Jörg Huschke

Delivery of Broadcast Services in 3G Networks

TV is regarded as a key service for mobile devices. In the past, Mobile TV was often associated with broadcast transmission. However, unicast technology is sufficient in many cases, especially since mobile users prefer to access content on-demand, rather than following a fixed schedule. In this paper we will focus on 3G mobile networks, which have been primarily optimized for unicast services. Based on a traffic model we will discuss the capacity limits of 3G networks for unicast distribution of Mobile TV. From the results it can be concluded that the capacity is sufficient for many scenarios. In order to address scenarios in which broadcast is a more appropriate technology, 3GPP has defined a broadcast extension, called Multimedia Broadcast Multicast Service (MBMS). MBMS introduces shared radio broadcast bearers and has thus the capabilities of a real broadcasting technology. We will give a short overview about MBMS including a discussion on MBMS capacity. Since MBMS is primarily a new transport technology, additional application and service layer technologies are required, like electronic service guide and service protection. These mechanisms are standardized by the Open Mobile Alliance (OMA) and are favorably combined with MBMS or 3G unicast distribution in order to create complete end-to-end solutions. In order to optimize a system for delivery of broadcast services over 3G networks, the advantages of broadcast and unicast should be combined. We argue that hybrid unicast-broadcast delivery offers the best system resource usage and also the best user experience, and is thus favorable not only for broadcast delivery in 3G networks, but actually also for non-cellular broadcast systems like DVB-H or DMB

MBMS—IP Multicast/Broadcast in 3G Networks

In this article, the Multimedia Broadcast and Multicast Service (MBMS) as standardized in 3GPP is presented. With MBMS, multicast and broadcast capabilities are introduced into cellular networks. After an introduction into MBMS technology, MBMS radio bearer realizations are presented. Different MBMS bearer services like broadcast mode, enhanced broadcast mode and multicast mode are discussed. Streaming and download services over MBMS are presented and supported media codecs are listed. Service layer components as defined in Open Mobile Alliance (OMA) are introduced. For a Mobile TV use case capacity improvements achieved by MBMS are shown. Finally, evolution of MBMS as part of 3GPP standardization is presented.

Dynamic Protected-Subframe Density Configuration in LTE Heterogeneous Networks

The protected-subframe (PSF) structure is one of the methods for downlink inter-cell interference coordination (ICIC) utilized in heterogenous networks and is featured in Rel-10 of the technical specification for 3GPPs E-UTRAN. Static configuration of PSF has proven to increase performance but the dynamic configuration is yet to be examined. In this paper, we study the effect of dynamically configuring PSF density according to a certain criterion in an attempt to increase system performance and maintain a quality of service for all users. Results show that with full buffer traffic, the impact of dynamic configuration is more noticeable in cases of large pico cell range expansions. With dynamic traffic, we find that in the majority of cases, dynamic configuration outperforms the static. In this paper we consider two forms of PSF known as almost blank subframes (ABS) and reduced power subframes (RPS) and show the results from implementing both these techniques.

Spectrum requirements for TV broadcast services using cellular transmitters

Wide-spread provisioning of TV services has strongly shaped the cultural development since the last century; terrestrial radio broadcast transmission has been the original form of TV distribution. Although the majority of TV reception is today based on alternative distribution means, like cable or satellite, TV broadcast enjoys still a significant amount of allocated terrestrial spectrum (∼300 MHz). However, it has been identified that TV broadcast does not efficiently use its allocated spectrum. At the same time, other spectrum users like mobile communication systems experience a tremendous growth and demand for spectrum. The scarcity of radio spectrum has led the US FCC rule that additional 500 MHz of spectrum are to be identified for mobile broadband systems in the next decade — out of which 120 MHz are to come from the TV band in the next 5 years. In this paper we identify an alternative transmission architecture for TV distribution based on cellular LTE MBMS, with densely placed low-power transmitters that transmit in a synchronized single frequency network. It is demonstrated that in this way a full frequency reuse at all sites is possible, in contrast to the large reuse distances in high-power high-tower TV transmission. As a result, we show that it is possible to support TV services with 84 MHz of spectrum via LTE MBMS, in contrast to the 300 MHz used by todays ATSC TV broadcast system. This approach can be realized in a cost-effective manner by re-using existing mobile network infrastructure and we also show that the total radiated power can be decreased.

Wireless Communication for Factory Automation: an opportunity for LTE and 5G systems

The evolution of wireless communication from 4G toward 5G is driven by application demands and business models envisioned for 2020 and beyond. This requires network support for novel use cases in addition to classical mobile broadband services. Wireless factory automation is an application area with highly demanding communication requirements. We classify these requirements and identify the opportunities for the current LTE air interface for factory automation applications. Moreover, we give an outlook on the relevant design considerations to be addressed by 5G communication systems.

Impact of decentralized adaptive frequency allocation on the system performance of HIPERLAN/2

Currently ETSI/BRAN develops standards for HLPERLAN/2, a wireless LAN operating in the 5 GHz band and supporting broadband multimedia communication. The standard supports adaptive frequency allocation (AFA) by protocols for field strength measurements and reports. This paper shows simulation results for a decentralized AFA autonomously operating in each access point and using field strength measurements for the decision of frequency selections. The performance of individual cells and the system as a whole is assessed for start-up, system extension and time varying traffic load scenarios.

Analytic Evaluation of a Hybrid Broadcast-Unicast TV Offering

Today mobile TV services in cellular spectrum are delivered over unicast radio bearers as offered by 3G technologies like WCDMA and HSDPA. Since unicast transmission does not scale very well if mobile TV becomes a true mass service, 3GPP has defined a broadcast extension for UMTS, called multimedia broadcast multicast service (MBMS). MBMS introduces radio broadcast bearers serving all users in common, thus providing true broadcast capabilities. A not so well known feature of MBMS is its support for hybrid broadcast-unicast transmission. In this mode the more popular channels are broadcasted over point- to-multipoint radio bearers while the less popular channels are delivered over point-to-point bearers only on request. In this paper we will present a theoretical framework which allows an analytic evaluation of the capacity limits when delivering mobile TV services over hybrid broadcast-unicast transmission schemes provided by MBMS.

Radio resource optimization for MBMS File transmissions

The 3GPP Multimedia Broadcast and Multicast Service (MBMS) for mobile networks enables the efficient distribution of files to a large audience using point-to-multipoint transmission. MBMS provides the so called file delivery service for this purpose. Residual errors are not tolerable in the received data of the file. Application Layer Forward Error Correction (AL-FEC) and transmit power need to be configured to yield low residual errors after the initial file transmission. In order to recover also the residual packet errors a repair phase is executed in which terminals can request additional AL-FEC encoded packets. The paper assumes repair packets are transmitted using HSDPA and evaluates the overall system efficiency, balancing ALFEC, transmit power, packet size and the amount of missing data that has to be retransmitted in the repair phase.

Graceful degradation in 3GPP MBMS mobile TV services using H.264/AVC temporal scalability

These days, there is an increasing interest in Mobile TV broadcast services shown by customers as well as service providers. One general problem of Mobile TV broadcast services is to maximize the coverage of users receiving an acceptable service quality, which is mainly influenced by the users position and mobility within the cell. In this paper, graceful degradation is considered as an approach for improved service availability and coverage. We present a layered transmission approach for 3GPPs Release 6 Multimedia and Broadcast Service (MBMS) based on temporal scalability using H.264/AVC Baseline Profile. A differentiation in robustness between temporal quality layers is achieved by unequal error protection approach based on either application layer Forward Error Correction (FEC) or unequal transmit power for the layers or even a combination of both. We discuss the corresponding MBMS service as well as network settings and define measures allowing for evaluating the amount of users reached with a certain mobile terminal play-out quality while considering the network cell capacity usage. Using simulated 3GPP Rel. 6 network conditions, we show that if the service and network settings are chosen carefully, a noticeable extension of the coverage of the MBMS service can be achieved.

Downlink capacity of UTRAN reusing frequencies of a DVB-T network with negligible influence on DVB-T performance

The paper investigates the possibility of reusing frequencies of a terrestrial digital video broadcasting (DVB-T) network for a UMTS Terrestrial Radio Access Network (UTRAN) with negligible influence on the DVB-T performance. A frequency division duplex (FDD) UTRAN is deployed such that it can reuse all frequencies of the DVB-T network in each DVB-T frequency reuse cluster in the downlink, with a predefined level of (negligible) interference from the UTRAN to DVB-T. The downlinks of both networks can thus coexist in the same frequency spectrum, thereby increasing the spectral efficiency. The uplink of UTRAN-FDD is assumed to operate in traditional non coexistence and is therefore not considered. Close to 100% of the capacity of a non coexisting UTRAN are achievable for typical UTRAN cell sizes, with only marginal increase of outage in the DVB-T network.