Применение математического метода планирования эксперимента для оптимального проектирования зубцовой зоны ротора ударного генератора

Методом математического планирования эксперимента проводится оптимизация зубцовой зоны ротора ударного генератора предельных габаритов для различной индукции в воздушном зазоре

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

Reliable file distribution over mobile broadcast systems

The 3GPP Multimedia Broadcast and Multicast Service (MBMS) provides new bearer services and procedures for efficient transmissions to large user groups. When the group is large, MBMS distributes content by using broadcast on the air-interface. This thesis evaluates the use of MBMS for reliable file distribution services. One important requirement for file distribution is that the files contain no transmission errors. The MBMS file distribution process is subdivided into two phases in this thesis: During the first phase, the radio access network sends the IP packets in each cell either using one broadcast channel or several ptp channels depending on the number of receivers. During the second phase, the file repair service is executed when needed. The file repair service uses either HSPA bearers or MBMS bearers. It is mandatory when minimizing the needed resources for reliable file transmission. In order to understand the transmission characteristics of the first phase, we analyze the packet transmission over the MBMS traffic channel (MTCH). The use of shorter IP packets leads to a lower IP packet error probability on the MTCH. When using shorter IP packets, a larger share of bits is spent on packet headers. To evaluate the information throughput over MTCH, we define the goodput as the fraction between received information bits and sent data bits. IP packets smaller than 500 Byte lead in case of block error rates larger than 10% to a higher goodput. We evaluate different optimization targets for MBMS file delivery. The most important evaluation target is to balance both transmission phases. The resource usage for the MBMS transmission is balanced with the resource needs for the file repair in order to increase the system efficiency of the file distribution of a certain size to all receivers. It is possible to trade the transmit power with the amount of application layer FEC redundancy at same load for the file repair service. The Raptor FEC is used for MBMS. Additional FEC redundancy increases the needed transmission energy, since the system resources are used for a longer time. The point-to-point file repair uses unicast HTTP connections and spreads the repair requests in a time window. The receivers draw randomly a start time out of a given wait-time window. The link between the file repair server and the system limits significantly the serving time and may even lead to an under utilization of the radio resources. The PTP file repair is well dimensioned when the radio links of all active file repair receivers and the link to the file repair server are just fully utilized. The smallest file repair service duration takes approximately 1.2 times the Sequential Delivery Time of all missing data over the link between the file repair server and the system

Reliable file distribution over mobile broadcast systems

The 3GPP Multimedia Broadcast and Multicast Service (MBMS) provides new bearer services and procedures for efficient transmissions to large user groups. When the group is large, MBMS distributes content by using broadcast on the air-interface. This thesis evaluates the use of MBMS for reliable file distribution services. One important requirement for file distribution is that the files contain no transmission errors. The MBMS file distribution process is subdivided into two phases in this thesis: During the first phase, the radio access network sends the IP packets in each cell either using one broadcast channel or several ptp channels depending on the number of receivers. During the second phase, the file repair service is executed when needed. The file repair service uses either HSPA bearers or MBMS bearers. It is mandatory when minimizing the needed resources for reliable file transmission. In order to understand the transmission characteristics of the first phase, we analyze the packet transmission over the MBMS traffic channel (MTCH). The use of shorter IP packets leads to a lower IP packet error probability on the MTCH. When using shorter IP packets, a larger share of bits is spent on packet headers. To evaluate the information throughput over MTCH, we define the goodput as the fraction between received information bits and sent data bits. IP packets smaller than 500 Byte lead in case of block error rates larger than 10% to a higher goodput. We evaluate different optimization targets for MBMS file delivery. The most important evaluation target is to balance both transmission phases. The resource usage for the MBMS transmission is balanced with the resource needs for the file repair in order to increase the system efficiency of the file distribution of a certain size to all receivers. It is possible to trade the transmit power with the amount of application layer FEC redundancy at same load for the file repair service. The Raptor FEC is used for MBMS. Additional FEC redundancy increases the needed transmission energy, since the system resources are used for a longer time. The point-to-point file repair uses unicast HTTP connections and spreads the repair requests in a time window. The receivers draw randomly a start time out of a given wait-time window. The link between the file repair server and the system limits significantly the serving time and may even lead to an under utilization of the radio resources. The PTP file repair is well dimensioned when the radio links of all active file repair receivers and the link to the file repair server are just fully utilized. The smallest file repair service duration takes approximately 1.2 times the Sequential Delivery Time of all missing data over the link between the file repair server and the system

Delivery of Broadcast Services in 3G Networks

Abstract—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