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Telephony and associated systems
Published in Geoff Lewis, Communications Technology Handbook, 2013
This development of CT2 technology utilises similar operating frequencies and the time division duplex (TDD) technique but exploits the advantages of time division multiple access (TDMA). As indicated by Fig. 36.3, 16 ms time frames are divided into 16 time slots each of 1 ms duration. The latter are alternately used for transmission in opposite directions (TDD) to provide a full duplex service, with a gross bit rate of 640 Kbit/s. By using TDMA, each time slot is capable of supporting eight speech channels or 32 Kbit/s of digital data. A further advantage of TDMA accrues as a mobile handset moves from one cell to another; the change of base station and operating channels (hand-off) is virtually transparent to the user. Figure 36.3 also shows how each time slot is divided into segments for synchronism, indent, data and error correction purposes.
Mobile communication systems
Published in J. Dunlop, D. G. Smith, Telecommunications Engineering, 2017
CT2 is a system designed primarily for voice communications. The main objective of the Digital European Cordless Telecommunications Standard, currently being produced by members of the European Telecommunications Standards Institute (ETSI), is to support a range of applications such as residential cordless telephone systems, business systems, public access networks (Telepoint) and radio local area networks. In addition DECT provides a system specification for both voice and non-voice applications and supports ISDN functions. DECT is a multi-frequency, TDM A-TDD cordless telecommunication system, however, the radio interface is significantly different to CT2 and DECT supports handover.
Access Methods
Published in Jerry D. Gibson, The Communications Handbook, 2018
CT2 operates in the frequency band 864-868 MHz and uses carriers spaced at 100 kHz. FDMA with time division duplexing is employed. The combined gross bit rate is 72 kb/s, transmitted in frames of 2-ms duration of which the first-half carries downlink and the second-half carries uplink information. This setup supports a net bit rate of 32 kb/s of user data (32-kb/s ADPCM encoded speech) and 2-kb/s control information in each direction. The CT2 modulation technique is binary frequency shift keying.
P2M Simulation Exercise on Past Fuel Melting Irradiation Experiments
Published in Nuclear Technology, 2023
V. D’Ambrosi, J. Sercombe, S. Bejaoui, A. Chaieb, B. Baurens, R. Largenton, A. Ambard, B. Boer, G. Bonny, M. Ševeček, L. E. Herranz, F. Feria Marquez, K. Inagaki, H. Ohta, F. Boldt, J. Sappl, R. Armstrong, A. Mohamad, Y. Udagawa, C. Cozzo, J. Klouzal, M. Vitezslav, J. Corson, J. Peltonen
After the HBC4 power ramp, the rodlet was first examined by neutron radiography.17 Three zones where voids had formed in the centerline of the fuel column were found. They were located near the PPN and at an axial level of 300 to 385 mm/BFC. The voids were not continuous in the axial direction but sometimes filled with fuel. Three transverse cross sections (named CT1 and CT2 in the failed region, CT3 out of the failed region) and one longitudinal cross section (named CL1) were cut from the rodlet. Figure 4 shows the axial diameter profile of the HBC4 rod after the power ramp, where the clad cracks are characterized by local peaks. The location of the three transverse cross sections (CT1, CT2, and CT3) and of the longitudinal cross section (CL1) are reported in Fig. 4 as well as the central holes obtained from neutron radiography. A fourth ceramography was obtained, CT1’, by grinding and polishing downward the CT1 cross section. The CT1, CT1’, CT2, and CL1 ceramographies are shown in Figs. 5, 6, 7, and 8, respectively.
2D(r,t) Simulations of the HBC-4 Power-to-Melt Experiment with the Fuel Performance Code ALCYONE
Published in Nuclear Technology, 2023
J. Sercombe, V. D’Ambrosi, S. Béjaoui, I. Zacharie-Aubrun
The CT1, CT2, and CT3 transverse ceramographies are presented in Fig. 7. The CT1 and CT2 ceramographies confirmed the presence of central voids and through-wall cracks in the cladding that showed the characteristic pattern of I-SCC with a bifurcation halfway through the clad thickness (slow crack propagation by I-SCC followed by a low ductile failure of the remaining clad ligament). The roundness of the central void was clear in the CT1 cross section, while it had an elliptic shape in the case of CT2 with the smallest dimension aligned with the clad crack. The fuel swelling was also markedly more important in the direction of the clad crack since no reopening of the pellet-clad gap is visible. This results in a central hole that appears to be shifted away from the clad crack. On the contrary, due to the lower local LHGR (56 kW·m−1), CT3 presents no central void and no crack in the cladding.
Reconfigurability consideration and scheduling of products in a manufacturing industry
Published in International Journal of Production Research, 2018
In continental, multi-product lines have been developed. Generally, one type of product is manufacturing and when the demand arises, the line is reconfigured for another type of product. For reconfiguration, some parts of the machines are changed and some fixtures are also changed. The parts of machines, which are changed, can be tools, tool holding devices, job holding devices and other supporting devices. These parts are also known as auxiliary modules. In WSS line, machines which are reconfigured are grommet insertion machine, crimping machine, moulding machine, and insulation testing machine. Machines with auxiliary modules used for different types of products have been identified and specific names have been given to these modules shown in Table 3. For example, crimping machine has two auxiliary modules CT1 and CT2. CT1 is used for PRODUCT A, PRODUCT B and PRODUCT C while CT2 is used for PRODUCT D Table 3. There are the operations which require only fixtures. Different fixtures are used for different products. These operations are Adjustment, Fastener, Cutting, Painting, Bracket crimping.