In IP-based CDMA systems, the two key problems need to be solved for soft handoff are data distribution and data content merging. A new scheme is introduced here, using a soft handoff distribute table maintained by th...
详细信息
ISBN:
(纸本)0863416446
In IP-based CDMA systems, the two key problems need to be solved for soft handoff are data distribution and data content merging. A new scheme is introduced here, using a soft handoff distribute table maintained by the access router. This makes it possible to distribute data accurately, retain multiple base stations (BSs) within an IP subnet, and let mobile station (MS) moves into one subnet without changing its IP address. Strict synchronization could be avoided by using different description of data and setting soft handoff mode bits. Therefore the MS receives the data accurately, and system capacity can be improved.
In this paper, we describe the Vannotea system - an application designed to enable collaborating groups to discuss and annotate collections of high quality images, video, audio or 3D objects. The system has been desig...
详细信息
Mobile phone besides being communication device is being transformed to another role as an entertainment device. Mobile devices enable the user to access entertainment such as TV anywhere and not limit it to just home...
详细信息
The increasing popularity of multimedia streaming applications introduces new challenges in content distribution networks. Streaming services such as Video on Demand (VoD) or digital television over the Internet (IPTV...
详细信息
ISBN:
(纸本)0769525946
The increasing popularity of multimedia streaming applications introduces new challenges in content distribution networks. Streaming services such as Video on Demand (VoD) or digital television over the Internet (IPTV) are very bandwidth-intensive and cannot tolerate the high delays and poor loss properties of today's Internet. To solve these problems, caching (a sliding segment of) popular streams at proxies could be envisaged. This paper presents a novel caching algorithm and architecture for time-shifted television (tsTV) and its implementation using the IETFs Real-Time Streaming Protocol (RTSP). The algorithm uses sliding caching windows with sizes depending on content popularity and/or distance metrics. The caches can work in stand-alone mode as well as in co-operative mode. This paper shows that the network load can already be reduced considerably using small diskless caches, especially when using cooperative caching. A brief overview of the functionality of a prototype proxy implementation is presented as well.
SIP-based multi-party conference service (MPCS) of IETF is adopted by 3GPP2 as conferencing solution. In MPCS, the service content received by multiple participants is the same. So, it is better to use multicast to su...
详细信息
ISBN:
(纸本)9780889866157
SIP-based multi-party conference service (MPCS) of IETF is adopted by 3GPP2 as conferencing solution. In MPCS, the service content received by multiple participants is the same. So, it is better to use multicast to support MPCS in 3G network, where air resources are limited. In 3GPP2, broadcast multicast service (BCMCS) is standardized allowing optimization of air resources for delivery of uniform content to multiple access terminals in CDMA2000 communication system. In this paper, a new solution is proposed, wherein service mapping is set up between BCMCS and MPCS in CDMA2000 network. By utilizing BCMCS, the radio and access network's resources of the CDMA systems could be saved for MPCS.
In this paper we study the problem of accessing video streams through handheld devices and wireless networks. We first review and discuss the major technologies of video transcoding. Then, we introduce a wireless vide...
详细信息
ISBN:
(纸本)0863416446
In this paper we study the problem of accessing video streams through handheld devices and wireless networks. We first review and discuss the major technologies of video transcoding. Then, we introduce a wireless video transcoding gateway system to handle the heterogeneous mobile devices and the smallness capability of the handheld devices. To gain higher video quality and lower complexity, we propose an efficient video transcoding structure based on close-loop model and a fast motion vector re-estimation algorithm. Based on this, we design a novel service scheme, which can provide better video contentaccess service on current mobile communication systems. Moreover, we implement a test prototype of MPEG2-to-H.264 transcoding system and simulate the video streams access service in a wireless LAN.
The proceedings contain 53 papers. The special focus in this conference is on Coding, Wireless networking, Representation and indexing, Authorization and security, Large real-time systems , content-based retrieval and...
ISBN:
(纸本)1891706195
The proceedings contain 53 papers. The special focus in this conference is on Coding, Wireless networking, Representation and indexing, Authorization and security, Large real-time systems , content-based retrieval and Media streaming. The topics include: H.264 fast encoder with adaptive interpolation based on motion detection algorithm;speed and area optimized implementation of H.264 8 X 8 DCT transform and quantizer;a new approach to watermark MPEG-2 videos;design and implementation issues for the mobfish;an evaluation of two policies for placement of continuous media in multi-hop wireless networks;a meta-index to integrate specific indexes;multiple spatial objects insertion in r-trees;multimedia streaming over IP with QoS and access control;SVD-based tamper proofing of multi-attribute motion data;an extra layer of security for unauthorized traffic based web services;a framework for pre-rendered virtual worlds navigation through motion tracking based interface;multimediaconference system supporting group awareness and remote management;log-analysis based characterization of multimedia documents for effective delivery of distributed multimedia presentations;a teleconference system by high definition omni-directional video transmission over IP network;robust and redundant disaster information system over Japan gigabit network;semantic categorization of images for the intuitive image retrieval;component based face recognition against occlusions;distributed storage and retrieval of document images.
Currently, information is very important to Internet users. Unfortunately, searching for specific information from the Internet is not easy as wishes. The existing search engine mechanisms cannot be performed using a ...
详细信息
ISBN:
(纸本)0819464899
Currently, information is very important to Internet users. Unfortunately, searching for specific information from the Internet is not easy as wishes. The existing search engine mechanisms cannot be performed using a pathname of URL as a search key. Therefore, users who have a partial pathname of URL cannot use their knowledge to narrow down the search results. Thus, users have to spend a long time searching for the required web site from the result list. This paper proposes a search protocol named Information Searching Protocol (ISP) that suppors the multiple search contents for users who know a partial pathname of URL and keywords. Moreover, the architecture of the Global Search Engine System (GSES) that cooperates with the ISP and is responsible for the search mechanism is also proposed. The GSES consists of two separated parts: an Internet Search Protocol agent at the client site, and GSES components at the server site. These components allow users to perform the search using a pathname of URL, composing with keywords. The functions of GSES components indicate that the ISP enhances the search mechanism. So, users receive more specific URL and can, shortly, get access to the required site.
Multi-hop wireless networks facilitate applications in metropolitan area broadband, home multimedia, surveillance and industrial control networks. Many of these applications require high end-to-end throughput and/or b...
详细信息
ISBN:
(纸本)9781424404247
Multi-hop wireless networks facilitate applications in metropolitan area broadband, home multimedia, surveillance and industrial control networks. Many of these applications require high end-to-end throughput and/or bounded delay. Random access link-layer protocols such as Carrier Sense Multiple access (CSMA) which are widely used in single-hop networks perform poorly in the multi-hop regime and provide no end-to-end QoS guarantees. The primary causes for their poor performance are uncoordinated interference and unfairness in exclusive access of the shared wireless medium. Furthermore, random access schemes do not leverage spatial reuse effectively and require routes to be linkaware. In this paper, we propose and study MAX, a time-division-multiplexed resource allocation framework for multi-hop networks with regular topologies. MAX tiling delivers optimal end-to-end throughput across arbitrarily large regularly structured networks while providing bounded delay. It outperforms CSMA-based random access protocols by a factor of 5 to 8. The MAX. approach also supports network services including flexible uplink and downlink bandwidth management, deterministic route admission control, and optimal gateway placement. MAX has been implemented on IEEE 802.15.3 embedded nodes and a test-bed of 50 nodes has been deployed both indoors and outdoors.
An emerging challenge to the realization of ubiquitous, mobile telecommunications is not ostensibly based on any underlying transport or network protocol but on the sheer complexity of technology presented to the user...
详细信息
ISBN:
(纸本)9780780397910
An emerging challenge to the realization of ubiquitous, mobile telecommunications is not ostensibly based on any underlying transport or network protocol but on the sheer complexity of technology presented to the user. Common scenarios of future mobile telecommunications often involve multiple devices with varied characteristics and rich and diverse multimedia applications delivered over heterogeneous wireless environments. Most users, however, cannot be expected to appreciate these technologies or participate in its configuration. To address this issue, a user-centric system is proposed that aims to hide complexity from the user. Incorporating concepts of the Personal Distributed Environment [1], the proposed system uses a Personal Assistant Agent to interact with, and react to, the environment and a Personal content Manager to be aware of content types, device capabilities and manage a user's digital content on behalf of the user.
暂无评论