111 research outputs found
WLAN-UMTS integration to optimize MBMS provision
Provision of multimedia services with high bandwidth demands is constantly increasing its share in mobile systems. Aiming a more efficient distribution of multicast/broadcast contents in the UMTS networks, 3GPP introduced the Multimedia Broadcast Multicast Service (MBMS). Even though this technology brought significant improvements regarding the network efficiency, the UTRAN (UMTS Terrestrial Radio Access Network) remains the network’s most vulnerable area due to its shortage resources. The integration of wireless LAN (WLAN) access technology in cellular data networks to enhance their services coverage and increase data rates, is an extremely interesting solution for operators. In addition, this solution based on WLAN is easily deployed and can provide additional license-free bandwidth. Therefore, this paper addresses a possible WLAN integration, which uses a UMTS Access Point (UAP) that establishes a WLAN tunnel to provide MBMS data services to UEs with both UMTS and WLAN interfaces. Using this simulation environment, we pretend to measure and conclude about the benefits achieved from merging these two access technologies when delivering MBMS services.info:eu-repo/semantics/acceptedVersio
Large Scale Content Distribution Protocols
This paper introduces large scale content distribution pro- tocols, which are capable of scaling to massive numbers of users and providing low delay end-to-end delivery. Delivery of files and static objects is described, with real-time con- tent streaming being outside the scope of this paper. The focus is on solutions provided by the IETF Reliable Multi- cast Transport Working Group. More precisely, the paper explains FLUTE, ALC and the associated building blocks. Then it discusses how these components are used in the Multimedia Broadcast Multicast Service (MBMS) for 3G systems and in the IP Datacast (IPDC) service for Digital Video Broadcast for Handheld devices (DVB-H)
An Accurate and Efficient Analysis of a MBSFN Network
A new accurate analysis is presented for an OFDM-based multicast-broadcast
single-frequency network (MBSFN). The topology of the network is modeled by a
constrained random spatial model involving a fixed number of base stations
placed over a finite area with a minimum separation. The analysis is driven by
a new closed-form expression for the conditional outage probability at each
location of the network, where the conditioning is with respect to the network
realization. The analysis accounts for the diversity combining of signals
transmitted by different base stations of a given MBSFN area, and also accounts
for the interference caused by the base stations of other MBSFN areas. The
analysis features a flexible channel model, accounting for path loss, Nakagami
fading, and correlated shadowing. The analysis is used to investigate the
influence of the minimum base-station separation and provides insight regarding
the optimal size of the MBSFN areas. In order to highlight the percentage of
the network that will fail to successfully receive the broadcast, the area
below an outage threshold (ABOT) is here used and defined as the fraction of
the network that provides an outage probability (averaged over the fading) that
meets a threshold.Comment: 5 pages, 4 figures, IEEE International Conference on Acoustics,
Speech and Signal Processing (ICASSP), 2014, to appea
V2X Meets NOMA: Non-Orthogonal Multiple Access for 5G Enabled Vehicular Networks
Benefited from the widely deployed infrastructure, the LTE network has
recently been considered as a promising candidate to support the
vehicle-to-everything (V2X) services. However, with a massive number of devices
accessing the V2X network in the future, the conventional OFDM-based LTE
network faces the congestion issues due to its low efficiency of orthogonal
access, resulting in significant access delay and posing a great challenge
especially to safety-critical applications. The non-orthogonal multiple access
(NOMA) technique has been well recognized as an effective solution for the
future 5G cellular networks to provide broadband communications and massive
connectivity. In this article, we investigate the applicability of NOMA in
supporting cellular V2X services to achieve low latency and high reliability.
Starting with a basic V2X unicast system, a novel NOMA-based scheme is proposed
to tackle the technical hurdles in designing high spectral efficient scheduling
and resource allocation schemes in the ultra dense topology. We then extend it
to a more general V2X broadcasting system. Other NOMA-based extended V2X
applications and some open issues are also discussed.Comment: Accepted by IEEE Wireless Communications Magazin
Analysis of the impact of FEC techniques on a multicast video streaming service over LTE
The proceeding at: European Conference on Networks and Communications (EuCNC 2015), took place in June 29/July 2, 2015, in Paris, France.In a multicast video streaming service the same multimedia content is sent to a mass audience using only one multicast stream. In multicast video streaming over a cellular network, due to the nature of the multicast communication, from a source to multiple recipients, and due to the characteristics of the radio channel, different for each receiver, transmission errors are addressed at the application level by using Forward Error Correction (FEC) techniques. However, in order to protect the communication over the radio channel, FEC techniques are also applied at the physical layer. Another important technique to improve the communication of the radio channel is the use of a single-frequency network. This paper analyzes the performance of a video streaming service over a cellular network taking into account the combined impact of different factors that affect the transmission, both the physical deployment of the service and the two levels of FEC.This work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525-430000).Publicad
Resource Allocation Management for Broadcast/Multicast Services
Ponencia presentada en: XXX Simposium Nacional de la UniĂłn CientĂfica Internacional de Radio, los dias 2 y 4 septiembre 2015, en Pamplona (españa).Video services are expected to become more than 70% of the mobile traffic in 2020. Broadcast and multicast service is the most efficient mechanism to deliver the same content to many users. Not only focusing on venue casting, but also distributing many other media such as software updates and breaking news, 5G broadcasting is a key driver to achieve the spectral efficiency needed for the 1,000 times traffic growth that is expected for the upcoming years. Improvements in some areas, such as resource allocation techniques for broadcast/multicast services, are needed. The utilization of the Conventional Multicast Scheme (CMS) approach for multicast resource allocation presents intrinsic inefficiencies, because of the different channel conditions of the users which demand the service. This paper presents some resource allocation strategies based on the use of multicast subgroups. We propose a multicast resource allocation algorithm including memory, which results in improvements of the service throughput at the time a high fairness among the users is guaranteed. In addition, an algorithm of joint resource allocation among multicast and unicast transmissions is developed. This strategy allows the system to take advantage of the subframes reserved for each purpose by the Long Term Evolution (LTE) standard, looking for the best joint allocation of the available resources, and results in important improvements in the service throughputThis work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525-430000), and the projects TEC2011-29006-C03-03 (GRE3NSYST) and TEC2014-59255-C3-3-R (ELISA).Publicad
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