6 resultados para Coding Scheme
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Tutkimuksen päätavoitteena oli ymmärtää, kuinka konteksti vaikuttaa t&k-toiminnan suorituskyvyn mittaamiseen pk-yrityksissä. Tutkimus kartoitti ja kuvaili kontekstin vaikutusta mallilla, joka jaottelee mittaamisen sisältöön, kontekstiin ja prosessiin. Kontekstin vaikutusta sisältöön ja prosessiin tutkittiin sekä suoraan että välillisesti mittaamisen tavoitteen kautta. Tutkimuksessa käytettiin case survey-tutkimusmenetelmää, jossa yhdistyy survey-tutkimuksen ja tapaustutkimuksen strategiat. Empiirisenä aineistona käytettiin olemassa olevia tapaustutkimuksia, joiden laadulliset havainnot muunnettiin systemaattisesti määrällisiksi muuttujiksi koodausjärjestelmällä. Muuttujien yhteyksien ristiintaulukoinnit analysoitiin tilastollisesti merkitsevien riippuvuuksien tunnistamiseksi ja laajempaa joukkoa koskevien päätelmien johtamiseksi. Tulokset olivat yhteneväisiä aiemman tutkimustiedon kanssa, mikä osoittaa kontekstin vaikutuksen t&k-toiminnan suorituskyvyn mittaamiseen olevan samankaltainen pk-yrityksissä kuin suuremmissakin yrityksissä. Empiirisinä yleistyksinä tunnistettiin uusia riippuvuuksia kontekstin ja sisällön sekä kontekstin ja prosessin välillä. Yleistykset suositellaan testattavaksi hypoteeseina jatkotutkimuksessa.
Resumo:
Modern sophisticated telecommunication devices require even more and more comprehensive testing to ensure quality. The test case amount to ensure well enough coverage of testing has increased rapidly and this increased demand cannot be fulfilled anymore only by using manual testing. Also new agile development models require execution of all test cases with every iteration. This has lead manufactures to use test automation more than ever to achieve adequate testing coverage and quality. This thesis is separated into three parts. Evolution of cellular networks is presented at the beginning of the first part. Also software testing, test automation and the influence of development model for testing are examined in the first part. The second part describes a process which was used to implement test automation scheme for functional testing of LTE core network MME element. In implementation of the test automation scheme agile development models and Robot Framework test automation tool were used. In the third part two alternative models are presented for integrating this test automation scheme as part of a continuous integration process. As a result, the test automation scheme for functional testing was implemented. Almost all new functional level testing test cases can now be automated with this scheme. In addition, two models for integrating this scheme to be part of a wider continuous integration pipe were introduced. Also shift from usage of a traditional waterfall model to a new agile development based model in testing stated to be successful.
Resumo:
Broadcasting systems are networks where the transmission is received by several terminals. Generally broadcast receivers are passive devices in the network, meaning that they do not interact with the transmitter. Providing a certain Quality of Service (QoS) for the receivers in heterogeneous reception environment with no feedback is not an easy task. Forward error control coding can be used for protection against transmission errors to enhance the QoS for broadcast services. For good performance in terrestrial wireless networks, diversity should be utilized. The diversity is utilized by application of interleaving together with the forward error correction codes. In this dissertation the design and analysis of forward error control and control signalling for providing QoS in wireless broadcasting systems are studied. Control signaling is used in broadcasting networks to give the receiver necessary information on how to connect to the network itself and how to receive the services that are being transmitted. Usually control signalling is considered to be transmitted through a dedicated path in the systems. Therefore, the relationship of the signaling and service data paths should be considered early in the design phase. Modeling and simulations are used in the case studies of this dissertation to study this relationship. This dissertation begins with a survey on the broadcasting environment and mechanisms for providing QoS therein. Then case studies present analysis and design of such mechanisms in real systems. The mechanisms for providing QoS considering signaling and service data paths and their relationship at the DVB-H link layer are analyzed as the first case study. In particular the performance of different service data decoding mechanisms and optimal signaling transmission parameter selection are presented. The second case study investigates the design of signaling and service data paths for the more modern DVB-T2 physical layer. Furthermore, by comparing the performances of the signaling and service data paths by simulations, configuration guidelines for the DVB-T2 physical layer signaling are given. The presented guidelines can prove useful when configuring DVB-T2 transmission networks. Finally, recommendations for the design of data and signalling paths are given based on findings from the case studies. The requirements for the signaling design should be derived from the requirements for the main services. Generally, these requirements for signaling should be more demanding as the signaling is the enabler for service reception.