and the backbone network was relatively small, the metro area network became a bottleneck in the whole network. The RPR (resilient packet ring) protocol is proposed as a solution of the metro area network's problems. In this paper, we propose a design scheme of the RPR module using a NP which does not support the RPR protocol and implement a protocol converter. To implement the proposed RPR module, the protocol converter is needed. The main functions of the protocol converter are RPR/Ethernet frame conversion, SPI/FlexBus conversion, and frame classification. We describe the structure and function of the proposed protocol converter and also discuss about the implementation and validation of it. The protocol converter is an essential part of the proposed RPR module.
{"title":"An implementation of protocol converter for RPR(resilient packet ring) module","authors":"Sang Woo Lee, Heyungsub Lee, Hyeongho Lee, Daeyoung Kim","doi":"10.1109/APCC.2003.1274346","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274346","url":null,"abstract":"As an investment in metro area network which connects the access network and the backbone network was relatively small, the metro area network became a bottleneck in the whole network. The RPR (resilient packet ring) protocol is proposed as a solution of the metro area network's problems. In this paper, we propose a design scheme of the RPR module using a NP which does not support the RPR protocol and implement a protocol converter. To implement the proposed RPR module, the protocol converter is needed. The main functions of the protocol converter are RPR/Ethernet frame conversion, SPI/FlexBus conversion, and frame classification. We describe the structure and function of the proposed protocol converter and also discuss about the implementation and validation of it. The protocol converter is an essential part of the proposed RPR module.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128791950","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274263
S. Seker, A. Morgul, O. İleri
The purpose of this study is to develop a new model to analyze the attenuation of EM waves in tunnel environments, using the scattering properties of discrete thin curved surfaces. There are various models in literature that are developed to calculate attenuation in tunnels. In this paper a new model will be introduced. The simulation results would compare to the simulation results of the previously published models along with the results of various measurements.
{"title":"A discrete approach for modelling the EM wave attenuation in tunnels","authors":"S. Seker, A. Morgul, O. İleri","doi":"10.1109/APCC.2003.1274263","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274263","url":null,"abstract":"The purpose of this study is to develop a new model to analyze the attenuation of EM waves in tunnel environments, using the scattering properties of discrete thin curved surfaces. There are various models in literature that are developed to calculate attenuation in tunnels. In this paper a new model will be introduced. The simulation results would compare to the simulation results of the previously published models along with the results of various measurements.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128641698","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274333
M. Hamarsheh, M. Abdullah
Typical approaches in writing apodized fiber Bragg gratings (FBG) use approximated profiles such as Gaussian or raised cosine distributions. The typical approximation approaches are complicated to be implemented and affect the characteristics of the fiber Bragg gratings especially on the side lobes. In this paper, we report the study on the piecewise stepped approximated Gaussian apodization profile, a new approach proposed to relax the requirement for FBG fabrication setups. The results show no detrimental effects on the side lobes.
{"title":"Analysis of fiber Bragg gratings apodized with linearly approximated segmented Gaussian function","authors":"M. Hamarsheh, M. Abdullah","doi":"10.1109/APCC.2003.1274333","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274333","url":null,"abstract":"Typical approaches in writing apodized fiber Bragg gratings (FBG) use approximated profiles such as Gaussian or raised cosine distributions. The typical approximation approaches are complicated to be implemented and affect the characteristics of the fiber Bragg gratings especially on the side lobes. In this paper, we report the study on the piecewise stepped approximated Gaussian apodization profile, a new approach proposed to relax the requirement for FBG fabrication setups. The results show no detrimental effects on the side lobes.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114194620","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274293
J. Lundberg, C. Candolin
Multicast is an efficient way of sending data to multiple receivers simultaneously. To support mobility, multicast caching has been introduced as a method for allowing roaming clients to request packets that they have been unable to receive during the change from one access network to another. The basic idea has been to introduce a multicast cache, which stores the multicast streams as individual, uniquely defined, packets. The mobile clients may upon entering an access network request the packets that they lack from the multicast cache. The main problem with the current approach is that a multicast cache that does not contain the requested packets merely returns an error message to the mobile client. To solve this problem, we extend the model to allow multicast caches to forward client requests according to some dynamically configurable policy. If another multicast cache contains the data, it is sent it to the client, which then can continue processing the multicast stream as it normally would.
{"title":"Hierarchical multicast caching","authors":"J. Lundberg, C. Candolin","doi":"10.1109/APCC.2003.1274293","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274293","url":null,"abstract":"Multicast is an efficient way of sending data to multiple receivers simultaneously. To support mobility, multicast caching has been introduced as a method for allowing roaming clients to request packets that they have been unable to receive during the change from one access network to another. The basic idea has been to introduce a multicast cache, which stores the multicast streams as individual, uniquely defined, packets. The mobile clients may upon entering an access network request the packets that they lack from the multicast cache. The main problem with the current approach is that a multicast cache that does not contain the requested packets merely returns an error message to the mobile client. To solve this problem, we extend the model to allow multicast caches to forward client requests according to some dynamically configurable policy. If another multicast cache contains the data, it is sent it to the client, which then can continue processing the multicast stream as it normally would.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114423028","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274359
E. Karami, M. Shiva
In this paper, a new joint channel estimation and detection algorithm for frequency selective fading multiple-input multiple-output (MIMO) channels is proposed. In the channel estimation section, using a generalized form of least square (LS) algorithm, a very accurate estimate of channel parameters is obtained. The procedure of detection is done in two stages. In the first stage the inter-symbol-interference (ISI) of previous stages is subtracted and then in the second stage, using a joint detection algorithm, the transmitted symbols are estimated. Parallel-interference-cancellator (PIC) and minimum-mean-square-estimator (MMSE) are used as MIMO detectors. The efficiency of the proposed algorithm, in time-varying MIMO channels is confirmed through various simulations.
{"title":"A new joint channel estimation and detection algorithm for MIMO channels","authors":"E. Karami, M. Shiva","doi":"10.1109/APCC.2003.1274359","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274359","url":null,"abstract":"In this paper, a new joint channel estimation and detection algorithm for frequency selective fading multiple-input multiple-output (MIMO) channels is proposed. In the channel estimation section, using a generalized form of least square (LS) algorithm, a very accurate estimate of channel parameters is obtained. The procedure of detection is done in two stages. In the first stage the inter-symbol-interference (ISI) of previous stages is subtracted and then in the second stage, using a joint detection algorithm, the transmitted symbols are estimated. Parallel-interference-cancellator (PIC) and minimum-mean-square-estimator (MMSE) are used as MIMO detectors. The efficiency of the proposed algorithm, in time-varying MIMO channels is confirmed through various simulations.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116195009","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274253
M. A. Mazlan, A. Samsudin, R. Budiarto
The use of mobile agents based computing in this emerging world of electronic transaction is becoming increasingly prevalent due to the enormous benefits and services that can be derived from it. They are good for distributed applications and hence an excellent paradigm when group communications are involved. Secure group communication is a significant research area prompted by the growing popularity of many types group based cryptography and collaborative application. In this paper, we focus on secure group communication based on mobile agents. In doing so, we use elliptic curve cryptography (ECC) as key exchange protocol, XOR operation and hash function to achieve provable secure and efficient management for group communication.
{"title":"Secure groups communication for mobile agents based on public key infrastructure","authors":"M. A. Mazlan, A. Samsudin, R. Budiarto","doi":"10.1109/APCC.2003.1274253","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274253","url":null,"abstract":"The use of mobile agents based computing in this emerging world of electronic transaction is becoming increasingly prevalent due to the enormous benefits and services that can be derived from it. They are good for distributed applications and hence an excellent paradigm when group communications are involved. Secure group communication is a significant research area prompted by the growing popularity of many types group based cryptography and collaborative application. In this paper, we focus on secure group communication based on mobile agents. In doing so, we use elliptic curve cryptography (ECC) as key exchange protocol, XOR operation and hash function to achieve provable secure and efficient management for group communication.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114802972","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274220
J. Lee, W. Choi, C. Pyo, Jae-Ick Choi
In this paper, a high efficiency active array antenna module using microstrip patch subarrays with the stacked patch and the low cost packaged monolithic microwave integrated circuit (MMIC) phase shifters is developed, which is used in the active phased array antenna system. The antenna elements and the active circuitry are integrated to improve the array performance on the same substrate. It exhibits the antenna gain to noise temperature ratio (G/T) of 0 dB/K. The 3 /spl times/ 4 circularly polarized radiator subarray has a 3dB axial ratio bandwidth of 25% and 2:1 VSWR bandwidth of 15.2%. And the tracking performances for this antenna with gain of 24dBi (3 /spl times/ 8 radiator) are discussed from the moving test on urban road, national road, and expressway. The average receiving rates are 88% on urban area and 99% on highway except tunnels, respectively. In addition, the reduction of the relative receiving rate due to the blockings and the rainfall intensity is investigated.
{"title":"Ku-band active array antenna for mobile DBS reception","authors":"J. Lee, W. Choi, C. Pyo, Jae-Ick Choi","doi":"10.1109/APCC.2003.1274220","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274220","url":null,"abstract":"In this paper, a high efficiency active array antenna module using microstrip patch subarrays with the stacked patch and the low cost packaged monolithic microwave integrated circuit (MMIC) phase shifters is developed, which is used in the active phased array antenna system. The antenna elements and the active circuitry are integrated to improve the array performance on the same substrate. It exhibits the antenna gain to noise temperature ratio (G/T) of 0 dB/K. The 3 /spl times/ 4 circularly polarized radiator subarray has a 3dB axial ratio bandwidth of 25% and 2:1 VSWR bandwidth of 15.2%. And the tracking performances for this antenna with gain of 24dBi (3 /spl times/ 8 radiator) are discussed from the moving test on urban road, national road, and expressway. The average receiving rates are 88% on urban area and 99% on highway except tunnels, respectively. In addition, the reduction of the relative receiving rate due to the blockings and the rainfall intensity is investigated.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124373609","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274439
K. Munadi, M. Kurosaki, K. Nishikawa, H. Kiya
In this paper, a robust error protection scheme for JPEG2000 codestream is proposed. The error protection is achieved by combining the advantage of the codestream layer structure, a data hiding technique and an FEC code. At encoding stage, multiple quality layers of the codestream are protected by an FEC code with various strengths. The parity data is then hidden in the least significant layer. Prior to image decoding, error recovery is done by means of extracting the hidden data and performing the FEC decoding to the corresponding layers. The proposed method offers several benefits: it preserves the same codestream structure as the one in the JPEG2000 standard part 1, does not require additional bandwidth and can be integrated with the existing JPEG2000 error resilience tools. Hence, it accommodates one of the requirements for the upcoming wireless JPEG2000 (JPWL or JPEG2000 part 11). Simulations in a CDMA environment confirmed the proposal's effectiveness.
提出了一种适用于JPEG2000码流的鲁棒错误保护方案。错误保护是结合码流层结构、数据隐藏技术和FEC码的优点来实现的。在编码阶段，码流的多个质量层由不同强度的FEC码保护。奇偶校验数据然后隐藏在最低有效层中。在图像解码之前，通过提取隐藏数据并对相应层进行FEC解码来实现错误恢复。提出的方法有几个优点:它保留了与JPEG2000标准第1部分相同的码流结构，不需要额外的带宽，并且可以与现有的JPEG2000错误恢复工具集成。因此，它满足了即将到来的无线JPEG2000 (JPWL或JPEG2000 part 11)的要求之一。在CDMA环境下的仿真验证了该方案的有效性。
{"title":"A robust error protection technique for JPEG2000 codestream and its evaluation in CDMA environment","authors":"K. Munadi, M. Kurosaki, K. Nishikawa, H. Kiya","doi":"10.1109/APCC.2003.1274439","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274439","url":null,"abstract":"In this paper, a robust error protection scheme for JPEG2000 codestream is proposed. The error protection is achieved by combining the advantage of the codestream layer structure, a data hiding technique and an FEC code. At encoding stage, multiple quality layers of the codestream are protected by an FEC code with various strengths. The parity data is then hidden in the least significant layer. Prior to image decoding, error recovery is done by means of extracting the hidden data and performing the FEC decoding to the corresponding layers. The proposed method offers several benefits: it preserves the same codestream structure as the one in the JPEG2000 standard part 1, does not require additional bandwidth and can be integrated with the existing JPEG2000 error resilience tools. Hence, it accommodates one of the requirements for the upcoming wireless JPEG2000 (JPWL or JPEG2000 part 11). Simulations in a CDMA environment confirmed the proposal's effectiveness.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126324980","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 : 2003-09-21DOI: 10.1109/APCC.2003.1274453
Wu Weidong, L. Guangyuan
With the Internet's on-going evolution from a best effort network to a network with service differentiation, an important topic of interest is the problems what the router architecture will be and how many functions will be implemented in router. In this paper, we analyze characteristics of the next generation Internet services, give an abstract architecture, and present a novel, parallel and high-scalable control framework for next-generation IP routers. We can only modify the classifier to extend new services. It support the co-existence of best effort service and future services.
{"title":"A model of router for next generation Internet services","authors":"Wu Weidong, L. Guangyuan","doi":"10.1109/APCC.2003.1274453","DOIUrl":"https://doi.org/10.1109/APCC.2003.1274453","url":null,"abstract":"With the Internet's on-going evolution from a best effort network to a network with service differentiation, an important topic of interest is the problems what the router architecture will be and how many functions will be implemented in router. In this paper, we analyze characteristics of the next generation Internet services, give an abstract architecture, and present a novel, parallel and high-scalable control framework for next-generation IP routers. We can only modify the classifier to extend new services. It support the co-existence of best effort service and future services.","PeriodicalId":277507,"journal":{"name":"9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125793067","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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