D. Gemmell, 'Multimedia Network File Servers: Multi-Channel Delay Sensitive Data Retrieval", Proc. ACM Multimedia, 1993, p. 243.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....a common buffer space is used by the scheduler to 14 produce data, and by the clients to consume data. In a double buffer organization, two distinct sets of buffers are used alternatingly, one for production by the scheduler and another for consumption by clients. In [Chen et al. 1993] [Gemmell, 1993] a SCAN scheduling strategy is used in conjunction with single buffer organization. Other approaches have used fixed or der scheduling with double buffer organization ( Rangan and Vin, 1993a] Chen and Little, 1993] In our approach we use our scheduling strategy with a double buffer ....

....as early as [Frank, 1969] Teorey and Pinkerton, 1972] and [Fuller, 1975] More recently, Abbott and Garcia Molina, 1990] and [Chen et al. 1991] have addressed the problem in the context of real time systems. With the growing interest in continuous media server design, recent work by [Gemmell, 1993], Reddy and Wyllie, 1993] Chen et al. 1993] Anderson et al. 1992] Rangan and Vin, 1993a] Gemmell and Christodoulakis, 1992] Lougher and Shepherd, 1992] Ramakrishnan et al. 1993] Chang et al. 1994] Daigle and Strosnider, 1994] Chen and Little, 1993] have been significant. ....

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J. Gemmell. Multimedia Network File Servers: Multi channel Delay Sensitive Data Retrieval. In Proceedings of 18t A CM Multimedia Conference. ACM, October 1993.

....delivery timing, which is unacceptable for multimedia data. Proper decoding of multimedia data requires that data always be present for decoding when needed. The most common solution is to retrieve one unit of data from the disk for each multimedia stream during each xed disk service round, as in [9]. This scheme guarantees paper.tex; 25 05 2001; 16:29; p.3 4 S. T. Campbell and S. M. Chung timely delivery as long as the total number of requested streams is below a certain limit. The problem with the delivery scheme using a xed disk service round is that it is characterized as best e ort ....

D. J. Gemmell and J. Han, \Multimedia Network File Servers: Multichannel Delay-Sensitive Data Retrieval," Multimedia Systems, Vol. 1, No. 6, pp. 240{ 252, 1994.

....in residential broadband access networks using cable or ADSL. In Section 9 we conclude and discuss future work. 1. 1 Literature Review Work in the area of traffic management of prerecorded video falls into two classes: traffic management issues in the disk subsystem of the video server (e.g. see [12] [13] 26] 34] 36] and traffic management issues in the network. Although the ideas of this paper may be useful for disk subsystem design, our focus is on management of prerecorded VBR traffic in the network. The papers on the management of prerecorded VBR traffic in the network fall into three ....

D.J. Gemmell and J. Han. Multimedia network file servers: multichannel delay sensitive data retrieval. Multimedia Systems, 1:240--252, 1994.

....service time after admitting a new request must not exceed the new round duration which also takes into account the playback requirement of the new batch. 2. Scheduler: This software module schedules the services for the admitted batches of requests in Service Queue. Several scheduling techniques [2, 7, 12, 13] could be used. After the last media blocks for a batch have been fetched, the scheduler removes the batch from Service Queue. One obvious drawback of any admission control algorithms without pre admission is that many subscribers could renege prematurely within seconds of their scheduled service ....

D. J. Gemmell. Multimedia network file servers: Multi-channel delay sensitive data retrieval. In Proc. of ACM Multimedia, pages 243--250, June 1993.

....to multichannel playback. Rangan and Vin in [2,3] presented issues involving design of multiuser HDTV storage server. They proposed a constrained block allocation mechanism as the efficient way to represent and store multiple video streams on disk. Chen, Kandlur and Yu in [4] and Gemmell [5] independently developed functionally equivalent algorithms based on grouping streams into independent sets to reduce buffering requirements. Reddy and Wyllie [6] proposed a new disk scheduling technique combining SCAN seek optimization and EDF (Earliest Deadline First) algorithms. In this paper ....

D. J. Gemmell, "Multimedia Network File Servers: Multichannel Delay Sensitive Retrieval", ACM Multimedia 93

.... problem of scheduling accesses to I O systems has been studied extensively as early as [Fra69] and [TP72] Ful75] More recently [AGM90] and [ea91] have addressed the problem in the context of real time systems(RTS) With the growing interest in continuous media server design recent work by [Gem93] RW93] CKY93] AOG92] RV93a] GC92] LS92] RVG 93] CCP 94] DS94] CL93] has been very significant. While [GC92] presents a general theory of retrieval for continuous media there have been two distinct approaches to the retrieval problem at the CMS. First, approaches like ....

....the key to performance improvement greatly influenced our choice of incorporating batching and SCAN features into our scheduling strategy. However, their scheduling approaches do not address issues typical of CM data like handling frame oriented streams. In the second approach, like those in [Gem93] CKY93] AOG92] LS92] RV93a] CL93] the effort has been to derive new scheduling strategies that are aware of the continuous and real time requirements of a CMS. Our work draws heavily on work from the second approach. RV93a] proposes a fixed order cyclical scheduling strategy. Their ....

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J. Gemmell. Multimedia Network File Servers: Multi--channel Delay Sensitive Data Retrieval. In Proceedings of 1 st ACM Multimedia Conference. ACM, October 1993.

....layout schemes, and finally Section 9 demonstrates the performace and reliability of the proposed methods through a case study. 2 Related Work The issue of reducing the buffering requirement and maximizing the number of concurrent sessions in a video retrieval environment is addressed in [3] and [13] In [3] the sorting set al..gorithm is proposed, and in [13] the Grouped Sweeping Scheme (GSS) is introduced. These schemes are functionally equivalent techniques which are based on the idea of dividing the streams into sets which are serviced in a fixed order; the reads for the streams ....

....and finally Section 9 demonstrates the performace and reliability of the proposed methods through a case study. 2 Related Work The issue of reducing the buffering requirement and maximizing the number of concurrent sessions in a video retrieval environment is addressed in [3] and [13] In [3] the sorting set al..gorithm is proposed, and in [13] the Grouped Sweeping Scheme (GSS) is introduced. These schemes are functionally equivalent techniques which are based on the idea of dividing the streams into sets which are serviced in a fixed order; the reads for the streams within each set are ....

Gemmell, J. Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval. In Proc. ACM Multimedia '93, pp. 243--250, 1993.

....[13] examines the issue of collocational storage of multiple media segments on a disk. In [20] a new formulation for disk arm scheduling schemes called grouped sweeping scheduling is proposed and analyzed. The goal is to minimize the buffer requirement. A similar concept is also considered in [9]. Furthermore, 16] studies storage management and disk access algorithms in a disk array environment using this grouping approach. In [2] a cost performance analysis of a video server with hierarchical storage is presented. The remainder of this paper is organized as follows: In Section 2 we ....

D. Gemmell, "Multimedia Network File Servers: Multi-Channel Delay Senstitive Data Retrieval", ACM Multimedia 93, Anaheim CA, 1993.

....a class of active accumulation strategies. Simulation studies are used to validate analytical results presented here. 1. 2 Relation to Previous Work The problem of designing a scheduling strategy for CM data has been previously addressed in [RV93] CL93] LS92] AOG92] RVG 93] KEL94] Gem93] GC92] CKY94] TPBG93] Servicing strategies like [CKY93] RW93] and [Gem93] use single buffers while allowing head scheduling algorithms like C SCAN to decide the servicing order. Using single buffers can restrict the subscribers consumption sequence thereby disallowing certain kinds ....

....analytical results presented here. 1. 2 Relation to Previous Work The problem of designing a scheduling strategy for CM data has been previously addressed in [RV93] CL93] LS92] AOG92] RVG 93] KEL94] Gem93] GC92] CKY94] TPBG93] Servicing strategies like [CKY93] RW93] and [Gem93] use single buffers while allowing head scheduling algorithms like C SCAN to decide the servicing order. Using single buffers can restrict the subscribers consumption sequence thereby disallowing certain kinds of VCR like operations. RS92] enumerates a similar list of VCR like operations as ....

J. Gemmell. Multimedia Network File Servers: Multi--channel Delay Sensitive Data Retrieval. In Proceedings of 1 st ACM Multimedia Conference. ACM, October 1993. 28

....in resource utilization as well as the capacity of the CMS since it reserves resource commensurate with the clients playback quality. The efficacy of QBSCAN is demostrated via simulation studies. 1. 2 Relation to Previous Work Strategies to schedule accesses to the CMS is being widely researched [7], 4] 1] 17] 8] 16] and [5] Work examining the nature of Quality of Service for CM data can be found in [18] 23] 2] Recently, 15] 21] 6] 20] and [24] have attempted to devise strategies that reserve statistically estimated bandwidth instead of worst case to handle ....

J. Gemmell. Multimedia Network File Servers: Multi--channel Delay Sensitive Data Retrieval. In Proceedings of 1 st ACM Multimedia Conference. ACM, October 1993. 16

....blocks and consequently have very poor resolution. In other related work, issues such as admission control and selection of service size to support multimedia applications are addressed in [5, 9] Disk scheduling schemes for optimizing the throughput of the DASD storage system are considered in [10, 11, 12]. This paper is organized as follows. In Section 2, the storage method and the playout method are presented. The segment sampling and segment placement schemes are devised in Section 3. Some experimental results are described in Section 4. This paper concludes with Section 5. 2 Video Data ....

D. J. Gemmell, "Multimedia network file servers: Multi-channel delay sensitive data retrieval," in Proc. ACM Multimedia '93, pp. 243--250, ACM, Aug. 1993.

....policies for selective discard when loss is unavoidable. In Section 7 we conclude and discuss future work. 1. 1 Literature Review Work in the area of traffic management of prerecorded video falls into two classes: traffic management issues in the disk subsystem of the video server (e.g. see [7] [8] 19] 27] 28] and traffic management issues in the network. Although the ideas of this paper may be useful for disk subsystem design, our focus is on management of prerecorded VBR traffic in the network. The papers on the management of prerecorded VBR traffic in the network fall into three ....

D.J. Gemmell and J. Han. Multimedia network file servers: multichannel delay sensitive data retrieval. Multimedia Systems, 1:240--252, 1994.

....rates. For example, a Seagate ST31200W disk consists of 23 zones with bandwidths varying from 2.33 to 4.17 megabytes per second (MB s) see Table 1b. A number of studies have investigated techniques to support a hiccup free display of continuous media, video and audio, using magnetic disk drives [AH91, RVR92, RV93, VR93, CL93, TPBG93, RW94a, YCK93, Gem93]. These studies assume a fixed transfer rate for a disk drive. If a system designer elects to use one of these techniques, the system is forced to use the minimum transfer rate of the zones for the entire disk in order to guarantee a continuous display of video objects. We term these studies ....

D. J. Gemmell. Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval. In First ACM Conference on Multimedia, pages 243--250, August 1993.

....Our conclusion and future research directions are contained in Section 5. 2 Related Work The physical design of a storage manager that can support continuous media data types has also been investigated in several earlier studies, including [AH91, RVR92, RV93, VR93, CL93, TPBG93, RW94, YCK93, Gem93] All of these studies assume that the bandwidth required to display an object is lower than the bandwidth of a single disk drive. Several studies investigate either disk scheduling [RW94, TPBG93] or the placement of data across the surface of a disk drive [CL93, RV93] to enhance the performance ....

D. J. Gemmell. Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval. In First ACM Conference on Multimedia, pages 243--250, August 1993.

....could support the most real time streams because of its goal of seek optimization. When non real time requests were interspersed with real time requests, Scan EDF supports the most streams. CHAPTER 4. DESIGN OF THE VIDEO STORAGE SUBSYSTEM 26 Like Scan EDF, the Grouped Sweeping Scheme (GSS) Gem93, PY92] is a hybrid algorithm. This algorithm partitions each round into a number of groups. Each client is assigned to a certain group, and the groups are serviced in a fixed order in each round. For each group, the CScan algorithm is used. If all clients are assigned to the same group, the GSS ....

....As data is emptied out of a buffer during the beginning of a cycle, data can be read into that same buffer later in the cycle. The paper shows that the memory requirement for this scheme is half of the amount needed for the double buffer scheme, but incurs increased complexity. Mou96, LS93, Gem93, TPBG93, PY92] also discuss optimizations that reduce the amount of buffering by appropriately scheduling disk accesses. Because of the way the RETHER system is integrated with the I O subsystem, the SBVS adopts the simple double buffering algorithm. In addition, the maximum amount of physical ....

[Article contains additional citation context not shown here]

D. Gemmell. Multimedia network file servers: Multi-channel delay sensitive data retrieval. In Proceedings ACM Multimedia, page 243, Anaheim, CA, 1993.

....components: audio, video and text. It is the responsibility of the management system to ensure that these multiple streams can be synchronized during retrieval. Many excellent studies regarding the storage and retrieval of audio and video data have been conducted, such as those reported in [1, 2, 3, 4, 10, 11, 13, 14]. With respect to the topic area of this paper, these studies can be grouped into two major categories. The first group is primarily concerned with intelligent disk scheduling. Studies in this group include the sweeping scheme proposed by Chen, Kandlur and Yu [2] the sorting set al..gorithm ....

....to the topic area of this paper, these studies can be grouped into two major categories. The first group is primarily concerned with intelligent disk scheduling. Studies in this group include the sweeping scheme proposed by Chen, Kandlur and Yu [2] the sorting set al..gorithm developed by Gemmel [3], the SCAN EDF strategy designed by Reddy and Wyllie [11] and the hard real time approach analyzed by Tindell and Burns [13] The second group deals with constrained block allocation, which limits the distance between successive blocks of a multimedia stream. Studies in this group include the ....

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J. Gemmell. (1993) Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval, Proc. ACM-Multimedia, pp 243--250.

....may contain multiple components with very different playback rates, such as video, audio and text. The server must ensure that these multiple components be synchronized during playback. For performance reasons, multiple multimedia streams are usually serviced simultaneously in a cyclic fashion [5, 3, 8, 2, 6]. During each service cycle, data from each stream are retrieved from disk into the buffer for continuous playback. An admission control algorithm is used to ensure that, once a stream is admitted, there be enough data in the buffer for the continuous playbacks of all active streams. Due to ....

....criterion; and (3) increased retrievals of an active stream is more effective than prefetching in minimizing buffer consumption and thus maximizing the system throughput. There are many studies focused on the storage and retrieval aspects of video and audio data, such as those presented in [1, 8, 2, 3, 5, 6, 7]. These studies generally were concerned with intelligent disk scheduling, or data allocation and placement of multimedia data. The issues of utilizing spare disk bandwidth to improve system throughput was first considered by Ng and Yang [4] In [4] sharing buffer space among active streams and ....

[Article contains additional citation context not shown here]

J. Gemmell. Multimedia network file servers: Multi-channel delay sensitive data retrieval. In Proc. of ACM Multimedia, pages 243--250, 1993.

....seek delay, while on the other hand we would like to minimize the worst case bound on the times between two consecutive services to the same request stream. GSS tries to strike a balance between these two conflicting requirements. This concept is exploited in various VOD server designs and studies [7, 18]. Scheduling Issues in VOD 21 GSS divides the number of video streams n which will be served by a disk into g groups. In fact, g serves as a tuning parameter whose value will be used to optimize the buffer requirement. The assignment of streams to groups is arbitrary in the homogeneous video ....

Gemmell, D., "Multimedia Network File Servers: Multi-Channel Delay Senstitive Data Retrieval," Proc. ACM Multimedia 93, Anaheim, CA, Aug. 1993, pp. 243-250.

....of a stream must be known and reserved, there is a limit to the number of simultaneous users that can be supported by any continuous media system. Every previous system must provide a method of admission control that does not result in violation of continuity requirements. In particular, [3, 9, 15, 18] provide acceptance tests based on disk bandwidth and network bandwidth assuming the maximum possible data transmission rate at any point in the life of a stream connection. Their admission control is efficient because it can be done as a constant time calculation, but does not take advantage of ....

D. James Gemmell. Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval. In ACM Multimedia, pages 243--250, June 1993.

....blocks and consequently have very poor resolution. In other related work, issues such as admission control and selection of service size to support multimedia applications are addressed in [12, 15] Disk scheduling schemes for optimizing the throughput of the DASD storage system are considered in [7, 13, 4]. This paper is organized as follows. In Section 2, the storage method and the playout method for MPEG video are presented. The segment sampling and segment placement schemes are devised in Section 3 and Section 4, respectively. Some experimental results are described in Section 5. This paper ....

....the number z = nm lcm(n;m) 1 and the two formulas of h 1 (k; r) in algorithm S become the same. Hence, there is no shift required in this case. As an illustrative example, we have z = 73 lcm(7;3) 1. For r = 1 and k = 4, we get h 1 (4,1) 1 Gamma 1 [4] 1 ) lcm(7; 3) 4 7 [b 3 Gamma[7] 3 1 4 1 c] 3 = 4 72=18, as indicated in Table 3. Clearly, the fewer shifts, the better sampling an FF retrieval achieves. It can be proved that the number of shifts incurred by algorithm S is the minimum among all fast retrieval Disk No. 0 1 2 3 4 5 6 1st round 0 1 2 3 4 5 6 7 8 9 10 11 ....

D. J. Gemmell. Multimedia network file servers: Multi-channel delay sensitive data retrieval. In Proc. ACM Multimedia '93, pages 243--250. ACM, August 1993.

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D. Gemmell, 'Multimedia Network File Servers: Multi-Channel Delay Sensitive Data Retrieval", Proc. ACM Multimedia, 1993, p. 243.

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Gemmell, J. and Han, J. "Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval", Multimedia Systems 1(6):240-252, 1994.

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Gemmell, D.J., Han, J.: Multimedia Network File Servers: Multichannel Delay Sensitive Data Retrieval, Multimedia Systems, Vol. 1, No. 6, April 1994, pp. 240-252

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D. James Gemmell. Multimedia Network File Servers: Multi-channel Delay Sensitive Data Retrieval. In ACM Multimedia, pages 243--250, June 1993.

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