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Integration of Multimedia and Satellite Communication Technologies for Teaching and Learning

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Integration of Multimedia and

Satellite Communication Technologies for Teaching and Learning

Li-Pin Liu

Department of Information Management, I-Shou University Kaohsiung, 84008, Taiwan, ROC

E-mail: lipin@acm.org

Leroy J. Tuscher

College of Education, Lehigh University Iacocca Hall, 111 Research Dr. Bethlehem, PA 18015

E-mail: ljt1@lehigh.edu

Woei Hung

College of Education, Lehigh University Iacocca Hall, 111 Research Dr. Bethlehem, PA 18015

E-mail: woh2@lehigh.edu

Abstract

This paper presents a study on integration of both multimedia and satellite communication technologies for teaching and learning. We design an experiment with use of these technologies on the Internet and WWW to provide a hybrid information delivery system for teaching and learning. The experiment,

one of Pennsylvania Link-to-Learn

technology testbed project, is to design, develop, implement, and evaluate a hybrid information delivery system that integrates the broadband capabilities of direct broadcast satellite (DBS) and the peer to peer attributes of Internet technologies using satellites. The hybrid system was designed to integrate networked, broadcast, digital, interactive and multimedia technologies for delivery of media rich content to targeted users. With the use of large screen multimedia PC/TV convergent systems, multimedia-based teaching materials can be comfortably viewed by all students in the classroom and can be easily manipulated by the teacher via wireless controls. This research demonstrated the use of these technologies in selected K-12 classrooms and community agencies in the Lehigh Valley of eastern Pennsylvania, USA.

Keyword: Multimedia, Satellite

Communication, DBS, DirecPC, DirecTV, K-12 education, PC/TV convergent systems.

1. Introduction

The purpose of this testbed project was to design, develop, implement, and evaluate a hybrid information delivery system that integrates the broadband capabilities of direct broadcast satellite (DBS) and the peer to peer attributes of narrow bandwidth Internet technologies. The hybrid system was designed to integrate networked, broadcast, digital, interactive and multimedia technologies for delivery of media rich content to targeted users. By means of large screen multimedia PC/TV convergent systems, multimedia-based teaching materials can be comfortably viewed by all students in the classroom and can be easily manipulated by the teacher via wireless controls.

This project demonstrated the use of these technologies in selected K-12 classrooms and community agencies in the Lehigh Valley of eastern Pennsylvania.[1] For example, curriculum-based video clips on Coral Reefs off the coast of Florida and Jason Explorations were either digitized / archived on a video server or broadcast via DBS

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satellite transponder to stand-alone learner workstations. That is, digital resource materials could be received on demand or on a scheduled basis from the Hughes satellite transponder via the Internet browser and a 24-inch satellite dish wired to a desktop computer in a classroom.

2. Rationale for Project

The goals of the this project were: to assimilate, deploy, and evaluate a hybrid Internet and Direct Broadcast Satellite (DBS) system linking digital content with targeted K-12 schools in the region with advanced digital

telecommunications, computing, and

information technologies for the purpose of creating and delivering enhanced interactive broadband learning media; to create networkable interactive digital multimedia learning materials to be deployed through a regional digital library. And to foster innovation and experimentation in the design, development, and deployment of digital learning materials utilizing delivery systems capable of accommodating different learning styles based on either learner-controlled

and/or teacher-controlled learning

environments.

3. Objectives

The objectives of this testbed project were to

create and evaluate the following

infrastructures for the creation and distribution of digital media learning resources:

(1) A single stand-alone DirecPC workstation with access to both the Internet and Direct Broadcast Satellite transmission of media resources (Test Sites: Bethlehem, Parkland, Centennial, Hispanic American Organization, WLTV Channel 39, Service Electric Cable Company, and Lehigh University),

(2) A DirecPC workstation with access to Direct Broadcast Satellite transmission of media resources for distribution on a LAN (Test Site: Schnecksville Elementary School, Parkland School District),

(3) Satellite digital video media (MPEG-I) transmitted from the Direct Broadcast Satellite and redistributed to project partners. (4) A single stand-alone DirecPC workstation with a portable receive dish that can be repositioned as the Educational Space Shuttle travels to diverse and remote locations to redistribute media resources received from the Direct Broadcast Satellite, and

(5) Create curriculum-based digital media resources for archival to and distribution from a Regional Digital Distribution Center at Lehigh University.

The content delivered in these test environments were the Video feed and Internet resources created for the JASON IX: Oceans of Earth and Beyond expedition, the CNN video feed from the Hughes transponder, and digital media content, Coral Reefs, created as a result of objective (5) above.

4. Technical Description The computing and telecommunications industry has drawn considerable attention with the emergence of two different but complementary technologies. The Internet has captured the imagination of the educational establishment, corporate America, and the individual consumer. More recently Direct Broadcast Satellite (DBS) systems have gained some prominence by offering high-speed data transmission (DirecPC) and broadcast quality television (DirecTV) to corporate America and into the home. The Internet has been characterized by a narrow bandwidth technology in most cases

inadequate for serious interactive multimedia interchanges; impregnated with HTML formatted content; governed by a set of standard protocols (TCP/IP and HTTP); and generally perceived to have limitations of speed and service to remote areas by conventional means. Direct Broadcast Satellite on the other hand offers Internet access at speeds exceeding ISDN connections by a factor of 3 and at considerably less cost. DirectPC is a system with satellite down-link and a modem back-channel. Based on the study in[10] , DirectPC is one of the fast-Internet technology.

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Direct Broadcast Satellite technology can deliver video on demand and high-speed connection to the Internet today. They provide five different services/bandwidths to transmit information based on the users’ needs.[2][3[5][7]

1) Turbo Internet Service – based on TCP/IP protocols. Users can get 400Kbps average bandwidth from the total 24Mbps bandwidth.

2) Multimedia Service – provides 1.5Mbps bandwidth for MPEG-1 or AVI video broadcast or real-time media streams. 3) Package Delivery Service – can deliver file

packages to users at 3Mbps speed.

4) File Broadcast – can transfer files to unlimited number of users using push technology at speed of 3Mbps.

5) Package Explorer – Users can download information package at the speed of 3Mbps. The overall architecture of data transmission using DirecPC and PC/TV systems is illustrated at figure 5.

Direct broadcast to a host server and distributed via high-speed ATM networks on LANs and Intranets have been demonstrated to be an effective means for delivering interactive learning materials to the desktop. Unlike the point to point connectivity model of the Internet, the digital broadcast medium has demonstrated its ability to be used in real-time or in download mode to broadcast, multicast, and pointcast a set of educational materials and content on a pre-arranged schedule or on demand. Methodologies to capitalize on the broadcast medium also include the use of cable. Broadcasting can fully complement access to the Internet or can be deployed stand-alone, that is, without a terrestrial network. Direct Broadcast Satellite and cable networks have demonstrated their capacity to enable broadcast applications and services. In addition, standard developments such as Digital VideoBroadcast (DVB) and recent deployment of DBS systems such as DirecTV and DirecPC have created ready access to the technology and the services and applications of broadcasting to the classroom. Previously unrealized video on-demand, interactive television models and interactive

multimedia applications have been replaced by the realities of the emergence of the massive deployment of DBS and the Internet. As a result access to DBS and the Internet can offer a competitive alternative or complementary adjunct to terrestrial network systems for delivery of the same services.

5. DBS/Internet/LAN Infrastructure The DBS solutions are ideal for massive distribution of educational content organized for delivery to a single point client device or a Video Server for subsequent dissemination. The broadcast delivery mode enables the universal deployment of broadcast, multicast, and pointcast media. This therefore makes it suitable for :

 uniform content delivery to all schools and homes in a geographic region.  targeted content delivery to a subset of

very disperse schools, or

 targeted content delivery to only one target school in a remote region.

This implies that in addition to providing access to all forms of content anywhere, the same deployment over DBS can be configured to provide multilingual capabilities via audio tracks, multimedia tracks, or different text tracks. The Model exploits extensively the educational potential of standard formatted MPEG content, because of the rich set of educational content that can be packed in short clips of multisensory media and its applicability for transmission via Direct Broadcast Satellite.

6. Value as a Testbed

Direct Broadcast Satellite technologies conform to standard data transmission protocols that are compatible with most telephone, cable, and computer network systems. Consequently, the DBS technologies can be combined with any of the standard network systems to form regional hybrid network configurations compatible with a statewide telecommunications system as envisioned for the Commonwealth PEN network system.[9] DBS technologies are

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both competitive and complementary to terrestrial-based delivery systems. The DBS system offers the prospect of broad bandwidth distribution of curriculum-based media resources at an affordable cost to school districts. Indeed, DBS technologies provide the enabling technologies for video on demand or on a scheduled basis from regional, national, or international databases of mediated curriculum. In addition, DBS technologies promote the development of shareable curriculum-based media resources archived in digital libraries.

7. Partners

Partners collaborating on this project include the Bethlehem Area School District, the Parkland School District, the Centennial School, the Diocese of Allentown, the Hispanic American Organization, the area public broadcasting station (WLVT Channel 39), Service Electric Cable Company, and the Interactive Digital Multimedia Research and Development Laboratory at Lehigh University. Major corporations participating in this project on a contractual or service basis are Hughes Technical Operations Company and Service Electric Cable Company.

The immediate beneficiaries of this project are selected middle school age children in the Parkland School District, high school students in the Bethlehem Area School District, elementary school age children at Holy Child Elementary School, the severely emotional disturbed learners attending Centennial School, and the learner constituents served by the Hispanic American Organization of the Lehigh Valley. While elementary, middle, and high school age children are the primary beneficiaries of this test project, the benefits of these technologies can be extended to any individual or group of individuals in either a formal or informal setting depending only on the nature of the content to be delivered and access to Direct Broadcast Satellite and the Internet, and in some cases access to high speed ATM fiber networks.

8. Evaluation and Measurement

The outcomes and benefits projected for this project were measured against the following criteria: (1) system reliability, (2) information transfer rate, (3) ability to rapidly scale and deploy systems, (4) the quality of transmitted resources, (5) compatibility with existing terrestrial networks, (6) the competitive and complementary nature of the DirecPC system; (7) user acceptability; (8) efficacy of procedures for creating curriculum-based media resources for archival to and distribution from digital libraries, and (9) adaptability to other communities. Instrumentation for assessing the project outcomes was developed to evaluate the project relative to the criteria listed above. (1) System reliability

The project personnel experienced problems with the initial setup of the Compaq Theatre, primarily with the 36 inch monitor (two of four had to be replaced) and problems with the TV tuner card for the Gateway System. On May 19th, 1998, the Galaxy IV satellite disappeared from its orbit and could not be contacted. Subsequently, the DirecPC dishes had to be repositioned to point to a new satellite, GE I. The new satellite required an update in DirecPC software and the implantation of a new PCI card. The new PCI card created hardware conflicts with both the sound card and the video card on both the Gateway and Compaq systems. These problems were resolved by the project technician. The type of hardware and software problems encountered are not the type one would typically expect the classroom teacher to fix nor for that matter many computer technicians.

One must understand however, the convergent systems were basically new technologies. It should also be noted that on the other hand, there is some questions whether Compaq will continue production of the PC Theatre and Gateway has enhanced their Destination System improving both the quality and size of their monitor with an improved computer box design having the analog and digital connections on the front panel of the computer rather than on the rear of the computer.

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(2) Information transfer rate

Multiple readings on different media applications were taken at three different times during the day: morning, noon, and early afternoon. See the matrix chart of times, file formats, encoded bandwidth rates, and download speeds. Use comparison charts: 56, 300, 500 kps.

(3) Ability to rapidly scale and deploy systems

The DirecPC is a wireless technology with MPEG-I and Internet distribution capability to anywhere in the United States and into parts of Canada and South America. Large scale projects utilizing the small dish technology have been or are being established in the rural communities of California and Nevada. (4) The quality of transmitted resources Direct broadcast of MPEG-I encoded video to client station via DBS produced VHS quality video, 30 frames/sec in screen size 320 x 240 pixels. The best quality transmission of RealVideo encoded video was done at 300 kps.

(5) Compatibility with existing terrestrial networks

The DirecPC convergent system is compatible with and requires connection to a terrestrial Internet distribution carrier to request information to be down streamed to the DirecPC dish for individual consumption, LAN distribution, or WAN real-time terrestrial distribution systems.

(6) The competitive and complementary nature of the DirecPC system

The DirecPC is competitive with terrestrial ISP providers on several accounts: First the DirecPC can be quickly deployed to geographically dispersed or remote users without an expansive infrastructure. And secondly, the dollar/speed trade-off is favorable for the DirecPC distribution system. New vendors such Skystream Inc. and others are beginning to offer satellite services. (7) User acceptability

Users' responses to a likert type attitude scale revealed a positive predisposition toward system as well as quality of content delivered. (8) Efficacy of media-based Instructional Applications?

The Coral Reefs application was developed for distribution on the Internet via DirecPC. The DirecPC system permits faster access to digital resources than either 28.8kps, 56kps, or ISDN distribution system. See comparison charts. Hughes had recently joined forces with Apollo Group to provide multimedia instructional resources for schools.

(9) Adaptability to other communities During the past 18 months DirecPC system have been widely adopted by schools in remote areas of Canada, California, and Nevada.

9. Experimental Results

In this section, we present two experimental results obtaining during the project.: 1) transmission performance results for combinations of different media contents, time and transmission bandwidth, and 2) convergent technology survey results for the use of PC/TV convergent systems in the classroom.

The best transmission rate obtained from the testing is encoded in 300kps, 15 fps using RealVideo. Although Windows Media format files transmission rate was between 62 to 91 kps, the actual performance was not as expected as the transmission rate shown, and it was not reliable as Realvideo.

Generally, 4:00pm is the lowest transmission rate for most of formats of files. This result is corresponding to the usual Internet traffic load. DirecPC transmission speed testing results are listed in Figure 1.

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Time Format bandwidth 10/14/98 10/15/98 10/19/98 10/20/98 11/02/98 11/10/98 11/11/98 Average 56k 47.9kps 46.5kps 45.8kps 46.5kps 47.7kps 45.6kps 46kps 46.57kps 300k 286.8kps 277kps 283.7kps 261kps 317.7kps 292.8kps 317.8kps 290.97kps Real Video 500k 227.5kps 239kps 238.9kps 223.8kps 236.7kps 238.9kps 206.5kps 230.11kps Download 56.7kps 48k 46.8kps 43.4kps 45.3kps 46.4kps 20.1kps 43.81kps Quick Time Streaming 32.7kps 36.1kps 53.6kps 24.7kps 37.5kps 32.7kps 54.3kps 38.8kps 11:00 AM Windows Media High bandwidth 54.8kps 90.2kps 51.8kps 42.3kps 55.1kps 50.5kps 102kps 63.81kps 56k 45.5kps 45.8kps 45.7kps 45kps 33kps 47kps 45.6kps 43.94kps 300k 295.2kps 307.6kps 312.9kps 298kps 313kps 275kps 318kps 302.81kps Real Video 500k 256.4kps 155.2kps 208.7kps 239kps 228kps 237kps 208kps 218.9kps Download 45.4kps 54.4kps 53.6kps 31kps 30.1kps 53.7kps 33.4kps 43.09kps Quick Time Streaming 32.2kps 71.2kps 45.3kps 23kps 13.8kps 31.2kps 31.2kps 35.41kps 1:00 PM Windows Media High bandwidth 36kps 78.9kps 103kps 86.7kps 42.1kps 57.5kps 132.9kps 76.73kps 56k 45.8kps 44.6kps 45kps 48kps 45kps 45.7kps 41.7kps 45.11kps 300k 265.5kps 214.3kps 276kps 284.2kps 217.8kps 309.6kps 318kps 269.34kps Real Video 500k 236.7kps 229.6kps 239kps 236.7kps 234.4kps 238.9kps 236.9kps 236.3kps Download 14.2kps 40.8kps 39.5kps 48.7kps 51.2kps 46.7kps 45.1kps 40.89kps Quick Time Streaming 2.3kps 10.2kps 32.2kps 69.3kps 23.4kps 20.5kps 64.7kps 31.8kps 4:00 PM Windows Media High bandwidth 108.5kps 44.8kps 84.9kps 45.5kps 50.3kps 54.1kps 51.7kps 62.83kps Figure 1. DirecPC transmission speed testing results.

The convergent technology survey for Lehigh Link to Learn project has ten criteria listed as below:

1) The large screen monitor was an effective display for group instruction.

2) The speed of Internet access via DirecPC satellite was satisfactory.

3) I could recommend the DirecPC and convergent technology to other teachers. 4) The use of the convergent technology

system enhanced my instructional

environment.

5) I didn’t have time to learn how to use the convergent technology effectively.

6) Using the convergent technology helps me feel like a competent professional.

7) Advanced technical equipment is difficult for me to deal with.

8) I would like to share with others my experience with the convergent technology. 9) It’s difficult to keep-up with technology change.

10) Convergent computer technology will dramatically change how schools educate children. Strongly agree = SA (5) Agree = A (4) Undecided = U (3) Disagree = D (2) Strongly Disagree = SD (1) Criteria Result 1) 4.75 2) 4.5 3) 4.75 4) 5 5) 1.75 6) 4.75 7) 1.25 8) 5 9) 4.25 10) 4.5

Figure 2. Convergent technology survey results.

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Figure 3. Lehigh Link-to-Learn Project Website.

Figure 4. Coral Reefs curriculum.

Figure 5. Overall architecture of data transmission using DirecPC and PC/TV systems.

10. Conclusion

We found that users can deal with the new convergent systems and satisfy with satellite transmission from the results of the convergent technology survey.[8] They would like to recommend these systems with

hybrid satellite communication and

multimedia PC/TV convergent technologies for use in teaching and learning.

Clearly, knowledge generation and learning now centralized and institutionalized will become distributed and individually paced. The combination of interactive television and the transition from a philosophy of mass communication to custom communication systems will increase both the level of user control and the complexity of design for distributed information and learning systems. It seems quite clear however, that these new systems are doomed to failure unless the learner is provided with some form of embedded help to acquire the prescribed domain knowledge. Hence the need to create new hybrid models for designing and delivering interactive mediated curricula. The benefits of this testbed project included

the identification of affordable

communication structures that complement or extend extant infrastructures and add value to the educational process through the shared development and use of educational digital media resources.

11. References

[1] Lehigh Link2Learn Team, Integration of Narrow bandwidth (Internet) and Broadband (TV) Satellite Technologies for Teaching and Learning, WWW, URL::

http://home.mml.lehigh.edu/link2learn/ [2] Hughes Network Systems, DirecPC

Home Page, WWW, URL::

http://www.direcpc.com/, October 1996. [3] AsiaCast Network Systems, AsiaCast

DirecPC Home Page, WWW, URL::

http://www.asiacast.com.tw

[4] Daniel Glover, Satellite Communications

Network, NASA Communications

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URL::

http://sulu.lerc.nasa.gov/dglover/network. html

[5] Uyless Black, Emerging

Communications Technologies, 2nd ed., Prentice Hall PTR, 1998.

[6] Ruel T. Hernandez, Ruel's PC-TV Net

Page, WWW, URL::

http://www.ruel.net/pctv.html

[7] John Montgomery, The orbiting Internet -- Fiber in the Sky. Byte, p.58--72, November, 1997

[8] Lehigh Link2Learn Team, Convergent technology survey results, WWW, URL:: http://home.mml.lehigh.edu/link2learn/co nvergence/evaluation/index.html

[9] Link-to-Learn organization,

Link-to-Learn Project, WWW, URL::

http://L2L.org/

[10] Modeling the performance of HTTP over several transport protocols, IEEE/ACM Transactions on Networking, Vol. 5, No. 5, pp.616-630, Oct. 1997.

數據

Figure  2.  Convergent  technology  survey  results.
Figure 3. Lehigh Link-to-Learn Project  Website.

參考文獻

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