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A radio-frequency and baseband beamforming scheme is presented for spatial division multiple access (SDMA) of 60 GHz applications using planar antenna arrays (PAA). PAA with phase shifters for each element antenna is partitioned into sub-blocks and each block or multiple blocks are applied to a user in the SDMA system. According to the analysis for the signal to interference plus noise ratios (SINRs)...
This paper presents a framework for the error concealment of multimedia signals transmitted over wireless and IP networks. This framework is based on two elements. First, the replacements for the erroneous channel outputs are obtained from a minimum mean square error (MMSE) estimation which takes into account both the source and all the available information from the transmission channel. Then, hidden...
Increasing demand for high-speed and efficient multimedia transmission over wireless networks has driven tremendous research on enhancing the performance of multimedia communications over noisy channels. Multimedia applications increasingly require efficient transmission of still and moving images over wireless channels. In response to the rapidly increasing demand of the data-rate requirements, of...
In this paper, a concept of a network-driven adaptive video streaming is proposed and investigated in a state-of-the art UMTS/HSDPA network in order to alleviate the impact of strongly time-varying quality of wireless links on video quality. We propose making adaptation decisions in a radio access network based on channel-quality information available there. This is done by a so-called Multimedia...
As currently specified by 3GPP, MBMS (multimedia broadcast multicast service) content can be provided in a cell by either point-to-point (P-t-P) or point-to-multipoint (P-t-M) transmission mode, but not both at the same time. In earlier work we highlighted the deficiencies of the current approach and proposed the concept of the ldquodual transmission mode cellrdquo, in which P-t-P (DCH) and P-t-M...
Handover Control is one of the essential means to guarantee the continuity of mobile services to a user traveling in a cellular infrastructure, without interruption. In previous work we illustrated that using the current 3GPP specified handover control algorithm to provide continuity of MBMS (Multimedia Broadcast Multicast Service) services to a user crossing cell boundaries results either in capacity...
This paper presents a novel coopetition paradigm based on bargaining theory for collaborative multimedia resource management. The paradigm consists of a judicious mixture of competition and cooperation. For competition, the well-known Kalai-Smorodinsky bargaining solution (KSBS) is adopted as the fairness criteria, and for cooperation each user stops competing for resources as long as it achieves...
This paper estimates quality of experience (QoE), i.e., user-level QoS from MAC-level QoS for audio-video transmission over an IEEE 802.11e EDCA wireless LAN. The MAC-level QoS in this case has already been studied extensively; however, it may not provide exact information on QoE, which we can obtain by the estimation. We first examine MAC-level QoS by simulation in the case where wireless stations...
This paper describes properties of a network management concept designed in the scope of the project ldquoHOMEPLANErdquo. Following to the projectpsilas vision, the future home network has a strong focus on multimedia applications. For the userspsila convenience, media transfers are realized based on IEEE 802.11 WLAN. To ensure high quality of service different enhancement concepts have been developed...
Multimedia broadcast and multicast service (MBMS) specification was introduced in the release 6 of the 3GPP standard to deliver multimedia content to a large group of users in the UMTS network. With the MBMS system generally the same content is transmitted to multiple users in a unidirectional fashion, typically by multiple base stations to improve the coverage over a large geographical area. From...
Beyond 3G wireless systems will be composed of a variety of radio access technologies (RATs) with different, but also complementary, performance and technical characteristics. To exploit such diversity while guaranteeing the interoperability and efficient management of the different RATs, common radio resource management (CRRM) techniques need to be defined. This work proposes and evaluates a CRRM...
This paper defines a retransmission scheme for transmitting video data which allows the use of robust decoding (such as joint source and channel decoding) jointly with acknowledgement procedures. Conventional video communications use CRC-based retransmissions to obtain a nominal quality of the video (defined by the source coder). A lot of work has also been done on robust video transmission, which...
Multimedia applications for mobile devices are increasing and growing more sophisticated. Many of these applications require computationally intensive processing, such as image processing, source coding, feature extraction and feature matching. If all of this processing were performed on the mobile device, its limited battery supply would quickly deplete. However, if the request must be transmitted...
Efficient support of multimedia services in next generation wireless networks requires advanced scheduling schemes that achieve both system capacity maximization and full QoS differentiation. This paper proposes a new MAC scheduling scheme for multiuser OFDM wireless networks. Designed in an opportunistic cross-layer approach, this scheme uses a system of weights that dynamically adjusts the priority...
The 3GPP IMS is a ubiqituous communications architecture that makes Internet technologies available to any user, anywhere and at any time. The success of IMS technology will depend heavily on customer uptake of services. Network operators need to justify charging for services that are typically freely available on the Internet - one way to do this is by introducing reliability through QoS provisioning...
Next generation wireless systems are expected to provide broadband access service and efficient support to multimedia applications. To overcome the limitation due to harsh propagation environments and the scarce spectrum availability, advanced transmission techniques based on multicarrier schemes and adaptive modulation are commonly considered key elements. However, in order to fully exploit these...
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