This paper proposes a new practical packet scheduling scheme for wireless LANs called SoCPS and also explores extensively the effectiveness of wireless packet scheduling under a variety of conditions over an actual wireless LAN. One well-known aspect in packet scheduling at the base station is consideration of channel state dependency. In conventional studies, the channel state is expressed in microscopic two states in the Markovian sense. To eliminate a large overhead associated with acquiring such a fine-grain channel state and to establish a software-based enhancement, we introduce the notion of Strength of Connection (SoC) which can be expressed as the long-term strength of the connectivity between the base station and an end host. We examine schemes for identifying the channel state and examine the applicability to packet scheduling. We also design a packet scheduling scheme based on SoC called SoCPS. Finally, we investigate the performance under various conditions of traffic and wireless channel states. We have designed and implemented SoCPS on FreeBSD computers. Our evaluation results obtained with up to eight wireless-LAN nodes have determined the applicability of SoCPS and limitation in wireless packet scheduling for wireless LANs. In particular, while FIFO is sufficient in many cases where TCP traffic is dominant, scheduling with SoC consideration is effective for real-time UDP traffic.
{"title":"A software approach to channel-state dependent scheduling for wireless LANs","authors":"H. Aida, Y. Tobe, M. Saito, H. Tokuda","doi":"10.1145/605991.605996","DOIUrl":"https://doi.org/10.1145/605991.605996","url":null,"abstract":"This paper proposes a new practical packet scheduling scheme for wireless LANs called SoCPS and also explores extensively the effectiveness of wireless packet scheduling under a variety of conditions over an actual wireless LAN. One well-known aspect in packet scheduling at the base station is consideration of channel state dependency. In conventional studies, the channel state is expressed in microscopic two states in the Markovian sense. To eliminate a large overhead associated with acquiring such a fine-grain channel state and to establish a software-based enhancement, we introduce the notion of Strength of Connection (SoC) which can be expressed as the long-term strength of the connectivity between the base station and an end host. We examine schemes for identifying the channel state and examine the applicability to packet scheduling. We also design a packet scheduling scheme based on SoC called SoCPS. Finally, we investigate the performance under various conditions of traffic and wireless channel states. We have designed and implemented SoCPS on FreeBSD computers. Our evaluation results obtained with up to eight wireless-LAN nodes have determined the applicability of SoCPS and limitation in wireless packet scheduling for wireless LANs. In particular, while FIFO is sufficient in many cases where TCP traffic is dominant, scheduling with SoC consideration is effective for real-time UDP traffic.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"81 1","pages":"33-42"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81216868","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}
This paper proposes a framework for performance evaluation and optimization of an emerging multimedia, packet Direct-Sequence Code Division Multiple Access (DS-CDMA) network with a wide range of Quality of Service (QoS) requirements on losses and delays. The need for a new framework arises from inability of the traditional approach, based on the outage probability, to capture the queueing aspects of DS-CDMA network behavior in presence of delay tolerant traffic. Accounting for these aspects becomes essential for emerging multimedia DS-CDMA networks attempting to approach their capacity limits by using coding and spreading gain control, retransmissions, as well as transmission scheduling/power control. Since in a DS-CDMA network transmissions compete for simultaneous access to several resources, including wireless bandwidth and transmission power, the paper proposes to approximate the feasible QoS region for the network by the intersection of the feasible QoS regions for the corresponding single-resource systems. The feasible QoS region for a single-resource system is estimated by using M / G / 1 conservation laws. Based on this "bottleneck resource" approximation, the paper estimates the admission region for the network and outlines the approach to the network management aimed at maximizing the admission region.
本文提出了一种用于新兴多媒体、分组直接序列码分多址(DS-CDMA)网络的性能评估和优化框架，该网络对损失和延迟有广泛的服务质量(QoS)要求。由于传统的基于中断概率的方法无法捕捉到容忍延迟业务存在时DS-CDMA网络行为的排队方面，因此需要一个新的框架。考虑这些方面对于新兴的多媒体DS-CDMA网络至关重要，这些网络试图通过使用编码和扩展增益控制、重传以及传输调度/功率控制来接近其容量极限。由于在DS-CDMA网络中，传输竞争同时访问多个资源，包括无线带宽和传输功率，因此本文提出通过相应单资源系统的可行QoS区域的交集来近似网络的可行QoS区域。利用M / G / 1守恒定律估计单资源系统的可行QoS区域。基于这种“瓶颈资源”近似，本文估计了网络的允许区域，并概述了以最大化允许区域为目标的网络管理方法。
{"title":"A framework for performance evaluation and optimization of an emerging multimedia DS-CDMA network","authors":"V. Marbukh","doi":"10.1145/605991.605999","DOIUrl":"https://doi.org/10.1145/605991.605999","url":null,"abstract":"This paper proposes a framework for performance evaluation and optimization of an emerging multimedia, packet Direct-Sequence Code Division Multiple Access (DS-CDMA) network with a wide range of Quality of Service (QoS) requirements on losses and delays. The need for a new framework arises from inability of the traditional approach, based on the outage probability, to capture the queueing aspects of DS-CDMA network behavior in presence of delay tolerant traffic. Accounting for these aspects becomes essential for emerging multimedia DS-CDMA networks attempting to approach their capacity limits by using coding and spreading gain control, retransmissions, as well as transmission scheduling/power control. Since in a DS-CDMA network transmissions compete for simultaneous access to several resources, including wireless bandwidth and transmission power, the paper proposes to approximate the feasible QoS region for the network by the intersection of the feasible QoS regions for the corresponding single-resource systems. The feasible QoS region for a single-resource system is estimated by using M / G / 1 conservation laws. Based on this \"bottleneck resource\" approximation, the paper estimates the admission region for the network and outlines the approach to the network management aimed at maximizing the admission region.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"22 1","pages":"55-64"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81713167","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}
Recently, QoS issues have initiated to be studied in both wired and wireless networks, to support multimedia and real-time applications. In this paper, we propose a framework for the admission control of multimedia multicast traffic and for the system configuration in MANETs. We present a mechanism to ensure bandwidth guarantees to multicast sessions (Call-Admission Multicast Protocol for MANETs, M-CAMP). M-CAMP is scalable, operates on a per-call basis and supports the group membership dynamics. It adopts a measurement-based approach to evaluate the end-to-end bandwidth availability between the traffic source and the group of destinations. M-CAMP is independent of the underlying wireless technology and protocols, as far as a multicast routing service is available. It does not require any maintenance of status information in the mobile hosts.
{"title":"A framework for the admission control of QoS multicast traffic in mobile ad hoc networks","authors":"E. Pagani, G. P. Rossi","doi":"10.1145/605991.605993","DOIUrl":"https://doi.org/10.1145/605991.605993","url":null,"abstract":"Recently, QoS issues have initiated to be studied in both wired and wireless networks, to support multimedia and real-time applications. In this paper, we propose a framework for the admission control of multimedia multicast traffic and for the system configuration in MANETs. We present a mechanism to ensure bandwidth guarantees to multicast sessions (Call-Admission Multicast Protocol for MANETs, M-CAMP). M-CAMP is scalable, operates on a per-call basis and supports the group membership dynamics. It adopts a measurement-based approach to evaluate the end-to-end bandwidth availability between the traffic source and the group of destinations. M-CAMP is independent of the underlying wireless technology and protocols, as far as a multicast routing service is available. It does not require any maintenance of status information in the mobile hosts.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"80 1","pages":"2-11"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90476057","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}
We consider the problem of routing to endpoints with very high "effective" mobility, i.e., when the period between changes in an endpoint's location is comparable to the time it takes for the location tracking mechanism to converge. This could happen due to increased endpoint speed, decreased cell size, or increased control message latency. When this happens, conventional location tracking approaches fail -- by the time such mechanisms converge, the endpoint has already moved to a new location.We characterize the performance degradation of a location tracking mechanism with increasing effective mobility. Specifically, we show that a typical mobile network has three operating states -- reactable, late-reactable, and unreactable, and identify theoretically and experimentally, the endpoint speeds at which the system transitions from one state to another. We then describe "spray routing" -- a new routing mechanism that uses controlled multicasting to the vicinity of the endpoint's last-known location. We show experimentally that the throughput is dramatically increased to acceptable levels even for highly mobile endpoints while maintaining reasonable end-to-end delay.
{"title":"Tracking Highly Mobile Endpoints","authors":"F. Tchakountio, R. Ramanathan","doi":"10.1145/605991.606003","DOIUrl":"https://doi.org/10.1145/605991.606003","url":null,"abstract":"We consider the problem of routing to endpoints with very high \"effective\" mobility, i.e., when the period between changes in an endpoint's location is comparable to the time it takes for the location tracking mechanism to converge. This could happen due to increased endpoint speed, decreased cell size, or increased control message latency. When this happens, conventional location tracking approaches fail -- by the time such mechanisms converge, the endpoint has already moved to a new location.We characterize the performance degradation of a location tracking mechanism with increasing effective mobility. Specifically, we show that a typical mobile network has three operating states -- reactable, late-reactable, and unreactable, and identify theoretically and experimentally, the endpoint speeds at which the system transitions from one state to another. We then describe \"spray routing\" -- a new routing mechanism that uses controlled multicasting to the vicinity of the endpoint's last-known location. We show experimentally that the throughput is dramatically increased to acceptable levels even for highly mobile endpoints while maintaining reasonable end-to-end delay.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"16 1","pages":"83-94"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88399193","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}
Rapid advances in communication networks and device technologies have enabled people with powerful means of communications. It is common for any individual to be associated with a number of heterogeneous communication devices (such as phones, pagers, PDAs) or a variety of applications (such as e-mail, instant messaging, or chat-rooms). This phenomenon has spurred a great demand for unifie dcommunication [20] services which integrate one's various communication mechanisms in a meaningful and seamless fashion. To meet this demand, the research community and communication industry are experimenting and building Internet-based, unified communication network systems (UCN) in which heterogeneous devices are unified for individuals and access networks are linked together through a core IP network. In this paper, we investigate the mobility issues in UCN systems. We discuss traditional mobility problems such as personal mobility and terminal mobility in the new UCN context, and present our design, analysis, and implementation of a new form of mobility in UCNs, service mobility [12] where active services can be retained across heterogeneous devices and networks.
{"title":"Mobility support in unified communication networks","authors":"Helen J. Wang, R. Katz","doi":"10.1145/605991.606004","DOIUrl":"https://doi.org/10.1145/605991.606004","url":null,"abstract":"Rapid advances in communication networks and device technologies have enabled people with powerful means of communications. It is common for any individual to be associated with a number of heterogeneous communication devices (such as phones, pagers, PDAs) or a variety of applications (such as e-mail, instant messaging, or chat-rooms). This phenomenon has spurred a great demand for unifie dcommunication [20] services which integrate one's various communication mechanisms in a meaningful and seamless fashion. To meet this demand, the research community and communication industry are experimenting and building Internet-based, unified communication network systems (UCN) in which heterogeneous devices are unified for individuals and access networks are linked together through a core IP network. In this paper, we investigate the mobility issues in UCN systems. We discuss traditional mobility problems such as personal mobility and terminal mobility in the new UCN context, and present our design, analysis, and implementation of a new form of mobility in UCNs, service mobility [12] where active services can be retained across heterogeneous devices and networks.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"48 1","pages":"95-102"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75620956","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}
The delay performance for self-similar data traffic over a prioritized Time Division Multiple Access with Dynamic Reservation (TDMA/DR) MAC protocol in a wireless ATM setting is evaluated using simulation and approximate analysis. An approximate analysis of heavy-tailed ON/OFF data traffic yields very accurate mean delay and delay distribution of the data traffic in the traffic range up to 70% of the total channel capacity. The reasonableness of the approximate analysis is verified by simulation. The aggregate of the heavy-tailed ON/OFF sources, with Pareto-distributed ON and OFF periods, forms a self-similar data traffic. In the computer simulation, we consider three service classes representing real-time voice, real-time Variable Bit Rate (VBR) Markov Modulated Poisson Process (MMPP) video and data traffic. Numerical results indicate that the delay performance for heavy-tailed ON/OFF data traffic is well within the delay tolerance under light to medium loads.
采用仿真和近似分析的方法，对无线ATM环境下TDMA/DR (priority Time Division Multiple Access with Dynamic Reservation) MAC协议下自相似数据流量的延迟性能进行了评价。对重尾ON/OFF数据流量的近似分析可以得出非常准确的数据流量平均延迟和延迟分布，其流量范围可达总信道容量的70%。仿真验证了近似分析的合理性。重尾ON/OFF源的聚合，具有帕累托分布的ON和OFF周期，形成自相似的数据流量。在计算机模拟中，我们考虑了三种业务类别，分别代表实时语音、实时可变比特率(VBR)马尔可夫调制泊松过程(MMPP)视频和数据流量。数值结果表明，在轻、中负载下，重尾开/关数据流量的延迟性能完全在延迟容忍范围内。
{"title":"Delay performance of data traffic in a cellular wireless ATM network","authors":"D. Wong, J. Mark, K. Chua, B. Kannan, Y. Chew","doi":"10.1145/605991.606000","DOIUrl":"https://doi.org/10.1145/605991.606000","url":null,"abstract":"The delay performance for self-similar data traffic over a prioritized Time Division Multiple Access with Dynamic Reservation (TDMA/DR) MAC protocol in a wireless ATM setting is evaluated using simulation and approximate analysis. An approximate analysis of heavy-tailed ON/OFF data traffic yields very accurate mean delay and delay distribution of the data traffic in the traffic range up to 70% of the total channel capacity. The reasonableness of the approximate analysis is verified by simulation. The aggregate of the heavy-tailed ON/OFF sources, with Pareto-distributed ON and OFF periods, forms a self-similar data traffic. In the computer simulation, we consider three service classes representing real-time voice, real-time Variable Bit Rate (VBR) Markov Modulated Poisson Process (MMPP) video and data traffic. Numerical results indicate that the delay performance for heavy-tailed ON/OFF data traffic is well within the delay tolerance under light to medium loads.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"22 1","pages":"65-73"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74458913","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}
IEEE 802.11 contains a mechanism for transmission of data with realtime constraints known as Point Coordination Function. This supplementary medium access protocol resides on top of the basic medium access mechanism Distributed Coordination Function and uses a centralized polling approach. Due to the complexity of a PCF implementation and the predicted inefficiency of the PCF several proposals have been presented for providing QoS support without the need of a centralized scheduler. Those solutions suffer from the fact that they are shifting implementation complexity from the access point to the mobile nodes. In this paper we compare the suitability of the basic DCF and PCF protocols for the transmission of audio data in an interactive scenario. We show that a simple priority mechanism used on the mobiles as well as the access point is suitable for providing improved QoS in terms of band-width and without the need of an extended DCF protocol. In combination with the PCF an adequate delay characteristic for audio flows is achievable as well. To overcome the limitations in channel capacity caused by the PCF we suggest an implicit signaling scheme for improving the channel capacity by avoiding unsuccessful PCF polling attempts.
{"title":"Voice transmission in an IEEE 802.11 WLAN based access network","authors":"Andreas Köpsel, A. Wolisz","doi":"10.1145/605991.605995","DOIUrl":"https://doi.org/10.1145/605991.605995","url":null,"abstract":"IEEE 802.11 contains a mechanism for transmission of data with realtime constraints known as Point Coordination Function. This supplementary medium access protocol resides on top of the basic medium access mechanism Distributed Coordination Function and uses a centralized polling approach. Due to the complexity of a PCF implementation and the predicted inefficiency of the PCF several proposals have been presented for providing QoS support without the need of a centralized scheduler. Those solutions suffer from the fact that they are shifting implementation complexity from the access point to the mobile nodes. In this paper we compare the suitability of the basic DCF and PCF protocols for the transmission of audio data in an interactive scenario. We show that a simple priority mechanism used on the mobiles as well as the access point is suitable for providing improved QoS in terms of band-width and without the need of an extended DCF protocol. In combination with the PCF an adequate delay characteristic for audio flows is achievable as well. To overcome the limitations in channel capacity caused by the PCF we suggest an implicit signaling scheme for improving the channel capacity by avoiding unsuccessful PCF polling attempts.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"10 7 1","pages":"23-32"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84593702","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}
The convergence of the Internet with new wireless and mobile networks is creating a whole new level of heterogeneity in multimedia communications. This increased level of heterogeneity emphasizes the need for scalable and adaptive video solutions both for coding and transmission purposes. However, in general, there is an inherent tradeoff between the level of scalability and the quality of scalable video streams. In other words, the higher the bandwidth variation, the lower the overall video quality of the scalable stream that is needed to support the desired bandwidth range. In this paper, we introduce the notion of TranScaling (TS) which is a generalization of (non-scalable) transcoding. With transcaling, a scalable video stream, that covers a given bandwidth range, is mapped into one or more scalable video streams covering different bandwidth ranges. Our proposed TS framework exploits the fact that the level of heterogeneity changes at different points of the video distribution tree over wireless and mobile Internet networks. This provides the opportunity to improve the video quality by performing the appropriate transcaling process. We argue that an Internet/wireless network gateway represents a good candidate for performing transcaling. Moreover, we describe Hierarchical TranScaling (HTS) which provides a "Transcalar" the option of choosing among different levels of transcaling processes with different complexities. We illustrate the benefits of transcaling by considering the recently developed MPEG-4 Fine-Granular-Scalability (FGS) video coding. Simulation results of video transcaling are also presented.
{"title":"TranScaling: a video coding and multicasting framework for wireless IP multimedia services","authors":"H. Radha","doi":"10.1145/605991.605994","DOIUrl":"https://doi.org/10.1145/605991.605994","url":null,"abstract":"The convergence of the Internet with new wireless and mobile networks is creating a whole new level of heterogeneity in multimedia communications. This increased level of heterogeneity emphasizes the need for scalable and adaptive video solutions both for coding and transmission purposes. However, in general, there is an inherent tradeoff between the level of scalability and the quality of scalable video streams. In other words, the higher the bandwidth variation, the lower the overall video quality of the scalable stream that is needed to support the desired bandwidth range. In this paper, we introduce the notion of TranScaling (TS) which is a generalization of (non-scalable) transcoding. With transcaling, a scalable video stream, that covers a given bandwidth range, is mapped into one or more scalable video streams covering different bandwidth ranges. Our proposed TS framework exploits the fact that the level of heterogeneity changes at different points of the video distribution tree over wireless and mobile Internet networks. This provides the opportunity to improve the video quality by performing the appropriate transcaling process. We argue that an Internet/wireless network gateway represents a good candidate for performing transcaling. Moreover, we describe Hierarchical TranScaling (HTS) which provides a \"Transcalar\" the option of choosing among different levels of transcaling processes with different complexities. We illustrate the benefits of transcaling by considering the recently developed MPEG-4 Fine-Granular-Scalability (FGS) video coding. Simulation results of video transcaling are also presented.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"11 1","pages":"12-22"},"PeriodicalIF":0.0,"publicationDate":"2001-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84307085","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}
Advances in hardware imaging technology and user demand for convenient mobile electronic image capture are fueling the development of inexpensive image capture devices that can acquire images rivaling the image quality of photographic film. Improvements in the hardware imaging technology have to be matched with intelligent image storage mechanisms that are aware of local storage and battery constraints. In this paper, we explore using a dynamic, informed image transcoding technique to manage the consumed battery and storage resources in digital cameras. Such application aware technologies are fundamental for the mass consumer acceptance of these newer digital technologies. We show that this technique can allow the camera to store an order of magnitude more images. For a moderate number of images (e.g. 40), transcoding techniques can also maintain high quality images. The availability of fast wireless networks can allow the camera to capture 58 high quality images (51 uploaded) before running out of battery power. Storage technologies with expensive read and write operations (such as micro disks) can have a minor negative impact on battery life because of the extra read and write operations associated with transcoding operations. We show that the ability to effectively communicate the power vs. size vs. quality tradeoff to the end user is important for applications to adapt to the prevailing operating conditions.
{"title":"Managing the storage and battery resources in an image capture device (digital camera) using dynamic transcoding","authors":"Surendar Chandra, C. Ellis, Amin Vahdat","doi":"10.1145/345867.345897","DOIUrl":"https://doi.org/10.1145/345867.345897","url":null,"abstract":"Advances in hardware imaging technology and user demand for convenient mobile electronic image capture are fueling the development of inexpensive image capture devices that can acquire images rivaling the image quality of photographic film. Improvements in the hardware imaging technology have to be matched with intelligent image storage mechanisms that are aware of local storage and battery constraints. In this paper, we explore using a dynamic, informed image transcoding technique to manage the consumed battery and storage resources in digital cameras. Such application aware technologies are fundamental for the mass consumer acceptance of these newer digital technologies.\u0000We show that this technique can allow the camera to store an order of magnitude more images. For a moderate number of images (e.g. 40), transcoding techniques can also maintain high quality images. The availability of fast wireless networks can allow the camera to capture 58 high quality images (51 uploaded) before running out of battery power. Storage technologies with expensive read and write operations (such as micro disks) can have a minor negative impact on battery life because of the extra read and write operations associated with transcoding operations. We show that the ability to effectively communicate the power vs. size vs. quality tradeoff to the end user is important for applications to adapt to the prevailing operating conditions.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"37 1","pages":"73-82"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84635233","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}
In a wireless communications network, the movement of mobile users presents significant technical challenges to providing efficient access to the wired broadband network. In this paper, we construct a new analytical/numerical model that characterizes mobile user behavior and the resultant traffic patterns. The model is based on a semi-Markov process representation of mobile user behavior in a general state-space. Using a new algorithm for parameter estimation of a general Hidden Semi-Markov Model (HSMM), we develop an efficient procedure for dynamically tracking the parameters of the model from incomplete data. We then apply our integrated model to obtain estimates of the computational and bandwidth resources required at the wireless/wired network interface to provide high performance wireless Internet access and quality-of-service to mobile users. Finally, we develop a threshold-based admission control scheme in the wireless network based on the velocity information that can be extracted from our model.
{"title":"An integrated mobility and traffic model for resource allocation in wireless networks","authors":"Hisashi Kobayashi, Shunzheng Yu, B. L. Mark","doi":"10.1145/345867.345880","DOIUrl":"https://doi.org/10.1145/345867.345880","url":null,"abstract":"In a wireless communications network, the movement of mobile users presents significant technical challenges to providing efficient access to the wired broadband network. In this paper, we construct a new analytical/numerical model that characterizes mobile user behavior and the resultant traffic patterns. The model is based on a semi-Markov process representation of mobile user behavior in a general state-space. Using a new algorithm for parameter estimation of a general Hidden Semi-Markov Model (HSMM), we develop an efficient procedure for dynamically tracking the parameters of the model from incomplete data. We then apply our integrated model to obtain estimates of the computational and bandwidth resources required at the wireless/wired network interface to provide high performance wireless Internet access and quality-of-service to mobile users. Finally, we develop a threshold-based admission control scheme in the wireless network based on the velocity information that can be extracted from our model.","PeriodicalId":91426,"journal":{"name":"World of wireless mobile and multimedia networks. IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks","volume":"36 1","pages":"39-47"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80629963","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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