Interactive RTP services with predictable reliability

As the enabling technologies for broadband services become mature and affordable, new multimedia applications are emerging and being implemented by computing and telecommunication vendors. A particularly attractive one in this fast growing area is interactive video services which are being trialed and developed by a number of product and service providers. A number of technical challenges have to be resolved however before the service can be viable. In this paper, we report some results of our recent studies in three specific areas regarding the design of large-scale interactive consumer video services: server design issues, transport and distribution network design issues, and signaling and interactive response issues. We focus on techniques for building a scalable and reliable media delivery system capable of providing flexible, interactive access to multimedia content for a large number of users.

There exists a tremendous growth in photonic materials and device research as a result of both the explosion in telecommunications as well as the expected traffic requirements needed for interactive video and multimedia services.

Interactive video services for consumers, delivered to residences via broadband networks and standard TV's, could be offered over the next several years. Such services include movie on demand, video telephony, interactive television, home shopping, computer games, etc. Economics dictate that a common infrastructure be deployed that can support all the services envisioned today, with future expandability. This paper presents a comprehensive large-scale end-to-end services platform architecture meeting these requirements and describes the field trials of this system scheduled to begin in 1994.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

With the advance of multimedia and network technology, it is possible to integrate telecommunication, broadcasting, and information processing services as a new interactive multimedia service. However, the current service has problems of incompatibilities between service systems and proprietary standard based services. To solve these problems, DAVIC (Digital Audio-Visual Council) is establishing standardization of interactive multimedia services. We have designed and implemented an interactive multimedia service system based on the DAVIC specification. In this paper, we describe the overall system architecture of our approach and implementation results.

The main purpose of this study is to examine the factors that influence the adoption of interactive cable television services in Taiwan. The literature review identifies 5 factors-innovation attributes, technology ownership, innovativeness, demographics, and mass media use-as having significant effects on the adoption of interactive cable television services. A telephone survey with 1,012 valid interviews was used to collect data for this study. The data analysis shows that age, personal income, relative advantage, relative disadvantage, ownership of interpersonal technologies, innovativeness, and newspaper reading were significantly related to the adoption of interactive cable television services.

Since the inception of IEEE 802.11 wireless local area networks (WLANs) in 1997, wireless networking technologies have tremendously grown in the last few decades. The fundamental IEEE 802.11 physical (PHY) and medium access control (MAC) protocols have continuously been enriched with new technologies to provide the last mile wireless broadband connectivity to end users. Consequently, several new amendments of the basic IEEE 802.11 gradually came up in the forms of IEEE 802.11a, IEEE 802.11b, and IEEE 802.11g. More recently, IEEE 802.11n, IEEE 802.11ac, and IEEE 802.11ad are introduced with enhanced PHY and MAC layers that boost up physical data rates to the order of Gigabit per second. So, these amendments are generally known as high throughput WLANs (HT-WLANs). In HT-WLANs, PHY layer is enhanced with multiple-input multiple-output antenna technologies, channel bonding, short guard intervals, enhanced modulation and coding schemes. The MAC sublayer overhead is reduced by introducing frame aggregation and block acknowledgement technologies. However, several existing studies reveal that, many a time, the aforesaid PHY and MAC enhancements yield negative impact on various upper layer protocols, that is end-to-end transport and application layer protocols. As a consequence, a large number of researchers have focused on improving the coordination among PHY/MAC and upper layer protocols. In this survey, we discuss impact of HT-WLAN PHY and MAC layer enhancements on various transport and application layer protocols. This paper also summarizes several research works that use aforesaid enhancements effectively to boost up data rate of end-to-end protocols. We also point out limitations of the existing researches and list down different open challenges that can be meaningfully explored for the development of the next generation HT-WLAN technologies.

On 29 February 2000 the Independent Television Commission (ITC) published its long-awaited consultation paper on the regulation of interactive television services. Following discussions with broadcasters and various interested parties, the ITC has set out its flexible approach to the emerging new services. Rather than increasing the regulation of interactive services, it is proposing a more streamlined approach which will operate within the existing ITC regulatory framework. Responses are being sought to the consultation paper and a further report is scheduled to be published by the end of the summer.

The objective of the MEMO project is to design, integrate and operate applications which utilise interactive DAB services, i.e. combining the existing GSM mobile telecommunications network and the Digital Audio Broadcasting system. A first trial with this platform for mobile multimedia services was performed to demonstrate the results achieved after one year of work and cooperation of the European partners involved. The MEMO architecture comprises DAB transmitter equipment and PC-based terminals. During the specification of the first generation prototype and the software/hardware development the following results were achieved: Infrastructure and transmitter equipment (Specification and implementation of a protocol for information interchange between contents providers and the DAB network; design and implementation of the multi-network server (MNS) with an interface to the DAB-network-server (DNS) to feed the DAB transmitter; set-up of a DAB test transmitter at CCETT, Rennes; specification of a protocol for broadcasting Multimedia data on DAB) and Terminal (development of prototype DAB receivers with a data interface and PC plug-in card, notebook PCs and interface equipment to connect the PCs to the DAB receiver for data transfer at data rates up to 256 kbit/s; implementation of the GSM interaction channel between the mobile terminal and the MNS; definition and partial implementation of Application Programming Interfaces (APIs); development of terminal software for the network/system/application service layer and adaptation of publishing and construction industry applications to demonstrate mobile, interactive services). For the trial, the transmission chain from GSM request to DAB download was successfully completed and operated, including the connection between information provider and network operator. Three interactive applications were implemented and tested — a specialised software for the building construction industry, a system to download issues of a newspaper and a general software to transmit data objects — representing the contrary edges of services MEMO is targeting. Thus, the approach of interactive mobile services at high data rates was presented for the first time to potential customers and users providing valuable results.

Web Real-Time Communication (WebRTC) introduces real-time multimedia communication as native capabilities of Web browsers. With the adoption of WebRTC the Web browsers will be able to use WebRTC to communicate with one another (peer-to-peer), and with WebSocket servers such as Mobicents SIP Servlets and other server technologies that support WebSocket communication to enable SIP-to-WebRTC communication. This paper outlines the potential of WebRTC and discusses the two common methods of doing real-time communication in Web browsers through WebRTC. The methods are JavaScript Object Notation (JSON) via XMLHttpRequest (XHR) and Session Initiation Protocol (SIP) via WebSocket. A three-user WebRTC video chat prototype application was developed and used to evaluate both methods. Additional signalling overhead introduced into a browser by each method was determined. The results showed WebRTC-SIP/WS has more overhead than WebRTC-JSON/XHR. These signalling overhead findings are useful in that they could help application developers make decision on their choice of technologies and protocols when developing WebRTC-supported applications.

Users worldwide are spending more and more of their time on smart device platforms providing ubiquitous multimedia experience. Smart phones, tablets, e-Readers, web enabled television sets and other device platforms are all participating in this revolution. From the point of view of human-system interaction, however, such platforms pose distinct research problems. A consumer engaged in playing fantasy football has different interaction needs to one researching an address on a cell phone. Today, the vast majority of publishers simply do not have the ability to provide both the scale and quality of rich content to offer a usage experience targeted for multiple platforms. This special issue of MTAP devoted to Intelligent Interactive Multimedia Systems and Services” is aimed at providing an overview of recent research results in this hot area, highlighting interdisciplinary aspects as well as the links between basic multimedia techniques and smart device applications. We believe that all papers featured in this special issue, while providing outstanding research contributions, succeeded in remaining clear and understandable enough to have a string appeal for nonspecialists wishing to understand the state of the art in this field. Some papers, like the one by Othmani et al. (DOI 10.1007/s11042-010-0697-6) “A novel approach for high dimension 3D object representation using Multi-Mother Wavelet Network” deal with basic research results in the representation and processing of multimedia objects. Other papers cover advanced human-system interaction; for instance, the paper by Sakurai et al. “A retrieval method adaptively reducing user’s subjective impression gap (DOI 10.1007/s11042-010-0690-0) deals with improving the user’s perception of retrieval Multimed Tools Appl (2012) 59:1–5 DOI 10.1007/s11042-012-1076-2

The objective of the ACTS project MEMO (Multimedia Environment for Mobiles) is to develop, implement and demonstrate a communication system which brings interactive Multimedia services to fully mobile users. This is realised by combining the high-speed broadcasting facilities of DAB with a bi-directional telecommunications network like GSM. On the platform of these two European success stories three categories of services can be offered: Broadcast, Interactive Broadcast and Personal Services. Based on experience gained from first successful trials in 1996 with this platform for mobile Multimedia services a second generation equipment has been implemented using newest developments on DAB-Receivers. This paper reports on the basic principles of MEMO, the implementation of the second generation equipment, as well as on trial design and example services.KeywordsMobile UserMultimedia ServicePersonal ServiceGeneration EquipmentMultimedia BroadcastThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Two distinct error and flow control schemes may be simultaneously involved in wireless Internet networks. One is an end-to-end transport protocol, TCP, which provides reliable packet delivery with flow and congestion control, and the other is a radio link ARQ protocol which provides radio link layer frame error recovery. In this paper, we investigate interactions between these two separate error control mechanisms by simulating TCP Reno over IS-707, a radio link ARQ protocol standard for spread spectrum digital cellular systems. We show the effects of TCP sliding window size to the overall system performance under a variety of radio link scenarios, and present the beneficial effects of longer persistence in radio link frame error recovery for best-effort bulk data applications.

Since retransmission-based error control for real-time communication will be feasible in the future high speed network environment, we have proposed R/sup 3/TP (retransmission based reliable real-time data transfer protocol). R/sup 3/TP is a transport layer protocol which provides high quality real-time data transfer by adopting ATM block transfer (ABT) and retransmission-based error control. A fast and accurate packet loss detection scheme is indispensable for retransmission based error control in real-time communication. A novel packet loss detection scheme for R/sup 3/TP and its evaluation results in comparison with other loss detection schemes are described.

New interactive multimedia services have increased the urgent requirement for more bandwidth and turn broadband wireless technology as one of the most competitive solutions for the last mile problem. This paper presents an adaptive transport protocol design and evaluation for a multicarrier point-to-multipoint outdoor broadband wireless access system, in the 5.8 GHz and 10.5 GHz frequency bands. With minimal overhead, the protocol is able to support multiple terminals and services that range from video broadcasting to full symmetric traffic. Moreover, adaptive modulation and coding schemes can be applied per terminal per time frame, in either the downlink or the uplink direction. In the proposed system various innovative techniques are used for efficient utilization of the available bandwidth. Finally, the protocol gain is evaluated.

Service access procedure (SAP) for a transport layer protocol